The 2008 Reston ebolavirus infection event in domestic pigs has triggered continuing epidemiologic investigations among Philippine health and veterinary agencies in collaboration with international filovirus experts. Prior to this, there were only 3 known and documented Reston ebolavirus outbreaks in nonhuman primates in the world, all traced back to a single geographic source in the Philippines in a monkey breeding/export facility. The first one in 1989 was the first-ever Ebola virus that emerged outside of Africa and was also the first known natural infection of Ebola virus in nonhuman primates. When it was first discovered among laboratory monkeys in the United States, the source was immediately traced back to the farm located in the Philippines. The second outbreak was in 1992-93. The third episode in 1996 was the last known outbreak before Reston ebolavirus reemerged in pigs in 2008. The isolated outbreaks involving 2 animal species bring forth issues requiring further investigations, and highlight the significance of intersectoral collaboration to effectively address zoonoses prevention and control/response in the interest of minimizing public health risk.

No abstract

To describe the transmission pattern of natural infection with Ebola Reston (EBO-R) virus in a breeding colony, the chronological and spatial analysis of mortality during the 1996 EBO-R virus outbreak was done in this study. The EBO-R virus infection among monkeys in the facility was widespread. Over a period of 3 months, 14 out of 21 occupied units were contaminated with antigen positive animals. A large number of wild-caught monkeys were involved in this outbreak suggesting that wild-caught monkeys have a high susceptibility to EBO-R virus infection. In this outbreak, morbidity patterns for individual animal units were very different regardless of the type and size of cages, individual or gang cages. The results suggest that not only the cage size but also poor animal husbandry practices may be risk factors for the spread of EBO-R infection.

In August 2015, a nonhuman primate facility south of Manila, the Philippines, noted unusual deaths of 6 cynomolgus monkeys (Macaca fascicularis), characterized by generalized rashes, inappetence, or sudden death. We identified Reston ebolavirus (RESTV) infection in monkeys by using serologic and molecular assays. We isolated viruses in tissues from infected monkeys and determined viral genome sequences. RESTV found in the 2015 outbreak is genetically closer to 1 of the 4 RESTVs that caused the 2008 outbreak among swine. Eight macaques, including 2 also infected with RESTV, tested positive for measles. Concurrently, the measles virus was circulating throughout the Philippines, indicating that the infection of the macaques may be a reverse zoonosis. Improved biosecurity measures will minimize the public health risk, as well as limit the introduction of disease and vectors.