Outbreak investigation of needle sharing-induced malaria, Ahvaz, Iran

Background: Humans acquire malaria from the bite of infected anopheline mosquitoes. Malaria is very rarely acquired by needle sharing among intravenous drug users (IVDUs). The aim of this report is to describe the role of injecting drug usage in malaria outbreaks occurring in malaria-free regions. Materials and methods: This investigation was conducted to control a febrile illness occurring in IVDUs in a camp near Ahvaz, a city in the southwest of Iran, during the summer of 2000. All 98 men (mean age 25 years) in this camp took part in the study. A questionnaire was completed for data collection. Peripheral blood smears were examined for Plasmodium by Wright and Giemsa staining. Those who were positive for Plasmodium were treated with chloroquine 600 mg immediately on day 1, with a 300 mg follow-up dose 6 h later; this was followed by 300 mg doses on days 2 and 3. Results: Twenty-seven patients (27.6%) were positive for Plasmodium falciparum, and all of them had shared needles and syringes in the days before their illness. One of the men had been transferred into the camp from Bandar Abbas two weeks previously. There were no anopheline mosquitoes in the camp environment and none within a 1-km radius. There had been no report of malaria transmission previously in this camp, nor among the population living within the 1-km radius. All of the cases (100%) were negative for P. falciparum at follow-up examination. Conclusions: With regard to increasing injecting drug addiction and the presence of malaria in some parts of Iran, malaria should be included in the differential diagnosis of IVDU cases with fever. (C) 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.