Prevalence of yellow head virus in cultured black tiger shrimp (Penaeus monodon Fabricius) from selected shrimp farms in the Philippines

The prevalence and geographic distribution of Yellow head virus (YHV) in cultured Penaeus monodon in the Philippines was documented by Western blot assay. Fifty-three out of 219 samples (24.2%) were found to be positive for YHV infection. Among the ten provincial sampling sites, selected shrimp farms from Misamis Occidental had the highest prevalence of infection with 66.7% followed by South Cotabato, Negros Occidental and Capiz with 43.7%, 35.4% and 33.3% respectively. Selected shrimp farms in Agusan del Norte and Bohol were also positive for YHV infection at lower prevalence. Samples from Bataan, Batangas, Cebu and Misamis Oriental were all negative for YHV infection. The prevalence of YHV in the different life stages of shrimp was also determined. Post larval stage had the highest prevalence of infection with 54.5% followed by the juvenile stage with 40.8% and adult stage with 16.9%. Infectivity studies resulted to 60% cumulative mortality 17 days post-infection in juvenile shrimp and 50% cumulative mortality 19 days postinfection in adult shrimp. YHV infection was further confirmed by electron microscopical examination, histopathological examination and in vitro infectivity assay

Prevalence of Chlamydia trachomatis Infection among Low- and High-Risk Filipino Women and Performance of Chlamydia Rapid Tests in Resource-Limited Settings▿

The prevalence of urogenital Chlamydia trachomatis infection was determined with a PCR-based test of women from low- and high-risk populations in Iloilo City, Philippines, between August 2002 and March 2006. Two rapid tests for C. trachomatis, Clearview Chlamydia MF and the Chlamydia Rapid Test (CRT), were also evaluated in these resource-limited settings. Specimens were obtained from female sex workers (FSWs; n = 1,484) attending a social hygiene clinic (SHC) and from women (n = 838) attending an obstetrics-gynecology (OB-GYN) clinic. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the rapid tests were determined, with PCR as the gold standard. The PCR positivity rate for SHC participants (72% asymptomatic) ranged from 17.9 to 32.0% during the study period. Compared with those of PCR, the sensitivities and specificities of the Clearview test were 53.5 and 99.1%, respectively, with endocervical swab specimens (CS; n = 822) from the FSWs and 31.1 and 95.2%, respectively, with vaginal swab specimens (VS; n = 333) from these women. The sensitivity, specificity, PPV, and NPV of the CRT with VS from the FSWs were 71.0, 99.0, 97.1, and 87.9%, respectively. At the OB-GYN site, the PCR positivity rate with VS was 6.3%. The sensitivity, specificity, PPV, and NPV of the CRT with these specimens were 86.8, 99.6, 93.9, and 99.1%, respectively. The performance of the Clearview test at the SHC was thus markedly lower with VS than with CS, whereas the CRT performed well with VS from both populations