Tracking the entry routes of hepatitis C virus as a surrogate of HIV in an HIV-low prevalence country, the Philippines.

From 2002 to 2007, 1,590 individuals were enrolled in an active surveillance program conducted in Metro Cebu, Philippines, where the anti-HCV-positive rate was significantly and constantly high among injecting drug users (83%, 793/960; 71-88%), especially among those living in downtown (89%, 683/770; 87-100%), despite the extremely low percentage of anti-HIV-positives (0.34%, 3/874). Sampling areas were then enlarged nationwide and the number of samples increased to 2,645 at the end of 2007. A total of 444 samples were positive for HCV RNA. Phylogenetic analysis based on NS5B and E1-E2 regions revealed that the most dominant HCV subtype was 1a, and followed by 2b, 2a, and 1b, and that the HCV strains had the largest variety in Metro Manila and its vicinity (P < 0.01). Interestingly, subtype 1b was detected solely in Metro Manila, and four HCV strains collected in this area showed higher homology to specific foreign strains retrieved from the Genbank/EMBL/DDBJ database with bootstrap values of 68-95% comparing with other strains analyzed in this nationwide study. These data suggest that HCV strains may be introduced occasionally into the Philippines possibly through Metro Manila as a main entry point. Considering the fact that an HIV epidemic started primarily via contaminated needle sharing in Asia, the constantly high rate of HCV infections and the newly introduced foreign HCV strains in the absence of HIV epidemic warrant further investigation on HCV entry and spread for early detection of an HIV epidemic in the Philippines.

The prevalence of HIV, HBV and HCV among Filipino blood donors and overseas work visa applicants.

OBJECTIVE: Our aim was to estimate the prevalence of HIV, HBV and HCV among the general population of the Philippines using data sources outside of the limited existing active surveillance network. METHODS: We analysed aggregate HIV, HBV and HCV test results for hospital-based blood donors (BDs) and overseas Filipino worker candidates (OFWCs) that had been reported from licensed laboratories to the National STD/AIDS Cooperative Central Laboratory in Manila between 2002 and 2004. FINDINGS: From over 144 000 blood-screening results, the HIV prevalence was 0.006% in BDs and 0.001% in OFWCs; that of HBV was 4.2% in both groups; and that of HCV was 0.3% in BDs and 0.9% in OFWCs. Males were at increased risk of both HBV and HCV; among OFWCs, younger women were at increased risk. Laboratories that tested sequentially but stopped testing after the first positive result were far less likely to detect HCV, indicating that sequential testing protocols may underestimate HCV and HIV prevalence. OFWCs were at low risk of HIV, and the risk of testing positive for these viruses was not increased among OFWCs applying for a repeated work visa, compared with first time-applicants. CONCLUSION: Based on these data, we conclude that HIV is rare in the Philippines. In contrast with prior reports, we found no evidence that OFWCs constitute a high-risk group for HIV. Further research is needed to understand why younger women are at increased risk of acquiring HBV.