The Schistosoma japonicum self-cure phenomenon in water buffaloes: potential impact on the control and elimination of schistosomiasis in China.
Schistosomiasis japonica, caused by Schistosoma japonicum, is an important zoonotic disease in China, the Philippines and small pockets of Indonesia. In addition to infecting people, S. japonicum can infect over 40 species of wild and domestic animals which have varying impacts on human infection. It is now generally accepted that bovines, particularly water buffaloes, are the major reservoir for human infection in China as they are naturally infected with schistosomes and deposit more eggs into the environment than humans or any other animal host. This complicates control efforts and the economic burden associated with schistosomiasis morbidity and mortality has taken its toll on both human and livestock populations. Over the last 50years, the schistosomiasis control program in China has made great strides in reducing prevalence and morbidity, and the Chinese authorities now aim to eliminate the disease nationwide in the next decade. Current Chinese control strategies place particular importance on interventions targeting bovines including: praziquantel treatment, barrier farming to prevent grazing in transmission areas, their replacement with mechanized tractors and possible bovine vaccination. A number of studies have shown that in the period following S. japonicum infection, the worm burden drops sharply in water buffaloes and some other animal hosts such as pigs. This is due to a self-cure phenomenon whereby there is parasite clearance by both immune and non-immune factors. Here we review studies investigating the self-cure effect, paying particular attention to S. japonicum infection in water buffaloes, and discuss its potential impact on the future schistosomiasis control and elimination efforts in China. Further understanding of the mechanism of self-cure in water buffaloes could be important for future schistosome vaccine design and delivery.
Hunan Institute of Parasitic Diseases, World Health Organisation Collaborating Centre for Research and Control of Schistosomiasis in Lake Region, Yueyang, Hunan Province, People's Republic of China; Molecular Parasitology Laboratory, Infectious Diseases Division, Queensland Institute of Medical Research, Brisbane, Australia; School of Population Health, University of Queensland, Brisbane, Australia.
Yue-Sheng
YS
Li
Molecular Parasitology Laboratory, Infectious Diseases Division, Queensland Institute of Medical Research, Brisbane, Australia; School of Population Health, University of Queensland, Brisbane, Australia.
Donald P
DP
McManus
Jiangxi Institute of Parasitic Diseases, Nanchang, Jiangxi, People's Republic of China.
Dan-Dan
DD
Lin
School of Population Health, University of Queensland, Brisbane, Australia.
Gail M
GM
Williams
College of Veterinary Medicine, University of Georgia, Athens, USA.
Donald A
DA
Harn
Griffith Health Institute, Griffith University, Gold Coast, Australia.
Allen G
AG
Ross
National Institute of Parasitic Diseases, Chinese Centre for Disease Control and Prevention, Shanghai, People's Republic of China.
Zheng
Z
Feng
Molecular Parasitology Laboratory, Infectious Diseases Division, Queensland Institute of Medical Research, Brisbane, Australia; School of Population Health, University of Queensland, Brisbane, Australia. Electronic address: darren.gray@uq.edu.au.
Darren J
DJ
Gray
D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use; D002020:Buffaloes / Q000276:immunology / Q000469:parasitology*; D002417:Cattle; D002681:China; D004197:Disease Reservoirs / Q000469:parasitology; D005260:Female; D006801:Humans; D008297:Male; D011223:Praziquantel / Q000627:therapeutic use; D012549:Schistosoma japonicum / Q000276:immunology / Q000472:pathogenicity; D012554:Schistosomiasis japonica / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control*; D015047:Zoonoses / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control*
D000871:Anthelmintics; D011223:Praziquantel
China; Infection; Schistosoma japonicum; Schistosomiasis; Self-cure phenomenon; Water buffaloes