Effect of Cricket Frass Fertilizer on growth and pod production of green beans (Phaseolus vulgaris L.).

Cricket Frass Fertilizer (CFF) was tested for its efficiency and potential as a fertilizer on the growth of green beans (Phaseolus vulgaris L.) in central Madagascar from April 2020 to October 2020. We grew green beans experimentally for 93 days with seven different fertilizer treatments: NPK 200 kg/ha (0.47 g of N/plant), GUANOMAD (guano from bat) 300 kg/ha (0.26 g of N/ plant), CFF 100 kg/ha (0.12 g of N/plant), CFF 200 kg/ha (0.24 g of N/plant), CFF 300 kg/ha (0.38 g of N/plant), CFF 400 kg/ha (0.52 g of N/plant), and no fertilizer (0 g of N/plant). Three plant traits were measured: survival proportion, vegetative biomass, and pod biomass. The survival proportion of plants treated with the highest dose of CFF (400 kg/ha, 88.1%), NPK (79.8%), and GUANOMAD (81.2%) were similar, but plants treated with the former yielded significantly higher vegetative (35.5 g/plant) and pod biomass (11 g/plant). These results suggest that fertilizing green beans with CFF at a 400 kg/ha dose is sufficient for plant survival and growth, and improves pod production. In Madagascar where soil quality is poor, dependence on imported chemical fertilizers (NPK) and other organic fertilizer (GUANOMAD) can be reduced. Cricket Frass Fertilizer can be used as an alternative sustainable fertilizer for beans.

Dog ecology and rabies control including canine vaccination coverage: Impacts from a survey in Madagascar.

BACKGROUND: Rabies virus (RABV; species Lyssavirus rabies) is causing one of the oldest zoonotic diseases known to mankind, leading to fatal encephalomyelitis in animals and humans. Despite the existence of safe and effective vaccines to prevent the disease, an estimated 99% of human rabies deaths worldwide are caused by dog-mediated rabies with children at the highest risk of infection. Rabies has been endemic in Madagascar for over a century, yet there has been little research evaluating local knowledge and practices impacting on the rabies control and prevention. Thus, this study was undertaken to better understand the dog ecology including canine vaccine coverage and to assess knowledge and practices of dog owners and veterinarians. METHODOLOGY: A cross-sectional study was conducted among 123 dog-owning households in thirteen fokontanys in Mahajanga from July 4 to September 13, 2016. Single and multi-member dog-owning households in the study area on the day of the interview were eligible for inclusion and purposively selected with the support of a local guide. The survey included a household questionnaire capturing information on the dog's demographics, husbandry practices, knowledge and practices towards rabies and its control measures; the dog ecology questionnaire collected dog characteristics, vaccination status and husbandry practices. All households that reported a dog bite incident, were invited to participate in a dog bite questionnaire. In addition, direct observations of roaming dogs were conducted to assess dog population demographics and to document behavioural characteristics. Two veterinarians were purposively selected and took part in an interview during the survey period, providing information on rabies control activities, including dog-care practices in the area. Descriptive and inferential data analyses were performed using Epi Info version 7.1.5.0 (CDC Atlanta, USA). RESULTS: We recorded a total of 400 dogs, of which 338 (84.5%) were owned amongst 123 households. More than half (67.8%) of owned dogs were between 1 to 5 years old and 95.6% were kept for guarding purposes. 45% of the surveyed dogs had free access to roam outside the premises. The majority (85.4%) of dog owners were knowledgeable that a dog bite could potentially transmit RABV to humans. 19 dog bites were reported and of these 73.6% were caused by the owner's or a neighbour's dog. In 6 of the 19 cases, children between 7 and 15 years of age were the victims. Dog vaccination coverage against rabies was 34% among owned dogs. Of the participants aware of a veterinarian, the majority (55/82) indicated that they accessed veterinarian services at irregular intervals. The main obstacles to vaccinations cited by dog owners were limited financial resources and difficulty accessing veterinary care. CONCLUSION: This study contributes to enhanced understanding of the dog ecology including canine vaccine coverage as well as knowledge and practices of dog owners in Madagascar. Most dogs in the study area were accessible for preventive vaccination through their owners, however only one third of the investigated canine population was vaccinated against rabies. Concerted national efforts towards rabies prevention and control should aim to address financial challenges and access to veterinary services.

Survival within 12months after stroke in Madagascar.

The data on the long-term prognosis of stroke are scarce in Madagascar. Our objective was to determine survival within 12months after a stroke event. A longitudinal study was carried out on a hospital cohort of subjects with stroke in Mahajanga in western Madagascar. We included in the study all subjects admitted to adult emergencies at Mahajanga University Hospitals during the year 2019 and diagnosed with stroke. A follow-up by telephone call or by descent at the home of the patients was carried out after at least 12months from the onset of the disease. We analyzed in-hospital mortality and survival within 12months after the stroke. At the end of the study period, 144 stroke cases were retained. Strokes accounted for 5.07% of emergency admission causes. Male gender accounted for 51.4% of the population. The average age of the subjects was 60.7years. In-hospital mortality was 32.6%. Survival at 1month was 50%, at 3months 48.4%, and at 12months 43%. High blood pressure was found as a risk factor for stroke in 79.9% of patients, 76.5% of whom were undertreated. Stroke mortality was high in our population. Most of the deaths occurred during the first month. Improved prevention and care are needed in Madagascar.

Effects of an intervention program to improve mental health and epilepsy care in Madagascar.

BACKGROUND: Despite the high prevalence of mental disorders and epilepsy in low- and middle-income countries, nearly 80% of patients are not treated. In Madagascar, initiatives to improve access to epilepsy and mental health care, including public awareness and training of general practitioners (GPs), were carried out between 2013 and 2018. Our study's main objective was to assess the effectiveness of these initiatives, two to five years post-intervention. METHODS: This quasi-experimental study (intervention vs. control areas) included five surveys assessing: general population's Knowledge Attitudes and Practices (KAP), GPs' KAP , number of epilepsy and mental health consultations at different levels of the healthcare system, diagnostic accuracy, and treatments' availability. OUTCOMES: In the general population, KAP scores were higher in intervention areas for epilepsy (11.4/20 vs. 10.3/20; p = 0.003). For mental disorders, regardless of the area, KAP scores were low, especially for schizophrenia (1.1/20 and 0.1/20). Among GPs, KAP scores were higher in intervention areas for schizophrenia (6.0/10 vs. 4.5/10; p = 0.008) and epilepsy (6.9/10 vs. 6.2/10; p = 0.044). Overall, there was a greater proportion of mental health and epilepsy consultations in intervention areas (4.5% vs 2.3%). Although low, concordance between GPs' and psychiatrists' diagnoses was higher in intervention areas. There was a greater variety of anti-epileptic and psychotropic medications available in intervention areas. INTERPRETATION: This research has helped to better understand the effectiveness of initiatives implemented in Madagascar to improve epilepsy and mental health care and to identify barriers which will need to be addressed. FUNDING: Sanofi Global Health, as part of the Fight Against STigma Program.

Schistosome infection among pregnant women in the rural highlands of Madagascar: A cross-sectional study calling for public health interventions in vulnerable populations.

INTRODUCTION: Schistosomiasis is a parasitic infection highly prevalent in sub-Saharan Africa (SSA) with Madagascar being among the countries with highest burden of the disease worldwide. Despite WHO recommendations, suggesting treatment of pregnant women after the first trimester, this group is still excluded from Mass Drug Administration programs. Our study, had the objective to measure the prevalence of schistosome infection among pregnant women in Madagascar in order to inform public health policies for treatment in this vulnerable population. METHODS: Women were recruited for this cross-sectional study between April 2019 and February 2020 when attending Antenatal Care Services (ANCs) at one of 42 included Primary Health Care Centers. The urine-based upconverting reporter particle, lateral flow (UCP-LF) test detecting circulating anodic antigen was used for the detection of schistosome infections. To identify factors associated with the prevalence of schistosome infection crude and adjusted prevalence ratios and 95% CIs were estimated using mixed-effect Poisson regression. RESULTS: Among 4,448 participating women aged between 16 and 47 years, the majority (70.4%, 38 n = 3,133) resided in rural settings. Overall, the prevalence of schistosome infection was 55.9% (n = 2486, CI 95%: 53.3-58.5). A statistically significant association was found with age group (increased prevalence in 31-47 years old, compared to 16-20 years old (aPR = 1.15, CI 95%: 1.02-1.29) and with uptake of antimalaria preventive treatment (decreased prevalence, aPR = 0.85, CI 95%: 0.77-0.95). No other associations of any personal characteristics or contextual factors with schistosome infection were found in our multivariate regression analysis. DISCUSSION AND CONCLUSION: The high prevalence of schistosome infection in pregnant women supports the consideration of preventive schistosomiasis treatment in ANCs of the Malagasy highlands. We strongly advocate for adapting schistosomiasis programs in highly endemic contexts. This, would contribute to both the WHO and SDGs agendas overall to improving the well-being of women and consequently breaking the vicious cycle of poverty perpetuated by schistosomiasis.

Identifying and characterizing high-risk populations in pilot malaria elimination districts in Madagascar: a mixed-methods study.

BACKGROUND: In Madagascar, the districts of Antsirabe II, Faratsiho and Antsiranana I have relatively low malaria incidence rates and have been selected by the National Malaria Control Programme for pilot elimination strategies. The districts have residual transmission despite increasing coverage and quality of malaria services. This study sought to identify priority subpopulations at highest risk for malaria and collect information on intervention preferences and methods that will inform subnational tailoring of malaria service delivery. METHODS: This mixed methods study employed (i) a quantitative malaria risk factor assessment in Antsirabe II and Faratsiho comprising a test-negative frequency matched case-control study and a qualitative risk factor assessment in Antsiranana I; and (ii) a qualitative formative assessment in all three districts. For the case-control study, a mixed effects logistic regression was used with age, sex and district included as fixed effects and health facility included as a random effect. The qualitative risk factor assessment used semi-structured interview guides and key informant interviews. For the qualitative formative assessment in the three districts, a summary report was generated following semi-structured interviews and focus group discussions with high-risk populations (HRPs) and stakeholders. RESULTS: In Antsirabe II and Faratsiho districts, rice agriculture workers, outdoor/manual workers, particularly miners, and those with jobs that required travel or overnight stays, especially itinerant vendors, had higher odds of malaria infection compared to other (non-rice) agricultural workers. In Antsiranana I, respondents identified non-rice farmers, mobile vendors, and students as HRPs. Risk factors among these groups included overnight stays and travel patterns combined with a lack of malaria prevention tools. HRPs reported treatment cost and distance to the health facility as barriers to care and expressed interest in presumptive treatment and involvement of gatekeepers or people who have influence over intervention access or participation. CONCLUSIONS: The study results illustrate the value of in-depth assessments of risk behaviours, access to services and prevention tools, surveillance and prevention strategies, and the involvement of gatekeepers in shaping subnational tailoring to reach previously unreached populations and address residual transmission in elimination settings.

Prevalence of pulmonary tuberculosis and HIV infections and risk factors associated to tuberculosis in detained persons in Antananarivo, Madagascar.

The incidence rate of tuberculosis in prisons is estimated to be 8 times greater than that in the general population in Madagascar. Our objectives were to estimate the prevalence of pulmonary tuberculosis and HIV infection among prisoners and to identify risk factors associated with tuberculosis. We conducted a cross-sectional study at the central prison of Antananarivo from March to July 2021. Individual male and female inmates aged ≥ 13 years who had lived in the prison for at least three months prior to the study period were included as participants. Acid-fast bacilli detection by microscopy and/or culture, an intradermal tuberculin test, a chest X-ray, and a rapid diagnostic orientation test for HIV were performed. Among 748 participants, 4 (0.5%) were confirmed to have pulmonary tuberculosis. Overall, 14 (1.9%) patients had "confirmed" or "probable" tuberculosis [0.90-2.84, 95% CI]. The proportion of participants with latent tuberculosis infection was 69.6% (517/743) based on a positive tuberculin test without clinical symptoms or radiography images indicating tuberculosis. Out of 745 HIV screening tests, three showed reactive results (0.4%). Age (OR = 4.4, 95% CI [1.4-14.0]) and prior tuberculosis treatment (or episodes) were found to be associated with confirmed and probable tuberculosis.

Exploring the multi-level impacts of a youth-led comprehensive sexuality education model in Madagascar using Human-centered Design methods.

Comprehensive sexuality education (CSE) is recognized as a critical tool for addressing sexuality and reproductive health challenges among adolescents. However, little is known about the broader impacts of CSE on populations beyond adolescents, such as schools, families, and communities. This study explores multi-level impacts of an innovative CSE program in Madagascar, which employs young adult CSE educators to teach a three-year curriculum in government middle schools across the country. The two-phased study embraced a participatory approach and qualitative Human-centered Design (HCD) methods. In phase 1, 90 school principals and administrators representing 45 schools participated in HCD workshops, which were held in six regional cities. Phase 2 took place one year later, which included 50 principals from partner schools, and focused on expanding and validating findings from phase 1. From the perspective of school principals and administrators, the results indicate several areas in which CSE programming is having spill-over effects, beyond direct adolescent student sexuality knowledge and behaviors. In the case of this youth-led model in Madagascar, the program has impacted the lives of students (e.g., increased academic motivation and confidence), their parents (e.g., strengthened family relationships and increased parental involvement in schools), their schools (e.g., increased perceived value of schools and teacher effectiveness), their communities (e.g., increased community connections), and impacted broader structural issues (e.g., improved equity and access to resources such as menstrual pads). While not all impacts of the CSE program were perceived as positive, the findings uncovered opportunities for targeting investments and refining CSE programming to maximize positive impacts at family, school, and community levels.

Inter-facility transfers for emergency obstetrical and neonatal care in rural Madagascar: a cost-effectiveness analysis.

CONTEXT: There is a substantial lack of inter-facility referral systems for emergency obstetrical and neonatal care in rural areas of sub-Saharan Africa. Data on the costs and cost-effectiveness of such systems that reduce preventable maternal and neonatal deaths are scarce. SETTING: We aimed to determine the cost-effectiveness of a non-governmental organisation (NGO)-run inter-facility referral system for emergency obstetrical and neonatal care in rural Southern Madagascar by analysing the characteristics of cases referred through the intervention as well as its costs. DESIGN: We used secondary NGO data, drawn from an NGO's monitoring and financial administration database, including medical and financial records. OUTCOME MEASURES: We performed a descriptive and a cost-effectiveness analysis, including a one-way deterministic sensitivity analysis. RESULTS: 1172 cases were referred over a period of 4 years. The most common referral reasons were obstructed labour, ineffective labour and eclampsia. In total, 48 neonates were referred through the referral system over the study period. Estimated cost per referral was US$336 and the incremental cost-effectiveness ratio (ICER) was US$70 per additional life-year saved (undiscounted, discounted US$137). The sensitivity analysis showed that the intervention was cost-effective for all scenarios with the lowest ICER at US$99 and the highest ICER at US$205 per additional life-year saved. When extrapolated to the population living in the study area, the investment costs of the programme were US$0.13 per person and annual running costs US$0.06 per person. CONCLUSIONS: In our study, the inter-facility referral system was a very cost-effective intervention. Our findings may inform policies, decision-making and implementation strategies for emergency obstetrical and neonatal care referral systems in similar resource-constrained settings.

The effect of a political crisis on performance of community forests and protected areas in Madagascar.

Understanding the effectiveness of conservation interventions during times of political instability is important given how much of the world's biodiversity is concentrated in politically fragile nations. Here, we investigate the effect of a political crisis on the relative performance of community managed forests versus protected areas in terms of reducing deforestation in Madagascar, a biodiversity hotspot. We use remotely sensed data and statistical matching within an event study design to isolate the effect of the crisis and post-crisis period on performance. Annual rates of deforestation accelerated at the end of the crisis and were higher in community forests than in protected areas. After controlling for differences in location and other confounding variables, we find no difference in performance during the crisis, but community-managed forests performed worse in post-crisis years. These findings suggest that, as a political crisis subsides and deforestation pressures intensify, community-based conservation may be less resilient than state protection.

Characteristics of mesoscale eddies in the Mozambique Channel.

The mesoscale eddy characteristics of the Mozambique Warm Current were investigated by detecting and tracking satellite altimetry data from 2010 to 2019. A total of 1,086 eddies were identified in the Mozambique Channel, comprising 509 cyclonic eddies and 577 anticyclonic eddies. The results revealed that the bay area on the northwest coast of Madagascar was the main hotspot of eddy generation, and the mean amplitude and radius of the anticyclonic eddies in the Mozambique Channel were 24.23 cm and 82.7 km, respectively, which are larger than those of the cyclonic eddies. Local wind forcing had a significant impact on the formation of mesoscale eddies in the Mozambique Channel. In winter, the wind stress in the northern and southern areas of the Mozambique Channel exhibited a strong correlation with the distribution of eddy kinetic energy (EKE), where both monsoonal winds in the north and trade winds in the south could facilitate mesoscale anticyclonic eddy formation. In addition, the variability in the number of anticyclonic and cyclonic eddies in the Mozambique Channel may have exerted a significant influence on the seasonal anomalous fluctuations in local sea surface temperatures (SSTs). This study presented a novel analysis of the mesoscale eddy characteristics in the Mozambique Channel.

Consistency in Verreaux's sifaka home range and core area size despite seasonal variation in resource availability as assessed by Enhanced Vegetation Index (EVI).

Primates are adept at dealing with fluctuating availability of resources and display a range of responses to minimize the effects of food scarcity. An important component of primate conservation is to understand how primates adapt their foraging and ranging patterns in response to fluctuating food resources. Animals optimize resource acquisition within the home range through the selection of resource-bearing patches and choose between contrasting foraging strategies (resource-maximizing vs. area-minimizing). Our study aimed to characterize the foraging strategy of a folivorous primate, Verreaux's sifaka (Propithecus verreauxi), by evaluating whether group home range size varied between peak and lean leaf seasons within a seasonally dry tropical forest in Madagascar. We hypothesized that Verreaux's sifaka used the resource maximization strategy to select high-value resource patches so that during periods of resource depression, the home range area did not significantly change in size. We characterized resource availability (i.e., primary productivity) by season at Kirindy Mitea National Park using remotely-sensed Enhanced Vegetation Index data. We calculated group home ranges using 10 years of focal animal sampling data collected on eight groups using both 95% and 50% kernel density estimation. We used area accumulation curves to ensure each group had an adequate number of locations to reach seasonal home range asymptotes. Neither 95% home ranges nor 50% core areas differed across peak and lean leaf resource seasons, supporting the hypothesis that Verreaux's sifaka use a resource maximization strategy. With a better understanding of animal space use strategies, managers can model anticipated changes under environmental and/or anthropogenic resource depression scenarios. These findings demonstrate the value of long-term data for characterizing and understanding foraging and ranging patterns. We also illustrate the benefits of using satellite data for characterizing food resources for folivorous primates.

Implementation of an antibiotic resistance surveillance tool in Madagascar, the TSARA project: a prospective, observational, multicentre, hospital-based study protocol.

INTRODUCTION: Antimicrobial resistance (AMR) has become a significant public health threat. Without any interventions, it has been modelled that AMR will account for an estimated 10 million deaths annually by 2050, this mainly affects low/middle-income countries. AMR has a systemic negative perspective affecting the overall healthcare system down to the patient's personal outcome. In response to this issue, the WHO urged countries to provide antimicrobial stewardship programmes (ASPs). ASPs in hospitals are a vital component of national action plans for AMR, and have been shown to significantly reduce AMR, in particular in low-income countries such as Madagascar.As part of an ASP, AMR surveillance provides essential information needed to guide medical practice. We developed an AMR surveillance tool-Technique de Surveillance Actualisée de la Résistance aux Antimicrobiens (TSARA)-with the support of the Mérieux Foundation. TSARA combines bacteriological and clinical information to provide a better understanding of the scope and the effects of AMR in Madagascar, where no such surveillance tool exists. METHODS AND ANALYSIS: A prospective, observational, hospital-based study was carried out for data collection using a standardised data collection tool, called TSARA deployed in 2023 in 10 hospitals in Madagascar participating in the national Malagasy laboratory network (Réseau des Laboratoires à Madagascar (RESAMAD)). Any hospitalised patient where the clinician decided to take a bacterial sample is included. As a prospective study, individual isolate-level data and antimicrobial susceptibility information on pathogens were collected routinely from the bacteriology laboratory and compiled with clinical information retrieved from face-to-face interviews with the patient and completed using medical records where necessary. Analysis of the local ecology, resistance rates and antibiotic prescription patterns were collected. ETHICS AND DISSEMINATION: This protocol obtained ethical approval from the Malagasy Ethical Committee n°07-MSANP/SG/AGMED/CNPV/CERBM on 24 January 2023. Findings generated were shared with national health stakeholders, microbiologists, members of the RESAMAD network and the Malagasy academic society of infectious diseases.

Concordance of targeted and whole genome sequencing for Mycobacterium tuberculosis genotypic drug susceptibility testing.

Targeted Next Generation Sequencing (tNGS) and Whole Genome Sequencing (WGS) are increasingly used for genotypic drug susceptibility testing (gDST) of Mycobacterium tuberculosis. Thirty-two multi-drugs resistant and 40 drug susceptible isolates from Madagascar were tested with Deeplex® Myc-TB and WGS using the Mykrobe analysis pipeline. Sixty-four of 72 (89 %) yielded concordant categorical gDST results for drugs tested by both assays. Mykrobe didn't detect pncA K96T, pncA Q141P, pncA H51P, pncA H82R, rrs C517T and rpsL K43R mutations, which were identified as minority variants in corresponding isolates by tNGS. One discrepancy (rrs C517T) was associated with insufficient sequencing depth on WGS. Deeplex® Myc-TB didn't detect inhA G-154A which isn't covered by the assay's amplification targets. Despite those targets being included in the Deeplex® Myc-TB assay, a pncA T47A and a deletion in gid were not identified in one isolate respectively. The evaluated WGS and tNGS gDST assays show high but imperfect concordance.

Can cyclone exposure explain behavioural and demographic variation among lemur species?

Madagascar has a harsh and stochastic climate because of regular natural disturbances. This history of regular cyclones has been hypothesised to have directed evolutionary changes to lemur behaviour and morphology that make them more resilient to sudden environmental change. These adaptations may include: small group sizes, high degrees of energy-conserving behaviours, generalist habitat use, small home ranges, small body size, and a limited number of frugivorous species. To date, however, no one has tested how variation in cyclone exposure across Madagascar is associated with variation in these resilience traits. In this study, we created a detailed cyclone impact map for Madagascar using Koppen-Geiger climate class, historical cyclone tracks, the Saffir Class of cyclone and hurricane intensity, and precipitation data. We also used existing literature to calculate a resilience score for 26 lemur species for which data existed on resilience traits. Our cyclone impact map was then overlaid on known geographic ranges of these species and compared to resilience score while controlling for phylogenetic non-independence and spatial autocorrelation. We found no association between cyclone impact in a lemur range and their resilience score. When assessing traits individually, however, we found that cyclone impact was positively associated with body size, suggesting that the more impacted a species is by cyclones the smaller they are. We also found cyclone impact to be negatively associated with frugivory, with species in higher impact zones eating more fruit. While unexpected, this could reflect an increased production in fruit in tree fall gaps following cyclones. While we did not find a pattern between cyclone impact and behavioural resilience in lemurs, we suggest a similar study at a global scale across all primates would allow for more taxonomic variation and reveal larger patterns key to understanding past and future vulnerability to natural disturbances in primates.

Spatial heterogeneity of neo- and paleo-endemism for plants in Madagascar.

Madagascar is a biogeographically unique island with a remarkably high level of endemism. However, endemic taxa in Madagascar are massively threatened due to unprecedented pressures from anthropogenic habitat modification and climate change. A comprehensive phylogeny-based biodiversity evaluation of the island remains lacking. Here, we identify hotspots of taxonomic and phylogenetic plant diversity and neo- and paleo-endemism by generating a novel dated tree of life for the island. The tree is based on unprecedented sampling of 3,950 species (33% of the total known species) and 1,621 genera (93% of the total known genera and 69% of endemic genera) of Malagasy vascular plants. We find that island-endemic genera are concentrated in multiple lineages combining high taxonomic and phylogenetic diversity. Integrating phylogenetic and geographic distribution data, our results reveal that taxon richness and endemism are concentrated in the northern, eastern, and southeastern humid forests. Paleo-endemism centers are concentrated in humid eastern and central regions, whereas neo-endemism centers are concentrated in the dry and spiny forests in western and southern Madagascar. Our statistical analysis of endemic genera in each vegetation region supports a higher proportion of ancient endemic genera in the east but a higher proportion of recent endemic genera in the south and west. Overlaying centers of phylogenetic endemism with protected areas, we identify conservation gaps concentrated in western and southern Madagascar. These gaps should be incorporated into conservation strategies to aid the protection of multiple facets of biodiversity and their benefits to the Malagasy people.

Heterogeneity in elimination efforts could increase the risk of resurgence of lymphatic filariasis in Madagascar.

BACKGROUND: Progress in lymphatic filariasis (LF) elimination is spatially heterogeneous in many endemic countries, which may lead to resurgence in areas that have achieved elimination. Understanding the drivers and consequences of such heterogeneity could help inform strategies to reach global LF elimination goals by 2030. This study assesses whether differences in age-specific compliance with mass drug administration (MDA) could explain LF prevalence patterns in southeastern Madagascar and explores how spatial heterogeneity in prevalence and age-specific MDA compliance may affect the risk of LF resurgence after transmission interruption. METHODOLOGY: We used LYMFASIM model with parameters in line with the context of southeastern Madagascar and explored a wide range of scenarios with different MDA compliance for adults and children (40-100%) to estimate the proportion of elimination, non-elimination and resurgence events associated with each scenario. Finally, we evaluated the risk of resurgence associated with different levels of migration (2-6%) from surrounding districts combined with varying levels of LF microfilaria (mf) prevalence (0-24%) during that same study period. RESULTS: Differences in MDA compliance between adults and children better explained the observed heterogeneity in LF prevalence for these age groups than differences in exposure alone. The risk of resurgence associated with differences in MDA compliance scenarios ranged from 0 to 19% and was highest when compliance was high for children (e.g. 90%) and low for adults (e.g. 50%). The risk of resurgence associated with migration was generally higher, exceeding 60% risk for all the migration levels explored (2-6% per year) when mf prevalence in the source districts was between 9% and 20%. CONCLUSION: Gaps in the implementation of LF elimination programme can increase the risk of resurgence and undermine elimination efforts. In Madagascar, districts that have not attained elimination pose a significant risk for those that have achieved it. More research is needed to help guide LF elimination programme on the optimal strategies for surveillance and control that maximize the chances to sustain elimination and avoid resurgence.

Socio-ecological risk factors associated with human flea infestations of rural household in plague-endemic areas of Madagascar.

Plague is a flea-borne fatal disease caused by the bacterium Yersinia pestis, which persists in rural Madagascar. Although fleas parasitizing rats are considered the primary vectors of Y. pestis, the human flea, Pulex irritans, is abundant in human habitations in Madagascar, and has been found naturally infected by the plague bacterium during outbreaks. While P. irritans may therefore play a role in plague transmission if present in plague endemic areas, the factors associated with infestation and human exposure within such regions are little explored. To determine the socio-ecological risk factors associated with P. irritans infestation in rural households in plague-endemic areas of Madagascar, we used a mixed-methods approach, integrating results from P. irritans sampling, a household survey instrument, and an observational checklist. Using previously published vectorial capacity data, the minimal P. irritans index required for interhuman bubonic plague transmission was modeled to determine whether household infestations were enough to pose a plague transmission risk. Socio-ecological risk factors associated with a high P. irritans index were then identified for enrolled households using generalized linear models. Household flea abundance was also modeled using the same set of predictors. A high P. irritans index occurred in approximately one third of households and was primarily associated with having a traditional dirt floor covered with a plant fiber mat. Interventions targeting home improvement and livestock housing management may alleviate flea abundance and plague risk in rural villages experiencing high P. irritans infestation. As plague-control resources are limited in developing countries such as Madagascar, identifying the household parameters and human behaviors favoring flea abundance, such as those identified in this study, are key to developing preventive measures that can be implemented at the community level.