A retrospective study on distribution, frequency and rate of parasitaemia in patients infected with Plasmodium species in Kerman Province, Iran during the period 2009-2010

Malaria is still one of the major health problems in comparison with any other parasitic disease in Iran with considerable economic and mortality consequences. Sistan-and-Baluchestan, Hormozgan and Kerman are the most affected provinces in the country approximately 96% of the cases are reported from these three provinces. The aim of this study was to determine the frequency, distribution and rate of parasitaemia of human Plasmodium (P.) species in patients infected with malaria parasites in Kerman province. A total of 92,798 peripheral blood smears were collected from suspected malaria patients during the period 2009-10. Thin and thick blood smears were prepared according to the World Health Organization (WHO) standard procedure. Percentage of parasitaemia was determined based on the number of parasites in the positive slides. The Chi-square test was used for data analysis. A total of 571 samples were found to contain human Plasmodium species, including 523, 44, and 4 cases of P. vivax, P. falciparum and mixed infection, respectively. The results also showed that, as compared with the previous year, the total number of P. vivax cases decreased in 2010 by 33.96%. The highest level of parasitaemia was observed in one of the patients infected with P. falciparum, with 77240 parasites/µl of blood, and the lowest in a patient infected with P. vivax, with 48 parasites/µl of blood. There were no differences between the positive and negative cases as regards parameters such as nationality, habitat or gender (Chi-square, p<0.05). Furthermore, based on the Mann-Whitney test, there was no significant difference between the mean counts of P. falciparum and P. vivax (p-value = 0.464). Considering that Iran is in the elimination stage of malaria, patient finding and rapid, timely diagnosis of the disease are very important, particularly cases coming from Pakistan and Afghanistan, helping sustainability of the elimination program.