Epidemic characteristics of malaria and control effects in Jiulongpo District, Chongqing City, 1953 - 2013

Abstract

Objective To analyze the epidemic characteristics of malaria, evaluate the effects of control measures, and to provide a scientific basis for monitoring of malaria in local areas. Methods All the epidemiological data of malaria situation and monitoring from 1953 to 2013 were collected and analyzed, calculated incidence rates, analyzed distribution of season, region, age, gender, occupation; and summarize the control process. Results Totally 13 675 cases with malaria were reported in this district in 1961, and the average annual incidence was 43.16 per 100 000. Two epidemic peaks had happened in 1953 with an annual incidence of 3 172.23 per 100 000 and in 1977 with an annual incidence of 224.80 per 100 000. Onset of malaria had significant seasonality, mostly from June to August, accounting for 58.92%(2 815/4 778). The rate reached 77.50%(3 703/4 778) in rural areas; there was a higher rate of 81.12%(3 876/4 778) in the age group of 15 - 49 years old. The proportion of females to males was 1.56∶1.00. Most of the patients were farmers, with a proportion of 57.69% (510/884). The main carries of malaria were Anopheles anthropophagus and Anopheles sinensis. Tertian malaria was the most common type in this district. The control work was focused on the following four steps: survey and major prevention, control of the prevalence; integrated control; monitoring and consolidation to eliminate. There were related measures between each step. The incidence rate of malaria was controlled to less than 1.00 per 100 000 in 1993. The new cases in recent 2002 - 2013 years were proved to be exogenous imported cases. Conclusions The control of malaria in Jiulongpo district has met the national standard for eliminating, but imported cases should not be ignored. A long-term mechanism must be improved to implement and manage the monitoring of the floating population in malaria endemic areas, to help detecting and treating malaria cases in time, and also consolidate the eliminating achievement. Key words: Malaria; Epidemic characteristics; Control; Measures; Results