ABSTRACT
False-negative results for Plasmodium falciparum histidine-rich protein (HRP) 2-based rapid diagnostic tests (RDTs) are increasing in Eritrea. We investigated HRP gene 2/3 (pfhrp2/pfhrp3) status in 50 infected patients at 2 hospitals. We showed that 80.8% (21/26) of patients at Ghindae Hospital and 41.7% (10/24) at Massawa Hospital were infected with pfhrp2-negative parasites and 92.3% (24/26) of patients at Ghindae Hospital and 70.8% (17/24) at Massawa Hospital were infected with pfhrp3-negative parasites. Parasite densities between pfhrp2-positive and pfhrp2-negative patients were comparable. All pfhrp2-negative samples had no detectable HRP2/3 antigen and showed negative results for HRP2-based RDTs. pfhrp2-negative parasites were genetically less diverse and formed 2 clusters with no close relationships to parasites from Peru. These parasites probably emerged independently by selection in Eritrea. High prevalence of pfhrp2-negative parasites caused a high rate of false-negative results for RDTs. Determining prevalence of pfhrp2-negative parasites is urgently needed in neighboring countries to assist case management policies.
Subject(s)
Antigens, Protozoan/genetics , Gene Deletion , Malaria, Falciparum/prevention & control , Malaria, Falciparum/parasitology , Plasmodium falciparum/genetics , Protozoan Proteins/genetics , Adolescent , Adult , Aged , Child , Eritrea/epidemiology , Genetic Variation , Genotype , Geography , Humans , Malaria, Falciparum/diagnosis , Malaria, Falciparum/epidemiology , Microsatellite Repeats , Middle Aged , National Health Programs , Population Surveillance , Young AdultABSTRACT
BACKGROUND: The geographic distribution and burden of dengue is increasing globally. This study aims to evaluate dengue outbreaks and to substantiate the need for strengthened surveillance, reporting and control in Eritrea. METHODS: Data from two cross-sectional dengue epidemic investigations in 2005 and 2010 were analyzed. Samples were tested for dengue virus-specific IgM and IgG antibodies using capture enzyme-linked immunosorbent assays. Dengue vectors' breeding attributes were characterized and epidemic risk indices determined. National routine surveillance weekly reports from 2005 to the second quarter of 2015 were analyzed for spatiotemporal trends. RESULTS: Dengue outbreaks increased in Eritrea from 2005 to 2015 with clinical presentation varying markedly among patients. The house and container indices for Aedes aegypti were 40 and 39.6 % respectively, with containers having A. aeqypti varying significantly (P < 0.04). Serum from 33.3 % (n = 15) and 88 % (n = 26) of clinical dengue cases in Aroget sub-Zoba (district) of Gash Barka Zoba (region) contained anti-DENV IgM antibody in 2005 and 2006, respectively. The national surveillance data from 2005 to 2015 indicate an overall spatiotemporal increase of dengue fever. CONCLUSIONS: The increase in dengue outbreaks has been confirmed in Eritrea and necessitates strengthening of surveillance and health worker and laboratory capacity, as well as targeted vector control interventions.
ABSTRACT
BACKGROUND: Contemporary malaria vector control relies on the use of insecticide-based, indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs). However, malaria-endemic countries, including Eritrea, have struggled to effectively deploy these tools due technical and operational challenges, including the selection of insecticide resistance in malaria vectors. This manuscript outlines the processes undertaken in consolidating strategic planning and operational frameworks for vector control to expedite malaria elimination in Eritrea. CASE DESCRIPTION: The effort to strengthen strategic frameworks for vector control in Eritrea was the 'case' for this study. The integrated vector management (IVM) strategy was developed in 2010 but was not well executed, resulting in a rise in malaria transmission, prompting a process to redefine and relaunch the IVM strategy with integration of other vector borne diseases (VBDs) as the focus. The information sources for this study included all available data and accessible archived documentary records on malaria vector control in Eritrea. Structured literature searches of published, peer-reviewed sources using online, scientific, bibliographic databases, Google Scholar, PubMed and WHO, and a combination of search terms were utilized to gather data. The literature was reviewed and adapted to the local context and translated into the consolidated strategic framework. DISCUSSION: In Eritrea, communities are grappling with the challenge of VBDs posing public health concerns, including malaria. The global fund financed the scale-up of IRS and LLIN programmes in 2014. Eritrea is transitioning towards malaria elimination and strategic frameworks for vector control have been consolidated by: developing an integrated vector management (IVM) strategy (2015-2019); updating IRS and larval source management (LSM) guidelines; developing training manuals for IRS and LSM; training of national staff in malaria entomology and vector control, including insecticide resistance monitoring techniques; initiating the global plan for insecticide resistance management; conducting needs' assessments and developing standard operating procedure for insectaries; developing a guidance document on malaria vector control based on eco-epidemiological strata, a vector surveillance plan and harmonized mapping, data collection and reporting tools. CONCLUSION: Eritrea has successfully consolidated strategic frameworks for vector control. Rational decision-making remains critical to ensure that the interventions are effective and their choice is evidence-based, and to optimize the use of resources for vector control. Implementation of effective IVM requires proper collaboration and coordination, consistent technical and financial capacity and support to offer greater benefits.
Subject(s)
Anopheles , Health Planning , Insect Vectors , Malaria/prevention & control , Mosquito Control/methods , Animals , Eritrea , Health Planning/organization & administration , Humans , Mosquito Control/organization & administration , Public HealthABSTRACT
BACKGROUND: Eritrea, like most countries in sub-Saharan Africa, has expended much effort towards malaria control with the view of transitioning from reduction of the disease burden to elimination. This paper reports on the level of achievement as highlighted by the follow-on, malaria-endemic area representative, survey that aimed to provide data and to assess progress on malaria indicators and parasite prevalence at household level across the country. METHODS: In 2012, data were collected using a two-stage stratified cluster random sample of 1887 households in 96 clusters (villages in rural areas and census enumeration areas in urban centers) during a malaria indicator and prevalence survey in Eritrea. The survey determined parasite prevalence in vulnerable population groups and evaluated coverage, use and access to malaria control services. Standardized Roll-Back Malaria Monitoring and Evaluation Reference Group household and women's questionnaires were adapted to the local situation and used for collection of data that were analysed and summarized using descriptive statistics. RESULTS: The results of the survey showed that 90% (95% CI 89-91) of households owned at least one mosquito net. The proportion of the population with access to an insecticide-treated net (ITN) in their household was 55% (95% CI 54-56). The utilization of ITNs was 67% (95% CI 65-70) for children under 5 years and 60% (95% CI 58-63) for pregnant women (OR: 0. 73(95% CI 0.62-0.85); P = 0.52). Only 28% (95% CI 26-30) of households were covered by indoor residual spraying (IRS) the previous year with significant heterogeneity by zoba (Debub 50 % (95% CI 45-54) vs Gash Barka 32 % (95% CI 28-36); OR = 0. 47 (95% CI 0.36-0.61), P = 0.05). Malaria parasite prevalence was low; 1.1% (95% CI 0.9-1.3) in the general population and 1.4% (95% CI 1.0-2.0) in children under five and 0.7% (95% CI 0.4-1.1) among women aged 15-49 years. Only 19% (95% CI 15-26) of children under five had fever in the 2 weeks preceding the survey, with 61% (95% CI 54.1-67.1) seeking treatment from a health facility. Data on knowledge levels show that 92% reported that malaria is transmitted by mosquitoes, 92% mentioned that the use of mosquito nets could prevent malaria, 47% knew malaria prevention medication, 83% cited fever as a sign and symptom of malaria, and 35% had heard or seen malaria awareness messages. CONCLUSION: Notwithstanding confounders, the observed low malaria parasite prevalence could be associated with malaria intervention coverage, access and utilization as well as high and equitable knowledge levels in the population. This indicates that Eritrea is on the right track towards pre-elimination. However, technical and infrastructure capacity should be strengthened to facilitate implementation, surveillance, monitoring, and evaluation.