The resurgence of malaria in Northern Iran in 2023: a wake-up call.

Background: Control and elimination programs for malaria in Iran have consistently faced significant challenges due to various factors, including the presence of neighboring malaria-endemic countries such as Afghanistan and Pakistan. In recent years, Golestan Province in northern Iran has recorded few cases of imported malaria, with a sudden increase of 22 cases in 2023. This article provides an overview of the malaria situation in northern Iran, along with a detailed report of these 22 cases.

Methods: The study population comprises all individuals exhibiting symptoms suspected of malaria (n = 445) who were referred to the Malaria Diagnosis Center in Golestan Province, located in northeastern Iran, for diagnosis between March 23, 2023, and December 23, 2023. A drop of peripheral blood, collected from a finger prick of each patient, was utilized for Plasmodium falciparum/P. vivax antigen detection. Moreover, thin and thick smears were prepared for each patient to investigate morphological characteristics and parasitemia percentage of the parasites.

Results: In total, 4.94% (22/445) of individuals with malaria-suspected symptoms were infected with Plasmodium species. All 22 infected individuals were native to Golestan Province, and none had a previous history. The mean ± standard error of mean (SEM) for the number of parasites/µL of blood sample was 16,029 ± 5,060 for P. vivax and 105,460 ± 102,146 for P. falciparum. Among the patients, 77.27% (17/22) were infected with P. vivax, 18.18% (4/22) were infected with P. falciparum, and 4.54% (1/22) were co-infected with both P. vivax and P. falciparum. In the case of P. falciparum, 40% (1/5) of the samples presented the ring form, 60% (3/5) trophozoite form, and 20% (1/5) gametocyte form. All patients demonstrated a positive response to the treatment, with a decrease in both the number of parasites and the number of clinical symptoms over time.

Conclusions: This study discussed 22 cases of malaria diagnosed in 2023 in Golestan Province in northern Iran. Given the presence of malaria vectors in this area and the observation of gametocytes in specimens from some patients, the increase in reported malaria cases could be worrisome in terms of establishing local transmission in this area.