A Drug-Based Intervention Study on the Importance of Buffaloes for Human Schistosoma Japonicum Infection Around Poyang Lake, People’s Republic of China

Abstract

Schistosomiasis japonica is a zoonosis of major public health importance in southern China. We undertook a drug intervention to test the hypothesis that buffalo are major reservoirs for human infection in the marshlands/lake areas, where one million people are infected. We compared human and buffalo infection rates and intensity in an intervention village (Jishan), where humans and buffalo were treated with praziquantel, and a control village (Hexi), where only humans were treated, in the Poyang Lake region. Over the four-year study, human incidence in Jishan decreased but increased in Hexi. Adjustment of incidence by age, sex, water exposure, year, and village further confirmed the decreased human infection in Jishan. Chemotherapy for buffaloes resulted in a decrease in buffalo infection rates in Jishan, which coincided with the reduction in human infection rates there in the last two years of the study. Mathematical modeling predicted that buffalo are responsible for 75% of human transmission in Jishan.

Spatio-temporal correlation between human and bovine schistosomiasis in China: insight from three national sampling surveys

“…However, as depicted in Figures 2a-2c, there is a tendency of reduction both in the Spearman correlation coefficients and in the slope of the linear regression (from 0.395 in 1989 to 0.215 in 2004). The fact that bovines play a major role in the transmission of human schistosomiasis in China is supported by mathematical modelling (Williams et al, 2002), as well as by a recently completed intervention study where either humans alone or humans plus buffaloes were treated with praziquantel (Guo et al, 2006). The implications for schistosomiasis control, including development of a bovine vaccine, have been discussed (Guo et al, 2006;McManus and Dalton, 2006).…”

“…The fact that bovines play a major role in the transmission of human schistosomiasis in China is supported by mathematical modelling (Williams et al, 2002), as well as by a recently completed intervention study where either humans alone or humans plus buffaloes were treated with praziquantel (Guo et al, 2006). The implications for schistosomiasis control, including development of a bovine vaccine, have been discussed (Guo et al, 2006;McManus and Dalton, 2006). The evidence linking the contribution to transmission by domestic animals points to the looming threat of decreasing returns from human chemotherapy, as the higher the prevalence among domestic animals the higher the risk of infection for humans.…”

“…Sustained control efforts are needed to consolidate the achievements made to date and stepped-up efforts may be necessary to further reduce the number of infections and force of transmission (Bian et al, 2004;Wang et al, 2005;Fenwick and Webster, 2006;Guo et al, 2006;Liang et al, 2006). Transmission of schistosomiasis is closely related to environmental factors (Steinmann et al, 2006;Li et al, 2007;Liang et al, 2007).…”

Large Water Management Projects and Schistosomiasis Control, Dongting Lake Region, China

“…Most of these migrants will be engaged in daily activities such as agriculture, fishing, and reed cutting and will unavoidably have contact with water infested with schistosome cercariae. A recent drug-based intervention study showed that water buffaloes are the major host reservoir for transmission of S. japonicum to humans in the lake region of China and account for ≈80% of transmission; the highest numbers of eggs were released into the environment by young buffaloes <1 year of age ( 24 ). The use of domesticated buffaloes as working animals by farmers will continue to provide reservoirs for S. japonicum .…”

Optimisation of a droplet digital PCR assay for the diagnosis of Schistosoma japonicum infection: A duplex approach with DNA binding dye chemistry

“…There are three main species of schistosomes infecting humans, Schistosoma mansoni, endemic to Africa, the Middle East, and South America, S. haematobium endemic to Africa, and S. japonicum, endemic to regions of South East Asia specifically in China, the Philippines and Indonesia. Schistosomiasis japonica, caused by S. japonicum, is a zoonosis with water buffaloes and other bovines being major reservoirs for human infection in both China and the Philippines, significantly complicating the control and elimination of the disease Gordon et al, 2012;Gray et al, 2009;Guo et al, 2006). The World Health Organisation (WHO) strategic plan for 2012-2020 has determined that the goal of elimination of schistosomiasis, as a public health problem, is possible by 2025(WHO, 2013.…”