Haiti's Commitment to Malaria Elimination: Progress in the Face of Challenges, 2010-2016.

Haiti is committed to malaria elimination by 2020. Following a 2010 earthquake and cholera epidemic, Haiti capitalized on investments in its health system to refocus on malaria elimination. Efforts, including expanding diagnostics, ensuring efficacy of standard treatments, building institutional capacity, and strengthening surveillance were undertaken to complement the broad health system strengthening activities. These efforts led to the adoption and scale-up of malaria rapid diagnostic tests as a diagnostic modality. In addition, drug-resistant monitoring has been established in the country, along with the development of molecular testing capacity for the Plasmodium falciparum parasite at the National Public Health Laboratory. The development and piloting of surveillance activities to include an enhanced community-based approach for testing and treatment of patients has increased the ability of the Ministry of Health to map foci of transmission and respond promptly to outbreaks. The reinforcement of evidence-based approaches coupled with strong collaboration among the Ministry of Health and partners has demonstrated that malaria elimination by 2020 is a realistic prospect.

Effectiveness of insecticide-treated bednets in malaria prevention in Haiti: a case-control study.

BACKGROUND: Insecticide-treated bednets (ITNs) are effective in preventing malaria where vectors primarily bite indoors and late at night, but their effectiveness is uncertain where vectors bite outdoors and earlier in the evening. We studied the effectiveness of ITNs following a mass distribution in Haiti from May to September, 2012, where the Anopheles albimanus vector bites primarily outdoors and often when people are awake. METHODS: In this case-control study, we enrolled febrile patients presenting to outpatient departments at 17 health facilities throughout Haiti from Sept 4, 2012, to Feb 27, 2014, who were tested with malaria rapid diagnostic tests (RDTs), and administered questionnaires on ITN use and other risk factors. Cases were defined by positive RDT and controls were febrile patients from the same clinic with a negative RDT. Our primary analysis retrospectively matched cases and controls by age, sex, location, and date, and used conditional logistic regression on the matched sample. A sensitivity analysis used propensity scores to match patients on ITN use propensity and analyse malaria among ITN users and non-users. Additional ITN bioefficacy and entomological data were collected. FINDINGS: We enrolled 9317 patients, including 378 (4%) RDT-positive cases. 1202 (13%) patients reported ITN use. Post-hoc matching of cases and controls yielded 362 cases and 1201 matched controls, 19% (333) of whom reported consistent campaign net use. After using propensity scores to match on consistent campaign ITN use, 2298 patients, including 138 (7%) RDT-positive cases, were included: 1149 consistent campaign ITN users and 1149 non-consistent campaign ITN users. Both analyses revealed that ITNs did not significantly protect against clinical malaria (odds ratio [OR]=0·95, 95% CI 0·68-1·32, p=0·745 for case-control analysis; OR=0·95, 95% CI 0·45-1·97, p=0·884 for propensity score analysis). ITN and entomological data indicated good ITN physical integrity and bioefficacy, and no permethrin resistance among local mosquitoes. INTERPRETATION: We found no evidence that mass ITN campaigns reduce clinical malaria in this observational study in Haiti; alternative malaria control strategies should be prioritised. FUNDING: The Global Fund to Fight AIDS, Tuberculosis, and Malaria, and the US-based Centers for Disease Control and Prevention (CDC).

Malaria survey in post-earthquake Haiti--2010.

Haiti's Ministry of Public Health and Population collaborated with global partners to enhance malaria surveillance in two disaster-affected areas within 3 months of the January 2010 earthquake. Data were collected between March 4 and April 9, 2010 by mobile medical teams. Malaria rapid diagnostic tests (RDTs) were used for case confirmation. A convenience sample of 1,629 consecutive suspected malaria patients was included. Of these patients, 1,564 (96%) patients had malaria RDTs performed, and 317 (20.3%) patients were positive. Of the 317 case-patients with a positive RDT, 278 (87.7%) received chloroquine, 8 (2.5%) received quinine, and 31 (9.8%) had no antimalarial treatment recorded. Our experience shows that mobile medical teams trained in the use of malaria RDTs had a high rate of testing suspected malaria cases and that the majority of patients with positive RDTs received appropriate antimalarial treatment. Malaria RDTs were useful in the post-disaster setting where logistical and technical constraints limited the use of microscopy.

Applied genomics: data mining reveals species-specific malaria diagnostic targets more sensitive than 18S rRNA.

Accurate and rapid diagnosis of malaria infections is crucial for implementing species-appropriate treatment and saving lives. Molecular diagnostic tools are the most accurate and sensitive method of detecting Plasmodium, differentiating between Plasmodium species, and detecting subclinical infections. Despite available whole-genome sequence data for Plasmodium falciparum and P. vivax, the majority of PCR-based methods still rely on the 18S rRNA gene targets. Historically, this gene has served as the best target for diagnostic assays. However, it is limited in its ability to detect mixed infections in multiplex assay platforms without the use of nested PCR. New diagnostic targets are needed. Ideal targets will be species specific, highly sensitive, and amenable to both single-step and multiplex PCRs. We have mined the genomes of P. falciparum and P. vivax to identify species-specific, repetitive sequences that serve as new PCR targets for the detection of malaria. We show that these targets (Pvr47 and Pfr364) exist in 14 to 41 copies and are more sensitive than 18S rRNA when utilized in a single-step PCR. Parasites are routinely detected at levels of 1 to 10 parasites/µl. The reaction can be multiplexed to detect both species in a single reaction. We have examined 7 P. falciparum strains and 91 P. falciparum clinical isolates from Tanzania and 10 P. vivax strains and 96 P. vivax clinical isolates from Venezuela, and we have verified a sensitivity and specificity of ∼100% for both targets compared with a nested 18S rRNA approach. We show that bioinformatics approaches can be successfully applied to identify novel diagnostic targets and improve molecular methods for pathogen detection. These novel targets provide a powerful alternative molecular diagnostic method for the detection of P. falciparum and P. vivax in conventional or multiplex PCR platforms.

Prevalence of malaria parasitemia and accuracy of microscopic diagnosis in Haiti October 1995

In October 1995 the Ministry of Public Health and Population in Haiti surveyed 42 health facilities for the prevalence and distribution of malaria infection. They examined 1,803 peripheral blood smears from patients with suspected malaria; the overall slide positivity rate was 4.0 percent (range, 0.0 percent to 14.3 percent). The rate was lowest among 1-to 4-year-old children (1.6 percent) and highest among persons aged 15 and older (5.5 percent). Clinical and microscopic diagnoses of malaria were unreliable; the overall sensitivity of microscopic diagnosis was 83.6 percent, specificity was 88.6 percent, and the predictive value of a positive slide was 22.2 percent. Microscopic diagnoses need to be improved, and edequate surveillance must be reestablished to identify areas where transmission is most intense. The generally low level of malaria is encouraging and suggests that intensified control efforts (AU)