Trends in reported malaria cases and the effects of malaria control in the Democratic Republic of the Congo.

BACKGROUND: Considerable upscaling of malaria control efforts have taken place over the last 15 years in the Democratic Republic of Congo, the country with the second highest malaria case load after Nigeria. Malaria control interventions have been strengthened in line with the Millenium Development Goals. We analysed the effects of these interventions on malaria cases at health facility level, using a retrospective trend analysis of malaria cases between 2005 and 2014. Data were collected from outpatient and laboratory registers based on a sample of 175 health facilities that represents all eco-epidemiological malaria settings across the country. METHODS: We applied a time series analysis to assess trends of suspected and confirmed malaria cases, by health province and for different age groups. A linear panel regression model controlled for non-malaria outpatient cases, rain fall, nightlight intensity, health province and time fixed effects, was used to examine the relationship between the interventions and malaria case occurrences, as well as test positivity rates. RESULTS: Overall, recorded suspected and confirmed malaria cases in the DRC have increased. The sharp increase in confirmed cases from 2010 coincides with the introduction of the new treatment policy and the resulting scale-up of diagnostic testing. Controlling for confounding factors, the introduction of rapid diagnostic tests (RDTs) was significantly associated with the number of tested and confirmed cases. The test positivity rate fluctuated around 40% without showing any trend. CONCLUSION: The sharp increase in confirmed malaria cases from 2010 is unlikely to be due to a resurgence of malaria, but is clearly associated with improved diagnostic availability, mainly the introduction of RDTs. Before that, a great part of malaria cases were treated based on clinical suspicion. This finding points to a better detection of cases that potentially contributed to improved case management. Furthermore, the expansion of diagnostic testing along with the increase in confirmed cases implies that before 2010, cases were underreported, and that the accuracy of routine data to describe malaria incidence has improved.

Are overweight and obesity in children risk factors for anemia in early childhood? Results from a national nutrition survey in Tajikistan.

OBJECTIVES: To assess the association between overweight/obesity and anemia in early childhood in Tajikistan. METHODS: Using a two-stage-cluster sampling, a representative sample of 1342 children (48.7% girls) aged 25-60 months was included in a nationwide survey in Tajikistan in 2009. Weight status was defined by age- and gender-specific body mass index, anemia by hemoglobin < 11 g/dl, according to WHO cut-off values for children, adjusted for altitude. Gender-stratified association of anemia and overweight/obesity was estimated by mixed models, controlling for age, parental education, and location type and region. RESULTS: In the study population, the prevalence of anemia was 20.0%, overweight 13.0%, and obesity 9.5%. In multivariable analyses, obesity and overweight were not associated with anemia. Lower age and living in the remote region of Gorno-Badakhshan Autonomous Oblast were associated with a higher prevalence of anemia. CONCLUSIONS: In Tajikistan, anemia is at a moderate level, affecting every fifth child aged 25-60 months. Around every fifth child is overweight or obese. Interventions should focus on preventing anemia and overweight/obesity.

Prevalence of impaired glucose metabolism and potential predictors: a rapid appraisal among ≥ 45 years old residents of southern Tajikistan.

BACKGROUND: An estimated 2% of all deaths in Tajikistan can be attributed to diabetes but reliable data are scarce for the country and across Central Asia. We assessed the prevalence of impaired glucose tolerance and diabetes and associated predictors among residents aged ≥ 45 years in two districts in southern Tajikistan. METHODS: A population-representative survey following the WHO STEPwise approach to surveillance and including a two-stage cluster sampling was conducted. Enrolled participants were asked about risk factors for diabetes, and blood pressure, height and weight were measured. The blood glucose level was determined after overnight fasting, and the 2 h oral glucose tolerance test was performed if indicated. RESULTS: Complete datasets were available for 584 out of 672 study participants. One third of the cohort was male and half were 45-54 years old. Overall, 21.2% of the participants were found to be diabetic, 5.1% had impaired glucose tolerance and 4.3% impaired fasting glucose. An elevated body mass index ≥ 25 was observed in 61.5% of the cohort and an elevated blood pressure in 45.6% (systolic, cut-off 140 mm Hg) and 52.3% (diastolic, cut-off 90 mm Hg) respectively. Half of the participants classified as diabetic were aware of their status. CONCLUSIONS: Impaired glucose tolerance and overweight are common among elderly residents of southern Tajikistan. Primary health care services should be strengthened to improve early detection and ensure adequate treatment of diabetes and quality of care. Community-based awareness rising about available peripheral services is crucial.

Iodine nutritional status and risk factors for goitre among schoolchildren in South Tajikistan.

BACKGROUND: Iodine deficiency affects nearly 1.9 billion people worldwide, but it can be prevented by salt iodization. This cross-sectional survey assessed current iodine status, iodized salt coverage and risk factors for goitre among schoolchildren in South Tajikistan. METHODS: Ten primary schools in four districts in South Tajikistan were randomly selected. In schoolchildren aged 7 to 11 years, a spot urine sample was collected for measurement of urinary iodine, dried blood spots were collected for measurement of thyroglobulin, and goitre was assessed by palpation. Iodine content of salt samples and local selling points was determined by coloration using rapid test kits and titration method. RESULTS: Of 623 schoolchildren enrolled, complete data was obtained from 589. The overall median urinary iodine concentration (UIC) was 51.2 µg/L indicating mild-to-moderate iodine deficiency. Among all children, 46.6% (95% Confidence Interval (CI) = 42.4%-50.6%) of children were found to be goitrous (grade 1 goitre: 30.6%, 95% CI = 26.9%-34.5%; grade 2 goitre: 16.0%, 95% CI = 13.1%-19.2%). The risk factor for goitre remaining significant in the multivariable logistic regression model was 'buying salt once a month' (OR = 2.89, 95% CI = 1.01-8.22) and 'buying salt once every six months' (OR = 2.26, 95% CI = 1.01-5.04) compared to 'buying salt every one or two weeks'. The overall median thyroglobulin concentration was elevated at 13.9 µg/L. Of the salt samples from households and selling points, one third were adequately iodised, one third insufficiently and one third were not iodised. CONCLUSION: Iodine deficiency remains a serious health issue among children in southern Tajikistan. There is a persisting high prevalence of goitre, elevated thyroglobulin and low UIC despite interventions implemented by Tajikistan and international partners. Quality control of salt iodine content needs to be improved. Continued efforts to raise awareness of the health effects of iodine deficiency are needed to increase consumer demand for iodised salt.

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.

FLOTAC for the diagnosis of Hymenolepis spp. infection: proof-of-concept and comparing diagnostic accuracy with other methods.

Hymenolepis nana is the most common cestode parasitizing humans, yet it is under-diagnosed. We determined the optimal flotation solution (FS) for the diagnosis of this intestinal parasite with the FLOTAC method, and compared its diagnostic accuracy with an ether-concentration technique and the Kato-Katz method. Zinc sulphate (specific gravity 1.20) proved to be the best-performing FS. Using this FS, we detected 65 H. nana infections among 234 fixed fecal samples from Tajik and Sahrawi children (prevalence 27.8 %). The ether-concentration technique detected 40 infections (prevalence 17.1 %) in the same samples. Considering the combined results as a reference, the sensitivities of FLOTAC and ether-concentration were 95.6 % and 58.8 %, respectively. The Kato-Katz method resulted in a prevalence of only 8.7 %. In terms of eggs per gram of stool, a significantly (P <0.05) higher value was obtained with the FLOTAC and Kato-Katz techniques compared to ether-concentration. In another study carried out in China, the FLOTAC method detected six Hymenolepis diminuta infections in 302 fecal samples, whereas five samples were found positive with the Kato-Katz technique. We conclude that FLOTAC is an accurate coprodiagnostic technique for H. nana and H. diminuta, two species which join a growing list of intestinal parasites that can be reliably diagnosed by this technique.

Prevalence and risk factors of helminths and intestinal protozoa infections among children from primary schools in western Tajikistan.

BACKGROUND: Intestinal parasitic infections represent a public health problem in Tajikistan, but epidemiological evidence is scarce. The present study aimed at assessing the extent of helminths and intestinal protozoa infections among children of 10 schools in four districts of Tajikistan, and to make recommendations for control. METHODS: A cross-sectional survey was carried out in early 2009. All children attending grades 2 and 3 (age: 7-11 years) from 10 randomly selected schools were invited to provide a stool sample and interviewed about sanitary situation and hygiene behaviour. A questionnaire pertaining to demographic and socioeconomic characteristics was addressed to the heads of households. On the spot, stool samples were subjected to duplicate Kato-Katz thick smear examination for helminth diagnosis. Additionally, 1-2 g of stool was fixed in sodium acetate-acetic acid-formalin, transferred to a specialised laboratory in Europe and examined for helminths and intestinal protozoa. The composite results from both methods served as diagnostic 'gold' standard. RESULTS: Out of 623 registered children, 602 participated in our survey. The overall prevalence of infection with helminths and pathogenic intestinal protozoa was 32.0% and 47.1%, respectively. There was pronounced spatial heterogeneity. The most common helminth species was Hymenolepis nana (25.8%), whereas the prevalences of Ascaris lumbricoides, hookworm and Enterobius vermicularis were below 5%. The prevalence of pathogenic intestinal protozoa, namely Giardia intestinalis and Entamoeba histolytica/E. dispar was 26.4% and 25.9%, respectively. Almost half of the households draw drinking water from unimproved sources, such as irrigation canals, rivers and unprotected wells. Sanitary facilities were pit latrines, mostly private, and a few shared with neighbours. The use of public tap/standpipe as a source of drinking water emerged as a protective factor for G. intestinalis infection. Protected spring water reduced the risk of infection with E. histolytica/E. dispar and H. nana. CONCLUSIONS: Our data obtained from the ecological 'lowland' areas in Tajikistan call for school-based deworming (recommended drugs: albendazole and metronidazole), combined with hygiene promotion and improved sanitation. Further investigations are needed to determine whether H. nana represents a public health problem.

Accuracy of the Kato-Katz, adhesive tape and FLOTAC techniques for helminth diagnosis among children in Kyrgyzstan.

The purpose of this study was to assess the accuracy of three copro-microscopic techniques for helminth diagnosis: Kato-Katz, adhesive tape and FLOTAC. A total of 163 children from a peri-urban municipality near Bishkek, Kyrgyzstan, participated and submitted multiple stool samples and adhesive tapes. Ninety children supplied at least two stool samples and two adhesive tapes. Three stool samples and three adhesive tapes were available from 71 and 64 children, respectively. From each stool sample, a single Kato-Katz thick smear was prepared and examined quantitatively. Additionally, the first stool sample was subjected to the FLOTAC technique and helminth eggs were counted. Adhesive tapes were checked for the presence of Enterobius vermicularis eggs. Using pooled results as a diagnostic 'gold' standard, the prevalence of Ascaris lumbricoides, E. vermicularis, Hymenolepis nana and Dicrocoelium dendriticum were 54.4%, 13.3%, 11.1% and 11.1%, respectively. Infection intensities were low. When compared to triplicate Kato-Katz, a single FLOTAC was more sensitive for the diagnosis of A. lumbricoides (89.5% versus 39.5%) and D. dendriticum (88.9% versus 33.3%), but less sensitive for H. nana (66.7% versus 88.9%). For E. vermicularis, three adhesive tapes showed much higher sensitivity than a single FLOTAC (92.9% versus 14.3%). FLOTAC yielded significantly higher faecal egg counts than Kato-Katz for A. lumbricoides and D. dendriticum. Overall results suggest that, although FLOTAC represents a promising technique for helminth diagnosis in Kyrgyzstan, the repeated adhesive tape test remains so far the method of choice for diagnosing E. vermicularis.

History of malaria control in Tajikistan and rapid malaria appraisal in an agro-ecological setting.

BACKGROUND: Reported malaria cases in rice growing areas in western Tajikistan were at the root of a rapid appraisal of the local malaria situation in a selected agro-ecological setting where only scarce information was available. The rapid appraisal was complemented by a review of the epidemiology and control of malaria in Tajikistan and Central Asia from 1920 until today. Following a resurgence in the 1990s, malaria transmission has been reduced considerably in Tajikistan as a result of concerted efforts by the government and international agencies. The goal for 2015 is transmission interruption, with control interventions and surveillance currently concentrated in the South, where foci of Plasmodium vivax and Plasmodium falciparum persist. METHODS: The rapid malaria appraisal was carried out in six communities of irrigated rice cultivation during the peak of malaria transmission (August/September 2007) in western Tajikistan. In a cross-sectional survey, blood samples were taken from 363 schoolchildren and examined for Plasmodium under a light microscope. A total of 56 farmers were interviewed about agricultural activities and malaria. Potential Anopheles breeding sites were characterized using standardized procedures. A literature review on the epidemiology and control of malaria in Tajikistan was conducted. RESULTS: One case of P. vivax was detected among the 363 schoolchildren examined (0.28%). The interviewees reported to protect themselves against mosquito bites and used their own concepts on fever conditions, which do not distinguish between malaria and other diseases. Three potential malaria vectors were identified, i.e. Anopheles superpictus, Anopheles pulcherrimus and Anopheles hyrcanus in 58 of the 73 breeding sites examined (79.5%). Rice paddies, natural creeks and man-made ponds were the most important Anopheles habitats. CONCLUSION: The presence of malaria vectors and parasite reservoirs, low awareness of, and protection against malaria in the face of population movements and inadequate surveillance may render local communities vulnerable to potential epidemics. To attain malaria transmission interruption in Tajikistan by 2015, there is a need for rigorous surveillance along with strengthening of primary health care facilities for effective case management, and possibly a more differentiated vector control strategy based on additional local evidence.

Prior selfing and the selfing syndrome in animals: an experimental approach in the freshwater snail Biomphalaria pfeifferi.

Inbreeding species of hermaphroditic animals practising copulation have been characterized by few copulations, no waiting time (the time that an isolated individual waits for a partner before initiating reproduction compared with paired individuals) and limited inbreeding (self-fertilization) depression. This syndrome, which has never been fully studied before in any species, is analysed here in the highly selfing freshwater snail Biomphalaria pfeifferi. We conducted an experiment under laboratory conditions over two generations (G1 and G2) using snails sampled from two populations (100 individuals per population). G1 individuals were either isolated or paired once a week (potentially allowing for crosses), and monitored during 29 weeks for growth, fecundity and survival. Very few copulations were observed in paired snails, and there was a positive correlation in copulatory activity (e.g. number of copulations) between the male and female sexual roles. The waiting time was either null or negative, meaning that isolated individuals initiated reproduction before paired ones. G2 offspring did not differ in hatching rate and survival (to 28 days) between treatments, but offspring from paired individuals grew faster than those from isolated individuals. On the whole, the self-fertilization depression was extremely low in both populations. Another important result is that paired G1 individuals began laying (selfed) eggs several weeks prior to initiating copulation: this is the first characterization of prior selfing (selfing initiated prior to any outcrossing) in a hermaphroditic animal. A significant population effect was observed on most traits studied. Our results are discussed with regard to the maintenance of low outcrossing rates in highly inbreeding species.

Risk factors for Schistosoma mansoni and hookworm in urban farming communities in western Côte d'Ivoire.

OBJECTIVES: To identify risk factors for Schistosoma mansoni and hookworm infections in urban farming communities, and to investigate small-scale spatial patterns of infection prevalence. METHODS: A cross-sectional survey was carried out in 113 farming households (586 individuals) and 21 non-farming households (130 individuals) from six agricultural zones in the town of Man, western Côte d'Ivoire. Heads of households were interviewed on common agricultural activities, land and water use, education attainment, socioeconomic status and sanitation facilities. Household members provided stool specimens that were processed by the Kato-Katz technique and a formol-ether concentration method and diagnosed for S. mansoni, hookworms and other soil-transmitted helminths and intestinal protozoa. Bayesian statistics were employed for spatial analyses. RESULTS: The prevalences of S. mansoni and hookworm in farming households were 51.4% and 24.7%, respectively. Risk factors for a S. mansoni infection comprised living in close proximity to the Kô River, water contact with irrigation wells and ponds and low education attainment. Living in zones of smallholder irrigated rice plots or large rice perimeters, using water from domestic wells, and low socioeconomic status were risk factors for a hookworm infection. We found significant spatial heterogeneity between agricultural zones, with the highest infection prevalences of S. mansoni and hookworm in the zone where there was a large rice perimeter. CONCLUSIONS: In this urban setting, both S. mansoni and hookworm infections were related to specific agricultural activities. Health education and active participation of urban farmers for the control of schistosomiasis and soil-transmitted helminthiasis is recommended.

Spatial risk profiling of Schistosoma japonicum in Eryuan county, Yunnan province, China.

Bayesian spatial risk profiling holds promise to enhance our understanding of the epidemiology of parasitic diseases, and to target interventions in a cost-effective manner. Here, we present findings from a study using Bayesian variogram models to map and predict the seroprevalence of Schistosoma japonicum in Eryuan county, Yunnan province, China, including risk factor analysis. Questionnaire and serological data were obtained through a cross-sectional survey carried out in 35 randomly selected villages with 3,220 people enrolled. Remotely-sensed environmental data were derived from publicly available databases. Bivariate and non-spatial Bayesian multiple logistic regression models were used to identify associations between the local seroprevalence and demographic (i.e. age and sex), environmental (i.e. location of village, altitude, slope, land surface temperature and normalized difference vegetation index) and socio-economic factors. In the spatially-explicit Bayesian model, S. japonicum seroprevalence was significantly associated with sex, age and the location of the village. Males, those aged below 10 years and inhabitants of villages situated on steep slopes (inclination =20 degrees ) or on less precipitous slopes of >5 degrees above 2,150 m were at lower risk of seroconversion than their respective counterparts. Our final prediction model revealed an elevated risk for seroconversion in the plains of the eastern parts of Eryuan county. In conclusion, the prediction map can be utilized for spatial targeting of schistosomiasis control interventions in Eryuan county. Moreover, S. japonicum seroprevalence studies might offer a convenient means to assess the infection pressure experienced by local communities, and to improve risk profiling in areas where the prevalence and infection intensities have come down following repeated rounds of praziquantel administration.

Urban farming and malaria risk factors in a medium-sized town in Cote d'Ivoire.

Urbanization occurs at a rapid pace across Africa and Asia and affects people's health and well-being. A typical feature in urban settings of Africa is the maintenance of traditional livelihoods, including agriculture. The purpose of this study was to investigate malaria risk factors in urban farming communities in a medium-sized town in Côte d'Ivoire. Two cross-sectional surveys were carried out among 112 households from six agricultural zones. First, the heads of households were interviewed on agricultural land use, farming practices, water storage, sanitation facilities, and socioeconomic status. Second, a finger prick blood sample was taken from all household members and examined for the occurrence and density of Plasmodia. Geographic coordinates of houses, farming plots, and potential mosquito breeding sites were recorded and integrated into a geographic information system. Predictors of Plasmodium falciparum parasitemia were assessed using non-random and random effects Bayesian regression models. The overall prevalence of P. falciparum was 32.1%. In children < 15 years of age, risk factors for a P. falciparum infection included living in a specific agricultural zone, close proximity to permanent ponds and fish ponds, periodic stays overnight in temporary farm huts, and low socioeconomic status. Our findings indicate that specific crop systems and specific agricultural practices may increase the risk of malaria in urban settings of tropical Africa.

Urban agricultural land use and characterization of mosquito larval habitats in a medium-sized town of Côte d'Ivoire.

Urban agriculture is common across Africa and contributes to the livelihoods of urban dwellers. Some crop systems create suitable mosquito breeding sites and thus might affect malaria transmission. The purpose of this study was to identify, map, and characterize potential mosquito breeding sites in agricultural land use zones in a medium-sized town of western Côte d'Ivoire and to assess risk factors for productive Anopheles breeding sites. Two surveys were carried out; one toward the end of the rainy season and the second one during the dry season. In all identified potential mosquito breeding sites, two experienced entomologists searched for the presence of Anopheles larvae and pupae with a standardized technique. Totals of 369 and 589 sites were found in the rainy and dry seasons, respectively, mainly in vegetable gardens and irrigated rice fields. Anopheles larvae were present in 50.7% and 42.4% of the sites investigated during the rainy and dry seasons, respectively. Typical Anopheles larval habitats were characterized by the presence of algae, the absence of floating vegetation, and the co-occurrence of Culex larvae. The highest Anopheles larval productivity was observed in rice paddies, agricultural trenches between vegetable patches, and irrigation wells. An indirect link could be established between the occurrence of productive Anopheles breeding sites and agricultural land use through specific man-made habitats, in particular agricultural trenches, irrigation wells, and rice paddies. Our findings have important bearings for the epidemiology and control of urban malaria in sub-Saharan Africa.

Disparities in parasitic infections, perceived ill health and access to health care among poorer and less poor schoolchildren of rural Côte d'Ivoire.

Differences in the state of health between rural and urban populations living in Africa have been described, yet only few studies analysed inequities within poor rural communities. We investigated disparities in parasitic infections, perceived ill health and access to formal health services among more than 4000 schoolchildren from 57 primary schools in a rural area of western Côte d'Ivoire, as measured by their socioeconomic status. In a first step, we carried out a cross-sectional parasitological survey. Stool specimens and finger prick blood samples were collected and processed with standardized, quality-controlled methods, for diagnosis of Schistosoma mansoni, soil-transmitted helminths, intestinal protozoa and Plasmodium. Then, a questionnaire survey was carried out for the appraisal of self-reported morbidity indicators, as well as housing characteristics and household assets ownership. Mean travel distance from each village to the nearest health care delivery structure was provided by the regional health authorities. Poorer schoolchildren showed a significantly higher infection prevalence of hookworm than better-off children. However, higher infection prevalences of intestinal protozoa (i.e. Blastocystis hominis, Endolimax nana and Iodamoeba butschlii) were found with increasing socioeconomic status. Significant negative associations were observed between socioeconomic status and light infection intensities with hookworm and S. mansoni, as well as with several self-reported morbidity indicators. The poorest school-attending children lived significantly further away from formal health services than their richer counterparts. Our study provides evidence for inequities among schoolchildren's parasitic infection status, perceived ill health and access to health care in a large rural part of Côte d'Ivoire. These findings call for more equity-balanced parasitic disease control interventions, which in turn might be an important strategy for poverty alleviation.

Multiple parasite infections and their relationship to self-reported morbidity in a community of rural Côte d'Ivoire.

BACKGROUND: Concomitant parasitic infections are common in the developing world, yet most studies focus on a single parasite in a narrow age group. We investigated the extent of polyparasitism and parasite associations, and related these findings to self-reported morbidity. METHODS: Inhabitants of 75 randomly selected households from a single village in western Côte d'Ivoire provided multiple faecal specimens and a single finger prick blood sample. The Kato-Katz technique and a formol-ether concentration method were employed to screen faecal samples for Schistosoma mansoni, soil-transmitted helminths and intestinal protozoa. Giemsa-stained blood smears were analysed for malaria parasites. A questionnaire was administered for collection of demographic information and self-reported morbidity indicators. RESULTS: Complete parasitological data were obtained for 500/561 (89.1%) participants, similarly distributed among sex, with an age range from 5 days to 91 years. The prevalences of Plasmodium falciparum, hookworms, Entamoeba histolytica/E. dispar, and S. mansoni were 76.4%, 45.0%, 42.2%, and 39.8%, respectively. Three-quarters of the population harboured three or more parasites concurrently. Multivariate analysis revealed significant associations between several pairs of parasites. Some parasitic infections and the total number of parasites were significantly associated with self-reported morbidity indicators. CONCLUSIONS: Our data confirm that polyparasitism is very common in rural Côte d'Ivoire and that people have clear perceptions about the morbidity caused by some of these parasitic infections. Our findings can be used for the design and implementation of sound intervention strategies to mitigate morbidity and co-morbidity.