Phylogenetic dendrograms of rotavirus genes (a) VP7, (b) VP6, (c) VP3 and (d) NSP2 constructed by neighbour-joining methods with MEGA.5 program.Variation scale is described at bottom.Percent bootstrap support is indicated at each node (values <80% are omitted).Solid circle, triangle and inverted triangle indicate DS-1-like G1P[8] rotaviruses detected in Philippines; solid square indicates DS-1-like G1P[8] rotavirus in Japan; inverted open triangle indicates typical Wa-like rotaviruses in Philippines; open circle indicates typical DS-1-like rotaviruses in Philippines.

SUMMARYThe role that animals play in the transmission of Schistosoma japonicum to humans in the Philippines remains uncertain and prior studies have not included several species, adjustment for misclassification error and clustering, or used a cohort design. A cohort study of 2468 people providing stool samples at 12 months following praziquantel treatment in 50 villages of Western Samar, the Philippines, was conducted. Stool samples from dogs, cats, rats, and water buffaloes were collected at baseline (2003–2004) and follow-up (2005). Latent-class hierarchical Bayesian log-binomial models adjusting for misclassification errors in diagnostic tests were used. The village-level baseline and follow-up prevalences of cat, dog, and rat S. japonicum infection were associated with the 12-month cumulative incidence of human S. japonicum infection, with similar magnitude and precision of effect, but correlation between infection levels made it difficult to divide their respective effects. The cumulative incidence ratios associated with a 1% increase in the prevalence of infection in dogs at baseline and in rats at follow-up were 1·04 [95% Bayesian credible interval (BCI) 1·02–1·07] and 1·02 (95% BCI 1·01–1·04), respectively, when both species were entered in the model. Dogs appear to play a role in human schistosomiasis infection while rats could be used as schistosomiasis sentinels.

Background: Rhinovirus (Rhino) is one of the major viruses of respiratory illness. There is a report that rhinoviruses had the highest prevalence among diseased cases among children under 5 years old who are hospitalized by acute respiratory illness. The novel group of rhinovirus (rhino C) was found recently. However, details of epidemiological features, including rhino C, in tropical climate are still unknown. In this study, we tried to access the importance of rhinoviruses among severe respiratory infection of children in the Philippines. Methods: 816 nasopharyngeal swabs which were collected from May 2008 to May 2009 from children (age: 7days -14years old) who were diagnosed as severe pneumonia were used. RNA was extracted and subjected to RT-PCR targeting 5'Non Coding Region and VP4/VP2 region. Sequencing analysis was carried out and rhinoviruses genogroups (A∼C) were determined. Results: 243 out of 816 samples (30%) were positive for rhinoviruses. Among rhinoviruses positive samples, 131 (54%) were positive for rhino A, 25 (10%) were for rhino B, and 86 (35%) were for rhino C. The nucleotide sequence of Rhinovirses (A,B,C) in VP4/VP2 showed that variable types of rhinovirus are co-circulating in one area, and were related closely to the ones reported from various countries and year. No etiological correlation was seen between any genogroups or subspecies and severity. Rhinoviruses were detected all the year. However there was a peak for Rhino A in July to September, Rhino B in September to November, and Rhino C in February to March. Rhinovirus infection in tropical zone may have different seasonality from the one in template zone and each genogroups may have different seasonality. Conclusion: Rhinoviruses were detected with high prevalence among severe pneumonia which may suggest their importance among children in the Philippines. Abstracts for SupplementInternational Journal of Infectious DiseasesVol. 14Preview Full-Text PDF Open Archive

Background: Untreated groundwater is responsible for about half of the waterborne disease. Inadequate water distribution system in that may not be able to provide clean water, and use river water for the living are two main cause of water borne disease in developing countries. In addition, viruses causing diarrhea are stable in environmental water and serve as threat to humans In the Philippines, about 10,000 children died of severe diarrhea annually and data for viruses in the environment is not enough. So, detection of those viruses from river water is important as it indicates what viruses are circulating among human living in the area. We conducted environmental sampling in Metro Manila, the capital of the Philippines, and Bulacan, the area with a fifth of population of Metro Manila, to detect enteric viruses. Methods: From March, April and August 2009 water samples were collected from 14 sites of river running in Metro Manila and Bulacan region. Water was concentrated by Poly ethylene glycol precipitation method. We performed real time PCR and conventional PCR to detect virus that can cause water borne disease. All positive samples by conventional PCR underwent sequence analysis and phylogenic tree were constructed. Results: By both real time PCR and conventional PCR, almost all water samples were positive for viruses, including enteroviruses(100%), adenovirus(64.3%), rotavirus(85.7%), hepatitis A virus (HAV) (100%), astrovirus(42.9%) and noroviruses(87.5%) in these areas. Detected rotavirus belonging to G serotype 1 and this is identical to the virus detected in China Detected hepatitis A virus is belonging to genotype IA. The viral titers of samples in April, enterovirus, hepatitis A virus, norovirus G1, and rotavirus were higher than that of August. Conclusion: The result of our study substantially showed that seasonality of the rotavirus in the environment agreed with that of human rotavirus infection in the Philippines. In addition, our study suggested that other enteric viruses would spread in dry season in the Philippines. We believe focusing on the aspect may improve water quality as well as prevention of enteric viral diseases in the Philippines. Abstracts for SupplementInternational Journal of Infectious DiseasesVol. 14Preview Full-Text PDF Open Archive

The accuracy of the Kato-Katz technique in identifying individuals with soil-transmitted helminth (STH) infections is limited by day-to-day variation in helminth egg excretion, confusion with other parasites and the laboratory technicians' experience. We aimed to estimate the sensitivity and specificity of the Kato-Katz technique to detect infection with Ascaris lumbricoides, hookworm and Trichuris trichiura using a Bayesian approach in the absence of a 'gold standard'. Data were obtained from a longitudinal study conducted between January 2004 and December 2005 in Samar Province, the Philippines. Each participant provided between one and three stool samples over consecutive days. Stool samples were examined using the Kato-Katz technique and reported as positive or negative for STHs. In the presence of measurement error, the true status of each individual is considered as latent data. Using a Bayesian method, we calculated marginal posterior densities of sensitivity and specificity parameters from the product of the likelihood function of observed and latent data. A uniform prior distribution was used (beta distribution: α = 1, β = 1). A total of 5624 individuals provided at least one stool sample. One, two and three stool samples were provided by 1582, 1893 and 2149 individuals, respectively. All STHs showed variation in test results from day to day. Sensitivity estimates of the Kato-Katz technique for one stool sample were 96.9% (95% Bayesian Credible Interval [BCI]: 96.1%, 97.6%), 65.2% (60.0%, 69.8%) and 91.4% (90.5%, 92.3%), for A. lumbricoides, hookworm and T. trichiura, respectively. Specificity estimates for one stool sample were 96.1% (95.5%, 96.7%), 93.8% (92.4%, 95.4%) and 94.4% (93.2%, 95.5%), for A. lumbricoides, hookworm and T. trichiura, respectively. Our results show that the Kato-Katz technique can perform with reasonable accuracy with one day's stool collection for A. lumbricoides and T. trichiura. Low sensitivity of the Kato-Katz for detection of hookworm infection may be related to rapid degeneration of delicate hookworm eggs with time.

Background: Influenza virus causes respiratory infection and sometimes results in death. It causes annual epidemics because of antigenic changes as a result of mutations. To identify dominant strains is important in order to predict the epidemic scale, assess the efficacy of vaccines and determine vaccine strains for next season. Moreover, substantial increase in amantadine-resistant influenza A has been reported recently. It is also important to know the prevalence of resistance to consider how to care patients. Methods: We collected nasopharyngeal swabs of patient presenting influenza-like symptoms from two cities in Japan (Sendai and Fukuoka) and influenza surveillance sites in the Philippines, in two influenza seasons, 2005–2006 and 2006–2007 (influenza season was defined as from August to July of the following year). After virus isolation, randomly selected stains were subjected to RT-PCR and sequencing. Results: A total of 113 influenza A (H3N2) strains were analysed. Forty-four specimens were from Sendai, 22 from Fukuoka and 47 from Philippines. The rates of strains with the amantadine-resistance mutations were 88% in Sendai, 54% in Fukuoka and 19% in the Philippines. A phylogenic analysis constructed with HA gene indicated that the strains were grouped into two clades. A total of 8 stains were grouped into one clade. All strains in this clade were isolated in 2005–2006 season and they were amantadine-sensitive. Another clade had stains collected in both 2005–2006 and 2006–2007 seasons. All strains in this clade were amantadine resistant in 2005–2006, but both sensitive and resistant strains were found in 2006–2007. Conclusion: Japan had more amantadine-resistant viruses than the Philippines. That may be because two countries had different circulating strains although their genetic variation is small. It is intriguing that the clade, consisting of only amantadine-resistant strains previously, had amantadine-sensitive strains in 2006–2007.

Measles virus infection is a public health problem in the world, remains a main cause of mortality among young children. Molecular epidemiology can provide the useful information regarding the source of measles infection. Measles in the Philippines became under control after the mass vaccination campaign "Ligtas Tigdas" in 2004 and a few cases were reported in 2005 and 2006. However, the number of reported cases increased in 2007. The purpose of this study is to show the molecular characteristic of circulating measles strains before and after mass-vaccination in the Philippines. We randomly selected measles IgM positive serum samples from 2000 to 2007. The samples were collected from suspected measles cases and tested at Research Institute for Tropical Medicine (RITM), which is designated as the reference laboratory of measles surveillance in the Philippines. Those serum specimens were tested by RT-PCR for the detection of measles virus genome. PCR positive samples were sequenced and performed phylogenic analysis by using neighbor-joining method. The phylogenic analysis indicated that only genotype D3 was found between 2000 and 2004. In 2007, it was replaced by other genotypes, G3 and D9 among samples collected. This study suggested that the indigenous measles strain (D3 genotype) in the Philippines was interrupted circulating by the mass-vaccination. But other genotypes might have been introduced into the Philippines from other countries. This indicated that current status of measles in the Philippine is in transition from endemic to epidemic measles and also importance of maintenance of high vaccine coverage even after the successful mass-vaccination campaign. Further analysis of virological characterization is essential to assess the progress of the elimination of measles.

Background: In tropical climate, influenzavirus may be detected through out the year. But it would be important to see the seasonal distribution and the transition of the virus in order to determine the strain and the timing for seasonal vaccination. Methods: Research Institute for Tropical Medicine has been implementing influenza surveillance from 21 sites in 6 different regions with the support of the Philippine Department of Health and the US Centers for Disease Control. Patients who visited sentinel sites with influenza-like illness had nasopharyngeal sample taken, and samples under went virus isolation using MDCK and HEp2 cells. Influenzavirus isolation was confirmed by haemagglutination inhibition test. For phylogenic analysis, HA1 region of influenzavirus A(H1) and A(H3) were amplified by PCR, and the products were sequenced. Result: Between January 2006 and March 2007, there were 164 A (H1) and 86 A (H3) isolates. Although virus was isolated through study period, there was a peak for A(H1) in June and July, followed by peak of A(H3) in August and September. For phylogenic analysis, 99 A(H1) and 46 A(H3) isolates were selected from 4 sentinel cites; the Cordillera Autonomous Region in north, National Capital Region and Pampanga in the center, and Zamboanga in southern part of the Philippines. For A (H1), there was no apparent temporal and geographical cluster. On the other hand in A (H3), there were two distinct clusters; one was mainly consisted of samples in 2006 and the other was consisted of samples in late 2006 to 2007. Conclusion: The study has shown distinct peaks for both viruses within the rainy season of the Philippines. A(H3) had two temporal clusters while A(H1) did not. Continuation of this analysis may be needed to see the evolution of the influenzavirus in the tropical climates.

Background: Recently, novel viruses, such as human metapneumovirus (hMPV), human coronaviruses (HCoVs), and human bocavirus (HBoV), were identified, and are considered as one of the causative agents for respiratory infection among children in temperate climate. But little is known about them in tropical climate. Materials and Methods: Research Institute for Tropical Medicine in Philippines has been implementing influenza surveillance with the support of the Philippine Department of Health and the US Centers for Disease Control, and collecting the nasopharyngeal aspirates from patients with influenza-like illness. Samples were inoculated on to MDCK and HEp2 cells for virus isolation. Virus-culture negative samples were tested for hMPV, HCoVs, and HBoV by polymerase-chain-reaction (PCR). The PCR products were sequenced for confirmation and phylogenic analysis. Results: From January to December 2006, 226 samples underwent viral isolation. One hundred eighty five samples were virus isolation-negative and tested for hMPV, HBoV, and HCoVs. Two samples were positive for hMPV, three for HBoV, but none of them was positive for HCoVs. hMPV positive samples were collected from 1y2m and 1y5m old patients in October, and were categorized in A2 lineage. HBoV positive samples were collected from 0y7m, 0y9m and 1y3m old patients in January, May and July, respectively, and clustered in phylogenic analysis. Conclusion: Positive samples for both hMPV and HBoV were collected from patients under 2, and this may indicates that those viruses are the one of the important respiratory pathogens in that age group in tropical climate. Two hMPV positive samples were collected at the turn of the year between rainy and dry season, while each HBoV positive sample was collected in various time of the year. Our finding suggests further evaluation of those viruses in the tropical climates to elucidate the seasonal pattern and the clinical impacts.

1 Center for International Health Research (CIHR), Rhode Island Hospital, Brown University School of Medicine, Providence, RI, United States 2 Department of Pediatrics, Rhode Island Hospital, Brown University School of Medicine, Providence, RI, United States 3 Research Institute of Tropical Medicine, Manila, the Philippines 4 Center for Statistical Sciences, Brown University, Providence, RI, United States 5 Epidemiology Section, Department of Community Health and International Health Institute, Brown University, Providence, RI, United States 6 Department of Pathology and Laboratory Medicine, Rhode Island Hospital, Brown University School of Medicine, Providence, RI, United States

BACKGROUND:Schistosomiasis japonica is a chronic helminthic infection contracted through contact with water infested with Schistosoma japonicum. The infection is associated with severe disease and is an important public health concern in Philippines. OBJECT:To estimate the agreement in the frequency of water contact between bimonthly interviews, self-administered diaries and observations. METHODS:A total of 286 individuals were followed over either a 4 or a 6 months period. Agreement between direct observation and both the bimonthly and diary methods were estimated. RESULTS:The agreement between the observation and the bimonthly interview was 71.8% when days without any water contacts were considered, but decreased to 23.3% when only days with at least some water contact were considered. The agreement between the observation and the diary was 78.7% when days without any water contacts were considered and 40.8% when only days with some water contacts were considered. CONCLUSIONS:Agreement about the degree of water contact is poor between the different measurement tools. This has important implications for future research, since a high degree of measurement error can severely bias any results from studies involving water contact.

Schistosoma japonicum causes a chronic parasitic disease, which persists as a major public health concern in The Philippines, the People's Republic of China and Indonesia. This infection is unique among helminthic zoonoses because it can infect humans and more than 40 other mammals. The objective of this study was to estimate the sensitivity and specificity of the Danish Bilharziasis Laboratory technique in cats, dogs, pigs, water buffaloes and rats in the Philippines. Faecal samples from each animal were collected on up to five occasions on five consecutive days in four villages of Sorsogon and Western Samar Provinces between January and July 2003. The faecal samples were analysed with the filtration and sedimentation Danish Bilharziasis Laboratory technique. Sensitivity and specificity of one, two, three, four, and five faecal samples were estimated using a Bayesian latent class approach. A total of 59, 43, 74, and 80% of the censored cats, dogs, pigs, and water buffaloes in the four villages were sampled, respectively. For all species, the sensitivity estimates when using the results of only 1 day of sampling were less than 80%. However, the sensitivity improved to at least 96% in all species when three or more faecal samples were collected on three separate days. The specificity was estimated to be above 92% across all species, even if just a single sample is used. The prevalences and 95% credible intervals of S. japonicum, adjusted for imperfect sensitivity and specificity, in cats, dogs, pigs, rats, and water buffaloes were 11.9% (6.8–18.3%), 19.9% (15.1–25.2%), 2.9% (1.1–5.2%), 31.3% (18.3–45.6%) and 6.3% (2.1–12.6%), respectively. Our results suggest that the Danish Bilharziasis Laboratory technique is valid for the detection of infection with S. japonicum in animals, and that sensitivity estimates are excellent when faecal samples are collected on at least three different days. Monitoring S. japonicum infection in animal reservoirs with a valid test could contribute to more effective public health control programmes.

G. R. Olds, C. King, J. Hewlett, R. Olveda, G. Wu, J. Ouma, P. Peters, S. McGarvey, O. Odhiambo, D. Koech, C. Y. Liu, G. Aligui, G. Gachihi, Y. Kombe, I. Parraga, B. Ramirez, C. Whalen, R. J. Horton, and P. Reeve Case Western Reserve University, Cleveland, Ohio; Research Institute for Tropical Medicine, Manila, Philippines; Division of Viral Products, Office of Vaccines Research and Review, Food and Drug Administration, Washington, DC; Nanjing Medical University, Jiangsu, Nanjing, and Sichuan Institute of Parasitic Diseases, Sichuan, China; Kenya Medical Research Institute and Division of Vector Borne Diseases, Ministry of Health, Nairobi, Kenya; Miriam Hospital, Brown University School of Medicine, Providence, Rhode Island; and SmithKline Beecham, Brentfore, United Kingdom

A double-blind placebo-controlled study of the concurrent administration of albendazole and praziquantel was conducted in>1500 children with high prevalences of geohelminths and schistosomiasis. The study sites were in China and the Philippines, including 2 strains of Schistosoma japonicum, and 2 different regions of Kenya, 1 each with endemic Schistosoma mansoni or Schistosoma haematobium. Neither medication affected the cure rate of the other. There was no difference between the side effect rate from albendazole or the double placebo. Praziquantel-treated children had more nausea, abdominal pain, and headache but these side effects were statistically more common in children with schistosomiasis, suggesting a strong influence of dying parasites. The subjects were followed for 6 months for changes in infection status, growth parameters, hemoglobin, and schistosomiasis morbidity. In all 4 sites, a significant 6-month increase in serum hemoglobin was observed in children who received praziquantel, strongly supporting population-based mass treatment.

Schistosomiasis japonica differs significantly from Schistosoma mansoni infection in several epidemiologic, immunologic, and operational characteristics for control. Because of numerous nonhuman hosts, transmission remains high despite aggressive case finding and treatment of human cases. Diagnosis of infection using the Kato-Katz stool technique is less sensitive and specific in this than in other species of human schistosomes, making case finding and treatment a less effective approach to control. Clinically, morbidity induced by S. japonicum appears unrelated to intensity of infection, and is more severe than that of S. mansoni in terms of liver pathology and stunting of child growth and development. Both hepatic enlargement and fibrosis appear to be reversible and preventable with aggressive treatment but several operational characteristics for control of infection due to S. japonicum make the community impact of case-finding and treatment with praziquantel less pronounced than would have been predicted by the analysis of individual cases. In the Philippines, rebound morbidity following reinfection mandates short treatment intervals between screening and treatment to have a significant impact on morbidity, while in China inapparent infection (infection not diagnosed by a single stool examination) appears to be a common cause for persistent hepatic pathology. The authors conclude that for S. japonicum, mass treatment or targeted mass treatment is a more cost-effective approach than case-finding and treatment for control.

The hypothesis that infection with Schistosoma japonicum causes decreased nutritional status was studied in a randomized trial among 170 males and females, mean (SD) age 11.4 (3.5) years, residing in an endemic region of northeastern Leyte, Philippines. The S. japonicum-infected children were randomized to receive praziquantel or placebo and followed-up six months after randomization. Stature, weight, triceps, subscapular, and calf skinfold thicknesses and their sum, and hemoglobin level were measured at baseline and follow-up. Schistosoma japonicum eggs were detected in Kato-Katz stool smears and the intensity of infection was assessed by quantitative egg count. Intensities of hookworm, ascaris, and trichuris infections were also measured. The six-month levels of the anthropometric measures and hemoglobin were adjusted for age and their baseline levels and then compared between the praziquantel and placebo groups. Treatment interactions were also analyzed by sex. Baseline anthropometric and hemoglobin levels and parasite infection intensities were the same in the two groups. At six months, the praziquantel group had significantly higher hemoglobin levels (P < 0.001) and sum of skinfolds (P < 0.001) than the placebo group. Males had a significantly greater increase in hemoglobin levels with treatment than did females. The hemoglobin increase was not due to changes in hookworm intensity. The results show that schistosomiasis japonica caused decreased nutritional status in children and probably is partly responsible for the malnutrition and reduction in growth for age described in prior cross-sectional studies.

The association between schistosomiasis japonica and child growth was studied cross-sectionally in 1,561 males and females aged 4-19.9 years residing in an endemic region of northeastern Leyte, The Philippines. Stature, weight, upper arm muscle area, and sum of triceps and subscapular skinfold thicknesses were measured and related to presence of Schistosoma japonicum eggs in Kato stool smears and to the intensity of infection assessed by quantitative egg count. The presence of hookworm, ascaris, and trichuris eggs was also measured. Multivariable models were used to control for the effects of age, age2, and polyparasitism on growth. The prevalence of schistosomiasis was 31% in males and 22% in females, with the maximum prevalence in adolescence. In 8-19-year-old subjects, the intensity of schistosomiasis japonica was significantly related in males to reduced arm muscle area and sum of skinfolds (both P less than 0.01) and in females to reduced stature, weight, arm muscle area, and sum of skinfolds (all P less than 0.01). The greatest age-specific differences were during adolescence in both males and females. The growth retarding effects of intensity of schistosomiasis japonica were independent of the influence of other parasites, notably hookworm. Due to the magnitude of the schistosomiasis-associated growth differences in adolescence, adult body size, function and productivity may be affected.