[Evaluation of the comprehensive schistosomiasis control measures with emphasis on infection source of replacing...

To evaluate the effect of comprehensive measures with an emphasis on schistosomiasis infection source control by replacing cattle with machine.

In 2011, 2 villages from each of Jingzhou District, Jianli County and Jiangling County, Hubei Province, were selected as intervention group where the comprehensive measures were implemented, while 2 villages from Shishou City served as control with routine control activities. A cluster random sampling was carried out in the 8 villages with more than 300 people in each village were sampled. Stool examination using modified Kato-Katz was applied for identification of the infected persons and hatching test for cattle survey. The systemic sampling was applied for snail survey, fecal specimens from the field were examined by hatching test. Each sample was examined three times. Data were collected for the analysis of control effect between intervention and control groups in 2007 (baseline), 2009 (before implementation of comprehensive measures) and 2011 (post-intervention).

In intervention villages, the overall prevalence in human reduced significantly from 3.6% (135/3 772) in 2007 and 2.0% (63/3 116) in 2009 to 0.9% (21/2 396) in 2011 (chi2 = 43.411, chi2 = 11.840, P < 0.05). Until 2011, there were no cattle in intervention group; the prevalence decreased by 52.6% in human and about 100% in cattle from 2010 to 2011. In control group, the infection rate in residents in 2007, 2009 and 2011 was 4.5% (64/1 410), 2.6% (34/1 294) and 1.8% (24/1,320), respectively (chi2 = 16.178, P < 0.05), and 5.1% (8/158) in 2007, 1.6% (3/187) in 2009 and 1.6% (3/189) in 2011 in cattle, respectively (chi2 = 3.387, P > 0.05). The infection rate in human and cattle fell by 25.0% and 5.9% from 2010 to 2011, respectively. There was a significant difference in human infection rate between the intervention and control groups after intervention (chi2 = 6.309, P < 0.05). No infected snails were detected in intervention and control groups. No positive feces from the field was found in the intervention group, 7.5% positive rate was recorded in the control.

The comprehensive measures focused on infection source control by replacing cattle with machine can effectively control Schistosoma japonicum transmission, with a significant decrease of the prevalence in human and cattle.