Successful malaria elimination in the Ecuador–Peru border region: epidemiology and lessons learned

Abstract

BackgroundIn recent years, malaria (Plasmodium vivax and Plasmodium falciparum) has been successfully controlled in the Ecuador–Peru coastal border region. The aim of this study was to document this control effort and to identify the best practices and lessons learned that are applicable to malaria control and to other vector-borne diseases. A proximal outcome evaluation was conducted of the robust elimination programme in El Oro Province, Ecuador, and the Tumbes Region, Peru. Data collection efforts included a series of workshops with local public health experts who played central roles in the elimination effort, review of epidemiological records from Ministries of Health, and a review of national policy documents. Key programmatic and external factors are identified that determined the success of this eradication effort.Case descriptionFrom the mid 1980s until the early 2000s, the region experienced a surge in malaria transmission, which experts attributed to a combination of ineffective anti-malarial treatment, social-ecological factors (e.g., El Niño, increasing rice farming, construction of a reservoir), and political factors (e.g., reduction in resources and changes in management). In response to the malaria crisis, local public health practitioners from El Oro and Tumbes joined together in the mid-1990s to forge an unofficial binational collaboration for malaria control. Over the next 20 years, they effectively eradicated malaria in the region, by strengthening surveillance and treatment strategies, sharing of resources, operational research to inform policy, and novel interventions.Discussion and evaluationThe binational collaboration at the operational level was the fundamental component of the successful malaria elimination programme. This unique relationship created a trusting, open environment that allowed for flexibility, rapid response, innovation and resilience in times of crisis, and ultimately a sustainable control programme. Strong community involvement, an extensive microscopy network and ongoing epidemiologic investigations at the local level were also identified as crucial programmatic strategies.ConclusionThe results of this study provide key principles of a successful malaria elimination programme that can inform the next generation of public health professionals in the region, and serve as a guide to ongoing and future control efforts of other emerging vector borne diseases globally.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-016-1630-x) contains supplementary material, which is available to authorized users.

Thermal biology of mosquito‐borne disease

“…Temperature defines one dimension of the fundamental ecological niche for mosquito-borne disease transmissionthe range of conditions that is required for transmission to be possiblewhich also includes immature vector habitat and humidity. Within this fundamental niche, the realised ecological niche for transmission additionally depends on host factors including density, movement, behaviour, demography, susceptibility, control strategies, and exposure to mosquito bites (Gething et al 2010;Rodriguez-Barraquer et al 2011;Paaijmans & Thomas 2011a;Parham et al 2015;Wesolowski et al 2015;Krisher et al 2016;Metcalf et al 2017;Salje et al 2017Salje et al , 2018Jaramillo-Ochoa et al 2019). Mosquito and pathogen physiological responses to temperature determine fundamental transmission potential, but the realised impact of climate change on disease dynamics also depends on these host population processes, socio-economics, disease control efforts, or other mitigation measures (Gething et al 2010;Paaijmans & Thomas 2011a;Parham et al 2015;Wesolowski et al 2017).…”

Seasonal and geographic variation in insecticide resistance in Aedes aegypti in southern Ecuador

“…By contrast, the results from the test for Hardy-Weinberg equilibrium for the V1016I gene and the significant inter-seasonal differences in genotype frequencies indicate that the populations are still responding to varying selective pressures and are not in a state of equilibrium. Both of these mutations typically confer resistance to dichlorodiphenyltrichloroethane (DDT) as well as pyrethroids [36,37], meaning selection for these alleles likely began with earlier widespread usage of DDT (which was used by the MoH until 1996 [38]) and has persisted as pyrethroids became more commonly used [39]. Significant distinctions in genotypic and phenotypic frequencies were not detected for many cities in this study during subsequent seasons.…”

Malaria Epidemiology at the Clone Level

“…Geospatial surveillance systems to map index cases in real time are in place e.g. in Solomon Islands [52] or along the Ecuador-Peruvian border [53], and potentially could be expanded to include data on the origin of parasites based on genotyping.…”