Decreasing trend of imported malaria cases but increasing influx of mixed P. falciparum and P. vivax infections in malaria-free Kuwait

Abstract

Malaria still continues to be the most important parasitic disease worldwide, affecting 228 million people and causing 405,000 deaths each year. In this retrospective study during 2013 to 2018, we documented the incidence of imported malaria infection and evaluated the impact of malaria preventive measures in Kuwait, a non-endemic country. The epidemiologic and demographic data of all malaria cases was collected from the Infectious Diseases Hospital, Kuwait where all suspected cases of malaria are referred for confirmation and therapeutic intervention. The diagnosis of malaria infection was done by microscopy of Giemsa stained blood films. Selected samples were retested with BinaxNOW® Malaria rapid test and molecular assay to reconfirm the Plasmodium spp. or mixed infection. Overall, 1913 (25.9%) malaria cases were detected, 81.5% of which were among male subjects. Male subjects had higher incidence of P. vivax malaria (113; 91.1%) and mixed infection with P. falciparum and P. vivax (1245; 90.0%) compared to females who had higher rate of P. falciparum infection (52.4%). An overwhelming majority of malaria cases (1895; 99.1%) were detected among expatriates from malaria-endemic countries; India (1012; 52.9%), Pakistan (390; 20.4%), Afghanistan (94; 4.9%) and African countries (313; 16.3%). Only 18 cases involved Kuwaiti nationals, all with a history of travel to African countries. The majority of malaria cases were detected during the summer and fall months (May-October). Our data showed that the incidence rate of imported malaria cases was stable during 2013 to 2018, however, the incidence of total malaria cases showed a declining trend over the years. This study confirms that the preventive program has been successful in reducing the incidence of imported malaria infections in Kuwait. The most striking finding of this study was high incidence of mixed infection with P. falciparum and P. vivax, with almost all (97%) cases among workers from India.

Current Status and the Epidemiology of Malaria in the Middle East Region and Beyond

“…These cases were either newly arriving expatriate workers from endemic countries or resident workers who were returning to Kuwait after visiting their native countries [ 42 , 43 , 44 , 45 , 46 ]. However, the data from these and a more recent study have shown a declining trend in the incidence of imported malaria cases in Kuwait [ 26 , 43 , 45 ].…”

“…The study carried out in the last decade in Kuwait reported nearly 250–400 malaria cases annually and all cases represented imported malaria cases. A vast majority of cases were detected among expatriates and 80% of cases occurred among male expatriates aged 21–40 years [ 26 ]. P. vivax was responsible for 71% of malaria cases while P. falciparum infections accounted for 27% of malaria cases in Kuwait [ 26 ].…”

“…A vast majority of cases were detected among expatriates and 80% of cases occurred among male expatriates aged 21–40 years [ 26 ]. P. vivax was responsible for 71% of malaria cases while P. falciparum infections accounted for 27% of malaria cases in Kuwait [ 26 ]. A more recent epidemiological study which covered the period from 2013 to 2018 reported that 1913 (25.9%) subjects out of a total of 7386 suspected cases were positive for malaria.…”

“…A more recent epidemiological study which covered the period from 2013 to 2018 reported that 1913 (25.9%) subjects out of a total of 7386 suspected cases were positive for malaria. The positivity ranged from 262 cases in 2014 to 409 cases in 2017 and a calculated malaria incidence of 6.8/100,000 population in 2014 and 9.9/100,000 population in 2017 [ 26 ]. The study further showed that the overwhelming majority of malaria cases ( n = 1895; 99.1%) were detected in the expatriate population, of which >75% came from Asian countries.…”

“…Only 18 Kuwaiti nationals tested positive for malaria infection, all with a history of travel to malaria-endemic African countries. An important finding of the study was the detection of mixed P. falciparum and P. vivax infection in the majority ( n = 1383; 72.3%) of malaria cases ( Table 1 ) and nearly all the mixed infection cases (97%) were found among subjects from India [ 26 ]. Although no autochthonous malaria cases have been detected in Kuwait, certain risk factors for local transmission of infection have recently emerged which include a change in the present ecological and climate conditions due to an enthusiastic drive of making Kuwait green and extending plantations.…”