Malaria in Latin America Today

Malaria has been around for thousands of years and has touched every part of the world during its reign of terror. Today, malaria is still endemic to sub-Saharan Africa and Southeast Asia. It has also made a disconcerting return to Latin America. The perseverance of modern malaria in parts of Latin America is a fascinating case study dependent on the geographic and social factors that make Latin America unique. While some countries managed to control it during the twentieth century, others struggled. In addition, despite the best efforts of early malaria eradication campaigns, the disease has come back in some countries that eradicated it. Latin American malaria is constantly changing. It can serve as a case study on what to do right, just as much as it will serve as an example of how things can go wrong.

According to the most recent World Malaria Report, 92 percent of 2017’s malaria cases occurred in sub-Saharan Africa, where environmental compatibility and socio-political environments foster vulnerability to the disease (WHO, 2018). A combined 7 percent of cases occurred in the WHO South-East Asia region and the Middle East, leaving 1 percent of cases to the Americas and elsewhere. The World Malaria Report also indicated, however, that between 2016 and 2017, the Americas recorded a significant rise in cases. Most, if not all, of these cases were in Central and South America.

Malaria is caused by a family of parasites known as Plasmodium (World Health Organization, 2018). There are five species known to harm humans, with the two most common strains in Latin America being P. falciparum and P. vivax. Both grow in the bodies of mosquitoes before transmission into humans. Malarial parasites attack the liver and the bloodstream, causing the body to experience rapid chills and fevers within short periods of time (Shah, 2010). Without proper treatment, malaria can be fatal, especially in infants and children under five.

The distribution of malaria depends, first, on the habitats of its vector, the anopheles mosquito. There are more than 40 species of anopheles that can carry malaria, and nine of them live in the Americas (Sinka et al., 2012). Two of the most dominant species in Latin America are A. darlingi and A. pseudopunctipennis. The characteristic malaria vector of Amazonia, A. darlingi prefers rivers or pools of standing water, in mostly shady conditions, especially in disturbed rain forest environments (Massey, et al., 2016). A. pseudopunctipennis, by contrast, tends to lay its eggs in well-lit streams of valleys and foothills on the eastern flank of the Andes and Central American mountain chains, up to 3000 meters in elevation (Massey, et al., 2016).

However, regions with these mosquitoes do not necessarily have active transmission of malaria, thanks to continued public health initiatives. Last year, the World Health Organization designated Paraguay malaria-free, and Argentina is currently making a case for the title (World Malaria Report, 2018). Other countries like Ecuador and Mexico are also reporting lower annual case rates every year. Mexico and Argentina both benefited from intense anti-malaria campaigns in the mid-twentieth century. In Argentina, Perón’s public health ministry ignited a war against malaria and the A. pseudopunctipennis mosquito in the late 1940s (Carter, 2012). Carlos Alvarado, the director of the malaria control program, enacted an intensive, five-year eradication program that utilized DDT as an acting agent against malaria and the Anopheles mosquito. With military-like brigades, the administration sprayed DDT on every house in northwestern Argentina's endemic zone. Within months the A. pseudopunctipennis population dropped to zero. Since then, malaria rates have stayed low in Argentina.

The success of malaria elimination efforts using DDT in Argentina, Venezuela, and parts of the Caribbean led the WHO and PAHO to launch a hemispheric, then global malaria eradication program in the 1950s. In Mexico, this ambitious eradication program was only partially successful (Cueto, 2005). This was in part due to concerns from rural and indigenous populations, who noticed the negative effects of DDT on their crops and animals. DDT did somewhat reduce the incidence of malaria in Mexico and the initial program set up a framework for future systems.

Not every country can be a success story. Warm, humid climates in non-urbanized regions can foster the spread of malaria. Both Colombia and Brazil are indicative of this issue; despite attempts made by their respective health ministries, the wet environments of the Amazon and the Colombian coast allow malaria to flourish. In Colombia, malaria cases are found on the coast as well as the rainforest (Rodriguez et. al, 2016). The northern coast of Colombia has a tropical climate with vast forests hospitable to anopheles mosquitoes. This, in addition to Colombia’s small territory extending into the Amazonian rainforest in the south of the country, adds to its endemic malaria rate. The Amazon proves to be a complication for Brazil as well; according to the WHO, Brazil’s vast rainforest region is responsible for the increase in cases between 2016 and 2017. Brazil accounted for 24 percent of 2015’s Latin American cases, and only 0.5 percent of those were identified and treated outside of the Amazon (Recht et. al, 2017, pp. 2). Malaria is endemic in urban Amazonian centers like the Brazilian city of Manaus, whose largest hospital reported 316 cases of malaria in the span of two years. Brazil suffers from “urban malaria”, which refers to uncontrolled waves of migration from endemic areas to non-endemic areas (Recht et al., p. 7). While this can coincide with rural to urban migration, migration from one urban center to another can also bring malaria to previously secure regions.

There are still other countries dealing with malaria in Latin America, some of which previously declared malaria eradicated. In the early 1960s, Under the leadership of malariologist Arnoldo Gabaldón, Venezuela was the first Latin American country that the WHO declared as malaria-free (Daley, 2019). Today, Venezuela has the highest malaria case rate in Latin America, with the WHO reporting a 69% increase in cases from 2016 to 2017 (Nebehay, 2018). Venezuela suffers from poor drug adherence rates and a severe lack of proper antimalarial prevention programs. Affected regions have little to no access to drugs, worsening the situation as those same areas are prime regions for job attainment. Mining communities, in particular, are disadvantaged; workers who go to the mines pick up malaria and bring it back to their families. What ties Venezuela’s malaria crisis to other regions in Latin America is emigration. As migrants flee the economic crisis, they bring malaria into other nearby countries. In fact, 78 percent of Brazil’s 2015 imported malaria cases originated in Venezuela.

Malaria is a widespread issue throughout many parts of Latin America, though it pales in comparison to larger causes of mortality. This lack of severity is thanks in part to early DDT campaigns and some modern malaria initiatives. However, with modern conflicts in migration and drug access, combined with certain physical features, it may be a while before Latin America’s 1 percent contribution to international malaria cases drops to zero.

Related Articles:

• Venezuela: Healthcare in Times of Crisis
• Venezuelan Health Crisis: infectious and vaccine-preventable diseases

Additional Resources

https://mesamalaria.org/mesa-track?researchInstitution=4141

https://www.cdc.gov/parasites/malaria/index.html

https://map.ox.ac.uk/bionomics/

References:

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Carter, E.D. (2012). Enemy in the Blood: Malaria, Environment, and Development in Argentina. Tuscaloosa: University of Alabama Press.

Cueto, M. (2005). Appropriation and Resistance: Local responses to malaria eradication in Mexico, 1955-1970. Journal of Latin American Studies, 37, 533-559.

Daley, J. (2019). Infectious Diseases Spike amid Venezuela’s Political Turmoil, Scientific America. Retrieved From https://www.scientificamerican.com/article/infectious- diseases- spike-amid-venezuelas-political-turmoil/

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Recht, J., Siqueira, A.M., Monteiro, W.M., Herrera, S.M., Herrera, S., & Lacerda, M.V.G. (2017). Malaria in Brazil, Colombia, Peru and Venezuela: current challenges in malaria control and elimination. Malaria Journal, 16(273), 1-18. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5496604/pdf/12936_2017_Article_1925.pdf

Rodriguez, J.C., Uribe, G.A., Araújo, R.M., Narváez, P.C., & Valencia, S.H. (2016). Epidemiology and control of malaria in Colombia. Mem Inst Oswaldo Cruz, 106, 114-122. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4830684/pdf/nihms775591.pdf

Shah, S. (2010). The Fever: How Malaria has Ruled Humankind for 500,000 Years. New York, NY: Farrar, Straus and Giroux.

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