Vaccination of dogs in an African city interrupts rabies transmission and reduces human exposure.

Despite the existence of effective rabies vaccines for dogs, dog-transmitted human rabies persists and has reemerged in Africa. Two consecutive dog vaccination campaigns took place in Chad in 2012 and 2013 (coverage of 71% in both years) in the capital city of N'Djaména, as previously published. We developed a deterministic model of dog-human rabies transmission fitted to weekly incidence data of rabid dogs and exposed human cases in N'Djaména. Our analysis showed that the effective reproductive number, that is, the number of new dogs infected by a rabid dog, fell to below one through November 2014. The modeled incidence of human rabies exposure fell to less than one person per million people per year. A phylodynamic estimation of the effective reproductive number from 29 canine rabies virus genetic sequences of the viral N-protein confirmed the results of the deterministic transmission model, implying that rabies transmission between dogs was interrupted for 9 months. However, new dog rabies cases appeared earlier than the transmission and phylodynamic models predicted. This may have been due to the continuous movement of rabies-exposed dogs into N'Djaména from outside the city. Our results show that canine rabies transmission to humans can be interrupted in an African city with currently available dog rabies vaccines, provided that the vaccination area includes larger adjacent regions, and local communities are informed and engaged.

Human and livestock trematode infections in a mobile pastoralist setting at Lake Chad: added value of a One Health approach beyond zoonotic diseases research.

Background: At Lake Chad in Central Africa, mobile pastoralists face economic losses due to livestock trematodiases. Fasciola gigantica and Schistosoma bovis-trematodes that affect livestock-share transmission ecology traits with Schistosoma haematobium and S. mansoni that cause human schistosomiasis. This project aimed at assessing treatment strategies and elucidating the predictive potential of human and livestock trematode infections. Methods: Schistosomiasis and fascioliasis were investigated concurrently in humans and cattle by repeated cross-sectional surveys. Urine and stool samples from humans and faecal samples from cattle were examined for trematode eggs. Treatment strategies were assessed by means of focus group discussions and in-depth interviews. Results: Mobile pastoralists of four ethnic groups participated. Prevalence of human schistosomiasis and livestock trematodiases showed considerable heterogeneity from one ethnic group to another, but correlated within ethnic groups. Effective trematocidal drugs were not available in the study area. Conclusions: Mutual predictive potential of human schistosomiasis and livestock fascioliasis relates to distinct livestock husbandry practices. Introducing efficacious strategic treatment against human schistosomiasis and livestock fascioliasis might improve human and animal health and well-being. Our research provides evidence for the benefits of a One Health approach targeting diseases that share specific ecological traits.

Treatment of human and livestock helminth infections in a mobile pastoralist setting at Lake Chad: Attitudes to health and analysis of active pharmaceutical ingredients of locally available anthelminthic drugs.

Mobile pastoralists face challenges in accessing quality health care and medication for managing human and animal diseases. We determined livestock disease priorities, health seeking behaviour of people bearing helminthiases and - placing particular emphasis on trematode infections - treatment strategies and outcome satisfaction among mobile pastoralists of four ethnic groups in the Lake Chad area using focus group discussions. People suffering from schistosomiasis were interviewed about symptoms, health seeking behaviour and their satisfaction with respect to the provided treatment. Anthelminthic drugs for human and veterinary use obtained from various health care structures were analysed for active pharmaceutical ingredients (API) and quantity, using high pressure liquid chromatography-UV and liquid chromatography combined with tandem mass spectrometry. Most people suffering from schistosomiasis sought treatment at health care centres. Yet, they also consulted informal providers without medical training. Regarding animal health, self-mediated therapy was common to manage suspected livestock fascioliasis. Self-reported treatment satisfaction for human schistosomiasis and trematodiasis treatment outcome in livestock were low. Mobile pastoralists perceived the purchased drugs to be of low quality. Among 33 products locally sold as anthelminthic drugs for human or veterinary use, 27 contained albendazole or mebendazole, varying between 91% and 159% of the labelled amount. Six products were sold loosely with incomplete information and their API could not be identified. No counterfeit anthelminthic drugs were detected. None of the samples contained praziquantel or triclabendazole, the drugs of choice against schistosomiasis and fascioliasis, respectively. The perceived unsatisfactory treatment outcomes in humans and animals infected with trematodes are most likely due to empiric diagnosis and the resulting use of inadequate therapy for human schistosomiasis and the lack of efficacious drugs against livestock fascioliasis.

Re-infection with Fasciola gigantica 6-month post-treatment with triclabendazole in cattle from mobile pastoralist husbandry systems at Lake Chad.

At Lake Chad in central Africa, livestock fascioliasis caused by Fasciola gigantica represents a major veterinary health problem, particularly in cattle reared in mobile pastoralist husbandry systems. We assessed re-infection after a single dose of triclabendazole with fascioliasis in cattle in a mobile pastoralist setting towards the end of the dry season. Within the cattle herds of 14 groups of mobile pastoralists, 375 cattle were randomly selected. A faecal sample was obtained from each animal to determine the prevalence of F. gigantica. Animals were administered a single oral dose of triclabendazole (12mg/kg). A second faecal sample was obtained 6-month post-treatment after cattle had returned from the annual migration cycle. Faecal samples were fixed in sodium acetate-acetic acid-formalin (SAF), and examined for F. gigantica using the sedimentation technique. From the 375 cattle enrolled at baseline, 198 animals (53%) in 12 groups of mobile pastoralists were re-sampled at the 6-month follow-up. Baseline prevalence did not differ noteworthy between animals lost to follow-up and those re-examined. At baseline, bovine fascioliasis prevalence in cattle with follow-up data was 41.9% (95% confidence interval (CI) 35.2-48.9%). At the 6-month post-treatment follow-up, the prevalence was 46.0% (95% CI 39.2-52.9%), ranging between 0% and 75% at the herd level. The mean faecal egg counts at the unit of the herd were higher at follow-up compared to baseline. The observed persistent high prevalence of F. gigantica infection in cattle shows that a single pre-rainy season treatment does not prevent rapid re-infection despite the partial migration away from the high-risk areas at Lake Chad into drier areas. A locally adapted strategic control package for fascioliasis in cattle in the Lake Chad area ought to integrate targeted triclabendazole treatment and seasonal transhumance practices.

Validation of a Point-of-Care Circulating Cathodic Antigen Urine Cassette Test for Schistosoma mansoni Diagnosis in the Sahel, and Potential Cross-Reaction in Pregnancy.

On the shores of Lake Chad, schistosomiasis among mobile pastoralists was investigated in a field laboratory. Point-of-care circulating cathodic antigen (POC-CCA) cassette test, reagent strip, and filtration were conducted on urine samples. Fresh stool samples were subjected to the Kato-Katz technique, and fixed samples were examined with an ether-concentration method at a reference laboratory. POC-CCA urine cassette tests revealed a Schistosoma mansoni prevalence of 6.9%, compared with only 0.5% by stool microscopy. Three pregnant women with otherwise negative urine and stool testing had positive POC-CCA. This observation raises concern of cross-reactivity in pregnancy. Hence, two pregnant women in Switzerland with no history of schistosomiasis were subjected to POC-CCA and one tested positive. Our data suggest that POC-CCA can be performed under extreme Sahelian conditions (e.g., temperatures > 40°C), and it is more sensitive than stool microscopy for S. mansoni diagnosis. However, potential cross-reactivity in pregnancy needs further investigation.

Seroprevalence of Rift Valley fever, Q fever, and brucellosis in ruminants on the southeastern shore of Lake Chad.

The seroprevalence of Rift Valley fever (RVF), brucellosis, and Q fever among domestic ruminants on the southeastern shore of Lake Chad was studied. The study area consisted of two parts, including mainland and islands. On the mainland, the study was conducted in nine randomly selected villages and camps. On the islands, samples were collected from all four available sites. A total of 985 serum samples were collected and 924 were analyzed using enzyme-linked immunosorbent assay (ELISA) for RVF. A total of 561 samples collected from islands were analyzed using ELISA for Q fever and both ELISA and Rose Bengal tests (RBT) for brucellosis. The apparent RVF seroprevalence by species was 37.8% (95% confidence interval [CI] 34.2-41.3) in cattle, 18.8% (95% CI 12.3-25.2) in goats, and 10.8% (95% CI 3.0-18.5) in sheep. For brucellosis and Q fever, only cattle samples from islands were analyzed. For Q fever, the apparent seroprevalence was 7.8% (95% CI 5.6-10.1). For brucellosis, the RBT showed a prevalence of 5.7% (95% CI 3.8-7.6), and ELISA showed 11.9% (95% CI 9.3-14.6) with a kappa value of 0.53 showing a moderate agreement between the two tests. This study confirms the presence of the three diseases in the study area. More research is required to assess the importance for public health and conservation of the Kouri cattle breed.

The benefits of 'One Health' for pastoralists in Africa.

'One health' is particularly suited to serve mobile pastoralists. Dinka pastoralists in Sudan inspired Calvin Schwabe to coin the term 'one medicine', indicating that there is no difference in paradigm between human and veterinary medicine. Our contemporary definition of 'one health' is any added value in terms of improved health of humans and animals or financial savings or environmental services resulting from a closer cooperation of human and animal health sectors. Here we present a summary of 'one health' studies with mobile pastoralists in Africa which were done in research partnership, demonstrating such an added value. Initial joint human and animal health studies revealed higher livestock vaccination coverage than in the pastoralist community, leading to joint animal and human vaccination intervention studies which demonstrated a better access to primary health care services for pastoralists in Chad. Further simultaneous animal and human serological studies showed that camel breeding was associated with human Q-fever seropositivity. In Borana communities in Ethiopia, human cases of Mycobacterium bovis infection could be related to strains isolated from cattle. A challenge remained with regard to how to assess vaccination coverage in mobile populations. With the advent of mobile phones, health and demographic surveillance could be established for mobile pastoralists and their animals. This presents vast possibilities for surveillance and control of human and animal diseases. Pastoralists prefer a 'one health' approach and therefore contribute toward the validation of this concept by showing real added value of the cooperation between human and animal health services.

Diarrhoea, vomiting and the role of milk consumption: perceived and identified risk in Bamako (Mali).

OBJECTIVES: To evaluate the public health impact of milk contamination in Bamako, Mali. METHODS: A case-control study assessed the risk-factors for food-borne toxi-infections with diarrhoea and vomiting as main clinical picture. A total of 131 schoolchildren between 5 and 20 years of age were interviewed by trained interviewers in schools in Bamako. A structured questionnaire was used to record health problems, food and particularly milk consumption habits and socio-economic indicators. RESULTS: Final multivariate logistic regression analysis identified regular consumption of boiled milk [odds ratio(OR) = 4.38; 95% CI = 1.15-16.71], age between 5 and 10 years (OR vs. age group 11-15 years = 3.28; 95% CI = 1.09-9.85) and the existence of dry latrines in the household (OR = 7.65; 95% CI = 1.92-30.55) as risk factors for diarrhoea and vomiting. Other milk products and the socio-economic level of the household were not significantly associated with the outcome. Many people were unaware of the potential risks of milk consumption. CONCLUSIONS: Milk products may be a risk factor for food-borne toxi-infections. Attention has to be paid to products considered 'safe', such as boiled or pasteurized milk. The low awareness of potential risks of many people may increase the risk of milk consumption. To achieve a sustainable increase in local milk production in Africa, milk quantity and production and transformation quality should be improved simultaneously.

Doppler study of the uterine artery in patients using an intrauterine contraceptive device.

A Doppler flow study of the uterine artery was performed using transvaginal sonography in 68 women, including 44 using an intrauterine contraceptive device (IUCD) and 24 control women who were not using any method of contraception. Both the pulsatility index (PI) and resistance index (RI) were significantly lower in women with IUCD-induced bleeding than in those without abnormal vaginal bleeding (p < 0.001) or in women not using any method of contraception (p < 0.001). No significant variations in PI and RI levels (p > 0.05) were found with the duration of IUCD application or the duration of IUCD-induced bleeding in patients using the device. Also, no significant changes in blood flow indices were demonstrated between women using the device without abnormal vaginal bleeding and the control group. These preliminary results suggest that some women are more prone to develop IUCD-induced bleeding than others, and this bleeding may be due to decreased vascular resistance in the uterine artery. Transvaginal Doppler study of the uterine artery may be a helpful technique to identify such women.