Raising the red flag for malaria elimination and integrated fever surveillance in the Brazilian amazon
Authors: Andre M Siqueira, Quique Bassat, Sheila Rodovalho, Marcus V G Lacerda
Journal: The Lancet Global Health (2017)

In the past decade, Brazil has achieved considerable progress in malaria control, with 140 000 cases reported in 2015, the lowest numbers since 1980.1Siqueira AM Mesones-Lapouble O Marchesini P et al.Plasmodium vivax landscape in Brazil: scenario and challenges.Am J Trop Med Hyg. 2016; 95: 87-96Crossref PubMed Scopus (36) Google Scholar Part of this success has been attributed to the establishment of a large network of around 3000 diagnostic and treatment units for malaria.1Siqueira AM Mesones-Lapouble O Marchesini P et al.Plasmodium vivax landscape in Brazil: scenario and challenges.Am J Trop Med Hyg. 2016; 95: 87-96Crossref PubMed Scopus (36) Google Scholar A remarkable feature is that these services are provided for free as part of the public universal health-care system (Sistema Único de Saúde [SUS]) and cover rural and riverine areas in the Amazon region—where more than 83% of malaria transmission occurs. Populations in these areas have a low density and reduced level of mobility, and in spite of the high coverage for malaria-associated diagnosis and treatment by the SUS, scarce access to health care and other public services, characterising the precarious social conditions and relative neglectof malaria in this region,2Viana RL Freitas CMd Giatti LL Environmental health and development in legal amazon: socio-economic, environmental and sanitary indicators, challenges and perspectives.Saúde e Sociedade. 2016; 25: 233-246Crossref Scopus (19) Google Scholar a situation unfortunately shared with other Latin American countries. In the absence of a consistent presence of the state, a creative and original acute fever surveillance system based on the use of a red flag has been put in place (figure). This consists of hoisting a red flag (or piece of red cloth) in front of a household if an inhabitant presents fever or other malaria-associated symptoms. Whenever a community health-care worker roaming their catchment area observes a red flag, they stop at that household, fill the notification form with the data from the febrile person, and collect a blood sample for malaria diagnosis through either microscopy (done at that location's health post) or rapid diagnostic test. If the test is positive, the species-specific treatment is provided following the national guidelines. Such a system has contributed to partly overcome the problem of large distances to health facilities, which impairs efficiency of case detection in the region,3Branch O Casapia WM Gamboa DV et al.Clustered local transmission and asymptomatic Plasmodium falciparum and Plasmodium vivax malaria infections in a recently emerged, hypoendemic Peruvian Amazon community.Malaria. 2005; 4: 27Crossref PubMed Scopus (149) Google Scholar, 4Singer BH de Castro MC Agricultural colonization and malaria on the Amazon frontier.Ann N Y Acad Sci. 2001; 954: 184-222Crossref PubMed Scopus (77) Google Scholar and enabled more than 60% of malaria cases to be treated within 48 h of fever onset.1Siqueira AM Mesones-Lapouble O Marchesini P et al.Plasmodium vivax landscape in Brazil: scenario and challenges.Am J Trop Med Hyg. 2016; 95: 87-96Crossref PubMed Scopus (36) Google Scholar While acknowledging this system's efficacy at improving case detection, it is important to recognise its limitations, especially considering the more ambitious goals the country should incorporate: to decisively aim for malaria elimination and to provide comprehensive health care and disease surveillance in the Amazon. The renewed commitment and impetus from the international community towards malaria elimination requires a shift and re-orientation of control programmes. Besides diagnosing and treating symptomatic malaria cases, it is imperative to identify and manage the infectious reservoir, including asymptomatic and low parasite density infections not detected with routinely used tools and strategies,5Moonen B Cohen JM Snow RW Slutsker L Drakeley C Smith DL Operational strategies to achieve and maintain malaria elimination.Lancet. 2010; 376: 1592-1603Summary Full Text Full Text PDF PubMed Scopus (274) Google Scholar but which are critical for maintaining transmission in a given community. Therefore, to achieve elimination, surveillance needs to incorporate innovative and efficient strategies.5Moonen B Cohen JM Snow RW Slutsker L Drakeley C Smith DL Operational strategies to achieve and maintain malaria elimination.Lancet. 2010; 376: 1592-1603Summary Full Text Full Text PDF PubMed Scopus (274) Google Scholar, 6Sturrock HJ Hsiang MS Cohen JM et al.Targeting asymptomatic malaria infections: active surveillance in control and elimination.PLoS Med. 2013; 10: e1001467Crossref PubMed Scopus (233) Google Scholar From another perspective, decreasing incidence of malaria results in lower proportions of malaria-attributable fever,7Trape JF Tall A Sokhna C et al.The rise and fall of malaria in a West African rural community, Dielmo, Senegal, from 1990 to 2012: a 22 year longitudinal study.Lancet Infect Dis. 2014; 14: 476-488Summary Full Text Full Text PDF PubMed Scopus (126) Google Scholar, 8D'Acremont V Kilowoko M Kyungu E et al.Beyond malaria—causes of fever in outpatient Tanzanian children.N Engl J Med. 2014; 370: 809-817Crossref PubMed Scopus (294) Google Scholar which has fallen from around 25% to 10% in the past decade in Brazil.9Vitor-Silva S Siqueira AM de Souza Sampaio V et al.Declining malaria transmission in rural Amazon: changing epidemiology and challenges to achieve elimination.Malaria. 2016; 15: 266Crossref PubMed Scopus (29) Google Scholar This suggests that 75–90% of acute febrile illness in the Amazon do not receive an aetiological diagnosis, exposing a major failure in both surveillance of endemic and emerging infectious agents and in case-management of febrile individuals. Surveillance is complex owing to the variety of agents causing undifferentiated fever (eg, dengue, chikungunya, Zika, bacteria, and trypanosome) and the unavailability of point-of-care tests, and thus efficient syndromic surveillance becomes paramount to inform specific actions.8D'Acremont V Kilowoko M Kyungu E et al.Beyond malaria—causes of fever in outpatient Tanzanian children.N Engl J Med. 2014; 370: 809-817Crossref PubMed Scopus (294) Google Scholar, 10Joshi R Colford Jr., JM Reingold AL Kalantri S Nonmalarial acute undifferentiated fever in a rural hospital in central India: diagnostic uncertainty and overtreatment with antimalarial agents.Am J Trop Med Hyg. 2008; 78: 393-399Crossref PubMed Scopus (67) Google Scholar Concerning case-management, non-malarial fevers might need either specific treatments or referral to better equipped hospitals for appropriate care.8D'Acremont V Kilowoko M Kyungu E et al.Beyond malaria—causes of fever in outpatient Tanzanian children.N Engl J Med. 2014; 370: 809-817Crossref PubMed Scopus (294) Google Scholar Additionally, the low proportion of malaria-attributable fever results in lower sensitivity to detect positive cases, because neither users nor health workers prioritise it as a diagnostic hypothesis, leading to delay in diagnosis, higher rates of complications, and slower response to malaria outbreaks.6Sturrock HJ Hsiang MS Cohen JM et al.Targeting asymptomatic malaria infections: active surveillance in control and elimination.PLoS Med. 2013; 10: e1001467Crossref PubMed Scopus (233) Google Scholar Although Brazil made substantial efforts to expand primary health care throughout the country with initiatives such as recruiting international physicians to work in remote areas (Programa mais Médicos),11Macinko J Harris MJ Brazil's family health strategy—delivering community-based primary care in a universal health system.N Engl J Med. 2015; 372: 2177-2181Crossref PubMed Scopus (274) Google Scholar hard to reach small rural and riverine areas suffering the largest burden of malaria did not benefit equally. Furthermore, to maintain a malaria-specific parallel health-care system in low-transmission settings is probably not cost-effective and, amid scarce resources, threatens the sustainability of reducing malaria incidence. Malaria control success in Brazil shows that the country has the capacity to commit to eliminate malaria, establish ambitious and realistic mid-term and long-term targets, and help steer the continent towards elimination. Concomitantly, Brazil should implement more integral health-care strategies addressing the specificities of Amazonian populations. This will require a re-orientation of the health system in the region, combining integrated management of acute febrile illness, provided in a timely fashion by the closest health facility and professionals (eg, community health workers, nurses), with malaria-specialised surveillance and control teams able to carry out the required activities to reduce and prevent malaria transmission. A public health red flag is raised, calling for the bold commitment of civil society, politicians, academia, and others partners, to advance towards the attainable goal of eliminating malaria and providing integral health care in the Amazon, an important step to reduce the neglect suffered by its populations. We declare no competing interests.