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1.
Malar J ; 23(1): 226, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-39090589

ABSTRACT

BACKGROUND: Malaria community case management (CCM) can improve timely access to healthcare, and CCM programmes in sub-Saharan Africa are expanding from serving children under 5 years (CU5) only to all ages. This report characterizes malaria case management in the setting of an age-expanded CCM programme in Chadiza District, Zambia. METHODS: Thirty-three households in each of 73 eligible communities were randomly selected to participate in a household survey preceding a trial of proactive CCM (NCT04839900). All household members were asked about fever in the prior two weeks and received a malaria rapid diagnostic test (RDT); those reporting fever were asked about healthcare received. Weighted population estimates were calculated and mixed effects regression was used to assess factors associated with malaria care seeking. RESULTS: Among 11,030 (98.6%) participants with RDT results (2,357 households), parasite prevalence was 19.1% by RDT; school-aged children (SAC, 5-14 years) had the highest prevalence (28.8%). Prior fever was reported by 12.4% of CU5, 7.5% of SAC, and 7.2% of individuals ≥ 15 years. Among those with prior fever, 34.0% of CU5, 56.0% of SAC, and 22.6% of individuals ≥ 15 years had a positive survey RDT and 73.7% of CU5, 66.5% of SAC, and 56.3% of individuals ≥ 15 years reported seeking treatment; 76.7% across all ages visited a CHW as part of care. Nearly 90% (87.8%) of people who visited a CHW reported a blood test compared with 73.5% seen only at a health facility and/or pharmacy (p < 0.001). Reported malaria treatment was similar by provider, and 85.9% of those with a reported positive malaria test reported getting malaria treatment; 66.9% of the subset with prior fever and a positive survey RDT reported malaria treatment. Age under 5 years, monthly or more frequent CHW home visits, and greater wealth were associated with increased odds of receiving healthcare. CONCLUSIONS: Chadiza District had high CHW coverage among individuals who sought care for fever. Further interventions are needed to increase the proportion of febrile individuals who receive healthcare. Strategies to decrease barriers to healthcare, such as CHW home visits, particularly targeting those of all ages in lower wealth strata, could maximize the benefits of CHW programmes.


Subject(s)
Case Management , Malaria, Falciparum , Zambia/epidemiology , Humans , Child, Preschool , Adolescent , Child , Male , Infant , Female , Case Management/statistics & numerical data , Malaria, Falciparum/epidemiology , Adult , Young Adult , Middle Aged , Infant, Newborn , Aged , Prevalence , Quality of Health Care/statistics & numerical data , Diagnostic Tests, Routine/statistics & numerical data
2.
Article in English | MEDLINE | ID: mdl-39012294

ABSTRACT

A 69-year-old male presented with a superior palpebral conjunctival white leukoplakic lesion. Excisional biopsy showed Langerhans cell histiocytosis. Positron emission tomography scanning revealed no lesions beyond this site. Native Langerhans cells are known to exist in the conjunctiva, yet only a few cases in the literature have described Langerhans cell histiocytosis of the conjunctiva, mostly in children. Conjunctival Langerhans cell histiocytosis has rarely been reported in an adult as leukoplakia. The authors advocate excisional biopsy for palpebral conjunctival Langerhans cell histiocytosis in older patients if the morbidity of closure is minimal, in addition to surveillance for multifocal disease.

3.
Nat Med ; 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38965434

ABSTRACT

Malaria-elimination interventions aim to extinguish hotspots and prevent transmission to nearby areas. Here, we re-analyzed a cluster-randomized trial of reactive, focal interventions (chemoprevention using artemether-lumefantrine and/or indoor residual spraying with pirimiphos-methyl) delivered within 500 m of confirmed malaria index cases in Namibia to measure direct effects (among intervention recipients within 500 m) and spillover effects (among non-intervention recipients within 3 km) on incidence, prevalence and seroprevalence. There was no or weak evidence of direct effects, but the sample size of intervention recipients was small, limiting statistical power. There was the strongest evidence of spillover effects of combined chemoprevention and indoor residual spraying. Among non-recipients within 1 km of index cases, the combined intervention reduced malaria incidence by 43% (95% confidence interval, 20-59%). In analyses among non-recipients within 3 km of interventions, the combined intervention reduced infection prevalence by 79% (6-95%) and seroprevalence, which captures recent infections and has higher statistical power, by 34% (20-45%). Accounting for spillover effects increased the cost-effectiveness of the combined intervention by 42%. Targeting hotspots with combined chemoprevention and vector-control interventions can indirectly benefit non-recipients up to 3 km away.

4.
Parasit Vectors ; 17(1): 306, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39014474

ABSTRACT

BACKGROUND: The protective effectiveness of vector control in malaria relies on how the implemented tools overlap with mosquito species-specific compositions and bionomic traits. In Ethiopia, targeted entomological data enabling strategic decision-making are lacking around high-risk migrant worker camps in the lowlands and resident communities in the highlands-resulting in suboptimal malaria control strategies for both populations. This study investigates spatial and temporal mosquito behavior, generating baseline evidence that will improve malaria control for both migrant workers in the lowlands and their home communities in the highlands. METHODS: Hourly Centers for Disease Control and Prevention (CDC) light trap collections were performed indoors and outdoors during the peak (October to December 2022) and minor (March to May 2023) malaria transmission seasons. These seasons coincide with the post-long rain and post-short rain seasons, respectively. Eight resident households were sampled from each of four villages in the highlands and eight households/farm structures on and near farms in four villages in the lowlands. The sampling occurred between 18:00 and 06:00. Spatiotemporal vector behaviors and hourly indoor and outdoor mosquito capture rates, used as a proxy for human biting rates, were calculated for overall catches and for individual species. Adult mosquitoes were identified using morphological keys, and a subset of samples were confirmed to species by sequencing ribosomal DNA internal transcribed spacer region 2 (ITS2) and/or mitochondrial DNA cytochrome c oxidase subunit 1 (Cox1). RESULTS: In the highlands, 4697 Anopheles mosquitoes belonging to 13 morphologically identified species were collected. The predominant species of Anopheles identified in the highlands was An. gambiae sensu lato (s.l.) (n = 1970, 41.9%), followed by An. demeilloni (n = 1133, 24.1%) and An. cinereus (n = 520, 11.0%). In the lowland villages, 3220 mosquitoes belonging to 18 morphological species were collected. Anopheles gambiae s.l. (n = 1190, 36.9%), An. pretoriensis (n = 899, 27.9%), and An. demeilloni (n = 564, 17.5%) were the predominant species. A total of 20 species were identified molecularly, of which three could not be identified to species through comparison with published sequences. In highland villages, the indoor Anopheles mosquito capture rate was much greater than the outdoor rate. This trend reversed in the lowlands, where the rate of outdoor captures was greater than the indoor rate. In both highlands and lowlands, Anopheles mosquitoes showed early biting activities in the evening, which peaked between 18:00 and 21:00, for both indoor and outdoor locations. CONCLUSIONS: The high diversity of Anopheles vectors and their variable behaviors result in a dynamic and resilient transmission system impacting both exposure to infectious bites and intervention effectiveness. This creates gaps in protection allowing malaria transmission to persist. To achieve optimal control, one-size-fits-all strategies must be abandoned, and interventions should be tailored to the diverse spatiotemporal behaviors of different mosquito populations.


Subject(s)
Anopheles , Malaria , Mosquito Vectors , Seasons , Animals , Anopheles/classification , Anopheles/physiology , Anopheles/genetics , Ethiopia , Mosquito Vectors/classification , Mosquito Vectors/physiology , Mosquito Vectors/genetics , Humans , Malaria/transmission , Malaria/prevention & control , Female , Mosquito Control/methods
5.
medRxiv ; 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39072042

ABSTRACT

Background: In Africa, the scale-up of malaria control interventions, including seasonal malaria chemoprevention (SMC), has dramatically reduced malaria burden, but progress toward malaria elimination has stalled. We evaluated mass drug administration (MDA) as a strategy to accelerate reductions in malaria incidence in Senegal. Methods: We conducted an open-label, cluster-randomised controlled trial in a low-to-moderate transmission setting of Tambacounda, Senegal. Eligible villages had a population size between 200-800. All villages received pyrethroid-piperonyl butoxide bednets and proactive community case management of malaria at baseline. Sixty villages were randomised 1:1 to either three cycles of MDA with dihydroartemisinin-piperaquine+single-low dose primaquine administered to individuals aged ≥3 months, six-weeks apart starting the third week of June (intervention), or standard-of-care, which included three monthly cycles of SMC with sulfadoxine-pyrimethamine+amodiaquine administered to children aged 3-120 months starting end of July (control). MDA and SMC were delivered door-to-door. The primary outcome was clinical malaria incidence in all ages assessed during the peak transmission season (July-December), the year after intervention. Here, we report safety, coverage, and impact outcomes during the intervention year. The trial is registered at ClinicalTrials.Gov (NCT04864444). Findings: Between June 21, 2021 and October 3, 2021, 6505, 7125, and 7250 participants were administered MDA and 3202, 3174, and 3146 participants were administered SMC across cycles. Coverage of ≥1 dose of MDA drugs was 79%, 82%, and 83% across cycles. During the transmission season of the intervention year, MDA was associated with a 55% [95% CI: 28%-72%] lower incidence of malaria compared to control (MDA: 93 cases/1000 population; control: 173 cases/1000 population). No serious adverse events were reported in either arm. Interpretation: In low-to-moderate malaria transmission settings with scaled-up malaria control interventions, MDA with dihydroartemisinin-piperaquine+single-low dose primaquine is effective and well-tolerated for reducing malaria incidence. Further analyses will focus on the sustainability of this reduction. Funding: United States President's Malaria Initiative.

6.
PLoS Negl Trop Dis ; 18(5): e0012157, 2024 May.
Article in English | MEDLINE | ID: mdl-38739632

ABSTRACT

BACKGROUND: A number of studies have detected relationships between weather and diarrhea. Few have investigated associations with specific enteric pathogens. Understanding pathogen-specific relationships with weather is crucial to inform public health in low-resource settings that are especially vulnerable to climate change. OBJECTIVES: Our objectives were to identify weather and environmental risk factors associated with diarrhea and enteropathogen prevalence in young children in rural Bangladesh, a population with high diarrheal disease burden and vulnerability to weather shifts under climate change. METHODS: We matched temperature, precipitation, surface water, and humidity data to observational longitudinal data from a cluster-randomized trial that measured diarrhea and enteropathogen prevalence in children 6 months-5.5 years from 2012-2016. We fit generalized additive mixed models with cubic regression splines and restricted maximum likelihood estimation for smoothing parameters. RESULTS: Comparing weeks with 30°C versus 15°C average temperature, prevalence was 3.5% higher for diarrhea, 7.3% higher for Shiga toxin-producing Escherichia coli (STEC), 17.3% higher for enterotoxigenic E. coli (ETEC), and 8.0% higher for Cryptosporidium. Above-median weekly precipitation (median: 13mm; range: 0-396mm) was associated with 29% higher diarrhea (adjusted prevalence ratio 1.29, 95% CI 1.07, 1.55); higher Cryptosporidium, ETEC, STEC, Shigella, Campylobacter, Aeromonas, and adenovirus 40/41; and lower Giardia, sapovirus, and norovirus prevalence. Other associations were weak or null. DISCUSSION: Higher temperatures and precipitation were associated with higher prevalence of diarrhea and multiple enteropathogens; higher precipitation was associated with lower prevalence of some enteric viruses. Our findings emphasize the heterogeneity of the relationships between hydrometeorological variables and specific enteropathogens, which can be masked when looking at composite measures like all-cause diarrhea. Our results suggest that preventive interventions targeted to reduce enteropathogens just before and during the rainy season may more effectively reduce child diarrhea and enteric pathogen carriage in rural Bangladesh and in settings with similar meteorological characteristics, infrastructure, and enteropathogen transmission.


Subject(s)
Diarrhea , Rural Population , Humans , Bangladesh/epidemiology , Diarrhea/epidemiology , Diarrhea/microbiology , Infant , Child, Preschool , Risk Factors , Rural Population/statistics & numerical data , Prevalence , Male , Female , Weather , Enterotoxigenic Escherichia coli/isolation & purification , Cryptosporidium/isolation & purification , Temperature , Shiga-Toxigenic Escherichia coli/isolation & purification , Climate Change , Cryptosporidiosis/epidemiology
7.
Sci Rep ; 14(1): 7160, 2024 03 26.
Article in English | MEDLINE | ID: mdl-38531921

ABSTRACT

Cattle herders and agricultural workers have been identified has key high-risk populations for malaria in northern Namibia. Population size estimates for these groups are lacking but are important for planning, monitoring and evaluating the effectiveness of targeted strategies towards malaria elimination in the region. In this analysis, we extend population size estimation methods routinely used in HIV research, specifically social mapping and multiple source capture-recapture, to the context of malaria to estimate how many cattle herders and agricultural workers lived in two regions of northern Namibia over the course of the 2019-2020 malaria season. Both methods estimated two to three times more agricultural workers than cattle herders but size estimates based on the multiple source capture-recapture method were two to three times greater than the mapping-based, highlighting important methodological considerations to apply such methods to these highly mobile populations. In particular, we compared open versus closed populations assumptions for the capture-recapture method and assessed the impact of sensitivity analyses on the procedure to link records across multiple data sources on population size estimates. Our results are important for national control programs to target their resources and consider integrating routine population size estimation of high risk populations in their surveillance activities.


Subject(s)
Farmers , Malaria , Cattle , Animals , Humans , Namibia/epidemiology , Malaria/epidemiology , Risk Factors , Population Density
9.
JMIR Res Protoc ; 13: e47196, 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38416536

ABSTRACT

BACKGROUND: Mild cognitive impairment (MCI) is the stage between cognitive decline due to physiological aging and the severity of decline seen in neurodegenerative disorders like Alzheimer disease (AD), which is among the most prevalent neurodegenerative disorders characterized by cognitive impairment. People with MCI are at increased risk of developing AD. Although MCI and AD are incurable, nutritional interventions can potentially delay or prevent their onset. Consequently, effective interventions used to decelerate or alleviate the progress of cognitive impairment in older people are a significant focus in geriatric care. Given the synergistic effects of nutrition on health, assessing the effectiveness of nutritional supplements or dietary composition in preventing MCI or AD is essential for developing interventional strategies. OBJECTIVE: Our study aims to assess the effectiveness of various nutritional interventions, including special dietary types, dietary patterns, specific foods, nutritional intake, and nutritional supplements, in preventing cognitive decline among patients diagnosed with MCI or AD. To achieve this, we will use a comprehensive approach, including network meta-analysis, pairwise meta-analysis, and systematic review of randomized controlled trials (RCTs). METHODS: The review will follow the Population, Intervention, Comparison, Outcome (PICO) model and the PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols) guidelines. Two investigators will independently search PubMed electronically. Data extraction will follow the inclusion criteria, and data will be assessed for risk of bias using a revised tool. Additionally, evidence quality will be evaluated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework. The outcomes of interest are assessing the cognitive outcomes in patients with MCI or AD. A systematic literature search will be conducted, identifying randomized controlled trials that investigate the impact of these nutritional interventions on cognitive function decline in individuals with MCI and AD. Network meta-analyses (random-effects model) and pairwise meta-analyses will then estimate the relative effectiveness of different nutritional interventions. RESULTS: We included 51 studies, published between 1999 and 2023 (27 studies for AD and 24 studies for MCI) and involving 8420 participants. We completed data extraction for all 51 studies by December 2023. Currently, we are actively engaged in data analysis and manuscript preparation. We plan to finalize the manuscript and publish the comprehensive results by the end of 2024. CONCLUSIONS: Our study holds significant clinical relevance given the rising prevalence of AD and the potential influence of nutritional interventions on cognitive function in individuals with MCI and AD. By investigating this relationship, our research aims to inform evidence-based decision-making in the development of prevention strategies for MCI and AD. The outcomes are expected to contribute to the establishment of reliable recommendations for MCI or AD management, providing substantial support in the field. TRIAL REGISTRATION: PROSPERO CRD42022331173; http://tinyurl.com/3snjp7a4. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/47196.

10.
Malar J ; 23(1): 37, 2024 Jan 30.
Article in English | MEDLINE | ID: mdl-38291392

ABSTRACT

BACKGROUND: A major challenge to malaria elimination is identifying and targeting populations that are harbouring residual infections and contributing to persistent transmission. In many near-elimination settings in Southeast Asia, it is known that forest-goers are at higher risk for malaria infection, but detailed information on their behaviours and exposures is not available. METHODS: In Aceh Province, Indonesia, a near-elimination setting where a growing proportion of malaria is due to Plasmodium knowlesi, a case-control study was conducted to identify risk factors for symptomatic malaria, characteristics of forest-goers, and key intervention points. From April 2017 to September 2018, cases and controls were recruited and enrolled in a 1:3 ratio. Cases had confirmed malaria infection by rapid diagnostic test or microscopy detected at a health facility (HF). Gender-matched controls were recruited from passive case detection among individuals with suspected malaria who tested negative at a health facility (HF controls), and community-matched controls were recruited among those testing negative during active case detection. Multivariable logistic regression (unconditional for HF controls and conditional for community controls) was used to identify risk factors for symptomatic malaria infection. RESULTS: There were 45 cases, of which 27 were P. knowlesi, 17 were Plasmodium vivax, and one was not determined. For controls, 509 and 599 participants were recruited from health facilities and the community, respectively. Forest exposures were associated with high odds of malaria; in particular, working and sleeping in the forest (HF controls: adjusted odds ratio (aOR) 21.66, 95% CI 5.09-92.26; community controls: aOR 16.78, 95% CI 2.19-128.7) and having a second residence in the forest (aOR 6.29, 95% CI 2.29-17.31 and 13.53, 95% CI 2.10-87.12). Male forest-goers were a diverse population employed in a variety of occupations including logging, farming, and mining, sleeping in settings, such as huts, tents, and barracks, and working in a wide range of group sizes. Reported use of protective measures, such as nets, hammock nets, mosquito coils, and repellents was low among forest-goers and interventions at forest residences were absent. CONCLUSIONS: Second residences in the forest and gaps in use of protective measures point to key malaria interventions to improve coverage in forest-going populations at risk for P. knowlesi and P. vivax in Aceh, Indonesia. Intensified strategies tailored to specific sub-populations will be essential to achieve elimination.


Subject(s)
Malaria, Vivax , Malaria , Male , Humans , Indonesia/epidemiology , Case-Control Studies , Malaria/prevention & control , Malaria, Vivax/epidemiology , Malaria, Vivax/prevention & control , Forests
11.
Malar. j. (Online) ; 22(318): 1-11, out 20, 2023. mapas, tab
Article in English | AIM (Africa), RSDM | ID: biblio-1531694

ABSTRACT

Background The importation of parasites across borders remains a threat to malaria elimination. The Southern African Development Community Malaria Elimination Eight (E8) established 39 border health facilities on 5 key international borders between high and low-burden countries. These clinics aimed to improve access to prevention, diagnosis, and treatment of malaria for residents in border areas and for mobile and migrant populations who frequently cross borders. Studies were conducted in each of the four high-burden E8 countries (Angola, Mozambique, Zambia, and Zimbabwe) to evaluate malaria services in border areas. Methods Cross-sectional surveys were conducted within 30 km of recently established E8 Border Health Posts. Structured questionnaires were administered to randomly selected respondents to assess malaria-related knowledge and behavior, access to malaria prevention, diagnosis and treatment of malaria, and risk factors for malaria associated with local and cross-border travel. Results Results showed that most providers followed appropriate guidelines performing blood tests when individuals presented with fever, and that nearly all those who reported a positive blood test received medication. Lack of access to health care due to distance, cost or mistrust of the provider was rare. A minority of respondents reported not receiving timely diagnosis either because they did not seek help, or because they were not ofered a blood test when presenting with fever. There was a high level of correct knowledge of causes, symptoms, and prevention of malaria. A majority, of border residents had access to primary prevention against malaria through either long-lasting insecticidal nets (LLINs) or indoor residual spraying (IRS). Cross border travel was common with travellers reporting sleeping outside without protection against malaria. Conclusions The study demonstrated the importance of border health facilities in providing access to malaria services. Prevention needs to be improved for people who travel and sleep outdoors. Community health workers can play a key role in providing access to information, testing and treating malaria.


Subject(s)
Humans , Male , Female , Border Health , Malaria/prevention & control , South Africa/epidemiology , Solid Waste Grinding , Cross-Sectional Studies , Surveys and Questionnaires , Risk Factors , Malaria/diagnosis , Malaria/drug therapy , Mozambique/epidemiology
12.
Malar J ; 22(1): 365, 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-38037072

ABSTRACT

BACKGROUND: In 2020, the Zambia National Malaria Elimination Centre targeted the distribution of long-lasting insecticidal nets (LLINs) and indoor-residual spraying (IRS) campaigns based on sub-district micro-planning, where specified geographical areas at the health facility catchment level were assigned to receive either LLINs or IRS. Using data from the 2021 Malaria Indicator Survey (MIS), the objectives of this analysis were to (1) assess how well the micro-planning was followed in distributing LLINs and IRS, (2) investigate factors that contributed to whether households received what was planned, and (3) investigate how overall coverage observed in the 2021 MIS compared to the 2018 MIS conducted prior to micro-planning. METHODS: Households' receipt of ≥ 1 LLIN, and/or IRS within the past 12 months in the 2021 MIS, was compared against the micro-planning area under which the households fell. GPS points for 3,550 households were overlayed onto digitized micro-planning maps in order to determine what micro-plan the households fell under, and thus whether they received their planned intervention. Mixed-effects regression models were conducted to investigate what factors affected whether these households: (1) received their planned intervention, and (2) received any intervention. Finally, coverage indicators between the 2021 and 2018 MIS were compared. RESULTS: Overall, 60.0% (95%CI 55.4, 64.4) of households under a micro-plan received their assigned intervention, with significantly higher coverage of the planned intervention in LLIN-assigned areas (75.7% [95%CI 69.5, 80.9]) compared to IRS-assigned areas (49.4% [95%CI: 44.4, 54.4]). Regression analysis indicated that households falling under the IRS micro-plan had significantly reduced odds of receiving their planned intervention (OR: 0.34 [95%CI 0.24, 0.48]), and significantly reduced odds of receiving any intervention (OR: 0.51 [95%CI 0.37, 0.72] ), compared to households under the LLIN micro-plan. Comparison between the 2021 and 2018 MIS indicated a 27% reduction in LLIN coverage nationally in 2021, while IRS coverage was similar. Additionally, between 2018 and 2021, there was a 13% increase in households that received neither intervention. CONCLUSIONS: This analysis shows that although the micro-planning strategy adopted in 2020 worked much better for LLIN-assigned areas compared to IRS-assigned areas, there was reduced overall vector control coverage in 2021 compared to 2018 before micro-planning.


Subject(s)
Insecticide-Treated Bednets , Insecticides , Malaria , Humans , Mosquito Control , Zambia/epidemiology , Malaria/prevention & control
13.
medRxiv ; 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-37790419

ABSTRACT

Malaria elimination interventions in low-transmission settings aim to extinguish hot spots and prevent transmission to nearby areas. In malaria elimination settings, the World Health Organization recommends reactive, focal interventions targeted to the area near malaria cases shortly after they are detected. A key question is whether these interventions reduce transmission to nearby uninfected or asymptomatic individuals who did not receive interventions. Here, we measured direct effects (among intervention recipients) and spillover effects (among non-recipients) of reactive, focal interventions delivered within 500m of confirmed malaria index cases in a cluster-randomized trial in Namibia. The trial delivered malaria chemoprevention (artemether lumefantrine) and vector control (indoor residual spraying with Actellic) separately and in combination using a factorial design. We compared incidence, infection prevalence, and seroprevalence between study arms among intervention recipients (direct effects) and non-recipients (spillover effects) up to 3 km away from index cases. We calculated incremental cost-effectiveness ratios accounting for spillover effects. The combined chemoprevention and vector control intervention produced direct effects and spillover effects. In the primary analysis among non-recipients within 1 km from index cases, the combined intervention reduced malaria incidence by 43% (95% CI 20%, 59%). In secondary analyses among non-recipients 500m-3 km from interventions, the combined intervention reduced infection by 79% (6%, 95%) and seroprevalence 34% (20%, 45%). Accounting for spillover effects increased the cost-effectiveness of the combined intervention by 37%. Our findings provide the first evidence that targeting hot spots with combined chemoprevention and vector control interventions can indirectly benefit non-recipients up to 3 km away.

14.
Malar J ; 22(1): 318, 2023 Oct 20.
Article in English | MEDLINE | ID: mdl-37864245

ABSTRACT

BACKGROUND: The importation of parasites across borders remains a threat to malaria elimination. The Southern African Development Community Malaria Elimination Eight (E8) established 39 border health facilities on 5 key international borders between high and low-burden countries. These clinics aimed to improve access to prevention, diagnosis, and treatment of malaria for residents in border areas and for mobile and migrant populations who frequently cross borders. Studies were conducted in each of the four high-burden E8 countries (Angola, Mozambique, Zambia, and Zimbabwe) to evaluate malaria services in border areas. METHODS: Cross-sectional surveys were conducted within 30 km of recently established E8 Border Health Posts. Structured questionnaires were administered to randomly selected respondents to assess malaria-related knowledge and behavior, access to malaria prevention, diagnosis and treatment of malaria, and risk factors for malaria associated with local and cross-border travel. RESULTS: Results showed that most providers followed appropriate guidelines performing blood tests when individuals presented with fever, and that nearly all those who reported a positive blood test received medication. Lack of access to health care due to distance, cost or mistrust of the provider was rare. A minority of respondents reported not receiving timely diagnosis either because they did not seek help, or because they were not offered a blood test when presenting with fever. There was a high level of correct knowledge of causes, symptoms, and prevention of malaria. A majority, of border residents had access to primary prevention against malaria through either long-lasting insecticidal nets (LLINs) or indoor residual spraying (IRS). Cross border travel was common with travellers reporting sleeping outside without protection against malaria. CONCLUSIONS: The study demonstrated the importance of border health facilities in providing access to malaria services. Prevention needs to be improved for people who travel and sleep outdoors. Community health workers can play a key role in providing access to information, testing and treating malaria.


Subject(s)
Malaria , Humans , Cross-Sectional Studies , Malaria/prevention & control , Risk Factors , Africa, Southern , Surveys and Questionnaires
15.
Malar J ; 22(1): 254, 2023 Sep 03.
Article in English | MEDLINE | ID: mdl-37661286

ABSTRACT

BACKGROUND: Global interest in malaria elimination has prompted research on active test and treat (TaT) strategies. METHODS: A systematic review and meta-analysis were conducted to assess the effectiveness of TaT strategies to reduce malaria transmission. RESULTS: A total of 72 empirical research and 24 modelling studies were identified, mainly focused on proactive mass TaT (MTaT) and reactive case detection (RACD) in higher and lower transmission settings, respectively. Ten intervention studies compared MTaT to no MTaT and the evidence for impact on malaria incidence was weak. No intervention studies compared RACD to no RACD. Compared to passive case detection (PCD) alone, PCD + RACD using standard diagnostics increased infection detection 52.7% and 11.3% in low and very low transmission settings, respectively. Using molecular methods increased this detection of infections by 1.4- and 1.1-fold, respectively. CONCLUSION: Results suggest MTaT is not effective for reducing transmission. By increasing case detection, surveillance data provided by RACD may indirectly reduce transmission by informing coordinated responses of intervention targeting.


Subject(s)
Malaria , Humans , Malaria/diagnosis , Malaria/drug therapy , Malaria/prevention & control
16.
BMC Public Health ; 23(1): 1346, 2023 07 13.
Article in English | MEDLINE | ID: mdl-37438774

ABSTRACT

BACKGROUND: Reactive case detection (RACD) or testing and treatment of close contacts of recent malaria cases, is commonly practiced in settings approaching malaria elimination, but standard diagnostics have limited sensitivity to detect low level infections. Reactive drug administration (RDA), or presumptive treatment without testing, is an alternative approach, but better understanding regarding community acceptability and operational feasibility are needed. METHODS: A qualitative study was conducted as part of a two-arm cluster randomized-controlled trial evaluating the effectiveness of RDA targeting high-risk villages and forest workers for reducing Plasmodium vivax and P. falciparum malaria in Thailand. Key informant interviews (KIIs) and focus group discussions (FGDs) were conducted virtually among key public health staff, village health volunteers (VHVs), and household members that implemented or received RDA activities. Transcriptions were reviewed, coded, and managed manually using Dedoose qualitative data analysis software, then underwent qualitative content analysis to identify key themes. RESULTS: RDA was well accepted by household members and public health staff that implemented it. RDA participation was driven by fear of contracting malaria, eagerness to receive protection provided by malaria medicines, and the increased access to health care. Concerns were raised about the safety of taking malaria medicines without having an illness, particularly if underlying health conditions existed. Health promotion hospital (HPH) staff implementing RDA noted its operational feasibility, but highlighted difficulty in traveling to remote areas, and requested additional travel resources and hiring more VHVs. Other challenges were highlighted including the need for additional training for VHVs on malaria activities and the inability of HPH staff to conduct RDA due to other health priorities (e.g., Covid-19). More training and practice for VHVs were noted as ways to improve implementation of RDA. CONCLUSIONS: To maximize uptake of RDA, regular education and sensitization campaigns in collaboration with village leaders on the purpose and rationale of RDA will be critical. To alleviate safety concerns and increase participant safety, a rigorous pharmacovigilance program will be important. To accelerate uptake of RDA, trust between HPH staff and VHVs and the communities they serve must continue to be strengthened to ensure acceptance of the intervention. TRIAL REGISTRATION: This study was approved by the Committee on Human Research at the University of California San Francisco (19-28,060) and the local Ethics Committee for Research in Human Subjects at Tak Provincial Health office (009/63) and Kanchanaburi Provincial health office (Kor Chor 0032.002/2185). Local authorities and health officers in the provinces, districts, and villages agreed upon and coordinated the implementation of the study. All methods in this study were carried out in accordance with relevant guidelines and regulations.


Subject(s)
COVID-19 , Malaria, Falciparum , Malaria , Humans , Plasmodium vivax , Thailand , Feasibility Studies , Malaria/drug therapy , Malaria/prevention & control
18.
Pharmacogenomics J ; 23(4): 95-104, 2023 07.
Article in English | MEDLINE | ID: mdl-36966195

ABSTRACT

Previous observational studies reported associations between non-steroidal anti-inflammatory drugs (NSAIDs) and major depressive disorder (MDD), however, these associations are often inconsistent and underlying biological mechanisms are still poorly understood. We conducted a two-sample Mendelian randomisation (MR) study to examine relationships between genetic variants and NSAID target gene expression or DNA methylation (DNAm) using publicly available expression, methylation quantitative trait loci (eQTL or mQTL) data and genetic variant-disease associations from genome-wide association studies (GWAS of MDD). We also assessed drug exposure using gene expression and DNAm levels of NSAID targets as proxies. Genetic variants were robustly adjusted for multiple comparisons related to gene expression, DNAm was used as MR instrumental variables and GWAS statistics of MDD as the outcome. A 1-standard deviation (SD) lower expression of NEU1 in blood was related to lower C-reactive protein (CRP) levels of -0.215 mg/L (95% confidence interval (CI): 0.128-0.426) and a decreased risk of MDD (odds ratio [OR] = 0.806; 95% CI: 0.735-0.885; p = 5.36 × 10-6). A concordant direction of association was also observed for NEU1 DNAm levels in blood and a risk of MDD (OR = 0.886; 95% CI: 0.836-0.939; p = 4.71 × 10-5). Further, the genetic variants associated with MDD were mediated by NEU1 expression via DNAm (ß = -0.519; 95% CI: -0.717 to -0.320256; p = 3.16 × 10-7). We did not observe causal relationships between inflammatory genetic marker estimations and MDD risk. Yet, we identified a concordant association of NEU1 messenger RNA and an adverse direction of association of higher NEU1 DNAm with MDD risk. These results warrant increased pharmacovigilance and further in vivo or in vitro studies to investigate NEU1 inhibitors or supplements for MDD.


Subject(s)
Depressive Disorder, Major , Humans , Depressive Disorder, Major/drug therapy , Depressive Disorder, Major/genetics , Genome-Wide Association Study/methods , Quantitative Trait Loci/genetics , DNA Methylation/genetics , Anti-Inflammatory Agents
19.
Malar J ; 22(1): 96, 2023 Mar 17.
Article in English | MEDLINE | ID: mdl-36927440

ABSTRACT

BACKGROUND: Community case management of malaria (CCM) has been expanded in many settings, but there are limited data describing the impact of these services in routine implementation settings or at large scale. Zambia has intensively expanded CCM since 2013, whereby trained volunteer community health workers (CHW) use rapid diagnostic tests and artemether-lumefantrine to diagnose and treat uncomplicated malaria. METHODS: This retrospective, observational study explored associations between changing malaria service point (health facility or CHW) density per 1000 people and severe malaria admissions or malaria inpatient deaths by district and month in a dose-response approach, using existing routine and programmatic data. Negative binomial generalized linear mixed-effect models were used to assess the impact of increasing one additional malaria service point per 1000 population, and of achieving Zambia's interim target of 1 service point per 750 population. Access to insecticide-treated nets, indoor-residual spraying, and rainfall anomaly were included in models to reduce potential confounding. RESULTS: The study captured 310,855 malaria admissions and 7158 inpatient malaria deaths over 83 districts (seven provinces) from January 2015 to May 2020. Total CHWs increased from 43 to 4503 during the study period, while health facilities increased from 1263 to 1765. After accounting for covariates, an increase of one malaria service point per 1000 was associated with a 19% reduction in severe malaria admissions among children under five (incidence rate ratio [IRR] 0.81, 95% confidence interval [CI] 0.75-0.87, p < 0.001) and 23% reduction in malaria deaths among under-fives (IRR 0.77, 95% CI 0.66-0.91). After categorizing the exposure of population per malaria service point, there was evidence for an effect on malaria admissions and inpatient malaria deaths among children under five only when reaching the target of one malaria service point per 750 population. CONCLUSIONS: CCM is an effective strategy for preventing severe malaria and deaths in areas such as Zambia where malaria diagnosis and treatment access remains challenging. These results support the continued investment in CCM scale-up in similar settings, to improve access to malaria diagnosis and treatment.


Subject(s)
Antimalarials , Health Information Systems , Malaria , Child , Humans , Antimalarials/therapeutic use , Zambia/epidemiology , Case Management , Retrospective Studies , Inpatients , Artemether/therapeutic use , Artemether, Lumefantrine Drug Combination/therapeutic use , Malaria/drug therapy , Malaria/prevention & control , Malaria/epidemiology , Community Health Workers
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