Assessing the Potential for a Malaria Outbreak in Trinidad and Tobago Due to Migrant Populations From Guyana and Venezuela for the Period 2009-2019.

OBJECTIVE: This study aims to assess the risk of a malaria outbreak in Trinidad and Tobago (T&T) based on trends in imported cases from two malaria-endemic high-population-mobility countries, Guyana and Venezuela, for the period 2009-2019. METHODS: A census of all positive malaria cases in T&T for the period 2009-2019 was obtained from the Insect Vector Control Division of the Ministry of Health. This included sociodemographic data, malaria type, origin, and whether it was acquired locally or was imported. Over the study period, data on the number of arrivals from Guyana and Venezuela to all ports of entry were obtained from the Immigration Division. Descriptive analyses and linear regression analyses were used to investigate the relationship between positive malaria cases and Guyanese and Venezuelan arrivals. RESULTS: There were 211 positive malaria cases in the study; ages ranged from 3 to 81 years, with a mean age of 35 years (SD = 14.3), and 74% were males. Among malaria cases, the common parasites were Plasmodium vivax (68.2%) and Plasmodium falciparum (22.3%). The majority (91.9%) were imported, 6.2% were acquired locally, and 1.9% were of unknown origin. Of the 194 imported cases, the countries of origin were Guyana (39.7%), Venezuela (38.7%), and Sub-Saharan Africa (15.5%). The correlation between log-transformed Venezuelan arrivals and malaria cases was moderate (r = 0.642, R2 = 0.412) and reached statistical significance (p = 0.033), indicating that Venezuelan arrivals significantly predict malaria incidence. CONCLUSION: Population movement from high malaria risk areas may increase the likelihood of transmission in T&T, and the influx of people from Venezuela significantly predicts malaria incidence. Malaria literacy, health education, surveillance, prompt diagnosis, treatment, and vector control are some of the interventions urgently needed to prevent a malaria resurgence.