Travel Associated Malaria among Migrant Workers in Rural Murshidabad, West Bengal, India: A Retrospective Epidemiological Study

Abstract Background Malaria is an important public health concern in India, and migration of the population is an important challenge to malaria elimination as it facilitates the introduction of malaria parasites from endemic to receptive areas. In West Bengal, Kolkata contributes majorly to urban malaria, while Hosnabad Health Sub-Centre (HSC) under Bhagabangolla-II Block in Murshidabad district reported persistent rural malaria transmission despite ongoing control efforts. This study aims to assess the epidemiological characteristics and population demography details to find out the reasons for persistent malaria at Hosnabad HSC. Methods A retrospective assessment of routine malaria surveillance data from 2017 to 2024 was conducted utilizing records from Hosnabad HSC. Demographic characteristics, Plasmodium (P) species, and documented travel histories of laboratory confirmed malaria cases were extracted from surveillance registers. Cases were accessed according to their reported travel history and timing of symptoms onset to determine the likely origin of infection. Results Among 7,273 fever individuals screened, 233 (3.2%) were diagnosed with malaria. Most cases occurred among adult male (98.7%, mean age of 24.6 ± 8.0). The majority were migrant worker 230 (98.7%) predominantly engaged in construction work 219 (93.1%), followed by plumbing 11 (4.7%) and domestic work 2 (0.9%). P. vivax was the predominant species 209 (89.7%), followed by P. falciparum 15 (6.4%) and mixed infection 9 (3.9%). A documented travel history was available for 95.7% patients, of whom 87.1% had travelled to Kolkata, followed by Mumbai (3.5%) and Odisha (2.1%). Among cases with travel history, 66.1% returned with fever while 20.6% developed symptoms within two weeks of return, supporting a predominantly imported origin of infection. Conclusion Malaria cases reported at Hosnabad HSC was predominantly P. vivax , associated with population movement, particularly migration between Kolkata and the rural catchment area. These findings highlight the importance of integrating migrant sensitive surveillance into malaria elimination strategies, including systematic documentation of travel history, prompt diagnosis and treatment, and radical cure of P. vivax infections to prevent relapse and onward transmission. However, inter-district and inter-state cross-notification is important to improve surveillance and response between urban infection source and rural receiving areas to prevent re-establishment and support India's malaria elimination goal.