TITLE:
Increasing Trend of Mixed Infections of Plasmodium falciparum and Plasmodium vivax among Imported Malaria Cases in Kuwait, a Non-Endemic Country
AUTHORS:
Ali Sher, Saif A. Latif
KEYWORDS:
Plasmodium falciparum, Plasmodium vivax, Mixed Infection, Expatriates, Imported Malaria, Microscopy
JOURNAL NAME:
Open Access Library Journal,
Vol.10 No.2,
February
28,
2023
ABSTRACT: Background: Malaria in humans is caused by five Plasmodium species, i.e. Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale and Plasmodium knowlesi, which are transmitted by female Anopheles mosquitoes. Although a lot of progress has been made in the fight against malaria, an estimated half of the world’s population (-3.95 billion people) in 87 countries and territories is still at risk of malaria. Malaria was eradicated from Kuwait in 1963, and no autochthonous cases have been reported afterward. The cases reported after 1963 were imported primarily among expatriates coming to live or work in Kuwait. Methods: The epidemiologic and demographic data of all malaria cases from 1992 to 1996 were collected from the Medical Center for Labor Examination and from 2015 to 2019 from the Infectious Diseases Hospital, Kuwait. All the suspected cases of malaria are referred to Infectious Diseases Hospital for diagnosis confirmation and treatment. Blood samples were obtained from 5800 suspected malaria cases. Giemsa-stained thick and thin blood films were performed to identify the malaria cases and the infecting Plasmodium species. Selected samples (n = 24) were retested with microscopy and a real-time PCR assay to reconfirm the diagnosis and identify the Plasmodium species. Results: During the years (2015-2019), 1549 (26.7%) cases (average = 310 cases per year), out of 5800 tested, were identified by microscopy to have malaria. The gender distribution analysis showed that 78.6% of cases were males and 21.4% were females. An overwhelming majority (97.4%) of cases were expatriates coming from malaria-endemic regions, in India. Only 18 cases of malaria were found among Kuwaiti nationals, and all of them had a history of travel to malaria endemic African countries. The majority (71%) of cases were detected during the months of May and October of each year. The most infecting Plasmodium species were P. falciparum and P. vivax but the majority (69.5%) of cases had mixed infections with these species. The results of microscopy and PCR were 100% concordant with the diagnosis of malaria and the Plasmodium species. Conclusion: Our data showed that the incidence rate of imported malaria cases is in declining trend over the years. This study confirms that the migrant workers diagnosed with malaria and treated in their home countries before entering Kuwait for the 1st time have been successful in reducing the incidence of imported malaria infections in Kuwait. However, the number of cases infecting from mixed infections (69.5%) with P. falciparum and P. vivax has significantly increased compared to earlier findings. Mixed infection easily leads to misdiagnosis/misinterpretation of Plasmodium species to improper treatment, as the treatments for P. falciparum and P. vivax species are different. Therefore, in routine clinical laboratories, using an accurate combination of diagnostic procedures to identify suspected patients with mixed infections is crucial for therapeutic decisions, prompt treatment, and effective patient management.