Background: Zoonotic schistosomiasis, caused by Schistosoma japonicum, is prevalent in China, the Philippines and Indonesia. Rapid point-of-care (POC) diagnostics are attractive and promising tools for evaluating the efficacy of intervention strategies for schistosomiasis control.
Methodology: The diagnostic potential of five recombinant antigens was tested by enzyme-linked immunosorbent assay (ELISA) using sera from individuals with positive Kato-Katz (KK) results for S.
Immunomodulation enhances parasite fitness by reducing inflammation-induced morbidity in the mammalian host, as well as by attenuating parasite-targeting immune responses. Using a whole-proteome differential screening method, we identified Schistosoma japonicum helminth defense molecule 1 (SjHDM-1) as a target of antibodies expressed by S. japonicum-resistant but not S.
View Article and Find Full Text PDFSchistosoma japonicum is endemic in the Philippines. The Kato-Katz (KK) method was used to diagnose S. japonicum.
View Article and Find Full Text PDFObjectives: Fetal alcohol spectrum disorder (FASD) captures the broad range of emotional, cognitive, behavioral, and congenital abnormalities associated with maternal alcohol consumption, and women living in resource-limited settings may be higher risk. This study aims to examine knowledge, attitudes, practices, and beliefs (KAPB) of women in Leyte, The Philippines regarding prenatal alcohol consumption.
Methods: One hundred postpartum women were recruited from a birth cohort in Leyte.
Introduction: Dengue virus (DENV) is the leading cause of mosquito-borne viral diseases in humans. Dengvaxia, the first licensed dengue vaccine, is recommended for DENV-seropositive individuals aged 9-45 years. In the Philippines, Dengvaxia was administered to more than 830,000 children without prior serological testing in 2016-2017.
View Article and Find Full Text PDFBackground: We compared individuals' self-reported water contact from a questionnaire to direct observation of water contact. Questionnaires that accurately capture water contact are necessary to risk-stratify individuals and communities at high risk for schistosomiasis.
Methods: Individuals (N=677) ages 7-30 y were included from three Schistosoma japonicum-endemic villages in Leyte, The Philippines.
In the past decade, ecological surveys emphasized rats and dogs as the most significant animal reservoirs for Schistosoma japonicum (S.j) in the Philippines. However, recent studies demonstrated 51-91% prevalence of schistosomiasis among water buffalo using qPCR in the Sj endemic regions in the Philippines.
View Article and Find Full Text PDFIn areas endemic to schistosomiasis, fetal exposure to schistosome antigens prime the offspring before potential natural infection. Praziquantel (PZQ) treatment for Schistosoma japonicum infection in pregnant women has been demonstrated to be safe and effective. Our objectives were to evaluate whether maternal PZQ treatment modifies the process of in utero sensitization to schistosome antigens potentially impacting later risk of infection, as well as immune response to S.
View Article and Find Full Text PDFThe World Health Organization Western Pacific Region (WPR) set a hepatitis B virus (HBV) control target to achieve HBV surface antigen (HBsAg) prevalence of <1% among children aged 5 years by 2017. The estimated HBsAg prevalence in the Philippines among adults was 16.7% during the pre-vaccine era.
View Article and Find Full Text PDFSchistosomiasis remains a leading cause of chronic morbidity in endemic regions despite decades of widespread mass chemotherapy with praziquantel. Using our whole proteome differential screening approach, and plasma and epidemiologic data from a longitudinal cohort of individuals living in a Schistosoma japonicum-endemic region of the Philippines, we interrogated the parasite proteome to identify novel vaccine candidates for Schistosoma japonicum. We identified 16 parasite genes which encoded proteins that were recognized by immunoglobulin G or immunoglobulin E antibodies in the plasma of individuals who had developed resistance to reinfection, but were not recognized by antibodies in the plasma of individuals who remained susceptible to reinfection.
View Article and Find Full Text PDFSchistosomiasis is a chronic but preventable disease that affects 260 million people worldwide. In the Philippines, 860,000 people are afflicted with Schistosoma japonicum annually, and another 6.7 million live in endemic areas.
View Article and Find Full Text PDFBackground: Schistosomiasis japonica is a zoonosis and presents significant public health problems in China and the Philippines. Vaccines targeting domestic animals constitute attractive control measures.
Methods: We conducted three vaccine trials to evaluate the protective efficacy of recombinant full-length paramyosin (rSj97) in water buffalo.
Schistosomiasis, caused by three principal species of diecious trematodes (flatworms), currently afflicts over 250 million individuals, results in an estimated 2-15% chronic disability, and contributes to poor health and economic stagnation in endemic areas. Although schistosomiasis is effectively treated with praziquantel, rapid reinfection with rebound morbidity precludes effective control based on chemotherapy alone and justifies current efforts to develop vaccines for these parasites. Paramyosin (Pmy), an invertebrate muscle-associated protein, has emerged as a promising vaccine candidate for both Schistosoma mansoni and Schistosoma japonicum.
View Article and Find Full Text PDFThe cause of zoonotic schistosomiasis in the Philippines is Schistosoma japonicum, which infects up to 46 mammalian hosts, including humans and bovines. In China, water buffaloes have been identified as major reservoir hosts for schistosomiasis japonica, contributing up to 75% of human transmission. In the Philippines, water buffaloes (carabao; Bubalus bubalis carabanesis) have, historically, been considered unimportant reservoirs.
View Article and Find Full Text PDFBackground: Schistosomes infect 200 million individuals annually and cause significant hepatic fibrosis in up to 20%. Little is known regarding the mechanisms of schistosome-associated hepatic fibrosis in humans, and few biomarkers for risk of fibrosis have been identified.
Methods: We treated 611 Schistosoma japonicum-infected Filipinos with praziquantel (PZQ) and performed ultrasound to quantify hepatic fibrosis at baseline and 12 months after PZQ treatment.
One small previous study found that praziquantel reduced hookworm infection. In this study, 607 subjects were enrolled in a longitudinal study. At enrollment and every 3 months for 18 months, three stool samples were collected, and the intensity of infection with Schistosoma japonicum and soil-transmitted helminths (STHs) was quantified.
View Article and Find Full Text PDFCysticercosis is a significant public health problem in countries where pigs are raised for consumption and remains an important cause of neurological disease worldwide. The Philippines is considered an endemic area for cysticercosis because cases in both humans and pigs have been reported; however, epidemiologic information stays limited. We conducted a pilot survey of the seroprevalence of human cysticercosis in a village in Leyte, the Philippines, by measuring antibody specific for Taenia solium cyst-fluid antigen.
View Article and Find Full Text PDFBackground: Many studies have addressed the relationship between iron deficiency anemia (IDA) and cognitive impairment, but none have evaluated the role of non-iron deficiency anemia (NIDA). One of the main causes of NIDA in developing countries is AI, largely due to infectious diseases, whereby iron is shunted away from bio-available forms to storage forms, making it less accessible for use by host tissues. The objective of this study was to determine the effect of NIDA, due largely to AI in this context, on cognitive function after adjustment for potential confounders.
View Article and Find Full Text PDFSchistosomiasis remains a public health concern in developing countries, and rapid reinfection fostered by continued exposure to contaminated water sources necessitates a vaccine to augment current mass treatment-based control strategies. We report isotype-specific (immunoglobulin A [IgA], IgE, IgG1, IgG4, and IgG) antibody responses to soluble worm antigen preparation and the recombinant vaccine candidates rSj97, rSj67, and rSj22 from a Schistosoma japonicum-infected cohort in Leyte, the Philippines, where schistosomiasis is endemic. Sera were collected from infected individuals 1 month posttreatment with praziquantel, and antibody responses were measured using a bead-based multiplex platform.
View Article and Find Full Text PDFDespite effective chemotherapy, schistosomiasis remains a major public health problem in the developing world, with at least 200 million active infections resulting in significant morbidity. Rapid reinfection after treatment, accompanied by extensive residual morbidity, mandates alternative control strategies, including vaccine development. Paramyosin, a myofibrillar protein found only in invertebrates, has been widely studied as a vaccine candidate for both Schistosoma mansoni and Schistosoma japonicum.
View Article and Find Full Text PDFSchistosomiasis is associated with undernutrition, but the mechanisms involved remain unknown. We analyzed baseline and follow-up data from a longitudinal treatment-reinfection study in N = 477 Schistosoma japonicum-infected subjects 7-20 years of age from Leyte, the Philippines. After baseline treatment with praziquantel, follow-up visits were scheduled every 3 months for 18 months; stool, venous blood, and anthropometric measurements were collected at each visit.
View Article and Find Full Text PDFBackground: In communities where Schistosoma species are endemic, the prevalence and intensity of schistosomiasis is disproportionately high among children, compared with adults. This epidemiologic pattern is consistent with either the slow development of resistance or the requirement of host developmental changes for the expression of resistance.
Methods: We enrolled 87 individuals aged 7-18 years who did not have Schistosoma japonicum infection and 641 individuals aged 7-30 years with S.
Although schistosomiasis is effectively treated with Praziquantel, rapid reinfection with rebound morbidity precludes effective control based on chemotherapy alone and justifies current efforts to develop vaccines for these parasites. Using a longitudinal treatment-reinfection study design with 616 participants 7 to 30 years of age, we evaluated the relationship between cytokine responses to Schistosoma japonicum soluble adult worm extract (SWAP), Sj97, Sj22.6, and Sj67, measured 4 weeks after treatment with Praziquantel, and resistance to reinfection in a population from Leyte, The Philippines, where S.
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