Effect of a serogroup A meningococcal conjugate vaccine (PsA-TT) on serogroup A meningococcal meningitis and carriage in Chad: a community study [corrected].

BACKGROUND: A serogroup A meningococcal polysaccharide-tetanus toxoid conjugate vaccine (PsA-TT, MenAfriVac) was licensed in India in 2009, and pre-qualified by WHO in 2010, on the basis of its safety and immunogenicity. This vaccine is now being deployed across the African meningitis belt. We studied the effect of PsA-TT on meningococcal meningitis and carriage in Chad during a serogroup A meningococcal meningitis epidemic. METHODS: We obtained data for the incidence of meningitis before and after vaccination from national records between January, 2009, and June, 2012. In 2012, surveillance was enhanced in regions where vaccination with PsA-TT had been undertaken in 2011, and in one district where a reactive vaccination campaign in response to an outbreak of meningitis was undertaken. Meningococcal carriage was studied in an age-stratified sample of residents aged 1-29 years of a rural area roughly 13-15 and 2-4 months before and 4-6 months after vaccination. Meningococci obtained from cerebrospinal fluid or oropharyngeal swabs were characterised by conventional microbiological and molecular methods. FINDINGS: Roughly 1·8 million individuals aged 1-29 years received one dose of PsA-TT during a vaccination campaign in three regions of Chad in and around the capital N'Djamena during 10 days in December, 2011. The incidence of meningitis during the 2012 meningitis season in these three regions was 2·48 per 100,000 (57 cases in the 2·3 million population), whereas in regions without mass vaccination, incidence was 43·8 per 100,000 (3809 cases per 8·7 million population), a 94% difference in crude incidence (p<0·0001), and an incidence rate ratio of 0·096 (95% CI 0·046-0·198). Despite enhanced surveillance, no case of serogroup A meningococcal meningitis was reported in the three vaccinated regions. 32 serogroup A carriers were identified in 4278 age-stratified individuals (0·75%) living in a rural area near the capital 2-4 months before vaccination, whereas only one serogroup A meningococcus was isolated in 5001 people living in the same community 4-6 months after vaccination (adjusted odds ratio 0·019, 95% CI 0·002-0·138; p<0·0001). INTERPRETATION: PSA-TT was highly effective at prevention of serogroup A invasive meningococcal disease and carriage in Chad. How long this protection will persist needs to be established. FUNDING: The Bill & Melinda Gates Foundation, the Wellcome Trust, and Médecins Sans Frontères.

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.

La santé des pasteurs mobiles au Sahel - Bilan de 15 années de recherches et développement.

Dans le Sahel, entre la Mauritanie et la Somalie incluant le Nord Kenya, environ 20 à 30 millions de personnes vivent en transhumance. Le rythme de leur migration suit l'évolution saisonnière du climat et la disponibilité des ressources, telle que l'eau, le pâturage et le sel. Malgré une exposition élevée à certaines maladies comme les zoonoses et les problèmes conditionnés liés au climat, les pasteurs mobiles sont parmi les populations quasiment exclues du système de santé, car la mise à disposition des services sociaux adaptés à un mode de vie mobile est difficile. Suivant l'objectif de recherche d'un meilleur accès aux soins des pasteurs mobiles, l'Institut Tropical et de Santé Publique Suisse, en partenariat avec plusieurs institutions dans la région, est actif au Sahel depuis 15 ans, aussi bien dans le domaine de la recherche, que celui des actions de développement. Basées sur une approche orientée vers les besoins des pasteurs mobiles pour leur développement, des recherches interdisciplinaires ont contribué à mieux comprendre la situation et les problèmes des éleveurs. En relation de la proximité entre l'homme et son bétail, une approche unissant la santé humaine et animale s'est avérée bonne et la valeur ajoutée d'une meilleure collaboration entre médecine humaine, animale et l'environnement a été démontrée. Ces approches utiles devraient être poursuivies et consolidées dans les recherches et le développement des actions futurs.

Morbidity and nutrition patterns of three nomadic pastoralist communities of Chad.

As a part of an interdisciplinary research and action programme, morbidity and nutritional patterns were assessed in three nomadic communities: Fulani and Arab cattle breeders and Arab camel breeders, of two prefectures in Chad. The predominant morbidity pattern of Chadian nomadic pastoralists (representing approximately 10% of the total population of the country) had not been documented so far. A total of 1092 women, men and children was examined by a physician and interviewed during two surveys in the dry season and one in the wet season (1999--2000). Participants with no complaint were rare. Pulmonary disorders (e.g. bronchitis) were most often diagnosed for children under 5 years of age. Of the adult participants, 4.6% were suspected of tuberculosis. Febrile diarrhoea occurred more often during the wet season when access to clean drinking water was precarious. Malaria was only rarely clinically diagnosed among Arabs during the dry season, whereas Fulani, who stayed in the vicinity of Lake Chad, were also affected during this period. A 24-h dietary recall showed that less Arab women than men consumed milk during the dry season (66% versus 92%). Malnutrition was only documented for 3 out of 328 children (0--14 years). Arab women in childbearing age had a higher proportion of children not surviving when compared to Fulani women (0.2 versus 0.07). This study identified several implications for reseach and interventions in nomadic settings. Innovative and integrated health services for nomads can possibly be extended to many settings as nomadic pastoralists have in common a similar way of life driven by the needs of their animals.

[Morbidity patterns in three nomadic communities in Chari-Baguirmi and Kanem, Chad]. / Repartition de la morbidité dans trois communautés nomades du Chari-Baguirmi et du Kanem, Tchad.

Within the framework of an multidisciplinary research and action program, morbidity patterns were assessed in three nomadic communities, i.e., Fulani, Arab cattle breeders and Arab camel breeders, living in Chari-Baguirmi and Kanem, Chad. This is the first data about the health of Chadian nomadic pastoralists who account for approximately 6% of the total population. A total of 1092 women, men and children were interviewed and examined in the course of three surveys carried out by a physician during the dry and rainy season. Nomads reporting no health problems were rare. Tuberculosis was suspected in 4.6% of adults after clinical examination and bronchopulmonary disorders in children less than five years of age. Febrile diarrhea was more prevalent during the wet season when access to clean drinking water was more difficult. Simple malaria was rarely diagnosed in Arabs during the dry season. In contrast simple malaria was frequent in Fulani who stay in the vicinity of Lake Chad during the dry period. Protein-energy malnutrition was observed in only 3 of 328 children younger than 15 years of age.

[Health care services for nomadic people. Lessons learned from research and implementation activities in Chad]. / Quels types de services de santé pour les populations nomades? Apprentissages des activités de recherche et d'action au Tchad.

To overcome barriers of access to health care of nomadic people and to alleviate inequities in health, a transdisciplinary team has initiated research and intervention activities among three nomadic groups of Chad: Foulbé, Arabes and Gouranes. A regular and consistent communication among all actors involved (nomadic groups, researchers, planners and administrators of health and veterinary services, etc.) through repetitive meetings and workshops showed to be a crucial element for success. Differences between ethnic nomadic groups made it necessary to develop specific communication strategies adapted to each group. As to interventions to improve the vaccination coverage, mixed teams combining health and veterinary specialists were able to vaccinate an important number of children and women and showed to have a high potential in terms of organisational and logistic feasibility, acceptability as well as good cost-effectiveness. With regard to improving access to health care, Information--Education and Communication approaches adapted to the intervention context and linked to the provision of essential services and generic drugs showed to be crucial.

[An innovative approach combining human and animal vaccination campaigns in nomadic settings of Chad: experiences and costs]. / Approche novatrice des vaccinations en santé publique et en médecine vétérinaire chez les pasteurs nomades au Tchad: expériences et coûts.

The purpose of this report is to describe a network of public health care workers, veterinarians and nomadic pastoralists that was set up in Chad to increase vaccination coverage to nomadic children and women who had rarely been vaccinated before. The objectives of the project were to provide human vaccination in conjunction with existing veterinary services, to evaluate the feasibility and limitations of such campaigns, to determine what other services could be provided concurrently, and to estimate the savings for public health care cases in comparison with carrying out vaccination separately. In a series of 12 vaccination campaigns in the Chari-Baguirmi and Kanem districts, more than 2100 children, 2100 women and 52000 cattle were fully immunized. These results confirmed the feasibility of joint campaigns in nomadic settings and provided important experience for improving organization. Information-Education-Communication (IEC) campaigns adapted to the realities of the pastoral setting were an important factor in mobilizing nomadic pastoralists for attendance at vaccination clinics. The savings in logistics costs (i.e., personnel, transportation and cold chain costs excluding vaccine costs) was 15% in Gredaya where 3 out of 6 campaigns were carried out together with veterinarians and 4% in Chaddra/Am Dobak where only 1 out of 6 campaigns was carried out in conjunction with veterinarians. The cost per fully immunized child (FIC) was considerably higher in Chaddra/Am Dobak than Gredaya (EUR 29.2 vs. EUR 11.5). The joint vaccination campaign approach is innovative, appreciated by nomadic pastoralists and less expensive than separate vaccination. By using the mobility of veterinarians in remote zones far from health care facilities, vaccination can be provided to nomadic children and women in countries with limited resources.

Repartition de la morbidite dans trois communautes nomades du Chari-Baguirmi et du Kanem; Tchad

Within the framework of an multidisciplinary research and action program; morbidity patterns were assessed in three nomadic communities; i.e.; Fulani; A rab cattle bre e d e rs and A rab camel breeders; l iving in Chari - B ag u i rmi and Kanem; Chad. This is the first data about the health of Chadian nomadic pastoralists who account for approximately 6of the total population. A total of 1092 women; men and children were interviewed and examined in the course of three surveys carried out by a physician during the dry and rainy season. Nomads reporting no health problems were rare. Tuberculosis was suspected in 4;6of adults after clinical examination and bronchopulmonary disorders in children less than five years of age. Febrile diarrhea was more prevalent during the wet season when access to clean drinking water was more difficult. Simple malaria was rarely diagnosed in Arabs during the dry season. In contrast simple malaria was frequent in Fulani who stay inthe vicinity of Lake Chad during the dry period. Protein-energy malnutrition was observed in only 3 of 328 children younger than 15 years of age

Taux sérique de rétinol chez les femmes nomades pastoralistes tchadiennes en relation avec la teneur en rétinol et en carotène dans le lait de leur bétail

Dans le cadre d'une étude sur le statut sanitaire des pasteurs nomades et de leur bétail exécutée en étroite colla-boration entre les services de santé publique et vétérinaire tchadiens,le taux de rétinol sérique humain a été analysé en cor-rélation avec celui contenu dans le lait du bétail. Parmi les femmes examinées (n = 99),43% (IC95% 33 - 54 %) étaient défi-c i t a i resen rétinol (tauxde0,35µmol/Là0,7µmol/L) et 17% (IC95% 10 -26%) sévèrement défi c i t a i resen rétinol (tauxinféri e u rà0,35µmol/L). Aucunedesfemmesinterrogées(n=87)n'indiquaituneconsommation defruitset seulesdeux avaientconsommédeslégumesfraisau coursdesdern i è res 24 heures. Lelait était donc pratiquement la seule source devitamineA pour ces popu-lations. Parmi le bétail,les chèvres (n=6) avaient les taux moyens de rétinol les plus élevés dans leur lait (329 ± 84 µg/kg),sui-vies des bovins (n=25; 247 ± 32 µg/kg) et des dromadaires (n=12; 120 ± 18 µg/kg). Les concentrations de rétinol dans le sérumhumain dépendaient de manière significative de la concentration de rétinol dans le lait du bétail (pente partielle 0,23; inter-valle de confiance de 95% 0,008 - 0,47). Notre étude confirme que le lait de chèvre et de vache est une source importante devitamine A chez les pasteurs nomades. Par ailleurs,la promotion de la consommation de légumes verts,de fruits et de sup-pléments vitaminés reste nécessaire pour lutter contre les carences en vitamine A

Quels types de service de sante pour les populations nomades? Apprentissages des activites de recherche et d'action au Tchad

To overcome barriers of access to health care of nomadic people and to alleviate inequities in health; a transd isciplinary team has initiated research and intervention activities among three nomadic groups of Chad: Foulbe; A rabes and G o u ranes. A regular and consistent commu n i c ation among all actors involved (nomadic groups; re s e a rchers; planners and administrators of health and veterinary services; etc.) through repetitive meetings and workshops showed to be a crucial element for success. Differences between ethnic nomadic groups made it necessary to develop specific communication strategies adapted to each group. As to interventions to improve the va c c i n ation cove rage; m i xed teams combining health and veteri n a ry specialists were able to vaccinate an important number of children and women and showed to have a high potential in terms of o rga n i s ational and logistic feasibility; acceptability as well as good cost-effe c t iveness. With rega rd to improving access to health care; Information - Education and Communication approaches adapted to the intervention context and linked to the provision of essential services and generic drugs showed to be crucial

Approche novatrice des vaccinations en sante publique et en medecine veterinaire chez les pasteurs nomades au Tchad: Experiences et couts

The purpose of this report is to describe a network of public health care workers; veterinarians and nomadic pastoralists that was set up in Chad to increase vaccination coverage to nomadic children and women who had rarely been va c c i n ated befo re. The objectives of the project we re to provide human vaccination in conjunction with existing ve t e ri n a ry serv ices; to evaluate the feasibility and limitations of such campaigns; to determine wh at other services could be provided concurrently; and to estimate the savings for public health care cases in comparison with carrying out vaccination separately. In a s e ries of 12 vaccination campaigns in the Chari-Baguirmi and Kanem distri c t s ; more than 2100 children; 2100 women and 52000 c attle we re fully immu n i ze d. These results confirmed the feasibility of joint campaigns in nomadic settings and provided important experience for improving organization. Information-Education-Communication (IEC) campaigns adapted to the realities of the pastoral setting were an important factor in mobilizing nomadic pastoralists for attendance at vaccination clinics. The savings in logistics costs (i.e. ; personnel; transportation and cold chain costs ex cluding vaccine costs) was 15in Gre d aya where 3 out of 6 campaigns were carried out together with veterinarians and 4in Chaddra/Am Dobak where only 1 out of 6 campaigns was carried out in conjunction with veterinarians. The cost per fully immunized child (FIC) was considerably higher in Chaddra/Am Dobak than Gredaya (EUR 29.2 vs. EUR 11.5). The joint vaccination campaign approach is innovative; appreciated by nomadic pastoralists and less expensive than separate vaccination. By using the mobility of veterinarians in remote zones far from health care facilities; vaccination can be provided to nomadic children and women in countries with limited resources