High prevalence of Schistosoma japonicum and Fasciola gigantica in bovines from Northern Samar, the Philippines

PLoS Negl Trop Dis. 2015 Feb 2;9(2):e0003108. doi: 10.1371/journal.pntd.0003108. eCollection 2015 Feb.

Abstract

The 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. We therefore revisited the possible role of bovines in schistosome transmission in the Philippines, using the recently described formalin-ethyl acetate sedimentation (FEA-SD) technique and a qPCR assay to examine fecal samples from 153 bovines (both carabao and cattle) from six barangays in Northern Samar. A high prevalence of S. japonicum was found using qPCR and FEA-SD in both cattle (87.50% and 77.08%, respectively) and carabao (80.00% and 55.24%, respectively). The average daily egg output for each bovine was calculated at 195,000. High prevalence and infection intensity of F. gigantica was also found in the bovines by qPCR and FEA-SD (95.33% and 96.00%, respectively). The identification of bovines as major reservoir hosts for S. japonicum transmission suggests that bovine treatment and/or vaccination, as one becomes available, should be included in any future control program that aims to reduce the disease burden due to schistosomiasis in the Philippines.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Buffaloes / parasitology
  • Cattle
  • Cattle Diseases / epidemiology*
  • Cattle Diseases / transmission
  • China / epidemiology
  • Fasciola / isolation & purification*
  • Fascioliasis / epidemiology
  • Fascioliasis / transmission
  • Fascioliasis / veterinary*
  • Feces / parasitology
  • Humans
  • Philippines / epidemiology
  • Prevalence
  • Real-Time Polymerase Chain Reaction
  • Schistosoma japonicum / isolation & purification*
  • Schistosomiasis japonica / epidemiology
  • Schistosomiasis japonica / transmission
  • Schistosomiasis japonica / veterinary*
  • Zoonoses / epidemiology*
  • Zoonoses / parasitology
  • Zoonoses / transmission

Grants and funding

Funding was provided by the National Health and Medical Research Council (NHMRC) of Australia (Program grant ID 496600 and ID 1037304, and project grant ID 613671) and UBS Optimus. YL is an Australian Research Council (ARC) Future Fellow; DPM is an NHMRC Senior Principal Research Fellow; and DJG is an ARC Fellow (DECRA). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.