Dynamics in Malaria Transmission in the Cross-Border Areas of Mozambique, South Africa and Eswatini (Mosaswa), from March 2017 to March 2019

Introduction: malaria is considered a public health threat for the humankind worldwide, estimations indicate that more than 1/3 of the population is in equal risk of acquiring it. Shared borders between countries with different malaria prevalence and preventive strategies delays elimination goals. Aim: to analyze malaria transmission dynamics in the cross border areas of Mozambique, South Africa and ESwatini from March 2017 to March 2019. Methodology: a secondary malaria database was used. Ratio comparison tests and logistic regression model estimation were done. The sample consisted of 250563 migrants and residents in MOSASWA cross-border areas tested for malaria, between March 2017 to March 2019. Data were analyzed using SPSS 22.0. Results: 250563 people were tested, out of which, 93035 (37.13%) were migrant populations and 157528 (62.87%) were residents of the surrounding areas. Regarding gender and occupation, 50.1% were male and 76% had informal occupation. The positivity rate was 2.1% (5253), out of which, 33.3% (1751) were mobile and migrant populations, 45.9% of the total cases were asymptomatic carriers. 39.18% (686) and 28.44% (498) of the positive migrants were using the Macuacua and Ressano Garcia borders on their way to South Africa respectively. 66.7% of the positives cases were surrounding populations, out of which 20.5% and 20.6% crossed the borders three to four times a week. The predictive power of having malaria increased 5.090 and 3.540 times more if the migrant had been tested in Mozambique and if he/she was a resident in the neighbouring borders, crossing into the borders of the same country respectively. Conclusions: A large number of the moving cases were diagnosed in Mozambique on their way to South Africa through Macuacua border.