Diagnosis: Smallpox?

During a smallpox epidemic, the initial chill, followed by fever, headache, vomiting, and the severe pain in the back, are symptoms which should put the attending physician on his guard. Mistakes arise in the initial stage owing to the presence of scarlatinal or measly rashes which may be extremely deceptive. The scarlatinal rash has not always the intensity of the true rash of this disease. The measly rash cannot always be distinguished from true measles, instances of which may be mistaken for the initial smallpox rash.” -Sir William Osler

If you were to go back throughout recorded history and look at the evidence for smallpox, you would come to realize that many of the cases associated with this disease can be traced back to interchanging names for the same set of symptoms related to eruptions of the skin. The names varied based on the geographic location as well as the time in history that the terminology was used. In some cases, the diseases were all referred to as “the poxes.” The more severe symptoms were referred as the Great Pox while the less severe were known as the Lesser Pox. Europeans used differing names to distinguish disease severity such as la grosse verole and la petite verole. Germans used the name blattern to refer to both syphilis and smallpox synonymously. The Italian name for measles was morbilli yet it was also applied to scarlatina, rubella, and smallpox. Even the name chickenpox was just a term used to describe less severe, or “chicken,” cases of smallpox. This is why it is difficult, if not impossible, for clinicians to differentially diagnose smallpox from these other “separate” diseases as they are all varying stages of the same detoxification process.

This first source breaks down this confusion by looking at the history of both smallpox and measles. You will see the many names used interchangeably to describe these different stages of the same process as well as the challenges with separating them as distinct diseases:

Smallpox and measles: historical aspects and clinical differentiation

“The difficulty was in differentiating smallpox and measles in their early phases, which had important public health implications. The prodromal rash of smallpox sometimes resembled measles.”

Smallpox

“Both smallpox and measles were highly contagious and had in common rash and fever. Even though the Persian physician Rhazes Ar-Raz Abmiz was the first person to clinically distinguish smallpox from measles in 900 AD, European physicians continued to confuse the illnesses until relatively recent times [2]. In 1751, Thomas Sydenham clearly differentiated measles from smallpox [3]. Even Sir William Osler, the master clinician of the modern era, emphasized the difficulty in differentiating early measles from smallpox [4].”

“As many ancient pestilences were referred to as the plague, so was the case with poxes. The Great Pox referred to syphilis, and the Lesser Pox may have referred to rubella, chickenpox, and smallpox. The Europeans used distinctive terms to differentiate syphilis from smallpox. La grosse verole was a term used to describe syphilis, whereas smallpox was referred to as la petite verole. In other countries, the word for pox was applied to different diseases  during different times. In German, syphilis was initially referred to as blattern during the 16th and 17th centuries, but blattern later was applied to smallpox during the 18th century.”

Measles

“In the ancient world, measles and smallpox existed together. Measles, also known as morbilli, is the diminutive Italian term derived from morbillo. The term morbilli was used to differentiate the ‘‘small plague’’ of measles from the ‘‘great plague,’’ referred to as Il Morbo. For centuries, scarlatina, rubella, measles, and smallpox were undifferentiated febrile diseases with rashes. The terminology for measles is confusing, as is the clinical differentiation between measles and chickenpox. Scarlet fever was termed morbilli confluentes. Measles in German is masern; in French measles is rougeole; and the synonym for measles in English is rubeola [14].”

“Smallpox is no longer a common infectious disease, and differentiation from chickenpox is less critical from a public health standpoint than in the smallpox era. With the potential for the use of smallpox as an agent for bioterrorism, however, clinicians need to reacquaint themselves with the cardinal clinical findings of smallpox. Should smallpox reemerge, clinicians will face the same diagnostic dilemmas in differentiating smallpox from measles in its early stages. A presumptive diagnosis of measles or smallpox in its early stages is of critical importance to the individual and has important public health implications. Clinicians without previous experience should rely on careful clinical descriptions made by astute and discerning physicians, who by careful observations were able to sort out the key features between smallpox and measles, permitting clinical differentiation.”

doi: 10.1016/S0891-5520(03)00091-6.

As can be seen, the “poxes” were all considered varying stages of the same disease. It wasn’t until physicians looked for minute differences that the symptoms began to be separated as distinct diseases. I wrote about this practice of breaking down the stages in this article about the attempts by William Heberden to clinically separate smallpox from chickenpox in 1767. Regarding the separation of smallpox and measles, Muslim physician Al-Razi is given credit as the first person to distinguish between the two. While I am unable to find passages from his book, a section from a review provides a nice summary as to the differences Al-Razi noticed necessitating the split:

“The most common signs of both smallpox and measles were continuous fever, nose itching, allergy in the body, redness of the cheeks and eyes, sore throat, chest pain, breathing difficulties, cough, hoarseness, headache and sometimes syncope. It was not necessary for all these symptoms and signs to appear together, some might be absent. On the other hand, regarding the specific signs, he said that back pain was more severe in smallpox, while it might be slight or absent in measles. Distress, syncope and anxiety were more prominent in measles.”

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.qscience.com/content/journals/10.5339/qmj.2000.2.7%3Fcrawler%3Dtrue%26mimetype%3Dapplication/pdf&ved=2ahUKEwiZrpfDoYb4AhWRZDABHS-4Dfc4HhAWegQICRAB&usg=AOvVaw2sYRI7XGqIwE-z5Xf5WC7T

In other words, according to Al-Razi, the major differences necessitating the separation of one disease into two was that back pain was more severe with smallpox while distress, anxiety, and syncope were more prominent in measles. Beyond these slight variations in severity of certain symptoms, both smallpox and measles shared every single symptom of disease between them. Maybe this is why it is stated that every other physician of the time considered them one and the same:

“Many historians such as Justaph Lobon, Sigrid Honka, Dughlas and others considered Al-Razi to be the first in the history of medicine to differentiate between these two diseases. He described each disease separately and in detail, unlike all the Greek and Arab physicians before him, who considered the two diseases as one.“

As can be seen, even these minute differences were not enough for differentiation as the symptoms often were not specific and overlapped between the “separated” diseases. This is why the diagnosis of smallpox has commonly been mistaken for other ailments such as measles as well as chickenpox:

Chickenpox or Smallpox: The Use of the Febrile Prodrome as a Distinguishing Characteristic 

“Before its eradication, smallpox was confused with chickenpox more frequently than with any other illness [1]. The similarities between the diseases and the importance of making the correct diagnosis led an infectious disease expert to declare that there was “no more important diagnosis in clinical medicine than the differentiation of these two diseases.”

https://academic.oup.com/cid/article/39/12/1810/323131

And also why chickenpox is confused with monkeypox which itself is confused with smallpox:

Human monkeypox: confusion with chickenpox

“The question arose as to the possibility that clinical diagnostic errors cause some cases of monkeypox to be misdiagnosed as other eruptive diseases. This paper presents the results of a study assessing the extent of and reasons for these clinical diagnostic errors in areas where health staff as well as the general public are aware of human monkeypox. In Zaire in the period 1981-1986, 977 persons with skin eruption not clinically diagnosed as human monkeypox were laboratory tested. 3.3% of human monkeypox cases were found among 730 patients diagnosed as cases of chickenpox, 7.3% among cases diagnosed as “atypical chickenpox” and 6.1% among cases with skin rash for which clinical diagnosis could not be established. The diagnostic difficulties were mainly based on clinical features characteristic of chickenpox: regional pleomorphism (in 46% of misdiagnosed cases), indefinite body-distribution of skin eruptions (49%), and centripetal distribution of skin lesions (17%). Lymph-node enlargement was observed in 76% of misdiagnosed patients. In the absence of smallpox, the main clinical diagnostic problem is the differentiation of human monkeypox from chickenpox.”

https://pubmed.ncbi.nlm.nih.gov/2907258/

Clinical Diagnosis?

This raises the question of whether or not smallpox can even be diagnosed clinically based on symptoms alone as the intermingling of shared disease symptoms and presentation made the differential diagnosis of smallpox from the other related skin eruption diseases difficult. This difficulty was outlined in the first chapter of the 1988 WHO classic Smallpox and its Eradication which provided a comprehensive list of the many different diseases that smallpox was confused with at the time of diagnosis. Along with the acknowledgement to the near impossibility of diagnosing smallpox clinically as well as the numerous mistaken diagnoses throughout the centuries, it is also metioned that laboratory methods are needed in order to confirm a diagnosis. In other words, a case of smallpox could not be diagnosed based on symptom presentation alone:

CHAPTER 1: THE CLINICAL FEATURES OF SMALLPOX

Human monkeypox

“Although a rare disease, human monkeypox ranks first among the diseases that might be confused with smallpox, because differential diagnosis was impossible on clinical grounds alone, although gross lymphadenopathy was found in most cases of monkeypox and not in smallpox (see Chapter 29) . In the field, diagnosis depended on the occurrence  of a disease indistinguishable from ordinary-type smallpox in the appropriate epidemiological situation: a particular geographical area (western and central Africa), no endemic smallpox, and the appropriate environmental surroundings (a small village in a tropical rain forest). Laboratory confirmation was essential, either by recovery of the virus from lesion material or retrospectively by appropriate serological tests.

Chickenpox

“This disease of world-wide occurrence was the single most important infection to be considered in the differential diagnosis and was particularly important in three circumstances: in countries in which variola minor was endemic, in vaccinated individuals, and in situations in which chickenpox occurred rather frequently in adults, often as a severe disease, as in several parts of India. For example, in post-eradication searches in India in 1976, 63% of the “suspected smallpox” cases were in fact cases of chickenpox (Jezek et al ., 1978e).”

“Difficulties arose with severe chickenpox in adults (White, 1978), a disease found especially in some parts of India (Kerala,Tamil Nadu (formerly Madras State), and West Bengal). Indeed, some severe cases of chickenpox in adults were associated with such an extensive rash, including lesions on the palms and soles, that it was impossible to be certain at any stage of the disease as to whether it was chickenpox or smallpox. During the eradication programme, all such cases were regarded as smallpox and appropriate control measures were undertaken. Sometimes the lesions in this type of chickenpox were haemorrhagic, and it was in these cases that the rate of development of the rash and its distribution were important diagnostic features.”

Tanapox

“This poxvirus disease occurs as a zoonosis in parts of Kenya and Zaire, and probably elsewhere in Africa (see Chapter 29) . The lesions are usually single, and few in number if they are multiple. They are nodular rather than pustular and evolve much more slowly than the lesions of smallpox . However, when first seen, such lesions could be confused with those of mild smallpox in a vaccinated subject.

Measles

In the first 2 days of the rash, before vesicles developed, the most likely cause of confusion was measles (Plate 1 .29A), and this difficulty could persist for several more days in flat-type smallpox, although the severity of this disease was much greater than that of measles . The  presence of Koplik’s spots was, of course, diagnostic of measles, and in any case the difficulty disappeared as the rash evolved. Historically, measles did not present a problem in countries with endemic smallpox, but in non-endemic countries an early case of smallpox was sometimes diagnosed as measles, with possibly serious consequences in terms of secondary cases. On the other hand, in countries in which smallpox was endemic, physicians were often prone to diagnose all outbreaks of rash associated with deaths as smallpox and to report them as such to the health authorities. Some of these outbreaks later proved to be due to measles.

Syphilis

Earlier writers, e .g ., Councilman (1907) and Ricketts (1908), paid considerable attention to syphilitic rashes as presenting a problem in differential diagnosis. With the advent of penicillin and the consequent reduction in the incidence of syphilis especially of secondary syphilis-in the developed countries, the disease has ceased even to be mentioned by writers, such as Christie (1980), dealing with the general domain of infectious diseases. However, in African countries and India secondary syphilis remained a disease to be considered in the differential diagnosis of smallpox, up to the time of eradication.

Erythema multiforme

“This disease (Plate 1.29C) could cause difficulties at any stage of the rash; the distribution of lesions is sometimes very like that of smallpox. In both diseases the patient could be quite ill and have a profuse vesicular eruption particularly affecting the extremities.”

“In severe cases there could be confusion with flat-type smallpox, since the vesicles were occasionally soft, superficial and flat, individually resembling those of flat-type smallpox. They sometimes coalesced and produced large bullae, also seen in some cases of severe smallpox.”

Lesions due to vaccination

Generalized vaccinia, described in Chapter 7 (see Plate 7.7), rarely caused confusion; the history of vaccination and the nature and
distribution of the rash differed substantially from what was found in smallpox. However, problems of precise diagnosis sometimes arose in smallpox contacts who had been vaccinated during what turned out to be the incubation period of smallpox. They usually showed a positive take at the vaccination site and often a modified rash, which could have been caused by variola or vaccinia virus. Operationally, all such cases were regarded as smallpox from the point of view of management. Precise diagnosis could be made by the culture of virus from several of the vesicles or pustules.

Drug eruptions

Although less important in countries in which smallpox was still endemic, drug eruptions (Plate 1 .30A and B) were an important diagnostic problem in countries in which smallpox had been eradicated years before and doctors rarely considered the possibility of the disease. Many instances exist in which the rash of an imported case of smallpox, and sometimes the rashes of second generation cases deriving from it, were diagnosed as drug rashes, since the sick patients had customarily been treated with some kind of drug for the pre-eruptive fever. The diagnosis usually became quite clear with the passage of time and the evolution of the rash, but vaccine-modified smallpox could continue to mislead the physician if he had never considered smallpox as a possible diagnosis.

In endemic countries in recent years, since a wide variety of drugs have become available, cases of smallpox and drug eruption sometimes occurred coincidently. Rao (1972) described a case in which the drug rash completely obscured that due to smallpox and the diagnosis was only made when variola virus was recovered from some “seeds” extracted from the palms of the hands.

Rashes due to other causes

There are few diseases characterized by a rash that did not at some time suggest a diagnosis of smallpox, occasionally with dramatic effect in non-endemic countries. Acne, scabies and insect bites may be mentioned as examples. Coxsackievirus infections could pose a problem (Mukherjee et al ., 1976), and in countries in which both diseases were endemic, dengue haemorrhagic fever and other arbovirus infections associated with a rash were sometimes initially diagnosed as smallpox.”

LABORATORY CONFIRMATION OF
SMALLPOX DIAGNOSIS

“Laboratory methods played a crucial role in the global smallpox eradication programme; indeed, eradication could not have been confidently certified to have been achieved without their use. A detailed historical description of the laboratory methods used for the diagnosis of smallpox is presented in Chapter 2 and an account of the development of laboratory support for the Intensified Smallpox Eradication Programme is given in Chapter 10.

As well as being of critical importance in the global smallpox eradication programme, laboratory methods were also useful for the confirmation of clinical diagnoses. Indeed, although laboratory workers could make mistakes, the recovery of variola virus from a skin lesion was usually regarded as conclusive evidence that a particular patient was or had been suffering from smallpox. Such confirmation was rarely sought in endemic countries when smallpox was a common disease. Any doubtful case was always regarded as smallpox; containment and vaccination procedures operated independently of and were initiated before laboratory confirmation. However, laboratory confirmation or refutation of suspected smallpox was a valuable procedure in non-endemic countries and in smallpox-free regions of the endemic countries as eradication approached.

If an electron microscope was available, the examination of material from vesicles, pustules or scabs, examined by the negative staining technique, could give a rapid presumptive diagnosis of poxvirus, or sometimes herpesvirus, infection. Definitive diagnosis depended on the isolation of the causative virus on the chorioallantoic membrane of the developing chick embryo and its further characterization, if necessary, by biological tests. Usually the character of the pocks produced on the chorioallantoic membrane was distinctive enough for the diagnosis of variola, vaccinia, monkeypox or herpesvirus infection to be made (see Chapter 2).”

https://biotech.law.lsu.edu/blaw/bt/smallpox/who/red-book/index.htm

If there was any doubt about the confusion with other diseases and the impossibility of diagnosing smallpox clinically based on symptoms alone, the information contained within the WHO’S 1988 sci-fi classic was later confirmed by the CDC. Here is the CDC’s own official list of common conditions which can be confused with smallpox as well as the problems associated with clinical diagnosis and the need for laboratory confirmation:

Common Conditions That Might Be Confused with Smallpox

Varicella (primary infection with varicella-zoster virus)

• Most common in children <10 years
• Children usually do not have a viral prodrome

Disseminated herpes zoster

• Immunocompromised or elderly persons
• Rash looks like varicella, usually begins in dermatomal distribution

Impetigo (Streptococcus pyogenes, Staphylococcus aureus)

• Honey-colored crusted plaques with bullae are classic but may begin as vesicles
• Regional, not disseminated rash
• Patients generally not ill

Drug eruptions

• Exposure to medications
• Rash often generalized

Contact dermatitis

• Itching
• Contact with possible allergens
• Rash often localized in a pattern suggesting external contact

Erythema multiforme minor

• Target, “bull’s eye,” or iris lesion
• Often follows recurrent herpes simplex virus infections
• May involve hands and feet (including palms and soles)

Erythema multiforme major (Stevens-Johnson syndrome)

• Major form involves mucous membranes and conjunctivae
• There may be target lesions or vesicles

Enteroviruses infection, especially Hand, Foot, and Mouth Disease

• Summer and fall
• Fever and mild pharyngitis 1 to 2 days before rash onset
• Lesions initially maculopapular but evolve into whitish-grey, tender, flat, and often oval vesicles
• Peripheral distribution (hands, feet, mouth, or disseminated)

Disseminated herpes simplex

• Lesions indistinguishable from varicella
• Immunocompromised host

Scabies; insect bite (including fleas)

• Itching is a major symptom
• Patient is not febrile and is otherwise well

Molluscum contagiosum

• May disseminate in immunosuppressed persons
• Can occur anywhere on the body
• Presents as small, raised, and usually white, pink, or flesh-colored lesions with a dimple or pit in the center

Monkeypox

Also consider monkeypox in the differential diagnosis. The main difference between monkeypox and smallpox is that monkeypox causes swelling in the lymph nodes (lymphadenopathy) while smallpox does not. Swelling of the lymph nodes may be generalized (involving many different locations on the body) or localized to several areas (e.g., neck and armpit). Ask the patient questions about recent contact with any exotic or ill animals, as well as travel history to countries in Central or West Africa, where monkeypox is endemic.

Laboratory Confirmation

For patients with a high risk of having smallpox, the state health department will contact CDC to conduct laboratory testing to confirm or rule out smallpox. In the absence of known smallpox disease, the predictive value of a positive smallpox test diagnosis is low, so only cases that meet the clinical definition of the disease should be tested.

Laboratory Case Definition

Laboratory diagnostic testing for variola virus will occur in a CDC Laboratory Response Network (LRN) laboratory using LRN-approved PCR tests and protocols for variola virus. Initial positive results require confirmatory testing at CDC.

The laboratory criteria for diagnosis are:

• Polymerase chain reaction (PCR) identification of variola DNA in a clinical specimen, OR
• Isolation of smallpox (variola) virus from a clinical specimen (WHO Smallpox Reference Laboratory or laboratory with appropriate reference capabilities) with variola PCR confirmation.

Note: Generic orthopoxvirus PCR and negative stain electron microscopy (EM) identification of a poxvirus in a clinical specimen are suggestive of an orthopoxvirus infection but not diagnostic for smallpox.

https://www.cdc.gov/smallpox/clinicians/diagnosis-evaluation.html

Laboratory Diagnosis?

There is quite a bit of agreement between both the WHO and the CDC regarding the impossibility of diagnosing smallpox clinically due to the confusion with numerous other conditions and diseases. The best a clinical diagnosis can do is provide a “suspected” label. In order for a smallpox diagnosis to be confirmed, it must be done so by means of laboratory testing. However, can smallpox even be diagnosed by way of these methods?

Not if we are to believe the information provided by the CDC. While the CDC, like the WHO, stated that clinical diagnosis needed to be confirmed by laboratory methods, it supplied various caveats that paint this confirmation as an impossibility. According to the CDC, in the absence of known smallpox disease, the predictive value of a positive smallpox test diagnosis is low. I outlined this PCR prevalence problem previously.  As smallpox can not be diagnosed clinically, PCR testing is required to confirm any suspected cases. However, PCR results are not “valid” when disease prevalence is low and therefore can not be used to confirm clinical diagnosis. Even with this admittance, the CDC then listed both PCR verification and isolation in culture as the criteria for laboratory diagnosis. They even state that the culture needs to be confirmed by way of PCR. However, once again, it must be stated that they admit that PCR can not be used for confirmation when disease prevalence is low as this results in nothing but false-positives (granted, all PCR positives are false-positives). In other words, PCR can not be used to confirm the cases of smallpox in order to determine the level of disease prevalence needed in order to determine the accuracy of the PCR results. Thus, specific PCR detection is impossible for smallpox. Even if the CDC wanted to use generic PCR designed for all “orthopoxviruses” along with negative stain electron microscopy (EM) identification of a “poxvirus” in a clinical specimen, they admitted that these results would only be suggestive of an “orthopoxvirus” infection and not diagnostic for smallpox. This means that not only can there not be confirmation of smallpox by way of clinical diagnosis, there can also not be confirmation based on laboratory diagnosis either.

The reason for the inability to confirm the diagnosis of smallpox has to do with the lack of any paper showing the purification and isolation of any particles assumed to be the variola “virus.” I have looked for quite some time for any such paper making this claim and it is nowhere to be found. All that is ever claimed is the growth of the invisible “virus” by way of different culture techniques. However, in order to know what conditions are necessary in order to grow any “virus,” the “virus” in question must be shown to physically exist first by means of purification and isolation. Without such direct verification, any result from any indirect laboratory test is essentially useless and utterly meaningless as the tests can not be validated nor calibrated to the actual “viral” particles.

For more clarity on this laboratory diagnosis prblem, we now return to highlights from the second chapter of Smallpox and its Eradication, the WHO’s 1988 fictional retelling of the history of smallpox. In this chapter, you will see:

1. That most of the evidence for smallpox and other “orthopoxviruses” as well as the structure and chemical make-up came only from the study of vaccinia “virus”
2. The most useful laboratory test for distinguishing between species of “orthopoxvirus” is the appearance of pocks on the CA membrane which is heavily influenced by culture conditions and temperature thus negating any “viral” effect
3. In spite of the fact that variola “virus” is limited in which hosts it can infect, its contradictory nature apprently allows it to grow and produce a cytopathic effect in cultured cells derived from many species
4. Its contradictory nature also allows it to produce a cytopathogenic effect that does not have anything to do with “virus” growth due to its low cytopathogenicity and instead infected cells are pushed together by the growing non-infected cells around them
5. Light microscopy and electron microscopy could not be used to distinguish between variola, vaccinia and monkeypox “viruses,” which are morphologically indistinguishable
6. All of the indirect laboratory methods can not distinguish between “orthopoxviruses”
7. The most comprehensive analysis of 4 laboratory methods (EM, gel precipitation, CA membrane, tissue cultivation in Vero cells) showed inconsistent and contradictory results

CHAPTER 2: VARIOLA VIRUS AND OTHER ORTHOPOXVIRUSES

Variola virus 

“This virus, which caused human smallpox, has a restricted host range in laboratory animals. Early reports of its transfer to animals are dificult to interpret, but monkeys were used quite early (Zuelzer, 1874) and extensively (e.g., Brinckerhoff & Tyzzer, 1906). Variola virus was subsequently grown in the rabbit cornea and a test developed to differentiate it from chickenpox virus (Paul, 1915). Later it was grown in chick embryos (Torres & Teixeira, 1935), and North et al. (1944) and Downie & Dumbell (1947b) showed that the pocks produced by variola virus on the chorioallantoic membrane were suficiently distinctive to allow its differentiation from vaccinia and cowpox viruses. A detailed account of the virology of variola virus is presented later in this chapter.

Vaccinia virus

Though a different species of Orthopoxvirus from Jenner’s “variolae vaccinae”, vaccinia virus is the agent that has been most widely used for vaccination. Baxby (1 977c, 1981) has summarized speculations about its origins (see Chapter 7). Many strains are supposed to have been derived from variola virus (Wokatsch, 1972; see Chapter 11). However, when experiments were carried out under conditions which precluded the possibility of cross-infection with vaccinia virus, “transformation” of variola virus into vaccinia virus could not be demonstrated (Herrlich et al.,1963).

There are many strains of vaccinia virus with different biological properties, although all have many features in common, such as their wide host range, rapid growth on the chorioallantoic membrane and distinctive genome maps. Since vaccinia virus has a broad host range and has been very widely used for many decades, accidental infections of domestic animals were not uncommon when human vaccination was practised on a large scale (see Table 2.7). Sometimes serial transmission occurs naturally in such animals (cows, buffaloes, rabbits).

In the history of smallpox eradication, vaccinia virus is second only to variola virus in its importance. It is also the “model” orthopoxvirus, with which the vast majority of laboratory investigations of viruses of this genus have been performed. Aspects of its virology are further discussed later in this chapter and its use in the prevention of smallpox is described at length in Chapters 6, 7 and 11.”

CHARACTERISTICS SHARED BY ALL SPECIES OF ORTHOPOXVIRUS

“Having shown the way in which early studies of the morphology of poxvirus particles led to a classification of the family and the designation of the genus Orthopoxvirus, it is necessary now to outline current views on the structure and chemistry of these viruses. The vast majority of such studies were carried out with vaccinia virus, but they apply, with minor variations, to all orthopoxviruses.”

Appearance of Orthopoxvirus Pocks on the Chorioallantoic Membrane

“The most useful laboratory test for distinguishing between species of Orthopoxvirus is the appearance of pocks on the CA membrane. Unlike plaques in cultured cells, which result
from the direct interaction between cells and virus, a third component enters into the appearance of pocks-namely, leukocytes and erythrocytes delivered to the site via the bloodstream. Basically, a pock is a greyish-white focus, varying in diameter from 0.4 mm to 4 mm, according to virus species. It is produced by a combination of hyperplasia of the ectodermal layer of the CA membrane and the infiltration of cells into the mesodermal layer. Sometimes, as with variola virus, the surface of the pock is glossy white, owing to pronounced hyperplasia of the ectoderm; sometimes, as with monkeypox virus, the superficial layer ulcerates and there is a superficial haemorrhage into the crater. The pocks of cowpox virus are bright red, because very little leukocytic infiltration occurs and there are capillary haemorrhages into the pock.

Expression of the “characteristic” pock phenotype is influenced by the concentration of pocks and the temperature of incubation. Expression of the “red” pock phenotype is enhanced when the pocks are semiconfluent or confluent. Also, at higher temperatures pocks tend to be greyish-white and non-ulcerated, whereas at lower temperatures some species (but not variola virus) produce pocks with an ulcerated, haemorrhagic centre. For example, at 37° C camelpox virus produces small pocks very similar to those of variola virus (Mayr et al., 1972), but at 35° C it produces pocks with a haemorrhagic centre (Marennikova et al., 1973). Likewise, at 37° C monkeypox virus produces white pocks very like those of variola virus (Magnus et al., 1959), whereas at 35° C the pocks are ulcerated and haemorrhagic (Marennikova et al., 1971).”

Growth in Cultured Cells

“In contrast to its limited host range in laboratory animals, variola virus will grow and produce a cytopathic effect in cultured cells derived from many species (Hahon, 1958; Pirsch et al., 1963). However, it grows best in cells from humans and other primates in which it produces characteristic “hyperplastic” foci. In fact, this appearance (Plate 2.13) is not due to proliferation of the infected cells, but to their aggregation. Because of the low cytopathogenicity of variola virus, infected cells remain in the monolayer and are pushed together by the growing non-infected cells around them (On0 & Kato, 1968). Kitamura (1968) described an assay of variola virus based on counting the hyperplastic foci that develop in HeLa and FL cells (Plate 2.13); in primate cells (Vero and JINET) these foci progress to form small plaques
(Tsuchiya & Tagaya, 1970). Variola virus will replicate and produce a cytopathic effect in continuous-line pig embryo kidney cells (Marennikova et al., 1971), a test which has been used to differentiate it from monkeypox virus. However, Veda & Dumbell (unpublished observations, 1974) found that different strains of monkeypox virus varied in their capacity to grow and produce a cytopathic effect in pig embryo kidney cells; some hardly grew at all, others
grew moderately well, but none grew as well as variola or vaccinia viruses.”

“Like the examination of stained smears, electron microscopy could not be used to distinguish between variola, vaccinia and monkeypox viruses, which are morphologically indistinguishable, but it was of great value in confirming or possibly excluding poxvirus infection and in distinguishing between poxvirus infection and chickenpox.”

“Other serological tests for viral antigen were sometimes used but never became widely popular. Kitamura et al. (1977a) suggested that direct immunofluorescence could be used for rapid diagnosis in the field, but they and other workers (Tarantola et al., 1981) recorded a number of false positive results, a major disadvantage as the achievement of eradication approached.

All the methods described so far had the limitation that, if positive, they did not distinguish between different orthopoxviruses. This drawback was of little significance when smallpox was a common disease, but it became increasingly important as eradication proceeded, particularly after human monkeypox was recognized in 1970.”

“The most comprehensive analysis of the laboratory diagnosis of smallpox was reported by Nakano (1973), who kindly updated the figures in 1982 to show the situation at that time (Table 2.10). The material under study had been shipped to the Centers for Disease Control, Atlanta, USA, from Africa, South America and Asia and had usually been in transit for between 2 and 4 weeks, and occasionally longer, often at high ambient temperatures. Four methods were used: electron microscopy, gel precipitation, and cultivation on the CA membrane and in Vero cells. By March 1981 a total of 6919 specimens had been examined, many of them from suspected chickenpox cases during precertification testing in Ethiopia and Somalia. Of the 981 positive specimens, 940 were identified as variola virus and 41 as human monkeypox virus.

Electron microscopy had the advantage of being much the most rapid method of making a presumptive diagnosis, which was a very important requirement, especially in non-endemic countries. In scabs or material that had been some time in transit, it was also the most sensitive, although fields might have to be searched for as long as 30 minutes before a specimen was declared negative. The longer period of search undoubtedly accounted for the greater percentage of successes recorded by Nakano with stored specimens, compared with the experience of Noble et al. (1970). Inoculation on the CA membrane had the great advantage of allowing differentiation between the 4 orthopoxviruses that can infect man (variola, monkeypox, cowpox and vaccinia viruses). It was also the most sensitive with fresh specimens of vesicular fluid, since one infectious particle was potentially capable of producing a pock. Positive results were obtained on the CA membrane with 14 specimens that were negative by electron microscopy, whereas 97 specimens were positive by electron microscopy but negative by CA membrane inoculation. However, Nakano (1 979) found that the susceptibility of the CA membrane, although usually quite satisfactory, was sometimes unacceptably low, as judged by control inoculation in cultured cells. For this reason he found it useful to make inoculations on cultured cells, especially with critical specimens in which recovery of the responsible virus was very desirable (e.g., in suspected human monkeypox). Out of 186 specimens that were tested by all 4 methods, 182 were positive by electron microscopy, 135 by tissue culture inoculation and 117 by CA membrane inoculation-i.e., 18 specimens were positive by tissue culture but negative on the CA membrane. Growth in pig embryo kidney cells was sometimes used to differentiate between variola and monkeypox viruses. Nakano confirmed the finding of Noble et al. (1970) that gel precipitation was the least sensitive technique and that it was often negative in lesion material that had been exposed to ambient temperatures for several days.”

Click to access 9241561106_chp2.pdf

In Summary:

• There was much difficulty in differentiating smallpox and measles in their early phases due to the similar appearance of the rashes
• Even though the Persian physician Rhazes Ar-Raz Abmiz was the first person to clinically distinguish smallpox from measles in 900 AD, European physicians continued to confuse the illnesses until relatively recent times
• Sir William Osler, the master clinician of the modern era, emphasized the difficulty in differentiating early measles from smallpox
• The Great Pox referred to syphilis, and the Lesser Pox may have referred to rubella, chickenpox, and smallpox
• La grosse verole was a term used to describe syphilis, whereas smallpox was referred to as la petite verole
• In other countries, the word for pox was applied to different diseases during different times
• In German, syphilis was initially referred to as blattern during the 16th and 17th centuries, but blattern later was applied to smallpox during the 18th century
• The term morbilli was used to differentiate the ‘‘small plague’’ of measles from the ‘‘great plague,’’ referred to as Il Morbo
• For centuries, scarlatina, rubella, measles, and smallpox were undifferentiated febrile diseases with rashes
• The terminology for measles is confusing, as is the clinical differentiation between measles and chickenpox
• Scarlet fever was termed morbilli confluentes
• Measles in German is masern; in French measles is rougeole; and the synonym for measles in English is rubeola
• As smallpox is no longer a common infectious disease, differentiation from chickenpox is less critical
• In other words, since smallpox is claimed not to exist, they do not have to worry about any chickenpox cases that look exactly like smallpox
• Should smallpox reemerge, clinicians will face the same diagnostic dilemmas in differentiating smallpox from measles in its early stages
• According to Al-Razi, the first physician to separate smallpox and measles in 900 AD, the most common signs of both smallpox and measles were:
  1. Continuous fever
  2. Nose itching
  3. Allergy in the body
  4. Redness of the cheeks and eyes
  5. Sore throat
  6. Chest pain
  7. Breathing difficulties
  8. Cough
  9. Hoarseness
  10. Headache
  11. Syncope
• On the other hand, regarding the specific signs, he said that back pain was more severe in smallpox, while it might be slight or absent in measles and that distress, syncope and anxiety were more prominent in measles
• In other words, they shared every symptom of disease and the only difference was in regards to the severity of a few of the shared symptoms
• Al-Razi was unlike all the Greek and Arab physicians before him, who considered the two diseases as one
• Smallpox was confused with chickenpox more frequently than with any other illness
• The similarities between the diseases and the importance of making the correct diagnosis led an infectious disease expert to declare that there was “no more important diagnosis in clinical medicine than the differentiation of these two diseases.”
• The question arose as to the possibility that clinical diagnostic errors could cause some cases of monkeypox to be misdiagnosed as other eruptive diseases
• In Zaire in the period 1981-1986, 977 persons with skin eruption not clinically diagnosed as human monkeypox were laboratory tested
  1. 3.3% of human monkeypox cases were found among 730 patients diagnosed as cases of chickenpox
  2. 7.3% among cases diagnosed as “atypical chickenpox”
  3. 6.1% among cases with skin rash for which clinical diagnosis could not be established
• The diagnostic difficulties were mainly based on clinical features characteristic of chickenpox:
  1. Regional pleomorphism (in 46% of misdiagnosed cases)
  2. Indefinite body-distribution of skin eruptions (49%)
  3. Centripetal distribution of skin lesions (17%)
• In the absence of smallpox, the main clinical diagnostic problem is the differentiation of human monkeypox from chickenpox
• Diseases commonly mistaken with smallpox:
  1. Monkeypox
     • Human monkeypox ranks first among the diseases that might be confused with smallpox, because differential diagnosis was impossible on clinical grounds alone
     • In the field, diagnosis depended on the occurrence of a disease indistinguishable from ordinary-type smallpox in the appropriate epidemiological situation
  2. Chickenpox
     • In post-eradication searches in India in 1976, 63% of the “suspected smallpox” cases were in fact cases of chickenpox
     • Some severe cases of chickenpox in adults were associated with such an extensive rash, including lesions on the palms and soles, that it was impossible to be certain at any stage of the disease as to whether it was chickenpox or smallpox
     • During the eradication programme, all such cases were regarded as smallpox and appropriate control measures were undertaken
  3. Tanapox
     • Lesions could be confused with those of mild smallpox in a vaccinated subject
  4. Measles
     • In the first 2 days of the rash, before vesicles developed, the most likely cause of confusion was measles, and this difficulty could persist for several more days in flat-type smallpox
     • Historically, measles did not present a problem in countries with endemic smallpox, but in non-endemic countries an early case of smallpox was sometimes diagnosed as measles, with possibly serious consequences in terms of secondary cases
     • On the other hand, in countries in which smallpox was endemic, physicians were often prone to diagnose all outbreaks of rash associated with deaths as smallpox and to report them as such to the health authorities
     • Some of these outbreaks later proved to be due to measles
  5. Syphilis
     • Earlier writers, e .g ., Councilman (1907) and Ricketts (1908), paid considerable attention to syphilitic rashes as presenting a problem in differential diagnosis
     • In African countries and India secondary syphilis remained a disease to be considered in the differential diagnosis of smallpox, up to the time of eradication
  6. Erythema multiforme
     • This disease could cause difficulties at any stage of the rash; the distribution of lesions is sometimes very like that of smallpox
     • In both diseases the patient could be quite ill and have a profuse vesicular eruption particularly affecting the extremities
     • In severe cases there could be confusion with flat-type smallpox, since the vesicles were occasionally soft, superficial and flat, individually resembling those of flat-type smallpox
     • They sometimes coalesced and produced large bullae, also seen in some cases of severe smallpox
  7. Lesions due to vaccination
     • Problems of precise diagnosis sometimes arose in smallpox contacts who had been vaccinated during what turned out to be the incubation period of smallpox
     • They usually showed a positive take at the vaccination site and often a modified rash, which could have been caused by variola or vaccinia “virus”
     • All such cases were regarded as smallpox from the point of view of management
  8. Drug eruptions
     • Drug eruptions were an important diagnostic problem in countries in which smallpox had been eradicated years before and doctors rarely considered the possibility of the disease
     • Many instances exist in which the rash of an imported case of smallpox, and sometimes the rashes of second generation cases deriving from it, were diagnosed as drug rashes
     • Vaccine-modified smallpox could continue to mislead the physician if he had never considered smallpox as a possible diagnosis
     • In endemic countries where a wide variety of drugs have become available, cases of smallpox and drug eruption sometimes occurred coincidently
  9. Rashes due to other causes
     • There are few diseases characterized by a rash that did not at some time suggest a diagnosis of smallpox
     • Acne, scabies and insect bites may be mentioned as examples
     • Coxsackievirus infections could pose a problem
     • Dengue haemorrhagic fever and other arbovirus infections associated with a rash were sometimes initially diagnosed as smallpox
• Laboratory methods played a crucial role in the global smallpox eradication programme as eradication could not have been confidently certified to have been achieved without their use
• In other words, there was no way, based on clinical diagnosis, to declare smallpox eradicated as it was regularly confused with numerous conditions/diseases
• Laboratory methods were also useful for the confirmation of clinical diagnoses
• Laboratory workers could make mistakes, however, the recovery of variola “virus” from a skin lesion was usually regarded as conclusive evidence that a particular patient was or had been suffering from smallpox
• Such confirmation was rarely sought in endemic countries when smallpox was a common disease and any doubtful case was always regarded as smallpox
• Laboratory confirmation or refutation of suspected smallpox was a valuable procedure in non-endemic countries and in smallpox-free regions of the endemic countries as eradication approached
• If an electron microscope was available, the examination of material from vesicles, pustules or scabs, examined by the negative staining technique, could give a rapid presumptive diagnosis of poxvirus, or sometimes herpesvirus, infection (i.e. the type of particle observed could only be considered presumptive, not definitive)
• Definitive diagnosis depended on the isolation of the causative “virus” on the chorioallantoic membrane of the developing chick embryo and its further characterization, if necessary, by biological tests
• Usually the character of the pocks produced on the chorioallantoic membrane was distinctive enough for the diagnosis of variola, vaccinia, monkeypox or herpesvirus infection to be made (i.e. the pocks were not always distinctive enough to differentiate the “viruses”)
• The CDC’s own list of diseases commonly confused with smallpox included many of the same as those listed by the WHO as well as:
  1. Disseminated herpes zoster (shingles)
  2. Impetigo (Streptococcus pyogenes, Staphylococcus aureus)
  3. Contact dermatitis
  4. Enteroviruses infection, especially Hand, Foot, and Mouth Disease
  5. Disseminated herpes simplex (herpes)
  6. Molluscum contagiosum
• In the absence of known smallpox disease, the predictive value of a positive smallpox test diagnosis is low, so only cases that meet the clinical definition of the disease should be tested
• Initial positive results require confirmatory testing at CDC
• The laboratory criteria for diagnosis are:
  1. Polymerase chain reaction (PCR) identification of variola DNA in a clinical specimen, OR
  2. Isolation of smallpox (variola) “virus” from a clinical specimen (WHO Smallpox Reference Laboratory or laboratory with appropriate reference capabilities) with variola PCR confirmation
• Generic orthopoxvirus PCR and negative stain electron microscopy (EM) identification of a poxvirus in a clinical specimen are suggestive of an “orthopoxvirus” infection but not diagnostic for smallpox
• Variola “virus” was grown in the rabbit cornea and a test was developed to differentiate it from chickenpox “virus” (Paul, 1915)
• Later it was grown in chick embryos (Torres & Teixeira, 1935), and North et al. (1944) and Downie & Dumbell (1947b) showed that the pocks produced by variola “virus” on the chorioallantoic membrane were suficiently distinctive to allow its differentiation from vaccinia and cowpox “viruses”
• Though a different species of “orthopoxvirus” from Jenner’s “variolae vaccinae”, vaccinia “virus” is the agent that has been most widely used for smallpox vaccination
• Many strains are supposed to have been derived from variola “virus” yet when experiments were carried out under conditions which precluded the possibility of cross-infection with vaccinia “virus,” “transformation” of variola “virus” into vaccinia “virus” could not be demonstrated
• There are many strains of vaccinia “virus” with different biological properties
• In the history of smallpox eradication, vaccinia “virus” is second only to variola “virus” in its importance
• It is also the “model orthopoxvirus,” with which the vast majority of laboratory investigations of “viruses” of this genus have been performed
• The vast majority of studies on the structure and chemistry of pox “viruses” were carried out with vaccinia “virus,” but they claim to apply, with minor variations, to all “orthopoxviruses”
• In other words, the structure and chemical make-up of the pox “viruses” were derived from vaccinia “virus” and not by the study of the other “viruses” themselves as it was assumed that the results from vaccinia apply to them all
• The most useful laboratory test for distinguishing between species of “orthopoxvirus” is the appearance of pocks on the CA membrane
• Expression of the “characteristic” pock phenotype is influenced by the concentration of pocks and the temperature of incubation
• At higher temperatures pocks tend to be greyish-white and non-ulcerated, whereas at lower temperatures some species (but not variola “virus”) produce pocks with an ulcerated, haemorrhagic centre
• At 37° C camelpox “virus” produces small pocks very similar to those of variola “virus” but at 35° C it produces pocks with a haemorrhagic centre
• At 37° C monkeypox “virus” produces white pocks very like those of variola “virus” whereas at 35° C the pocks are ulcerated and haemorrhagic
• In other words, the pock formations are directly influenced by the culture conditions and tempature and have nothing to do with any “virus”
• In contrast to its limited host range in laboratory animals, variola “virus” is said to grow and produce a cytopathic effect in cultured cells derived from many species (i.e. it can’t infect the animals but it can somehow “grow” on their cells)
• It’s CPE in human and primate cells is not due to proliferation of the infected cells, but to their aggregation because of the low cytopathogenicity of variola “virus”
• In other words, the CPE is said not to be due to the growth of “virus”
• It is said that variola “virus” will replicate and produce a cytopathic effect in continuous-line pig embryo kidney cells, a test which has been used to differentiate it from monkeypox “virus”
• However, Veda & Dumbell found that different strains of monkeypox “virus” varied in their capacity to grow and produce a cytopathic effect in pig embryo kidney cells; some hardly grew at all, others grew moderately well (i.e. the CPE was not specific to smallpox thus it could not be used to distinguish between smallpox and monkeypox)
• Like the examination of stained smears, electron microscopy could not be used to distinguish between variola, vaccinia and monkeypox “viruses,” which are morphologically indistinguishable
• Serological tests for “viral” antigen were sometimes used but never became widely popular
• Kitamura et al. suggested that direct immunofluorescence could be used for rapid diagnosis in the field, but they and other workers recorded a number of false positive results
• All the methods described had the limitation that, if positive, they did not distinguish between different “orthopoxviruses”
• The most comprehensive analysis of the laboratory diagnosis of smallpox was reported by Nakano (1973), who updated the figures in 1982
• Four methods were used:
  1. Electron microscopy
  2. Gel precipitation
  3. Cultivation on the CA membrane
  4. Cultivation in Vero cells
• By March 1981 a total of 6919 specimens had been examined, many of them from suspected chickenpox cases during precertification testing in Ethiopia and Somalia
• Of the 981 positive specimens, 940 were identified as variola “virus” and 41 as human monkeypox “virus”
• Electron microscopy had the advantage of being much the most rapid method of making a presumptive diagnosis although fields might have to be searched for as long as 30 minutes before a specimen was declared negative (they would not need to search for the “virus” if the sample was purified and isolated)
• Positive results were obtained on the CA membrane with 14 specimens that were negative by electron microscopy, whereas 97 specimens were positive by electron microscopy but negative by CA membrane inoculation
• Nakano (1 979) found that the susceptibility of the CA membrane, although usually quite satisfactory, was sometimes unacceptably low, as judged by control inoculation in cultured cells
• Out of 186 specimens that were tested by all 4 methods:
  1. 182 were positive by electron microscopy
  2. 135 by tissue culture inoculation
  3. 117 by CA membrane inoculation-i.e., 18 specimens were positive by tissue culture but negative on the CA membrane
  4. Growth in pig embryo kidney cells was sometimes used to differentiate between variola and monkeypox “viruses”
• Nakano confirmed the finding of Noble et al. (1970) that gel precipitation was the least sensitive technique
• In other words, all of these indirect laboratory diagnostic tests gave inconsistent and contradictory results

In the past, all diseases involving eruptions of the skin were considered the same disease. This can be seen by the numerous descriptions and labels used interchangeably in order to describe these similar sets of symptoms over the centuries. The separation of the ailments into separate diseases based on minute and often overlapping differences is mainly a modern invention. This can be seen with smallpox which was distinguished from related diseases such as measles, chickenpox, shingles, scarlett fever, monkeypox, etc. Even with these separations, clinicians had a difficult and challenging time diagnosing these diseases based on just symptoms alone. There are numerous examples of clinical misdiagnosis between smallpox and its relatives. Thus, as laboratory methods became available, it became imperative to confirm any clinical diagnosis using these new methods. However, the older tests were unable to distinguish one “orthopoxvirus” from another and the newer tests such as PCR can not be used as a confirmation as they rely on the determination of disease prevalence to be high in order for the results to be valid. Prevalence can only be determined by clinical diagnosis, and clinical diagnosis, as noted by the WHO and CDC, requires laboratory confirmation. See the problem here?

This racket of labeling the same symptoms as different diseases can be seen throughout history as noted with the smallpox example but also regarding syphilis and AIDS, polio and acute flaccid myelitis, as well as “Covid-19” and allergies, the common cold, the flu, and pneumonia. This breakup of the symptoms into new diseases provides ample opportunity for the medical mafia to sell us both on the disease and the supposed pharmaceutical cure. It can be used to convince us on the idea of vaccination as a successful intervention leading to the eradication of the older disease which was actually phased out in favor of the identical symptom set which has been rebranded, repackaged, and relabelled. It is far past time we learn from history and break free of this symptomological pharmaceutical business model in order to have a future free from its toxic influence.