Introduction
Over time, smallpox, caused by the variola virus (VARV), a type of Orthopoxvirus within the Poxviridae family, instilled fear worldwide until its eradication in the late 20th century. Here, we delve into VARV’s characteristics, the disease it caused, its historical impact, and the monumental efforts leading to its extinction.
The Variola Virus and Smallpox: A Historical Overview
The variola virus, the culprit behind smallpox, has a disputed origin, with initial clinical accounts dating back to ancient societies spanning China, India, and the Mediterranean region. Historical records indicate that, before the 15th century, smallpox was widespread in both Europe and Asia, eventually spreading to the Americas, Southern Africa, and Australia via colonial expansion, with profound repercussions for indigenous communities (Meyer et al., 2020).
Clinical Features and Transmission
Smallpox spreads through airborne particles, close contact with those infected, or contact with contaminated objects. After an incubation period lasting about 7 to 19 days, individuals entered a prodromal stage marked by fever, fatigue, and headaches, eventually developing the distinctive rash and pustules. The illness was exceptionally contagious, particularly in the initial week of symptom emergence (Meyer et al., 2020).
Virulence and Diagnosis
The unique symptoms of smallpox, such as its characteristic rash and sores, made it distinguishable, though diagnosing it required considering other illnesses. Confirming the diagnosis in the lab required advanced biosafety measures due to the virus’s high contagiousness (Meyer et al., 2020).
Treatment and Prevention
Throughout history, there were few treatment options, and efforts to prevent illness focused mostly on immunization. The idea of immunization evolved from earlier methods like variolation to Edward Jenner’s groundbreaking use of cowpox virus, which led to the development of the smallpox vaccine. This vaccine was pivotal in the worldwide campaign led by the World Health Organization (WHO) under the Intensified Smallpox Eradication Program (Meyer et al., 2020).
Smallpox Eradication
The WHO’s declaration of smallpox eradication in 1980 marks a significant milestone in public health. The success of the eradication effort was driven by the distinctive transmission pattern of VARV among humans, the clear clinical symptoms aiding in early identification and vaccination of contacts, and the efficacy of the smallpox vaccine. Following eradication, attention has turned to research on diagnostic methods, antiviral treatments, and improved vaccine safety (Meyer et al., 2020).
Recent Insights on VARV’s Origin
In their study, Ferrari et al. (2020) used genomic analysis of an 18th-century sample to support the theory that VARV arose relatively recently, approximately 3000-4000 years ago. This investigation highlights the significance of historical and genomic research in revealing the origins and dissemination of infectious diseases by providing a more accurate timeline and a clearer understanding of VARV’s development.
Conclusion
In summary, the saga of smallpox and the variola virus illustrates humanity’s resilience and creativity in confronting a severe illness. The eradication of smallpox was a major achievement in public health, establishing a model for tackling infectious diseases. Ongoing research and vigilance are crucial to prevent the resurgence of such illnesses and to address new public health challenges effectively.
References
Ferrari, G., Neukamm, J., Baalsrud, H. T., Breidenstein, A. M., Ravinet, M., Phillips, C.,… & Schuenemann, V. J. (2020). Variola virus genome sequenced from an eighteenth-century museum specimen supports the recent origin of smallpox. Philosophical Transactions of the Royal Society B, 375(1812).
Meyer, H., Ehmann, R., & Smith, G. L. (2020). Smallpox in the post-eradication era. Viruses, 12(2).
