Malaria in Brazil: what happens outside the Amazonian endemic region

Abstract

Brazil, a country of continental proportions, presents three profiles of malaria transmission. The first and most important numerically, occurs inside the Amazon. The Amazon accounts for approximately 60% of the nation’s territory and approximately 13% of the Brazilian population. This region hosts 99.5% of the nation’s malaria cases, which are predominantly caused by Plasmodium vivax (i.e., 82% of cases in 2013). The second involves imported malaria, which corresponds to malaria cases acquired outside the region where the individuals live or the diagnosis was made. These cases are imported from endemic regions of Brazil (i.e., the Amazon) or from other countries in South and Central America, Africa and Asia. Imported malaria comprised 89% of the cases found outside the area of active transmission in Brazil in 2013. These cases highlight an important question with respect to both therapeutic and epidemiological issues because patients, especially those with falciparum malaria, arriving in a region where the health professionals may not have experience with the clinical manifestations of malaria and its diagnosis could suffer dramatic consequences associated with a potential delay in treatment. Additionally, because the Anopheles vectors exist in most of the country, even a single case of malaria, if not diagnosed and treated immediately, may result in introduced cases, causing outbreaks and even introducing or reintroducing the disease to a non-endemic, receptive region. Cases introduced outside the Amazon usually occur in areas in which malaria was formerly endemic and are transmitted by competent vectors belonging to the subgenus Nyssorhynchus (i.e., Anopheles darlingi, Anopheles aquasalis and species of the Albitarsis complex). The third type of transmission accounts for only 0.05% of all cases and is caused by autochthonous malaria in the Atlantic Forest, located primarily along the southeastern Atlantic Coast. They are caused by parasites that seem to be (or to be very close to) P. vivax and, in a less extent, by Plasmodium malariae and it is transmitted by the bromeliad mosquito Anopheles (Kerteszia) cruzii. This paper deals mainly with the two profiles of malaria found outside the Amazon: the imported and ensuing introduced cases and the autochthonous cases. We also provide an update regarding the situation in Brazil and the Brazilian endemic Amazon.

Spotlight on Plasmodium falciparum evolutionary system in the southeastern Atlantic forest

“…Beyond its importance as a vector of P. vivax to humans, it is related to transmission of Plasmodium simium among monkeys and/or humans (Pina-Costa et al 2014). Recently, Brasil et al (2017) suggested that transmission of P. simium to humans may have been neglected because it seems more important than previously thought.…”

Accuracy of the malaria epidemiological surveillance system data in the state of Amazonas

“…Northern Brazil is an endemic malaria region (Barata 1995, Oliveira-Ferreira et al 2010) and a growing number of researches make use of the Brazilian epidemiological surveillance system of malaria (SIVEP-Malaria) database. Costa et al 2014). The Malaria's Epidemiological Surveillance System (SIVEP-Malaria) is the main tool used by PNCM to improve the production of information about malaria.…”

Plasmodium Falciparum Infection: In Silico Preliminary Studies

“…Currently, these numbers are decreasing and the amount of cases of the disease recorded in recent years went down: 267 047 cases in 2011, 242,756 in 2012 (a reduction of 9.1%) and 178,613 in 2013 (down 26.4%). The predominant geographical location of cases is in Legal Amazonia (99.5%), with preponderance in the states of Acre, Amazonas, Pará and Rondônia (PINA-COSTA et al, 2014).…”