Species composition and insecticide resistance in malaria vectors in Ellibou, southern Côte d'Ivoire and first finding of Anopheles arabiensis in Côte d'Ivoire.

BACKGROUND: Knowing the species composition and insecticide resistance status of the target vector population is important to guide malaria vector control. The aim of this study was to characterize the malaria vector population in terms of species composition, insecticide susceptibility status and potential underlying resistance mechanisms in Ellibou, southern Côte d'Ivoire. METHODS: A 1-year longitudinal entomological survey was conducted using light traps and pyrethroid spray catches to sample adult mosquitoes in combination with larval sampling. The susceptibility status of Anopheles gambiae sensu lato (s.l.) to bendiocarb, deltamethrin, DDT and malathion was assessed using the World Health Organization insecticide susceptibility test. Additionally, An. gambiae specimens were screened for knockdown (kdr) and acetylcholineesterase (ace1) target site resistance alleles, and the expression levels of eight metabolic resistance genes, including seven cytochrome P450 monooxygenases (P450s) and one glutathione S-transferase (GST), measured with reverse transcription quantitative real-time polymerase chain reaction (qPCR). RESULTS: Overall, 2383 adult mosquitoes from 12 different taxa were collected with Culex quinquefasciatus and An. gambiae being the predominant taxa. Molecular identification of An. gambiae s.l. revealed the presence of Anopheles arabiensis, Anopheles coluzzii, An. gambiae sensu stricto (s.s.) and Anopheles coluzzii/An. gambiae s.s. hybrids. Anopheles gambiae mosquitoes were resistant to all insecticides except malathion. PCR diagnostics revealed the presence of ace1-G280S and the kdr L995F, L995S and N1570Y target-site mutations. Additionally, several genes were upregulated, including five P450s (i.e., CYP6P3, CYP6M2, CYP9K1, CYP6Z1, CYP6P1) and GSTE2. CONCLUSION: This is the first documented presence of An. arabiensis in Côte d'Ivoire. Its detection - together with a recent finding further north of the country - confirms its existence in the country, which is an early warning sign, as An. arabiensis shows a different biology than the currently documented malaria vectors. Because the local An. gambiae population was still susceptible to malathion, upregulation of P450s, conferring insecticide resistance to pyrethroids, together with the presence of ace1, suggest negative cross-resistance. Therefore, organophosphates could be an alternative insecticide class for indoor residual spraying in the Ellibou area, while additional tools against the outdoor biting An. arabiensis will have to be considered.

High prevalence of Schistosoma haematobium × Schistosoma bovis hybrids in schoolchildren in Côte d'Ivoire.

Schistosomiasis is a neglected tropical disease, though it is highly prevalent in many parts of sub-Saharan Africa. While Schistosoma haematobium-bovis hybrids have been reported in West Africa, no data about Schistosoma hybrids in humans are available from Côte d'Ivoire. This study aimed to identify and quantify S. haematobium-bovis hybrids among schoolchildren in four localities of Côte d'Ivoire. Urine samples were collected and examined by filtration to detect Schistosoma eggs. Eggs were hatched and 503 miracidia were individually collected and stored on Whatman® FTA cards for molecular analysis. Individual miracidia were molecularly characterized by analysis of mitochondrial cox1 and nuclear internal transcribed spacer 2 (ITS 2) DNA regions. A mitochondrial cox1-based diagnostic polymerase chain reaction was performed on 459 miracidia, with 239 (52.1%) exhibiting the typical band for S. haematobium and 220 (47.9%) the S. bovis band. The cox1 and ITS 2 amplicons were Sanger sequenced from 40 randomly selected miracidia to confirm species and hybrids status. Among the 33 cox1 sequences analysed, we identified 15 S. haematobium sequences (45.5%) belonging to seven haplotypes and 18 S. bovis sequences (54.5%) belonging to 12 haplotypes. Of 40 ITS 2 sequences analysed, 31 (77.5%) were assigned to pure S. haematobium, four (10.0%) to pure S. bovis and five (12.5%) to S. haematobium-bovis hybrids. Our findings suggest that S. haematobium-bovis hybrids are common in Côte d'Ivoire. Hence, intense prospection of domestic and wild animals is warranted to determine whether zoonotic transmission occurs.

Are schoolchildren less infected if they have good knowledge about parasitic worms? A case study from rural Côte d'Ivoire.

BACKGROUND: Parasitic worms (helminths) are common infections in low- and middle-income countries. For most helminth species, school-aged children are at highest risk of infection and morbidity, such as impaired cognitive and physical development. Preventive chemotherapy is the current mainstay for helminthiases control. Sanitation improvement and hygiene-related education are important complementary strategies, which act by altering children's behaviour. However, little is known about the effect of improved knowledge on the risk of helminth infection. The aim of this study was to assess the potential influence of knowledge that children acquired at home or in school, without any specific health education intervention, on helminth infections. METHODS: In May 2014, we conducted a cross-sectional survey in western Côte d'Ivoire. A total of 2498 children, aged 9-12 years, were subjected to three consecutive stool examinations using duplicate Kato-Katz thick smears to determine infections with soil-transmitted helminths and Schistosoma mansoni. Additionally, children were interviewed to assess their knowledge about helminth infections. Four knowledge scores were constructed by factor analysis; one, reflecting general knowledge about helminths and three manifesting helminth species-specific knowledge. The effect of general and specific knowledge on children's helminth infection status was determined using meta-analysis. RESULTS: Children who scored high in the hookworm-specific knowledge were less likely to be infected with hookworm but no association was found for the other helminth species. Moreover, greater general knowledge was not associated with lower odds of being infected with any helminth species. Most of the children interviewed believed that the effect of preventive chemotherapy is permanent, and hence, re-treatment is not necessary. CONCLUSIONS: Specific knowledge about different types of helminths might not suffice to induce behavioural change which in turn reduces infection and reinfection with helminths. Health education interventions should strive to strengthen the perception of risk and to clarify the true benefit of preventive chemotherapy.

Health-education package to prevent worm infections in Chinese schoolchildren.

BACKGROUND: Soil-transmitted helminths are among the most prevalent sources of human infections globally. We determined the effect of an educational package at rural schools in Linxiang City District, Hunan province, China, where these worms are prevalent. The intervention aimed to increase knowledge about soil-transmitted helminths, induce behavioral change, and reduce the rate of infection. METHODS: We conducted a single-blind, unmatched, cluster-randomized intervention trial involving 1718 children, 9 to 10 years of age, in 38 schools over the course of 1 school year. Schools were randomly assigned to the health-education package, which included a cartoon video, or to a control package, which involved only the display of a health-education poster. Infection rates, knowledge about soil-transmitted helminths (as assessed with the use of a questionnaire), and hand-washing behavior were assessed before and after the intervention. Albendazole was administered in all the participants at baseline and in all the children who were found to be positive for infection with soil-transmitted helminths at the follow-up assessment at the end of the school year. RESULTS: At the follow-up assessment, the mean score for the knowledge of helminths, calculated as a percentage of a total of 43 points on a questionnaire, was 90% higher in the intervention group than in the control group (63.3 vs. 33.4, P<0.001), the percentage of children who washed their hands after using the toilet was nearly twice as high in the intervention group (98.9%, vs. 54.2% in the control group; P<0.001), and the incidence of infection with soil-transmitted helminths was 50% lower in the intervention group than in the control group (4.1% vs. 8.4%, P<0.001). No adverse events were observed immediately (within 15 minutes) after albendazole treatment. CONCLUSIONS: The health-education package increased students' knowledge about soil-transmitted helminths and led to a change in behavior and a reduced incidence of infection within 1 school year. (Funded by UBS Optimus Foundation, Zurich, Switzerland; Australian New Zealand Clinical Trials Registry number, ACTRN12610000048088.).

Disparities of Plasmodium falciparum infection, malaria-related morbidity and access to malaria prevention and treatment among school-aged children: a national cross-sectional survey in Côte d'Ivoire.

BACKGROUND: There is limited knowledge on the malaria burden of school-aged children in Côte d'Ivoire. The aim of this study was to assess Plasmodium falciparum infection, malaria-related morbidity, use of preventive measures and treatment against malaria, and physical access to health structures among school-aged children across Côte d'Ivoire. METHODS: A national, cross-sectional study was designed, consisting of clinical and parasitological examinations and interviews with schoolchildren. More than 5,000 children from 93 schools in Côte d'Ivoire were interviewed to determine household socioeconomic status, self-reported morbidity and means of malaria prevention and treatment. Finger-prick blood samples were collected and Plasmodium infection and parasitaemia determined using Giemsa-stained blood films and a rapid diagnostic test (RDT). Haemoglobin levels and body temperature were measured. Children were classified into wealth quintiles using household assets and principal components analysis (PCA). The concentration index was employed to determine significant trends of health variables according to wealth quintiles. Logistic and binomial negative regression analyses were done to investigate for associations between P. falciparum prevalence and parasitaemia and any health-related variable. RESULTS: The prevalence of P. falciparum was 73.9% according to combined microscopy and RDT results with a geometric mean of parasitaemia among infected children of 499 parasites/µl of blood. Infection with P. falciparum was significantly associated with sex, socioeconomic status and study setting, while parasitaemia was associated with age. The rate of bed net use was low compared to the rate of bed net ownership. Preventive measures (bed net ownership, insecticide spray and the reported use of malaria treatment) were more frequently mentioned by children from wealthier households who were at lower risk of P. falciparum infection. Self-reported morbidity (headache) and clinical morbidity (anaemia) were more often reported by children from less wealthy households. CONCLUSION: Seven out of ten school-aged children in Côte d'Ivoire are infected with P. falciparum and malaria-related morbidity is considerable. Furthermore, this study points out that bed net usage is quite low and there are important inequalities in preventive measures and treatment. These results can guide equity-oriented malaria control strategies in Côte d'Ivoire.

Transmission of malaria in relation to distribution and coverage of long-lasting insecticidal nets in central Côte d'Ivoire.

BACKGROUND: The use of long-lasting insecticidal nets (LLINs) is an effective malaria control strategy. However, there are challenges to achieve high coverage, such as distribution sustainability, and coverage keep-up. This study assessed the effect of LLINs coverage and contextual factors on entomological indicators of malaria in rural Côte d'Ivoire. METHODS: The study was carried out between July 2009 and May 2012 in three villages (Bozi, N'Dakonankro and Yoho) of central Côte d'Ivoire. In Bozi and Yoho, LLINs were distributed free of charge by the national malaria control programme in 2008. In Bozi, an additional distribution was carried out in May 2011. No specific interventions were done in N'Dakonankro. Entomological surveys were conducted in July 2009 and July 2010 (baseline), and in August and November 2011 and in February 2012. Frequency of circumsporozoite protein was determined using an enzyme-linked immunosorbent assay. Regression models were employed to assess the impact of LLINs and changing patterns of irrigated rice farming on entomological parameters, and to determine associations with LLINs coverage and other contextual factors. RESULTS: In Bozi, high proportion of LLIN usage was observed (95-100%). After six months, 95% of LLINs were washed at least once and 79% were washed up to three times within one year. Anopheles gambiae was the predominant malaria vector (66.6% of all mosquitoes caught). From 2009 to 2012, in N'Dakonankro, the mean annual entomological inoculation rate (EIR) increased significantly from 116.8 infectious bites/human/year (ib/h/y) to 408.8 ib/h/y, while in the intervention villages, the EIR decreased significantly from 514.6 ib/h/y to 62.0 ib/h/y (Bozi) and from 83.9 ib/h/y to 25.5 ib/h/y (Yoho). The risk of an infectious bite over the three-year period was significantly lower in the intervention villages compared to the control village (p<0.001). CONCLUSION: High coverage and sensitization of households to use LLINs through regular visits (particularly in Bozi) and abandoning irrigated rice farming (in Yoho) resulted in highly significant reductions of EIR. The national malaria control programme should consider household sensitization and education campaigns and other contextual factors to maximize the benefit of LLINs.

Effect of deworming on school-aged children's physical fitness, cognition and clinical parameters in a malaria-helminth co-endemic area of Côte d'Ivoire.

BACKGROUND: Malaria and helminth infections are thought to negatively affect children's nutritional status and to impair their physical and cognitive development. Yet, the current evidence-base is weak. The purpose of this study was to determine the effect of deworming against soil-transmitted helminthiasis and schistosomiasis on children's physical fitness, cognition and clinical parameters in a malaria-helminth co-endemic setting of Côte d'Ivoire. METHODS: We designed an intervention study with a 5-month follow-up among schoolchildren aged 5-14 years from Niablé, eastern Côte d'Ivoire. In late 2012, a baseline cross-sectional survey was conducted. Finger-prick blood, stool and urine samples were subjected to standardised, quality-controlled techniques for the diagnosis of Plasmodium spp., Schistosoma spp., soil-transmitted helminths and intestinal protozoa infections. Haemoglobin level was determined and anthropometric measurements were taken for appraisal of anaemia and nutritional status. Children underwent memory (digit span) and attention (code transmission) cognitive testing, and their physical fitness and strength were determined (20 m shuttle run, standing broad jump and grip strength test). All children were treated with albendazole (against soil-transmitted helminthiasis) and praziquantel (against schistosomiasis) after the baseline cross-sectional survey and again 2 months later. Five months after the initial deworming, the same battery of clinical, cognitive and physical fitness tests was performed on the same children. RESULTS: Lower scores in strength tests were significantly associated with children with harbouring nutritional deficiencies. Surprisingly, boys infected with Schistosoma mansoni achieved longer jumping distances than their non-infected counterparts. Light-intensity infection with S. mansoni was associated with slightly better aerobic capacity. Deworming showed no effect on haemoglobin levels and anaemia, but children with moderate- to heavy-intensity Schistosoma infection at baseline gained weight more pronouncedly than non-infected children. Interestingly, children with soil-transmitted helminth or Schistosoma infection at baseline performed significantly better in the sustained attention test than their non-infected counterparts at the 5-month follow-up. CONCLUSIONS: This study revealed conflicting results regarding clinical parameters and cognitive behaviour of children after two rounds of deworming. We speculate that potential beneficial effects of deworming are likely to be undermined in areas where malaria is co-endemic and nutritional deficiencies are widespread.

Genetic diversity of Plasmodium falciparum among school-aged children from the Man region, western Côte d'Ivoire.

BACKGROUND: The genetic diversity of Plasmodium falciparum allows the molecular discrimination of otherwise microscopically identical parasites and the identification of individual clones in multiple infections. The study reported here investigated the P. falciparum multiplicity of infection (MOI) and genetic diversity among school-aged children in the Man region, western Côte d'Ivoire. METHODS: Blood samples from 292 children aged seven to 15 years were collected in four nearby villages located at altitudes ranging from 340 to 883 m above sea level. Giemsa-stained thick and thin blood films were prepared and examined under a microscope for P. falciparum prevalence and parasitaemia. MOI and genetic diversity of the parasite populations were investigated using msp2 typing by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Plasmodium falciparum prevalence and parasitaemia were both found to be significantly lower in the highest altitude village. Genotyping of the isolates revealed 25 potentially new msp2 alleles. MOI varied significantly across villages but did not correlate with altitude nor children's age, and only to a limited extent with parasitaemia. An analysis of molecular variance (AMOVA) indicated that a small, but close to statistical significance (p = 0.07), fraction of variance occurs specifically between villages of low and high altitudes. CONCLUSIONS: Higher altitude was associated with lower prevalence of P. falciparum but not with reduced MOI, suggesting that, in this setting, MOI is not a good proxy for transmission. The evidence for partially parted parasite populations suggests the existence of local geographical barriers that should be taken into account when deploying anti-malarial interventions.

Mapping malaria risk among children in Côte d'Ivoire using Bayesian geo-statistical models.

BACKGROUND: In Côte d'Ivoire, an estimated 767,000 disability-adjusted life years are due to malaria, placing the country at position number 14 with regard to the global burden of malaria. Risk maps are important to guide control interventions, and hence, the aim of this study was to predict the geographical distribution of malaria infection risk in children aged <16 years in Côte d'Ivoire at high spatial resolution. METHODS: Using different data sources, a systematic review was carried out to compile and geo-reference survey data on Plasmodium spp. infection prevalence in Côte d'Ivoire, focusing on children aged <16 years. The period from 1988 to 2007 was covered. A suite of Bayesian geo-statistical logistic regression models was fitted to analyse malaria risk. Non-spatial models with and without exchangeable random effect parameters were compared to stationary and non-stationary spatial models. Non-stationarity was modelled assuming that the underlying spatial process is a mixture of separate stationary processes in each ecological zone. The best fitting model based on the deviance information criterion was used to predict Plasmodium spp. infection risk for entire Côte d'Ivoire, including uncertainty. RESULTS: Overall, 235 data points at 170 unique survey locations with malaria prevalence data for individuals aged <16 years were extracted. Most data points (n = 182, 77.4%) were collected between 2000 and 2007. A Bayesian non-stationary regression model showed the best fit with annualized rainfall and maximum land surface temperature identified as significant environmental covariates. This model was used to predict malaria infection risk at non-sampled locations. High-risk areas were mainly found in the north-central and western area, while relatively low-risk areas were located in the north at the country border, in the north-east, in the south-east around Abidjan, and in the central-west between two high prevalence areas. CONCLUSION: The malaria risk map at high spatial resolution gives an important overview of the geographical distribution of the disease in Côte d'Ivoire. It is a useful tool for the national malaria control programme and can be utilized for spatial targeting of control interventions and rational resource allocation.

Willingness to use a rapid diagnostic test for malaria in a rural area of central Côte d'Ivoire.

BACKGROUND: Malaria mortality is mainly a direct consequence of inadequate and/or delayed diagnosis and case management. Some important control interventions (e.g. long-lasting insecticidal nests) have contributed to reduce malaria morbidity and mortality in different parts of the world. Moreover, the development and effective use of rapid diagnostic tests (RDTs) hold promise to further enhance the control and elimination of malaria, particularly in areas where health services are deficient. The aim of this study was to determine knowledge, attitudes, practices and beliefs in relation to RDTs for malaria in rural Côte d'Ivoire. METHODS: One hundred individuals from Bozi and Yoho who sought care at the health centre in Bozi and were offered an RDT for malaria were interviewed in April 2010 using a pre-tested questionnaire on practice and perceptions in relation to RDTs for malaria. The relationships between acceptance of RDTs and factors related to opinions were identified, using generalized linear mixed models. Qualitative data from open-ended questions complemented the quantitative analysis. RESULTS: Only 34 out of 100 patients who were offered an RDT for malaria were willing to undergo the test. People who perceived blood as a sacred body fluid were less likely to comply with an RDT. The concurrent availability and use of RDTs for HIV and malaria was associated with an unwilling attitude towards RDTs for malaria (Fisher's exact test, p <0.001). The initial willingness of patients to accept malaria testing with RDTs was significantly related to general fear and wanting to know malaria infection status. For further and regular use of RDTs, a strong relationship was observed between acceptance and the idea that an RDT is a pretext used by health worker to know HIV status (odds ratio (OR) = 16.61, 95% confidence interval (CI) = 1.03-268.5). Those thinking that blood samples were useful for medical diagnoses were 8.31-times (95% CI = 2.22-31.1) more likely to undergo an RDT compared to those rejecting blood sampling as a diagnostic strategy. CONCLUSION: Socio-cultural factors might be barriers for accepting RDTs in general health services. There are social representations of malaria and HIV/AIDS, symbolic for blood or experiences in relation to blood taking and blood-related diseases in relation to the introduction and routine use of RDTs. Special attention should be given to these barriers as otherwise the promotion of RDTs for prompt and effective diagnosis and subsequent management of malaria is hampered.

Population genetic structure of Schistosoma haematobium and Schistosoma haematobium × Schistosoma bovis hybrids among school-aged children in Côte d'Ivoire.

While population genetics of Schistosoma haematobium have been investigated in West Africa, only scant data are available from Côte d'Ivoire. The purpose of this study was to analyze both genetic variability and genetic structure among S. haematobium populations and to quantify the frequency of S. haematobium × S. bovis hybrids in school-aged children in different parts of Côte d'Ivoire. Urine samples were subjected to a filtration method and examined microscopically for Schistosoma eggs in four sites in the western and southern parts of Côte d'Ivoire. A total of 2692 miracidia were collected individually and stored on Whatman® FTA cards. Of these, 2561 miracidia were successfully genotyped for species and hybrid identification using rapid diagnostic multiplex mitochondrial cox1 PCR and PCR Restriction Fragment Length Polymorphism (PCR-RFLP) analysis of the nuclear ITS2 region. From 2164 miracidia, 1966 (90.9%) were successfully genotyped using at least 10 nuclear microsatellite loci to investigate genetic diversity and population structure. Significant differences were found between sites in all genetic diversity indices and genotypic differentiation was observed between the site in the West and the three sites in the East. Analysis at the infrapopulation level revealed clustering of parasite genotypes within individual children, particularly in Duekoué (West) and Sikensi (East). Of the six possible cox1-ITS2 genetic profiles obtained from miracidia, S. bovis cox1 × S. haematobium ITS2 (42.0%) was the most commonly observed in the populations. We identified only 15 miracidia (0.7%) with an S. bovis cox1 × S. bovis ITS2 genotype. Our study provides new insights into the population genetics of S. haematobium and S. haematobium × S. bovis hybrids in humans in Côte d'Ivoire and we advocate for researching hybrid schistosomes in animals such as rodents and cattle in Côte d'Ivoire.

Title: Structuration génétique des populations de Schistosoma haematobium et des hybrides Schistosoma haematobium × Schistosoma bovis chez les enfants d'âge scolaire en Côte d'Ivoire. Abstract: Alors que la génétique des populations de Schistosoma haematobium a été étudiée en Afrique de l'Ouest, seules quelques données sont disponibles pour la Côte d'Ivoire. Le but de cette étude était d'analyser à la fois la variabilité génétique et la structure génétique des populations de S. haematobium et de quantifier la fréquence des hybrides S. haematobium × S. bovis chez les enfants d'âge scolaire dans différentes régions de la Côte d'Ivoire. Des échantillons d'urine ont été soumis à une méthode de filtration et examinés au microscope pour les œufs de Schistosoma dans quatre sites de l'ouest et du sud de la Côte d'Ivoire. Au total, 2 692 miracidia ont été collectés individuellement et stockés sur des cartes Whatman® FTA. Parmi ceux-ci, 2 561 miracidia ont été génotypés avec succès pour l'identification des espèces et des hybrides à l'aide de la PCR multiplex de diagnostic rapide du cox1 mitochondrial et d'une analyse du polymorphisme de longueur des fragments de restriction de PCR (PCR-RFLP) de la région ITS2 de l'ADN nucléaire. Sur 2 164 miracidia, 1 966 (90,9 %) ont été génotypés avec succès en utilisant au moins 10 loci microsatellites nucléaires pour étudier la diversité génétique et la structure de la population. Des différences significatives ont été trouvées entre les sites dans tous les indices de diversité génétique et une différenciation génotypique a été observée entre le site de l'Ouest et les trois sites de l'Est. L'analyse au niveau de l'infrapopulation a révélé un regroupement des génotypes de parasites au sein de chaque enfant, en particulier à Duekoué (Ouest) et Sikensi (Est). Parmi les six profils génétiques cox1-ITS2 possibles obtenus à partir de miracidia, S. bovis cox1 × S. haematobium ITS2 (42,0 %) était le plus fréquemment observé dans les populations. Nous avons identifié seulement 15 miracidia (0,7 %) avec un génotype S. bovis cox1 × S. bovis ITS2. Notre étude apporte de nouvelles connaissances sur la génétique des populations de S. haematobium et des hybrides S. haematobium × S. bovis chez l'homme en Côte d'Ivoire et nous plaidons pour la recherche de schistosomes hybrides chez les animaux (rongeurs et bovins) en Côte d'Ivoire.

Malaria knowledge and long-lasting insecticidal net use in rural communities of central Côte d'Ivoire.

BACKGROUND: To improve effectiveness of malaria control interventions, it is essential to deepen the knowledge of contextual factors that govern people's practice for preventive and curative measures. The aim of this study was to determine factors that influence the use of long-lasting insecticidal nets (LLINs) in three rural communities of Côte d'Ivoire, two of which benefited from recent interventions. METHODS: The study was carried out in 957 households in three villages (Bozi, N'Dakonankro and Yoho) located in central Côte d'Ivoire. Indicators of socioeconomic position (SEP), malaria knowledge and practice, placing special emphasis on LLINs, were investigated during a cross-sectional questionnaire survey. Principal component analysis was used to calculate the SEP of households by means of a list of household assets ownership. The concentration index was used to assess the direction of the association between SEP and a given variable. To compare groups or means, Fisher's exact test, χ2 and Kruskal-Wallis test were used, as appropriate. RESULTS: Significant differences were found between SEP and reported malaria symptoms, such as fever or hot body, convulsion, anaemia and jaundice (yellow eyes). Individuals from the least poor group cited more often the use of bed nets and insecticide-treated nets (ITNs) compared to poorer groups. The mean number of individuals reporting the use of bed nets and LLINs was different between groups with different educational level. Moreover, the mean number of LLINs in a household was influenced by the presence of children below five years of age. CONCLUSION: The study not only confirmed that education and SEP play important roles in the prevention and control of malaria and promotion of health in general, but pointed at the basic essential knowledge and the key behavioural elements that should guide education and learning processes among the poorer segments of the population. In turn, such knowledge may change behaviour and lead to an increased utilization of LLINs.

Effect of an armed conflict on relative socioeconomic position of rural households: case study from western Côte d'Ivoire.

BACKGROUND: Current conceptual frameworks on the interrelationship between armed conflict and poverty are based primarily on aggregated macro-level data and/or qualitative evidence and usually focus on adherents of warring factions. In contrast, there is a paucity of quantitative studies about the socioeconomic consequences of armed conflict at the micro-level, i.e., noncommitted local households and civilians. METHODS: We conducted a secondary analysis of data pertaining to risk factors for malaria and neglected tropical diseases. Standardized questionnaires were administered to 182 households in a rural part of western Côte d'Ivoire in August 2002 and again in early 2004. Between the two surveys, the area was subject to intensive fighting in the Ivorian civil war. Principal component analysis was applied at the two time points for constructing an asset-based wealth-index and categorizing the households in wealth quintiles. Based on quintile changes, the households were labeled as 'worse-off', 'even' or 'better-off'. Statistical analysis tested for significant associations between the socioeconomic fates of households and head of household characteristics, household composition, village characteristics and self-reported events associated with the armed conflict. Most-poor/least-poor ratios and concentration indices were calculated to assess equity changes in households' asset possession. RESULTS: Of 203 households initially included in the first survey, 21 were lost to follow-up. The population in the remaining 182 households shrunk from 1,749 to 1,625 persons due to migration and natural population changes. However, only weak socioeconomic dynamics were observed; every seventh household was defined as 'worse-off' or 'better-off' despite the war-time circumstances. Analysis of other reported demographic and economic characteristics did not clearly identify more or less resilient households, and only subtle equity shifts were noted.However, the results indicate significant changes in livelihood strategies with a significant return to agricultural production and a decrease in the diversity of socioeconomic activities. CONCLUSION: Situational constraints and methodological obstacles are inherent in conflict settings and hamper conflict-related socioeconomic research. Furthermore, sensitive methods to assess and meaningfully interpret longitudinal micro-level wealth data from low-income countries are lacking. Despite compelling evidence of socioeconomic dynamics triggered by armed conflicts at the macro-level, we could not identify similar effects at the micro-level. A deeper understanding of household profiles that are more resilient to armed conflict could help to better prevent and/or alleviate adverse conflict-related and increasingly civilian-borne socioeconomic effects.

Comparison of two approaches for measuring household wealth via an asset-based index in rural and peri-urban settings of Hunan province, China.

BACKGROUND: There are growing concerns regarding inequities in health, with poverty being an important determinant of health as well as a product of health status. Within the People's Republic of China (P.R. China), disparities in socio-economic position are apparent, with the rural-urban gap of particular concern. Our aim was to compare direct and proxy methods of estimating household wealth in a rural and a peri-urban setting of Hunan province, P.R. China. METHODS: We collected data on ownership of household durable assets, housing characteristics, and utility and sanitation variables in two village-wide surveys in Hunan province. We employed principal components analysis (PCA) and principal axis factoring (PAF) to generate household asset-based proxy wealth indices. Households were grouped into quartiles, from 'most wealthy' to 'most poor'. We compared the estimated household wealth for each approach. Asset-based proxy wealth indices were compared to those based on self-reported average annual income and savings at the household level. RESULTS: Spearman's rank correlation analysis revealed that PCA and PAF yielded similar results, indicating that either approach may be used for estimating household wealth. In both settings investigated, the two indices were significantly associated with self-reported average annual income and combined income and savings, but not with savings alone. However, low correlation coefficients between the proxy and direct measures of wealth indicated that they are not complementary. We found wide disparities in ownership of household durable assets, and utility and sanitation variables, within and between settings. CONCLUSION: PCA and PAF yielded almost identical results and generated robust proxy wealth indices and categories. Pooled data from the rural and peri-urban settings highlighted structural differences in wealth, most likely a result of localized urbanization and modernization. Further research is needed to improve measurements of wealth in low-income and transitional country contexts.

Use of Insecticides in Agriculture and the Prevention of Vector-Borne Diseases: Population Knowledge, Attitudes, Practices and Beliefs in Elibou, South Côte d'Ivoire.

People's knowledge, attitudes, practices and beliefs (KAPB) pertaining to malaria are generally well described. However, little is known about population knowledge and awareness of insecticide resistance in malaria vectors. The aim of this study was to investigate KAPB related to insecticide resistance in malaria vectors due to the use of insecticides in agriculture and the prevention against mosquitoes. In mid-2017, we carried out a cross-sectional survey in Elibou, South Côte d'Ivoire, employing a mixed methods approach. Quantitative data were obtained with a questionnaire addressed to household heads. Interviews were conducted with key opinion leaders, including village chiefs, traditional healers, heads of health centres and pesticide sellers. Focus group discussions were conducted with youth and elders. A total of 203 individuals participated in the questionnaire survey (132 males, 65%). We found that people had good knowledge about malaria and mosquitoes transmitting the disease, while they felt that preventing measures were ineffective. Pesticides were intensively used by farmers, mainly during the rainy season. Among the pesticides used, insecticides and herbicides were most commonly used. While there was poor knowledge about resistance, the interviewees stated that insecticides were not killing the mosquitoes anymore. The main reason given was that insecticides were diluted by the manufacturers as a marketing strategy to sell larger quantities. More than a third of the farmers used agricultural pesticides for domestic purposes to kill weeds or mosquitoes. We observed a misuse of pesticides among farmers, explained by the lack of specific training. In the community, long-lasting insecticidal nets were the most common preventive measure against malaria, followed by mosquito coils and insecticide sprays. The interviewees felt that the most effective way of dealing with insecticide resistance was to combine at least two preventive measures. In conclusion, population attitudes and practices related to insecticides used in agriculture and the prevention against mosquitoes could lead to resistance in malaria vectors, while people's knowledge about insecticide resistance was limited. There is a need to raise awareness in communities about the presence of resistance in malaria vectors and to involve them in resistance management.

Efficacy and safety of single-dose 40 mg/kg oral praziquantel in the treatment of schistosomiasis in preschool-age versus school-age children: An individual participant data meta-analysis.

BACKGROUND: Better knowledge of the efficacy and safety of single-dose 40 mg/kg oral praziquantel in preschool-age children is required, should preventive chemotherapy programs for schistosomiasis be expanded to include this age group. METHODOLOGY: We analyzed individual participant-level data from 16 studies (13 single-arm or cohort studies and three randomized trials), amounting to 683 preschool-age children (aged <6 years) and 2,010 school-age children (aged 6-14 years). Children had a documented Schistosoma mansoni or S. haematobium infection, were treated with single 40 mg/kg oral praziquantel, and assessed between 21 and 60 days post-treatment. Efficacy was expressed as arithmetic mean and individual egg reduction rate (ERR) and meta-analyzed using general linear models and mixed models. Safety was summarized using reported adverse events (AEs). PRINCIPAL FINDINGS: Preschool-age children had significantly lower baseline Schistosoma egg counts and more losses to follow-up compared to school-age children. No difference in efficacy was found between preschool- and school-age children using a general linear model of individual-participant ERR with baseline log-transformed egg count as covariate and study, age, and sex as fixed variables, and a mixed model with a random effect on the study. Safety was reported in only four studies (n = 1,128 individuals); few AEs were reported in preschool-age children 4 and 24 hours post-treatment as well as at follow-up. Three severe but not serious AEs were recorded in school-age children during follow-up. CONCLUSIONS/SIGNIFICANCE: There is no indication that single-dose 40 mg/kg oral praziquantel would be less efficacious and less safe in preschool-age children compared to school-age children, with the caveat that only few randomized comparisons exist between the two age groups. Preventive chemotherapy might therefore be extended to preschool-age children, with proper monitoring of its efficacy and safety.

Spatial risk profiling of Plasmodium falciparum parasitaemia in a high endemicity area in Côte d'Ivoire.

BACKGROUND: The objective of this study was to identify demographic, environmental and socioeconomic risk factors and spatial patterns of Plasmodium falciparum parasitaemia in a high endemicity area of Africa, and to specify how this information can facilitate improved malaria control at the district level. METHODS: A questionnaire was administered to about 4,000 schoolchildren in 55 schools in western Côte d'Ivoire to determine children's socioeconomic status and their habit of sleeping under bed nets. Environmental data were obtained from satellite images, digitized ground maps and a second questionnaire addressed to school directors. Finger prick blood samples were collected and P. falciparum parasitaemia determined under a microscope using standardized, quality-controlled methods. Bayesian variogram models were utilized for spatial risk modelling and mapping of P. falciparum parasitaemia at non-sampled locations, assuming stationary and non-stationary underlying spatial dependence. RESULTS: Two-thirds of the schoolchildren were infected with P. falciparum and the mean parasitaemia among infected children was 959 parasites/microl of blood. Age, socioeconomic status, not sleeping under a bed net, coverage rate with bed nets and environmental factors (e.g., normalized difference vegetation index, rainfall, land surface temperature and living in close proximity to standing water) were significantly associated with the risk of P. falciparum parasitaemia. After accounting for spatial correlation, age, bed net coverage, rainfall during the main malaria transmission season and distance to rivers remained significant covariates. CONCLUSION: It is argued that a massive increase in bed net coverage, particularly in villages in close proximity to rivers, in concert with other control measures, is necessary to bring malaria endemicity down to intermediate or low levels.

Prevalence and Risk Factors for Schistosomiasis among Schoolchildren in two Settings of Côte d'Ivoire.

Schistosomiasis is a parasitic disease affecting more than 250 million people, primarily in sub-Saharan Africa. In Côte d'Ivoire both Schistosoma haematobium (causing urogenital schistosomiasis) and Schistosoma mansoni (causing intestinal schistosomiasis) co-exist. This study aimed to determine the prevalence of S. haematobium and S. mansoni and to identify risk factors among schoolchildren in the western and southern parts of Côte d'Ivoire. From January to April 2018, a cross-sectional study was carried out including 1187 schoolchildren aged 5-14 years. Urine samples were examined by a filtration method to identify and count S. haematobium eggs, while stool samples were subjected to duplicate Kato-Katz thick smears to quantify eggs of S. mansoni and soil-transmitted helminths. Data on sociodemographic, socioeconomic, and environmental factors were obtained using a pretested questionnaire. Multivariate logistic regression was employed to test for associations between variables. We found a prevalence of S. haematobium of 14.0% (166 of 1187 schoolchildren infected) and a prevalence of S. mansoni of 6.1% (66 of 1089 schoolchildren infected). In the southern part of Côte d'Ivoire, the prevalence of S. haematobium was 16.1% with a particularly high prevalence observed in Sikensi (35.6%), while S. mansoni was most prevalent in Agboville (11.2%). Swimming in open freshwater bodies was the main risk factor for S. haematobium infection (adjusted odds ratio (AOR) = 127.0, 95% confidence interval (CI): 25.0-634.0, p < 0.001). Fishing and washing clothes in open freshwater bodies were positively associated with S. haematobium and S. mansoni infection, respectively. Preventive chemotherapy using praziquantel should be combined with setting-specific information, education, and communication strategies in order to change children's behavior, thus avoiding contact with unprotected open freshwater.

Antagonistic effects of Plasmodium-helminth co-infections on malaria pathology in different population groups in Côte d'Ivoire.

INTRODUCTION: Plasmodium spp. and helminths are co-endemic in many parts of the tropics; hence, co-infection is a common phenomenon. Interactions between Plasmodium and helminth infections may alter the host's immune response and susceptibility and thus impact on morbidity. There is little information on the direction and magnitude of such interactions and results are conflicting. This study aimed at shedding new light on the potential interactions of Plasmodium and helminth co-infections on anemia and splenomegaly in different population groups in Côte d'Ivoire. METHODOLOGY: Parasitologic and clinical data were obtained from four cross-sectional community-based studies and a national school-based survey conducted between 2011 and 2013 in Côte d'Ivoire. Six scenarios of co-infection pairs defined as Plasmodium infection or high parasitemia, combined with one of three common helminth infections (i.e., Schistosoma mansoni, S. haematobium, and hookworm) served for analysis. Adjusted logistic regression models were built for each scenario and interaction measures on additive scale calculated according to Rothman et al., while an interaction term in the model served as multiplicative scale measure. PRINCIPAL FINDINGS: All identified significant interactions were of antagonistic nature but varied in magnitude and species combination. In study participants aged 5-18 years from community-based studies, Plasmodium-hookworm co-infection showed an antagonistic interaction on additive scale on splenomegaly, while Plasmodium-Schistosoma co-infection scenarios showed protective effects on multiplicative scale for anemia and splenomegaly in participants aged 5-16 years from a school-based study. CONCLUSIONS/SIGNIFICANCE: No exacerbation from co-infection with Plasmodium and helminths was observed, neither in participants aged 5-18 years nor in adults from the community-based studies. Future studies should unravel underlying mechanisms of the observed interactions, as this knowledge might help shaping control efforts against these diseases of poverty.