Malaria in Mazandaran, Northern Iran: Passive Case Finding During 1997-2012

Background Malaria is one of the most important parasitic diseases in tropical and temperate regions. The aim of this study was to determine the trend of malaria in Mazandaran Province, northern Iran during 1997-2012. Methods This retrospective study was conducted from 1997 to 2012. The population's study was individuals who registered at health centers of Mazandaran Province. Peripheral blood smear were prepared for each case, stained with Giemsa and examined by light microscope. In addition to demographic data, other parameters including Slide Positive Rate (SPR), Annual Parasite Incidence (API) and Annual Blood Examination Rate (ABER) were analyzed. Results In total, 844 cases of malaria were reported. Plasmodium vivax was predominant species with 821 cases (97.4%). The number of malaria cases increased from 1997 to 2005 and then decreased to 3 cases in 2011. Some cities had not reported any cases during last three years. The highest infection rate, 163(20.07%), was seen in 2001-02. The SPR had the highest value (0.54%) in 2004-05. The maximum API and ABER were observed in 2001-02 and 1997-98. 641(75.9%) of cases were imported from hyperendemic areas such as Afghanistan and South-eastern Iran and 94 (11.1%) malaria patients were recorded as introduced cases. The highest infection rate of malaria (21.3%) was seen in Babolsar. Conclusion Extensive malaria control should be continued to Mazandaran to become malaria-free region and in prevention of re-introduction stage.