Reemergence of Reston ebolavirus in Cynomolgus Monkeys, the Philippines, 2015.

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.

Hepatitis B seroprevalence among 5 to 6 years old children in the Philippines born prior to routine hepatitis B vaccination at birth.

To assess the prevalence of hepatitis B in the Philippines, we conducted a cross-sectional study among 5 to 6 year old children born in 2007-2008, when the birth dose started to be implemented in the country. The study was conducted from 25 July to 22 October 2013 in 24 provinces and used a 3-stage cluster design and probability-proportional to size sampling. Blood was obtained and sera were tested for hepatitis B surface antigen (HBsAg). The survey included 2,769 children, of whom 26% received a timely birth dose (within 24 hours of birth) and 89% received 3 doses of the hepatitis B vaccine. Due to problems in the initial testing algorithm, only 2,407 sera were available for HBsAg testing, 20 (weighted%, 0.86%) were HBsAg positive. By immunization card and recall, among HBsAg positive children, 2 (weighted%, 20%) received a timely birth dose while 17 (weighted%, 85%) received 3 doses of the hepatitis B vaccine. The seroprevalence of HBsAg that we detected was lower than expected. However, there were several limitations in the field and in the laboratory that may have affected the representativeness of the results. Follow up studies need to be conducted to validate these results.

Genetic characterization of measles virus in the Philippines, 2008-2011.

BACKGROUND: Large outbreaks of measles occurred in the Philippines in 2010 and 2011. Genetic analysis was performed to identify the genotype of measles virus (MeV) that was responsible for the large outbreaks. METHODS: A total of 114 representative MeVs that were detected in the Philippines from 2008 to 2011 were analyzed by sequencing the C-terminal region of nucleocapsid (N) gene and partial hemagglutinin (H) gene and by inferring the phylogenetic trees. RESULTS: Genetic analysis showed that genotype D9 was the predominant circulating strain during the 4-year study period. Genotype D9 was detected in 23 samples (92%) by N gene sequencing and 93 samples (94%) by H gene analysis. Sporadic cases of genotype G3 MeV were identified in 2 samples (8%) by N gene sequencing and 6 samples (6%) by H gene analysis. Genotype G3 MeV was detected mainly in Panay Island in 2009 and 2010. Molecular clock analysis of N gene showed that the recent genotype D9 viruses that caused the big outbreaks in 2010 and 2011 diverged from a common ancestor in 2005 in one of the neighboring Southeast Asian countries, where D9 was endemic. These big outbreaks of measles resulted in a spillover and were associated with genotype D9 MeV importation to Japan and the USA. CONCLUSION: Genotype D9 MeV became endemic and caused two big outbreaks in the Philippines in 2010 and 2011. Genotype G3 MeV was detected sporadically with limited geographic distribution. This study highlights the importance of genetic analysis not only in helping with the assessment of measles elimination program in the country but also in elucidating the transmission dynamics of measles virus.

Interruption of the circulation of an indigenous measles genotype and the introduction of other genotypes after a mass vaccination campaign in the Philippines.

Molecular analysis of measles viruses in the Philippines was conducted from 2000 to 2008. No confirmed measles cases were detected in the surveillance in 2005 after the mass vaccination campaign in 2004. However, a re-emergence of measles cases occurred in 2007, which was caused by other genotypes and the previous circulating genotype had disappeared.