Epidemiology of malaria in Hamadan province during a 20 -year period (1980-2001)

Background and objective: Malaria is endemic in the southern Iran.  The disease  has been controlled in most parts of Iran except  in three provinces in the southeastern Iran. There is a potential for occurrence of malaria in other parts of Iran. Therefore, continuous surveillance and epidemiological studies are necessary for sporadic cases  and local outbreaks.  

Materials and Methods: In order to evaluate malaria situation during a twenty -year period (1980-2000), all recorded cases were analyzed.  There is a systematic mode of recording and report of malaria in all provinces. All known cases were recorded in the  regional health center and followed up for the source of occurrence. Therefore, an archival review can reflect the real conditions. 

Results: A total of 506 cases of malaria were analyzed (25.3 cases per year). The highest incidence per year was observed at 1994 (50 cases), and lowest incidence occurred  in 1984 (5 cases). In sum, 91.1%  were Plasmodium falciparum, 7.7% P. vivax, two cases mixed infection and one case P. malariae.  Two cases were unidentified. Malaria had a downward  trend in this region after 1994, so that only 6 cases were recorded in 2000. 62% of total were imported from southern endemic areas, 13.4% were imported from outside of the country, and only 2.96%  had local  transmission. The highest incidence rate was in Hamadan and Nahavand. High incidence was recorded in August (19.96%) and lower incidence in March (1.58%).  Malaria was more prevalent in males(80.63%) than females, and 20-29 years age group had the highest infection rate. The majority of  cases were seasonal workers.

Discussion:  This survey indicated that, until 15 years after the Islamic Revolution, malaria has had a stable  situation in Hamadan, and the majority of cases had been imported , type A or B. Since1994 malaria has a downward trend.