Monkeypox virus is divided into Congo Basin and West African strains. The virulence and pathophysiology of two strains, Zr-599 (a Congo Basin monkeypox virus) and Liberia (a West African monkeypox virus), were evaluated in non-human primates. Four monkeys were infected by the subcutaneous (SC) and two by the intranasal (IN) inoculation routes for Zr-599 and Liberia at a dose of 10 p.f.u. One monkey in the Liberia/SC group was demonstrated to be co-infected with Gram-positive cocci and was excluded from analyses. Infections in three of the four Zr-599/SC monkeys and in one of the three Liberia/SC monkeys were fatal. Virus genome levels in blood in the Zr-599/SC monkeys were approximately 10 times higher than those in the Liberia/SC monkeys. Zr-599 affected respiratory, genito-urinary and gastrointestinal tract organs more severely than Liberia. Zr-599 was more virulent than Liberia and one of the factors might be the difference in organ tropism.


Article metrics loading...

Loading full text...

Full text loading...



  1. Arita, I., Jezek, Z., Khodakevich, L. & Ruti, K.(1985). Human monkeypox: a newly emerged orthopoxvirus zoonosis in the tropical rain forests of Africa. Am J Trop Med Hyg 34, 781–789. [Google Scholar]
  2. Breman, J. G., Nakano, J. H., Coffi, E., Godfrey, H. & Gautun, J. C.(1977). Human poxvirus disease after smallpox eradication. Am J Trop Med Hyg 26, 273–281. [Google Scholar]
  3. Breman, J. G., Kalisa, R., Steniowski, M. V., Zanotto, E., Gromyko, A. I. & Arita, I.(1980). Human monkeypox, 1970–79. Bull World Health Organ 58, 165–182. [Google Scholar]
  4. Chen, N., Li, G., Liszewski, M. K., Atkinson, J. P., Jahrling, P. B., Feng, Z., Schriewer, J., Buck, C., Wang, C. & other authors(2005). Virulence differences between monkeypox virus isolates from West Africa and the Congo basin. Virology 340, 46–63.[CrossRef] [Google Scholar]
  5. Damon, I.(2007). Poxviruses. In Fields Virology, 5th edn, pp. 2947–2975. Edited by D. M. Knipe & P. M. Howley. Philadelphia, PA: Lippincott Williams & Wilkins.
  6. Di Giulio, D. B. & Eckburg, P. B.(2004). Human monkeypox: an emerging zoonosis. Lancet Infect Dis 4, 15–25.[CrossRef] [Google Scholar]
  7. Foster, S. O., Brink, E. W., Hutchins, D. L., Pifer, J. M., Lourie, B., Moser, C. R., Cummings, E. C., Kuteyi, O. E., Eke, R. E. & other authors(1972). Human monkeypox. Bull World Health Organ 46, 569–576. [Google Scholar]
  8. Guarner, J., Johnson, B. J., Paddock, C. D., Shieh, W. J., Goldsmith, C. S., Reynolds, M. G., Damon, I. K., Regnery, R. L. & Zaki, S. R.(2004). Monkeypox transmission and pathogenesis in prairie dogs. Emerg Infect Dis 10, 426–431.[CrossRef] [Google Scholar]
  9. Heymann, D. L., Szczeniowski, M. & Esteves, K.(1998). Re-emergence of monkeypox in Africa: a review of the past six years. Br Med Bull 54, 693–702.[CrossRef] [Google Scholar]
  10. Janseghers, L., Matamba, M., Colaert, J., Vandepitte, J. & Desmyter, J.(1984). Fatal monkeypox in a child in Kikwit, Zaire. Ann Soc Belg Med Trop 64, 295–298. [Google Scholar]
  11. Jezek, Z. & Khodakevich, L. N.(1987). Ten years of freedom from smallpox: lessons and experiences. Dedicated to the tenth anniversary of worldwide freedom from smallpox. J Hyg Epidemiol Microbiol Immunol 31, 237–244. [Google Scholar]
  12. Khodakevich, L., Szczeniowski, M., Manbu-ma-Disu, Jezek, Z., Marennikova, S., Nakano, J. & Messinger, D.(1987). The role of squirrels in sustaining monkeypox virus transmission. Trop Geogr Med 39, 115–122. [Google Scholar]
  13. Khodakevich, L., Jezek, Z. & Messinger, D.(1988). Monkeypox virus: ecology and public health significance. Bull World Health Organ 66, 747–752. [Google Scholar]
  14. Ladnyj, I. D., Ziegler, P. & Kima, E.(1972). A human infection caused by monkeypox virus in Basankusu Territory, Democratic Republic of the Congo. Bull World Health Organ 46, 593–597. [Google Scholar]
  15. Learned, L. A., Reynolds, M. G., Wassa, D. W., Li, Y., Olson, V. A., Karem, K., Stempora, L. L., Braden, Z. H., Kline, R. & other authors(2005). Extended interhuman transmission of monkeypox in a hospital community in the Republic of the Congo, 2003. Am J Trop Med Hyg 73, 428–434. [Google Scholar]
  16. Likos, A. M., Sammons, S. A., Olson, V. A., Frace, A. M., Li, Y., Olsen-Rasmussen, M., Davidson, W., Galloway, R., Khristova, M. L. & other authors(2005). A tale of two clades: monkeypox viruses. J Gen Virol 86, 2661–2672.[CrossRef] [Google Scholar]
  17. Morikawa, S., Sakiyama, T., Hasegawa, H., Saijo, M., Maeda, A., Kurane, I., Maeno, G., Kimura, J., Hirama, C. & other authors(2005). An attenuated LC16m8 smallpox vaccine: analysis of full-genome sequence and induction of immune protection. J Virol 79, 11873–11891.[CrossRef] [Google Scholar]
  18. Mukinda, V. B., Mwema, G., Kilundu, M., Heymann, D. L., Khan, A. S. & Esposito, J. J.(1997). Re-emergence of human monkeypox in Zaire in 1996. Monkeypox Epidemiologic Working Group. Lancet 349, 1449–1450.[CrossRef] [Google Scholar]
  19. Nagata, N., Iwasaki, T., Ami, Y., Harashima, A., Hatano, I., Suzaki, Y., Yoshii, K., Yoshii, T., Nomoto, A. & Kurata, T.(2001). Comparison of neuropathogenicity of poliovirus type 3 in transgenic mice bearing the poliovirus receptor gene and cynomolgus monkeys. Vaccine 19, 3201–3208.[CrossRef] [Google Scholar]
  20. Nagata, N., Shimizu, H., Ami, Y., Tano, Y., Harashima, A., Suzaki, Y., Sato, Y., Miyamura, T., Sata, T. & Iwasaki, T.(2002). Pyramidal and extrapyramidal involvement in experimental infection of cynomolgus monkeys with enterovirus 71. J Med Virol 67, 207–216.[CrossRef] [Google Scholar]
  21. Reed, K. D., Melski, J. W., Graham, M. B., Regnery, R. L., Sotir, M. J., Wegner, M. V., Kazmierczak, J. J., Stratman, E. J., Li, Y. & other authors(2004). The detection of monkeypox in humans in the Western Hemisphere. N Engl J Med 350, 342–350.[CrossRef] [Google Scholar]
  22. Saijo, M., Ami, Y., Suzaki, Y., Nagata, N., Iwata, N., Hasegawa, H., Ogata, M., Fukushi, S., Mizutani, T. & other authors(2006). LC16m8, a highly attenuated vaccinia virus vaccine lacking expression of the membrane protein B5R, protects monkeys from monkeypox. J Virol 80, 5179–5188.[CrossRef] [Google Scholar]
  23. Saijo, M., Ami, Y., Suzaki, Y., Nagata, N., Iwata, N., Hasegawa, H., Ogata, M., Fukushi, S., Mizutani, T. & other authors(2008). Diagnosis and assessment of monkeypox virus (MPXV) infection by quantitative PCR assay: differentiation of Congo Basin and West African strains. Jpn J Infect Dis 61, 140–142. [Google Scholar]
  24. Sbrana, E., Xiao, S. Y., Newman, P. C. & Tesh, R. B.(2007). Comparative pathology of North American and central African strains of monkeypox virus in a ground squirrel model of the disease. Am J Trop Med Hyg 76, 155–164. [Google Scholar]
  25. Stagles, M. J., Watson, A. A., Boyd, J. F., More, I. A. & McSeveney, D.(1985). The histopathology and electron microscopy of a human monkeypox lesion. Trans R Soc Trop Med Hyg 79, 192–202.[CrossRef] [Google Scholar]
  26. Tesh, R. B., Watts, D. M., Sbrana, E., Siirin, M., Popov, V. L. & Xiao, S. Y.(2004). Experimental infection of ground squirrels (Spermophilus tridecemlineatus) with monkeypox virus. Emerg Infect Dis 10, 1563–1567.[CrossRef] [Google Scholar]
  27. Zaucha, G. M., Jahrling, P. B., Geisbert, T. W., Swearengen, J. R. & Hensley, L.(2001). The pathology of experimental aerosolized monkeypox virus infection in cynomolgus monkeys (Macaca fascicularis). Lab Invest 81, 1581–1600.[CrossRef] [Google Scholar]

Data & Media loading...


[ Single PDF file] (1.9 MB)


[ Single PDF file] (75 KB)

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error