[Survey of epidemic status of paragonimiasis in western mountainous areas in Hubei Province].

OBJECTIVE: To understand the current status of paragonimiasis epidemic in western mountain areas in Hubei Province. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

[Application of ARIMA model on prediction of malaria incidence].

OBJECTIVE: To predict the incidence of local malaria of Hubei Province applying the Autoregressive Integrated Moving Average model (ARIMA). METHODS: SPSS 13.0 software was applied to construct the ARIMA model based on the monthly local malaria incidence in Hubei Province from 2004 to 2009. The local malaria incidence data of 2010 were used for model validation and evaluation. RESULTS: The model of ARIMA (1, 1, 1) (1, 1, 0)12 was tested as relatively the best optimal with the AIC of 76.085 and SBC of 84.395. All the actual incidence data were in the range of 95% CI of predicted value of the model. The prediction effect of the model was acceptable. CONCLUSIONS: The ARIMA model could effectively fit and predict the incidence of local malaria of Hubei Province.

[Epidemiological analysis of malaria prevalence in Hubei Province from 2010 to 2014].

OBJECTIVE: To understand the malaria epidemic situation in Hubei Province from 2010 to 2014, so as to provide the evidence for formulating the effective malaria elimination strategies and measures in this province. METHODS: The data from the Disease Reporting Information System of Chinese Center for Disease Control and Prevention were collected and analyzed with the descriptive epidemiological method for the epidemiological characteristics of malaria in Hubei Province from 2010 to 2014. RESULTS: A total of 997 malaria cases were reported in Hubei Province from 2010 to 2014, there were 618 cases of vivax malaria, 352 cases of falciparum malaria, 18 cases of Plasmodium ovale infection, and 9 cases of Plasmodium malariae infection. Among all the reported cases, 479 were local cases and 518 were imported cases. No local malaria cases were reported from Hubei Province since 2013. The overall imported malaria cases showed a gradual increasing trend from 2010 to 2014, the proportion of falciparum malaria increased quite significantly from 2010 to 2014. The malaria cases were mainly distributed in Xiangyang, Wuhan, Xiaogan, Yichang, Jingmen and Suizhou cities, reaching 81.85% of the cases of the whole province. There were 810 male cases and 187 female cases, with a sex ratio of 4.33:1. The local malaria cases were mainly aged from 40 to 69 years, accounted for 78.29% of the total local cases, and 88.22% (457/518) of the whole local cases were concentrated in 20-49 age groups. The local cases were mainly farmers (67.01%). Among the imported malaria cases, the occupation distribution concentrated mainly on the worker, migrant worker, and farmer (63.90%). CONCLUSIONS: The local malaria epidemic situation has been effectively controlled in Hubei Province, which reflects the initiative achievements of malaria elimination. However, there are still many imported malaria cases from abroad. Therefore, the imported malaria from abroad still remains the key of malaria control in Hubei Province.

[Analysis of malaria epidemic situation and control in Hubei Province from 1974 to 2015].

OBJECTIVE: To analyze the malaria control measures and epidemic trend in Hubei Province from 1974 to 2015, so as to provide the evidence for malaria elimination path analysis. METHODS: The malaria control data in Hubei Province from 1974 to 2015 were collected and analyzed retrospectively by descriptive epidemiological methods. RESULTS: The epidemic process of malaria in Hubei Province was divided into four stages. From 1974 to 1979, it was high prevalence state of malaria, and the average annual incidence was 174.47/10 000. From 1980 to 1999, the main control strategies were to control the infection source and mosquitoes, and the average annual incidence was 17.30/10 000, significantly downward. From 2000 to 2009, through the surveillance of infection sources and controlling malaria outbreaks and strengthening the floating population management, the average annual incidence was 0.42/10 000. After 2010, followed by the elimination phase of malaria, the incidence continued to decline. In 2013, there was no local infection for the first time. The difference of average annual incidence among above-mentioned stages was statistically significant (χ2 = 1 254.36, P < 0.05). CONCLUSIONS: The malaria epidemic process in Hubei Provincial experienced the high epidemic stage, sharply drop stage, low incidence phase and the elimination phase. However, the natural factors affecting malaria still exist. Therefore, strengthening the control of imported malaria and surveillance should be the main task in the process of eliminating malaria in the future.