Be a Virus, See the World
- 254 Downloads
As the recent SARS epidemic has shown, viruses are able to migrate with remarkably high speed, endangering countries around the globe within hours. Since viruses are obligate parasites, their migration speed is dependent on the mobility of the respective host. Several examples of pathogenic viruses with different patterns of migration will be discussed.
Lassa virus is endemic in West Africa and causes a highly pathogenic hemorrhagic fever among humans. Lassa virus is transmitted by urine and feces of rodents that are persistently infected. Lassa virus, dependent on its rodent host, seems not to spread significantly outside its endemic regions. The human infection rather represents a dead end for the virus.
West Nile virus entrered the American public awareness in 1999 with the first human cases in the United States appearing in New York City. The virus is transmitted by mosquitoes that parasitize migrating birds, and also, e.g., crows. Transmitted to humans, West Niel virus can cause encephalitis that is especially dangerous for the elderly. West Nile virus spread remarkably fast over the North American continent. Nowadays, even several Canadian provinces are facing a severe problem with infected birds and human cases.
The SARS coronavirus caused not only epidemics with local transmissions in mainland China, Hong Kong, Taiwan, and Toronto, but was also spread to almost every country worldwide by infected patients. So far, this was the most impressive example for the speed a virus can achieve by the mobility of its host. The natural host of the SARS coronavirus is still unknown and, thus future outbreaks cannot be excluded.
The risk imposed by an emerging virus to the human population is a product of migration velocity, transmission route, and speed of detection. Most dangerous for the human population are highly pathogenic viruses that are transmitted from human to human via the air (SARS coronavirus). However, equally dangerous are viruses that are highly pathogenic, transmitted by blood to blood contact but have a long incubation period and, thus, detection and surveillance are complicated (human immunodeficiency virus).
KeywordsWest Nile Virus Severe Acute Respiratory Syndrome Yellow Fever Virus North American Continent Lassa Fever
- Drosten C, Gunther S, Preiser W, van der Werf S, Brodt HR, Becker S, Rabenau H, Panning M, Kolesnikova L, Fouchier RA, Berger A, Burguiere AM, Cinatl J, Eickmann M, Escriou N, Grywna K, Kramme S, Manuguerra JC, Muller S, Rickerts V, Sturmer M, Vieth S, Klenk HD, Osterhaus AD, Schmitz H, Doerr HW (2003) Identification of a novel coronavirus in patients with severe acute respiratory syndrome. N Engl J Med 348: 1967 - 1976PubMedCrossRefGoogle Scholar
- Guan Y, Zheng BJ, He YQ, Liu XL, Zhuang ZX, Cheung CL, Luo SW, Li PH, Zhang LJ, Guan YJ, Butt KM, Wong KL, Chan KW, Lim W, Shortridge KF, Yuen KY, Peiris JSM, Poon LLM (2003) Isolation and characterization of viruses related to the SARS coronavirus from animals in Southern China. Science 10:1126/Science 10: 87139Google Scholar
- Ksiazek TG, Erdman D, Goldsmith CS, Zaki SR, Peret T, Emery S, Tong S, Urbani C, Corner JA, Lim W, Rollin PE, Dowell SF, Ling AE, Humphrey CD, Shieh WJ, Guarner J, Paddock CD, Rota P, Fields B, DeRisi J, Yang JY, Cox N, Hughes JM, LeDuc JW, Bellini WJ, Anderson LJ (2003) A novel coronavirus associated with severe acute respiratory syndrome. N Engl J Med 348: 1953 - 1966PubMedCrossRefGoogle Scholar
- Peters CJ, Buchmeier M, Rollin PE, Ksiasek TG (1996) Arenaviruses. In: FEA (ed) Virology. Raven Press, New York, pp 1521 - 1551Google Scholar
- Rota PA, Oberste MS, Monroe SS, Nix WA, Campagnoli R, Icenogle JP, Penaranda S, Bankamp B, Maher K, Chen MH, Tong S, Tamin A, Lowe L, Frace M, DeRisi JL, Chen Q, Wang D, Erdman DD, Peret TC, Burns C, Ksiazek TG, Rollin PE, Sanchez A, Liffick S, Holloway B, Limor J, McCaustland K, Olsen-Rasmussen M, Fouchier R, Gunther S, Osterhaus AD, Drosten C, Pallansch MA, Anderson LJ, Bellini WJ (2003) Characterization of a novel coronavirus associated with severe acute respiratory syndrome. Science 300: 1394 - 1399PubMedCrossRefGoogle Scholar
- Ter Meulen J, Lukashevich I, Sidibe K, Inapogui A, Marx M, Dorlemann A, Yansane M L, Koulemou K, Chang-Claude J, Schmitz H (1996) Hunting of peridomestic rodents and consumption of their meat as possible risk factors for rodent-to-human transmission of Lassa virus in the Republic of Guinea. Am J Trop Med Hyg 55: 661 - 666PubMedGoogle Scholar