Survey of epidemic status of paragonimiasis in western mountainous areas in Hubei Province

Abstract

To understand the current status of paragonimiasis epidemic in western mountain areas in Hubei Province. Four counties (cities) of Western Hubei Province (Xingshan, Enshi, Yunxi, Baokang) were selected as the investigation sites for active surveillance. Crabs were captured and the metacercariae of Paragonimus were detected. Meanwhile, the blood samples were collected from the residents in the surveillance sites and the unique IgG and IgM antibodies against Paragonimus in the sera were detected by ELISA. In addition, a questionnaire survey about knowledge and behavior of prevention and control of paragonimiasis was taken among the residents. A total of 1 143 residents were investigated in the active surveillance, the total positive rate of the serology test was 1.84% (21/1 143), while the rates of the male and the female were 1.78% (10/562) and 1.89% (11/581), respectively, with no statistical significance between them ( χ2 = 0.002, P > 0.05). The average weight of 161 fresh-water crabs captured was 11.72 g, with the positive rate of 9.32% (15/161) and the infective density of 7.07 metacercariae per positive crab. The positive rates of the male and female crabs were 11.54% (9/78) and 7.23% (6/83), respectively ( χ2 = 0.884, P > 0.05), and the infective densities were 6.67 and 7.67 metacercariae per positive crab, respectively. Totally 1 143 residents were investigated by questionnaires, and 0.44% of them had the behavior of eating raw or half-done fresh-water crab, and 0.87% of them had the behavior of drinking un-boiled stream water. The transmission chain of paragonimiasis still exists in the nature environment of mountain area in Western Hubei Province. The positive rate of the second intermediate host rebounds in some investigation sites. Therefore, the measures of continuous surveillance and health education should be taken to avoid the appearance of the prevalence or outbreak.