SHASHWAT GUPTA RAY

While ongoing urbanisa tion in the State has increased, it has also raised concerns related to public health. A latest study by the Goa-based Indian Council of Medical Research (ICMR) lab, the National Institute of Malaria Re search (NIMR) field station, shows that even though zero malaria cas es were reported in 2023 among the local population, ‘imported cases’ — comprising mainly mi grant workers engaged at con struction sites — have emerged as a concern. The study has been published in the peer-reviewed Malaria Journal.

Titled ‘Spatiotemporal epidemiology of indigenous and imported malaria cases in Goa’, the study has been au thored by Dr Ajeet Kumar Mohanty and others. Historically, Goa was among the malaria-endemic States in India, with the Plasmodium vivax (P vivax) parasite ac counting for the majority of cases. Past malaria outbreaks in Goa have been linked to construction activities and im ported malaria cases, which threaten malaria elimination efforts in the State. Malaria data from the National Centre for Vector Borne Disease Control (NCVBDC) and the Directorate of Health Services, Goa, were used to study the spatiotemporal dy namics of Plasmodium falciparum, P vivax and mixed in fections in Goa from 2000 to 2023.

The spatiotemporal dis tribution of indigenous and imported malaria cases from 2014 to 2023 across different primary, urban and commu nity health centres (PHC/UHC/CHCs) in Goa was analysed using GIS. “The spatiotemporal changes over the last three decades in Goa’s land use and land cover were assessed using Land sat satellite images, and their effect on malaria distribution was analysed. Over the study period (2000–2023), P vivax contributed to 78.2% of the case-load. The malaria trend fluctuated from 2000 to 2008, with a steep decline ob served from 2009 onwards. In 2023, zero indigenous cases were reported,” the study stated. Six health centres — Candolim, Margao, Siolim, Vasco, Mapusa and Panjim — reported 57.8% of the total indige nous and imported malaria cases in Goa during 2014–2023. With 292 cases in 2023, the Porvorim UHC has emerged as a new hotspot for imported malaria cases. Meanwhile, land-use change analysis shows a four-fold increase in built-up area from around 70 sq km in 1991 to 260 sq km in 2024, with a strong spatial overlap between newly built-up areas and malaria cases.

“Due to concerted parasite and vector control strategies, the State health department has achieved the target of zero indigenous malaria cases in 2023. Despite achieving this milestone, the threat of imported malaria cases leading to local outbreaks remains a serious concern,” Dr Mohanty of NIMR Goa said. Since migration is a global phenomenon, it cannot be wished away. “Hence, the authorities must intensify screening of every migrant labourer reporting for work in the State so that there is timely medical intervention and the disease is pre vented from spreading,” Dr Mohanty said.