Programmatic options for monitoring malaria in elimination settings: easy access group surveys to investigate Plasmodium falciparum epidemiology in two regions with differing endemicity in Haiti.

BACKGROUND: As in most eliminating countries, malaria transmission is highly focal in Haiti. More granular information, including identifying asymptomatic infections, is needed to inform programmatic efforts, monitor intervention effectiveness, and identify remaining foci. Easy access group (EAG) surveys can supplement routine surveillance with more granular information on malaria in a programmatically tractable way. This study assessed how and which type of venue for EAG surveys can improve understanding malaria epidemiology in two regions with different transmission profiles. METHODS: EAG surveys were conducted within the departments of Artibonite and Grand'Anse (Haiti), in regions with different levels of transmission intensity. Surveys were conducted in three venue types: primary schools, health facilities, and churches. The sampling approach varied accordingly. Individuals present at the venues at the time of the survey were eligible whether they presented malaria symptoms or not. The participants completed a questionnaire and were tested for Plasmodium falciparum by a highly sensitive rapid diagnostic test (hsRDT). Factors associated with hsRDT positivity were assessed by negative binomial random-effects regression models. RESULTS: Overall, 11,029 individuals were sampled across 39 venues in Artibonite and 41 in Grand'Anse. The targeted sample size per venue type (2100 in Artibonite and 2500 in Grand'Anse) was reached except for the churches in Artibonite, where some attendees left the venue before they could be approached or enrolled. Refusal rate and drop-out rate were < 1%. In total, 50/6003 (0.8%) and 355/5026 (7.1%) sampled individuals were hsRDT positive in Artibonite and Grand'Anse, respectively. Over half of all infections in both regions were identified at health facilities. Being male and having a current or reported fever in the previous 2 weeks were consistently identified with increased odds of being hsRDT positive. CONCLUSIONS: Surveys in churches were problematic because of logistical and recruitment issues. However, EAG surveys in health facilities and primary schools provided granular information about malaria burden within two departments in Haiti. The EAG surveys were able to identify residual foci of transmission that were missed by recent national surveys. Non-care seeking and/or asymptomatic malaria infections can be identified in this alternative surveillance tool, facilitating data-driven decision-making for improved targeting of interventions

Association between the proportion of Plasmodium falciparum and Plasmodium vivax infections detected by passive surveillance and the magnitude of the asymptomatic reservoir in the community: a pooled analysis of paired health facility and community data.

BACKGROUND: Passively collected malaria case data are the foundation for public health decision making. However, because of population-level immunity, infections might not always be sufficiently symptomatic to prompt individuals to seek care. Understanding the proportion of all Plasmodium spp infections expected to be detected by the health system becomes particularly paramount in elimination settings. The aim of this study was to determine the association between the proportion of infections detected and transmission intensity for Plasmodium falciparum and Plasmodium vivax in several global endemic settings. METHODS: The proportion of infections detected in routine malaria data, P(Detect), was derived from paired household cross-sectional survey and routinely collected malaria data within health facilities. P(Detect) was estimated using a Bayesian model in 431 clusters spanning the Americas, Africa, and Asia. The association between P(Detect) and malaria prevalence was assessed using log-linear regression models. Changes in P(Detect) over time were evaluated using data from 13 timepoints over 2 years from The Gambia. FINDINGS: The median estimated P(Detect) across all clusters was 12·5% (IQR 5·3-25·0) for P falciparum and 10·1% (5·0-18·3) for P vivax and decreased as the estimated log-PCR community prevalence increased (adjusted odds ratio [OR] for P falciparum 0·63, 95% CI 0·57-0·69; adjusted OR for P vivax 0·52, 0·47-0·57). Factors associated with increasing P(Detect) included smaller catchment population size, high transmission season, improved care-seeking behaviour by infected individuals, and recent increases (within the previous year) in transmission intensity. INTERPRETATION: The proportion of all infections detected within health systems increases once transmission intensity is sufficiently low. The likely explanation for P falciparum is that reduced exposure to infection leads to lower levels of protective immunity in the population, increasing the likelihood that infected individuals will become symptomatic and seek care. These factors might also be true for P vivax but a better understanding of the transmission biology is needed to attribute likely reasons for the observed trend. In low transmission and pre-elimination settings, enhancing access to care and improvements in care-seeking behaviour of infected individuals will lead to an increased proportion of infections detected in the community and might contribute to accelerating the interruption of transmission. FUNDING: Wellcome Trust

Acceptability, Feasibility, Drug Safety, and Effectiveness of a Pilot Mass Drug Administration with a Single Round of Sulfadoxine-Pyrimethamine Plus Primaquine and Indoor Residual Spraying in Communities with Malaria Transmission in Haiti, 2018.

For a malaria elimination strategy, Haiti's National Malaria Control Program piloted a mass drug administration (MDA) with indoor residual spraying (IRS) in 12 high-transmission areas across five communes after implementing community case management and strengthened surveillance. The MDA distributed sulfadoxine-pyrimethamine and single low-dose primaquine to eligible residents during house visits. The IRS campaign applied pirimiphos-methyl insecticide on walls of eligible houses. Pre- and post-campaign cross-sectional surveys were conducted to assess acceptability, feasibility, drug safety, and effectiveness of the combined interventions. Stated acceptability for MDA before the campaign was 99.2%; MDA coverage estimated at 10 weeks post-campaign was 89.6%. Similarly, stated acceptability of IRS at baseline was 99.9%; however, household IRS coverage was 48.9% because of the high number of ineligible houses. Effectiveness measured by Plasmodium falciparum prevalence at baseline and 10 weeks post-campaign were similar: 1.31% versus 1.43%, respectively. Prevalence of serological markers were similar at 10 weeks post-campaign compared with baseline, and increased at 6 months. No severe adverse events associated with the MDA were identified in the pilot; there were severe adverse events in a separate, subsequent campaign. Both MDA and IRS are acceptable and feasible interventions in Haiti. Although a significant impact of a single round of MDA/IRS on malaria transmission was not found using a standard pre- and post-intervention comparison, it is possible there was blunting of the peak transmission. Seasonal malaria transmission patterns, suboptimal IRS coverage, and low baseline parasitemia may have limited the effectiveness or the ability to measure effectiveness

Differing Causes of Lactic Acidosis and Deep Breathing in Cerebral Malaria and Severe Malarial Anemia May Explain Differences in Acidosis-Related Mortality.

Lactic acidosis (LA) is a marker for mortality in severe malaria, but the mechanisms that lead to LA in the different types of severe malaria and the extent to which LA-associated mortality differs by type of severe malaria are not well described. We assessed the frequency of LA in children admitted to Mulago Hospital, Kampala, Uganda with cerebral malaria (CM, n = 193) or severe malarial anemia (SMA, n = 216). LA was compared to mortality and measures of parasite biomass and sequestration (P. falciparum histidine-rich protein-2 (PfHRP2) concentration, platelet count), and to a measure of systemic tissue oxygen delivery (hemoglobin level). LA was more frequent in children with SMA than CM (SMA, 47.7%, CM, 34.2%, P = 0.006), but mortality was higher in children with CM (13.0%) than SMA (0.5%, P<0.0001). In CM, LA was associated with increased PfHRP2 concentration and decreased platelet count but was not associated with hemoglobin level. In contrast, in SMA, LA was associated with a decreased hemoglobin level, but was not associated with PfHRP2 concentration or platelet count. LA was related to mortality only in CM. In multivariable regression analysis of the effect PfHRP2 and hemoglobin levels on LA and DB, only PfHRP2 level increased risk of LA and DB in CM, while in SMA, elevated hemoglobin strongly decreased risk of LA and DB, and PfHRP2 level modestly increased risk of LA. The study findings suggest that LA in CM is due primarily to parasite sequestration, which currently has no effective adjunctive therapy, while LA in SMA is due primarily to anemia, which is rapidly corrected with blood transfusion. Differing etiologies of LA in CM and SMA may explain why LA is associated with mortality in CM but not SMA

Demographic, clinical and laboratory findings children with cerebral malaria alone (CM) or severe malarial anemia alone (SMA) on admission.

<p>Demographic, clinical and laboratory findings children with cerebral malaria alone (CM) or severe malarial anemia alone (SMA) on admission.</p

Demographic, clinical and laboratory findings children with cerebral malaria (CM) who survived vs. died.

<p>Demographic, clinical and laboratory findings children with cerebral malaria (CM) who survived vs. died.</p

Study enrollment and testing for lactic acidosis.

<p>Study enrollment and testing for lactic acidosis.</p

Quality Interactions in Early Childhood Education and Care Center Outdoor Environments

Quality interactions are crucial for children\u27s learning and development. Early Childhood Education and Care (ECEC) centers have the opportunity to support children\u27s learning and development, yet the quality of interactions and influences on the quality of interactions in outdoor environments is not known. Research findings: this study assessed the quality of educator interactions in outdoor environments using the CLASS Pre-K assessment tool. 11 ECEC centres participated in the study, which included 110 educators and 490 children. 87 observations were collected to measure the CLASS Pre-K domains (1-lowest to 7-highest). Mean domain scores were 6.02 (emotional support), 5.23 (Classroom Organization) and 4.46 (Instructional Support). Regression analyses show free routines had significant relationships with Teacher Sensitivity (p = 0.03) and Instructional Learning Formats (p = 0.03), and increased amounts of time spent outside had the most significant relationships with Teacher Sensitivity (p = 0.001) and Behavior Management (p = 0.001). Practice or Policy: The major recommendations that would serve to improve the quality of interactions in outdoor environments include providing a free routine and increasing the amount of time spent in outdoor environments. As these recommendations are modifiable practices, they are potentially the easiest to alter and therefore, with minimal change, could enhance the quality of interactions between educators and children