Malaria, dengue and Zika are three diseases that are transmittable by the bites of infected mosquitoes. They are present in LAC with varying degrees of incidence. Malaria is a tropical disease caused by a parasite in the mosquito and causes symptoms such as fever, headache, and vomiting. As part of the SDG targets, the UN set a goal to end the epidemic of malaria by 2030. Globally, malaria case incidence declined by 25.6% between 2000 and 2015, however, it increased by 8.5% between 2015 and 2024. In terms of mortality rates, it almost halved between 2000 and 2015, but progress has slowed since then, with only a further 7.4% reduction over the past 9 years (WHO, 2025[1]).
In the LAC region, country efforts have greatly reduced new cases of malaria, nearly or completely eradicating it in Argentina, Belize, El Salvador, Paraguay, Suriname, Mexico, Dominican Republic, Ecuador, Guatemala, Honduras and Costa Rica, plus several countries no longer report incidence data. However, the region remains vulnerable to outbreaks. The biggest incidence in the region can be found in Guyana with 43 cases per 1 000 risk population in 2023 (Figure 3.28, left panel). In 2023, Venezuela shows the largest number of estimated malaria deaths with 118 people dying in the country, followed by Brazil, Haiti, and Guyana with 73, 60, and 42 deaths, respectively (Figure 3.28, right panel).
Dengue is a viral infection caused by the mosquito Aedes aegypti and remains a public health problem in the Americas despite countries’ efforts to prevent and mitigate it. Dengue causes a severe flu-like illness and sometimes can cause a potentially lethal complication called severe dengue. Incidence of dengue in the region is heterogeneous but has overall increased in the LAC region over the past four years. In some countries, such as Guyana, Brazil and Paraguay, the increase has been ten‑fold or more. Guyana has the highest incidence, with 5 572 cases per 100 000 population, followed by Brazil with 4 843 and Paraguay with 4 269 (Figure 3.29 – left panel). Lethality of the disease also varies, ranging from no reported deaths in 16 LAC countries, including Bahamas, Chile and Cuba, among others, to 3.2% of cases resulting in deaths in Suriname, which is the country with the fourth lowest incidence (Figure 3.29 – right panel). This could suggest underreporting of cases or healthcare system limitations.
Zika fever is a viral disease caused by Zika virus transmitted by the mosquito Aedes aegypti, consisting of mild fever, rash, headaches, arthralgia, myalgia, asthenia, and non-purulent conjunctivitis. Incidence of Zika is very high in Brazil with 20.4 cases per 100 000 population in 2024. Belize and Bolivia follow with 7.43 and 2.15 cases per 100 00 population. Brazil’s high reported incidence may partly reflect its comparatively strong surveillance and laboratory capacity for detecting Zika infections compared to other LAC countries that may underreport cases. Several countries in the region did not report any Zika cases in 2021 (Figure 3.30).
Mosquito borne diseases disproportionally affect economically disadvantaged communities, which lack adequate prevention methods and modern sanitation and infrastructure. It is essential that countries ensure equitable access to quality prevention and control services amongst these communities to protect them from communicable diseases like malaria, chikungunya, dengue, and zika. Outbreak preparedness and control are crucial for a proper prevention and response, for which countries should develop their capacities and resources. The use of insecticide‑treated nets and indoor residual spraying with insecticides are important preventive measures for at-risk populations to avoid mosquito bites, and increasing education and awareness helps ensure that communities know how to protect themselves.
