M. Bechir

Human and Animal Vaccination Delivery to Remote Nomadic Families, Chad

Vaccinating nomadic pastoralists and their livestock at the same time reduces delivery costs.

Towards Integrated and Adapted Health Services for Nomadic Pastoralists and their Animals: A North–South Partnership

Mobility of pastoralists in arid and semi-arid zones renders access to primary social services difficult. The experiences, local concepts and propositions of nomadic communities of Chad were essential to fill the information gaps on how to provide adapted health services to mobile communities. In Chad, we have taken an iterative, corkscrew-like research and action strategy: a better understanding of the determinants of health and communities’ health priorities – obtained by interdisciplinary collaborations between medicine, anthropology, epidemiology, social geography and microbiology – were integrated in the participatory identification of intervention options out of a range of possible responses by the health and veterinary services. Recommendations from national stakeholder workshops paved the way for implementing and testing new interventions. All stakeholders reviewed outcomes of interventions periodically. The programme provided opportunities for participatory processes and actions that were defined in an open way at the beginning. An appropriate North–South research partnership framework and the long-term commitment of all partners have been crucial in the process of building stakeholders’ ownership. University curricula rarely enable scientists to communicate with other disciplines, and researchers first needed to acquire skills in crossing the boundaries between human and natural sciences and between sectors. We describe here in a chronologic way the elements that led to innovative health and veterinary services for nomadic pastoralists of Chad; such as joint vaccination services of the public health and the livestock sectors and subsequent initiatives that were initiated by the nomadic communities once they began to trust the programme.

Health of mobile pastoralists in the Sahel - assessment of 15 years of research and development.

In the Sahel, between Mauritania and Somalia including Northern Kenya, about 20–30 million people live as mobile pastoralists. The rhythm of their migration follows the seasons and the availability of resources such as water, pasture and salt. Despite their high exposure to zoonoses and problems caused by extreme climatic conditions, mobile pastoralists are virtually excluded from health services because the provision of social services adapted to their way of life is challenging. In cooperation with various partners in the region, the Swiss Tropical and Public Health Institute has been active in research and development in the Sahel for 15 years. Based on the perceived needs of mobile pastoralists and the necessities of development, interdisciplinary research has considerably contributed to better understanding of their situation and their problems. Close contact between humans and livestock necessitates close cooperation between human and animal health specialists. Such useful approaches should be continued and extended.

Parasitic Infections, Anemia and Malnutrition Among Rural Settled and Mobile Pastoralist Mothers and Their Children in Chad

Malnutrition, resulting from various etiologies, is common in rural Chadian women and children. This cross-sectional study assessed the spectrum of parasitic infection and level of anemia and their effect on nutritional status in settled and mobile pastoral mothers and children near Lake Chad. Intestinal parasites were evaluated using direct fecal smears and the Kato–Katz technique. Malaria status was determined using Paracheck-Pf® rapid diagnostic test, and anemia was assessed with the Hemocue photometer. Nutritional status was evaluated using anthropometric parameters. At the end of the 2008 wet season, the prevalence of malnutrition was 36% [confidence interval (CI) 30–42] among women and 15% (CI 11–18) among children. The prevalence of intestinal parasitic infection was 75% (CI 68–83) among women and 60% (CI 53–66) among children. The predominant helminth species was Ascaris lumbricoides while Entamoeba histolytica/dispar was the most common protozoan. The hookworm prevalence was 14% (CI 8–20) in women and 18% (CI 13–23) in children. Malaria prevalence was low among women (1%, CI 0.5–2) and children (3% CI 2–5). No significant difference was observed in the prevalence of parasitic infection between the mobile pastoralist and rural sedentary populations. Thirty-four percent (CI 27–40) of nonpregnant women, 53% (CI 34–72) of pregnant women, and 27% (CI 23–32) of children were anemic. In subjects infected with Plasmodium, all women and 54% (CI 22–85) of children were anemic. Malnutrition was significantly associated with anemia in mothers and with selected intestinal parasites, anemia and age in their children.

Estimating population and livestock density of mobile pastoralists and sedentary settlements in the south-eastern Lake Chad area.

Mobile pastoralists provide major contributions to the gross domestic product in Chad, but little information is available regarding their demography. The Lake Chad area population is increasing, resulting in competition for scarce land and water resources. For the first time, the density of people and animals from mobile and sedentary populations was assessed using randomly defined sampling areas. Four sampling rounds were conducted over two years in the same areas to show population density dynamics. We identified 42 villages of sedentary communities in the sampling zones; 11 (in 2010) and 16 (in 2011) mobile pastoralist camps at the beginning of the dry season and 34 (in 2011) and 30 (in 2012) camps at the end of the dry season. A mean of 64.0 people per km2 (95% confidence interval, 20.3-107.8) were estimated to live in sedentary villages. In the mobile communities, we found 5.9 people per km2 at the beginning and 17.5 people per km2 at the end of the dry season. We recorded per km2 on average 21.0 cattle and 31.6 small ruminants in the sedentary villages and 66.1 cattle and 102.5 small ruminants in the mobile communities, which amounts to a mean of 86.6 tropical livestock units during the dry season. These numbers exceed, by up to five times, the published carrying capacities for similar Sahelian zones. Our results underline the need for a new institutional framework. Improved land use management must equally consider the needs of mobile communities and sedentary populations.

Seasonal dynamics of human retinol status in mobile pastoralists in Chad

Vitamin A deficiency is a prevalent public health problem in Africa and South-East Asia, although national population based surveys are lacking in many countries. This study investigated seasonal variation of human retinol concentrations in Chadian mobile pastoralists to identify critical time periods for interventions addressing vitamin A deficiency. The repeated cross-sectional study design used convenience sampling during three seasons to include 327 Fulani, Gorane and Arab adult mobile pastoralists in nine camps in the Lake Chad area. Human blood and pooled cattle milk retinol concentrations were rapidly assessed by portable flourometer (iCheck™). Linear regression models with random effects for correlation within camps were applied with human retinol concentration as outcome. Logistic regression models, with camp as random effect, were evaluated for the outcome human retinol deficiency. Human seasonal means were 2.14μmol/L (95% CI 1.82-2.46) in rainy, 0.99μmol/L (95% CI 0.91-1.07) in cold and 1.86μmol/L (95% CI 1.63-2.09) in dry season. Retinol concentration and deficiency varied according to season and ethnic group. Average values were highest in Gorane during rainy and in Fulani in the cold and dry seasons. Arabs had lowest average values in all seasons. Retinol deficiency (<0.70μmol/L) was found in 15% of study participants in the dry, 25% in the rainy and 32% in the cold season. Retinol concentrations varied according to age, sex, milk consumption level and pooled cattle milk retinol concentration. Effect sizes varied and not all were statistically significantly different. Pooled cattle milk retinol concentrations varied seasonally and were positively associated to human retinol concentrations. This study establishes seasonal variation in human blood and pooled cattle milk retinol concentrations in Chad, demonstrating a linkage from animals to humans through milk. Rapid analysis using portable technology is feasible in remote populations under harsh climatic conditions.

Human and animal health surveys among pastoralists.

Valid human and livestock health surveys, including longitudinal follow-up, are feasible among mobile pastoralists and provide fundamental information to agencies for interventions that are responsive to realities and effective in addressing the needs of pastoralists. However, pastoralists are often excluded from studies, surveillance systems and health programmes. The occurrence of preventable and treatable diseases such as perinatal tetanus, measles and tuberculosis are indicative of limited access to health providers and information. It is difficult for health services to include effective outreach with their available financial and human resources. One consequence is that maternal mortality rates among pastoralists are unacceptably high. Environmental determinants such as the quality of water and the pasture ecosystems further influence the morbidity of pastoralists. In the Sahel, the nutritional status of pastoralist children is seasonally better than that of settled children; but pastoralist women tend to have higher acute malnutrition rates. Pastoralist women are more vulnerable than men to exclusion from health services for different context-specific reasons. Evidence-based control measures can be assessed in cluster surveys with simultaneous assessments of health among people and livestock, where data on costs of disease and interventions are also collected. These provide important arguments for governmental and non-governmental agencies for intervention development. New, integrated One Health surveillance systems making use of mobile technology and taking into account local concepts and the experiences and priorities of pastoralist communities, combined with sound field data, are essential to develop and provide adapted human and animal health services that are inclusive for mobile pastoralist communities and allow them to maintain their mobile way of life.