Virulence and pathophysiology of the Congo Basin and West African strains of monkeypox virus in non-human primates Saijo, Masayuki and Ami, Yasushi and Suzaki, Yuriko and Nagata, Noriyo and Iwata, Naoko and Hasegawa, Hideki and Iizuka, Itoe and Shiota, Tomoyuki and Sakai, Kouji and Ogata, Momoko and Fukushi, Shuetsu and Mizutani, Tetsuya and Sata, Tetsutaro and Kurata, Takeshi and Kurane, Ichiro and Morikawa, Shigeru,, 90, 2266-2271 (2009), doi = https://doi.org/10.1099/vir.0.010207-0, publicationName = Microbiology Society, issn = 0022-1317, abstract= 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 106 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., language=, type=