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Since 2010, the introduction of an effective serogroup A meningococcal conjugate vaccine has led to the near-elimination of invasive Neisseria meningitidis serogroup A disease in Africa’s meningitis belt. However, a significant burden of disease and epidemics due to other bacterial meningitis pathogens remain in the region. High-quality surveillance data with laboratory confirmation is important to monitor circulating bacterial meningitis pathogens and design appropriate interventions, but complete testing of all reported cases is often infeasible. Here, we use case-based surveillance data from 5 countries in the meningitis belt to determine how accurately estimates of the distribution of causative pathogens would represent the true distribution under different laboratory testing strategies. Detailed case-based surveillance data was collected by the MenAfriNet surveillance consortium in up to 3 seasons from participating districts in 5 countries. For each unique country-season pair, we simulated the accuracy of laboratory surveillance by repeatedly drawing subsets of tested cases and calculating the margin of error of the estimated proportion of cases caused by each pathogen (the greatest pathogen-specific absolute error in proportions between the subset and the full set of cases). Across the 12 country-season pairs analyzed, the 95% credible intervals around estimates of the proportion of cases caused by each pathogen had median widths of ±0.13, ±0.07, and ±0.05, respectively, when random samples of 25%, 50%, and 75% of cases were selected for testing. The level of geographic stratification in the sampling process did not meaningfully affect accuracy estimates. These findings can inform testing thresholds for laboratory surveillance programs in the meningitis belt.

Background Meningococcal serogroup A conjugate vaccine (MACV) was introduced in Chad during 2011–2012. Meningitis surveillance has been conducted nationwide since 2003, with case-based surveillance (CBS) in select districts from 2012. In 2016, the MenAfriNet consortium supported Chad to implement CBS in 4 additional districts and real-time polymerase chain reaction (rt-PCR) at the national reference laboratory (NRL) to improve pathogen detection. We describe analysis of bacterial meningitis cases during 3 periods: pre-MACV (2010–2012), pre-MenAfriNet (2013–2015), and post-MenAfriNet (2016–2018). Methods National surveillance targeted meningitis cases caused by Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae. Cerebrospinal fluid specimens, inoculated trans-isolate media, and/or isolates from suspected meningitis cases were tested via culture, latex, and/or rt-PCR; confirmed bacterial meningitis was defined by a positive result on any test. We calculated proportion of suspected cases with a specimen received by period, and proportion of specimens with a bacterial meningitis pathogen identified, by period, pathogen, and test. Results The NRL received specimens for 6.8% (876/12813), 46.4% (316/681), and 79.1% (787/995) of suspected meningitis cases in 2010–2012, 2013–2015, and 2016–2018, respectively, with a bacterial meningitis pathogen detected in 33.6% (294/876), 27.8% (88/316), and 33.2% (261/787) of tested specimens. The number of N. meningitidis serogroup A (NmA) among confirmed bacterial meningitis cases decreased from 254 (86.4%) during 2010–2012 to 2 (2.3%) during 2013–2015, with zero NmA cases detected after 2014. In contrast, proportional and absolute increases were seen between 2010–2012, 2013–2015, and 2016–2018 in cases caused by S. pneumoniae (5.1% [15/294], 65.9% [58/88], and 52.1% [136/261]), NmX (0.7% [2/294], 1.1% [1/88], and 22.2% [58/261]), and Hib (0.3% [1/294], 11.4% [10/88], and 14.9% [39/261]). Of specimens received at the NRL, proportions tested during the 3 periods were 47.7% (418), 53.2% (168), and 9.0% (71) by latex; 81.4% (713), 98.4% (311), and 93.9% (739) by culture; and 0.0% (0), 0.0% (0), and 90.5% (712) by rt-PCR, respectively. During the post-MenAfriNet period (2016–2018), 86.1% (678) of confirmed cases were tested by both culture and rt-PCR, with 12.5% (85) and 32.4% (220) positive by culture and rt-PCR, respectively. Conclusions CBS implementation was associated with increased specimen referral. Increased detection of non-NmA cases could reflect changes in incidence or increased sensitivity of case detection with rt-PCR. Continued surveillance with the use of rt-PCR to monitor changing epidemiology could inform the development of effective vaccination strategies.

Rabies is a fatal but preventable disease that remains notoriously underreported. Weak data availability hampers advocacy, constitutes a barrier to resource allocation and inhibits effective prevention and control. To gain better insight into the global rabies burden and human vaccine demand several studies were funded through the Vaccine Alliance (GAVI) learning agenda. With the help of this funding, Swiss TPH and local in country partner organizations implemented a One Health research project in Chad, Cote d'Ivoire and Mali to collect data at household, public health facility and veterinary level. This paper describes the implementation of this research project and evaluates its success on amount of information gained, achieved capacity building, impact on knowledge creation and influence on national and international policies. The project was based on the One Health concept and guided by the principles of transboundary research partnerships formulated by the Swiss Academy of Sciences. Data was collected on bite incidents and health seeking from over 24'000 households, on access to treatment of over 8'800 bite cases registered in public health facilities and on the status of over 1'800 rabies suspect animals. Selected country specific datasets have contributed to more than 10 scientific articles so far. On the international level, the multi-level data collection provided a unique set of indicators to inform, along with results from other studies, new WHO rabies immunization recommendations and a vaccine investment case scenario to prevent human rabies. New rabies burden estimates based on the data gathered are published for Mali and will be modelled for the whole West and Central African region. On the national level, the project facilitated communication between animal health and human health workers catalyzing creation of local and national committees and formulation of national action plans for Mali and Cote D'Ivoire. Major challenges arose from lack of data collection and documentation experience of human health and veterinary workers and weak infrastructural capacities of the veterinary and human health systems of the project countries. Through adherence to the principles of transboundary research partnerships, project team members acquired valuable research and networking skills despite language barriers, enabling them to play key roles in the future agenda towards national, regional and global canine rabies elimination. Project external collaborations with local public institutions was facilitated through long-term local partnerships. Both factors enabled success in project implementation and outcomes by identifying and mitigating risks in advance, resolving challenges amiably and enabling mutual knowledge creation as a fructuous ground for sustained commitment. Lack of immediate follow-up funding did not allow to maintain activities beyond the project timeframe. However, the national and international policy changes triggered, as well as the strengthened local disease control and research capacities provides sustainable basis for the elimination of dog transmitted human rabies.

INTRODUCTION: In 2016, 1.7 million of people died from tuberculosis caused by bacteria of the Mycobacterium tuberculosis complex, of which some may have a zoonotic origin. The mycobacterial disease endemicity is worrying in Africa owing to the absence of a reliable strategy in relation with disease ecology. The objective of the study is to assess the reliability of different components of the tuberculosis research and surveillance system in Chad. METHODS: in 2012, a cross-sectional study was conducted in order to assess the importance of tuberculosis in southern Chad and Lake Chad regions. Nine health centers located in areas with a high proportion of pastoralist populations were visited. Microbiological and molecular diagnoses were performed on samples collected from tuberculosis-suspected patients. RESULTS: we assessed one quarter (26.4%) of all the suspected cases in our study site, as estimated in 2012. More males were infected than females (329 versus 147) and most of the suspected cases were aged between 16 and 60 years. Of the 478 sputa collected, 77 were identified as infected with acid fast bacilli, from which 71 were of the genus Mycobacterium, including 45 Mycobacterium tuberculosis, a case of co-infection Mycobacterium bovis/Mycobacterium avium, and 25 non-tuberculosis mycobacteria. Twelve suspected cases harbored other mycobacteria. CONCLUSION: the co-infection Mycobacterium bovis/Mycobacterium avium found in a poultry farmer was the first such co-infection in Chad related to human tuberculosis. Indeed, this finding highlights the importance of the zoonotic aspect of mycobacterial diseases and proves the value of molecular characterization in the tuberculosis surveillance.

OBJECTIVE: To investigate potential risk factors for acquisition in seven countries of the meningitis belt. METHODS: Households were followed up every 2 weeks for 2 months, then monthly for a further 4 months. Pharyngeal swabs were collected from all available household members at each visit and questionnaires completed. Risks of acquisition over the whole study period and for each visit were analysed by a series of logistic regressions. RESULTS: Over the course of the study, acquisition was higher in: (i) 5-to 14-year olds, as compared with those 30 years or older (OR 3.6, 95% CI 1.4-9.9); (ii) smokers (OR 3.6, 95% CI 0.98-13); and (iii) those exposed to wood smoke at home (OR 2.6 95% CI 1.3-5.6). The risk of acquisition from one visit to the next was higher in those reporting a sore throat during the dry season (OR 3.7, 95% CI 2.0-6.7) and lower in those reporting antibiotic use (OR 0.17, 95% CI 0.03-0.56). CONCLUSIONS: Acquisition of meningococcal carriage peaked in school age children. Recent symptoms of sore throat during the dry season, but not during the rainy season, were associated with a higher risk of acquisition. Upper respiratory tract infections may be an important driver of epidemics in the meningitis belt.

Background Trained healthcare workers are an essential resource for effective health systems. However, healthcare workers’ perspective on healthcare, the challenges they face to provide quality health services, and opportunities to improve motivation and providing adequate care are rarely investigated in resource-constrained settings of sub-Saharan Africa. Methods All reachable nurses of Abou Deia, a primarily rural district in the south-eastern part of Chad, were invited to participate. In-depth interviews were conducted to assess current challenges and opportunities faced in daily work, including factors that influence motivation and social wellbeing. Particular emphasis was placed on paediatric care. Results Eight nurses were interviewed. Main work challenges pertained to overall workload, a lack of training and support regarding a serious case mix to be managed on their own, adverse working conditions, issues related to the local communities, and the impact of postings on nurses’ private life. Poor working conditions and perceived lack of recognition emerged as the main demotivating factors. Motivation to improve nurses’ skills so that they can provide good care, coupled with small, suggested changes in working conditions and health care organisation provide opportunities worth exploring to improve health workers’ satisfaction, motivation and the care they can provide. Conclusions Health workers in a predominantly rural district in Chad face a wide variety of challenges, and hence their perspectives need to be taken into account to improve health services interventions that aim at enhancing quality of care. Nurses’ willingness to further develop skills and knowledge, proactive search of solutions to remedy stock-outs of drugs and other medical devices, and motivational factors to improve the quality of care represent important opportunities for improving health services for all.

International audience; 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.

This study compares data on animal rabies cases from the Chadian national rabies laboratory, hosted at the Insitut de Recherche en Elevage pour le Developpement (IRED), with bite case reporting from health facilities. The data collection accompanied a mass dog vaccination intervention over two years in N'Djamena, Chad. This allowed for a comparison of the dynamics of the incidence of animal rabies cases, human bite exposure incidence and post-exposure prophylaxis (PEP) demand during a dog rabies elimination attempt. Following the mass vaccination, the monthly animal rabies incidence dropped from 1.1/10,000 dogs, as observed prior to the campaign in 2012, to 0.061/10,000 dogs in 2014. However, the PEP demand was found to be largely unaffected. The suspicion of the rabies exposure as reported by health personnel in most cases did not reflect the status of the biting animal but rather the severity of the bite wound, resulting in inappropriate PEP recommendations. In addition, the levels of reporting dead or killed animals to the rabies laboratory was found to be very low. These results reveal a profound lack of communication between health facilities and veterinary structures and the absence of an integrated bite case management (IBCM) approach. Improved communication between human health and veterinary workers is imperative to prevent human rabies deaths through the appropriate use of PEP and to further translate success in animal rabies control into cost savings for the public health sector through a lower PEP demand. Improved training of health and veterinary personnel and the sensitisation of the public are needed to achieve good IBCM practice, to increase the rate of diagnostic testing, to provide adequate and timely PEP, and to reduce the wastage of scarce vaccine resources.

Rabies claims approximately 59,000 human lives annually and is a potential risk to 3.3 billion people in over 100 countries worldwide. Despite being fatal in almost 100% of cases, human rabies can be prevented by vaccinating dogs, the most common vector, and the timely administration of post-exposure prophylaxis (PEP) to exposed victims. For the control and prevention of human rabies in N'Djamena, the capital city of Chad, a free mass vaccination campaign for dogs was organized in 2012 and 2013. The campaigns were monitored by parallel studies on the incidence of canine rabies based on diagnostic testing of suspect animals and the incidence of human bite exposure recorded at selected health facilities. Based on the cost description of the campaign and the need for PEP registered in health centers, three cost scenarios were compared: cumulative cost-efficiency of (1) PEP alone, (2) dog mass vaccination and PEP, (3) dog mass vaccination, PEP, and maximal communication between human health and veterinary workers (One Health communication). Assuming ideal One Health communication, the cumulative prospective cost of dog vaccination and PEP break even with the cumulative prospective cost of PEP alone in the 10th year from the start of the calculation (2012). The cost efficiency expressed in cost per human exposure averted is much higher with canine vaccination and One Health communication than with PEP alone. As shown in other studies, our cost-effectiveness analysis highlights that canine vaccination is financially the best option for animal rabies control and rabies prevention in humans. This study also provides evidence of the beneficial effect of One Health communication. Only with close communication between the human and animal health sectors will the decrease in animal rabies incidence be translated into a decline for PEP. An efficiently applied One Health concept would largely reduce the cost of PEP in resource poor countries and should be implemented for zoonosis control in general.

INTRODUCTION: la rage canine demeure une preoccupation en Afrique comme au Tchad. La presente etude vise a evaluer les Connaissances-Attitudes-Pratiques des populations pour la prise en charge appropriee des personnes exposees et une lutte efficace. METHODES: c’etait une etude transversale descriptive realisee en juillet et septembre dans quatre districts sanitaires au Tchad en 2015. Les donnees ont ete collectees a l’aide d’un questionnaire aupres des menages recrutes suivant un sondage aleatoire a 3 degres. RESULTATS: c’etait 2428 personnes enquetees avec un niveau maximum primaire (54,12%). L’âge moyen etait de 36 ± 13,50 ans. Ils etaient cultivateurs (35,17%), commercants (18,04%), menageres (12,81%). La rage etait definie comme une maladie transmise du chien a l’homme (41,43%), une alteration du cerveau (41,27%), une sous-alimentation (10,26%). Le chat etait faiblement connu reservoir (13,84%) et vecteur (19,77%) ainsi que la griffure comme moyen de transmission (4,61%) et la vaccination du chat comme mesure preventive (0,49%). Les premiers soins en cas de morsure a domicile etaient les pratiques traditionnelles (47,69%), le lavage des plaies (19,48%) ou aucune action entreprise (20,43%). Les menages consultaient la sante humaine (78,50%), la sante animale (5,35%) et les guerisseurs traditionnels (27%). CONCLUSION: la communication en rapport avec des premiers soins a la maison en cas de morsure, la connaissance du chat comme reservoir et vecteur, celle de la griffure comme moyen de transmission et la promotion de la consultation des services veterinaires en cas de morsure sont necessaires.

Close to 69,000 humans die of rabies each year, most of them in Africa and Asia. Clinical rabies can be prevented by post-exposure prophylaxis (PEP). However, PEP is commonly not available or not affordable in developing countries. Another strategy besides treating exposed humans is the vaccination of vector species. In developing countries, the main vector is the domestic dog, that, once infected, is a serious threat to humans. After a successful mass vaccination of 70% of the dogs in N'Djamena, we report here a cost-estimate for a national rabies elimination campaign for Chad. In a cross-sectional survey in four rural zones, we established the canine : human ratio at the household level. Based on human census data and the prevailing socio-cultural composition of rural zones of Chad, the total canine population was estimated at 1,205,361 dogs (95% Confidence interval 1,128,008-1,736,774 dogs). Cost data were collected from government sources and the recent canine mass vaccination campaign in N'Djamena. A Monte Carlo simulation was used for the simulation of the average cost and its variability, using probability distributions for dog numbers and cost items. Assuming the vaccination of 100 dogs on average per vaccination post and a duration of one year, the total cost for the vaccination of the national Chadian canine population is estimated at 2,716,359 Euros (95% CI 2,417,353-3,035,081) for one vaccination round. A development impact bond (DIB) organizational structure and cash flow scenario were then developed for the elimination of canine rabies in Chad. Cumulative discounted cost of 28.3 million Euros over ten years would be shared between the government of Chad, private investors and institutional donors as outcome funders. In this way, the risk of the investment could be shared and the necessary investment could be made available upfront - a key element for the elimination of canine rabies in Chad.

International audience; The pattern of epidemic meningococcal disease in the African meningitis belt may be influenced by the background level of population immunity but this has been measured infrequently. A standardised enzyme-linked immunosorbent assay (ELISA) for measuring meningococcal serogroup A IgG antibodies was established at five centres within the meningitis belt. Antibody concentrations were then measured in 3930 individuals stratified by age and residence from six countries. Seroprevalence by age was used in a catalytic model to determine the force of infection. Meningococcal serogroup A IgG antibody concentrations were high in each country but showed heterogeneity across the meningitis belt. The geometric mean concentration (GMC) was highest in Ghana (9.09 μg/mL [95% CI 8.29, 9.97]) and lowest in Ethiopia (1.43 μg/mL [95% CI 1.31, 1.57]) on the margins of the belt. The force of infection was lowest in Ethiopia (λ = 0.028). Variables associated with a concentration above the putative protective level of 2 μg/mL were age, urban residence and a history of recent vaccination with a meningococcal vaccine. Prior to vaccination with the serogroup A meningococcal conjugate vaccine, meningococcal serogroup A IgG antibody concentrations were high across the African meningitis belt and yet the region remained susceptible to epidemics.

Transmission of rabies from animals to people continues despite availability of good vaccines for both human and animal use. The only effective strategy to achieve elimination of dog rabies and the related human exposure is to immunize dogs at high coverage levels. We present the analysis of two consecutive parenteral dog mass vaccination campaigns conducted in N’Djamena in 2012 and 2013 to advocate the feasibility and effectiveness for rabies control through proof of concept. The overall coverage reached by the intervention was >70% in both years. Monthly reported rabies cases in dogs decreased by more than 90% within one year. Key points were a cooperative collaboration between the three partner institutions involved in the control program, sufficient information and communication strategy to access local leaders and the public, careful planning of the practical implementation phase and the effective motivation of staff.The dynamic and semi to non-restricted nature of dog populations in most rabies endemic areas is often considered to be a major obstacle to achieve sufficient vaccination coverage. However, we show that feasibility of dog mass vaccination is highly dependent on human determinants of dog population accessibility and the disease awareness of dog owners. Consequently, prior evaluation of the human cultural and socio-economic context is an important prerequisite for planning dog rabies vaccination campaigns.

There is a paucity of epidemiological and malacological data pertaining to schistosomiasis in Chad. In view of a recently articulated elimination agenda, a deeper understanding of the spatio-temporal distribution of schistosomiasis inter- mediate host snails is pivotal. We conducted cross-sectional malacological surveys during the dry season (April/May 2013) and after the short rainy season (October 2013) in N’Djamena, the capital of Chad. Snails were identified at the genus and species level using morphological keys and molecular DNA barcoding approaches. Those belonging to Bulinus and Biomphalaria were examined for cercarial shedding. Snail habitats were characterised and their predictive potential for the presence of schistosomiasis intermediate host snails explored. Seasonal patterns were studied using geographical information system and kriging in order to interpolate snail abundance data to make predictions at non-sampled locations across N’Djamena. Overall, 413 Bulinus truncatus, 369 Bulinus forskalii and 108 Biomphalaria pfeifferi snails were collected and subjected to cercarial shedding. During the dry season, one Bu. truncatus of 119 snails collected shed Schistosoma spp. cer- cariae (0.84%), while S. mansoni was shed by one of 108 Bi. pfeifferi snails (0.93%). None of the snails collected after the rainy season shed Schistosoma spp. cercariae. The abundance of Bu. truncatus and Bu. forskalii showed an inverse U-shape relationship with the square term of conductivity, i.e. low abundance at the lowest and highest levels of conductivity and high abundance at intermediate levels. Bi. pfeifferi showed a negative, linear association with pH in the dry seasons. It is planned to link these intermediate host snail data to infection data in human populations with the goal to draw a predictive risk map that can be utilised for control and elimination of schistosomiasis in N’Djamena.

Rural African communities, especially those that are nomadic, often have poor access to health care. Collaboration with other services could help improve coverage Livestock contribute to the livelihood of at least 70% of the worlds' rural poor.1 In arid and semi-arid ecosystems of sub-Saharan Africa, livestock holders (mobile or settled pastoralists and agro-pastoralists) use vast grazing lands and residuals of crops that otherwise could not be used productively2 Yet, they are marginalised from development processes and vulnerable to exclusion from health services because of their geographical, social, and cultural environment. The weak infrastructure and quality of service in both the public health and veterinary sectors are closely related to resource constraints, especially lack of qualified staff.3 4 Therefore, professionals from the World Health Organisation and UN Food and Agriculture Organisation have suggested that public health and veterinary services should share resources.5 6 Few experiences of joint delivery of services to pastoral communities have been documented.7 We describe the implementation and effects of a joint project in Chad Veterinary services have a crucial role in controlling highly contagious diseases and zoonotic infections, which have implications for human health as well as that of livestock. However, in many contexts veterinary services could also contribute to the provision of essential public health interventions. This is particularly important in areas with unacceptably low health service coverage, as is often the case in rural settings of low income countries. One example of collaboration between public health and veterinary services is in providing child vaccination, one of the most cost effective health interventions, in developing countries.8 In southern Sudan, the Expanded Programme on Immunization shared cold chain equipment with the veterinary service,7 and the International Red Cross has implemented vaccination campaigns using veterinarians' vehicles (B Peterhans, personal communication). Similar …

A critical appraisal has been presented of the CHOP for a large-scale energy infrastructure development project that was implemented in two of the world's poorest countries. The project is under close scrutiny from various independent monitoring groups, civil society organizations, and human rights groups. Reviewing the achievements and shortcomings permits the extraction of important lessons that will be critical for the future adoption of the CHOP in the current setting and for the implementation of additional CHOPs elsewhere in the developing world. The authors believe that the design must be flexible, efficient, and innovative so that a CHOP promptly can address pressing public health issues as they arise (eg, epidemic outbreak) and include the needs and demands of the concerned communities. An innovative feature of the current project is the high degree and mix of public-private partnerships. The project's CHOP also relies on partnerships. As elaborated elsewhere, public-private partnerships should be seen as a social experiment--they reveal promise but are not the solution for every problem. For this CHOP, the focus is on partnerships between a multinational consortium, government agencies, and international organizations. The partnerships also include civil society organizations for monitoring and evaluation and local NGOs designated for the implementation of the selected public health interventions within the CHOP. The governments and their respective health policies often form the umbrella under which the partnerships operate. With the increase in globalization, however, the importance and capacities of governments have diminished, and there is growing private-sector involvement. Private enterprise is seen as an efficient, innovative, pragmatic, and powerful means to achieve environmental and social sustainability. Experiences with the partnership configurations in the current CHOP are of importance for tackling grand challenges in global health by applying a systemic approach. Other innovations of the project in general, and the CHOP in particular, are the strong emphases on institutional-capacity building, integration, and sustainability. In countries like Chad and Cameroon, there are serious shortages of well-qualified health personnel. The CHOP described in this article provides leverage for initiating better healthcare that will reduce the high burden of disease in the developing world. Reducing mortality rates for infants and children younger than 5 years in sub-Saharan Africa requires massive scaling-up of malaria-control interventions (eg, large-scale distribution of ITNs to protect millions of African children), thereby approaching the Abuja targets (see Armstrong Schellenberg et al). The local NGOs that took a lead within the framework of the CHOP in the distribution of ITNs and accompanying health education messages can extend these activities to communities living outside the vicinity of the project area. Serious shortcomings of the current CHOP, consistently identified by the external monitoring groups, include the lack of a regional health plan, cumulative impact assessment, and provision of clean water and sanitation outside the narrowly defined project area. This point is of central importance, particularly for Chad, where access to clean water and improved sanitation facilities is low. Another limitation of the current CHOP is the insufficient amount of significance addressed to tuberculosis and the apparent lack of concerted control efforts against HIV infection, AIDS, and tuberculosis. These criticisms, however, must be balanced against the lack of clarity in international discourse about the proper extent of responsibility of the corporate sector for dealing with the health problems of countries in which they do business. In an elegant analysis, the environmental risk factor "unsafe water, sanitation and hygiene" was shown to be one of the major contributors to loss of healthy life, particularly in the developing world. Provision of clean water and sanitation is a key factor for sustainable control of schistosomiasis and soil-transmitted helminths. Reduction of helminth infections might have a beneficial effect on the HIV and AIDS pandemic. The question still remains: What is, or should be, the scope and limits of responsibility of the corporate sector in solving these problems? There is a critical need for the monitoring and evaluation of the long-term impact of a CHOP that develops in parallel with a large development project, emphasizing the broadest possible determinants of health and well-being. To become operational, it requires the establishment and running of a longitudinal demographic surveillance system in the area and in adjacent areas that are unlikely to be affected by the project. This approach, coupled with regular household surveys for in-depth appraisal of health-seeking and asset indices, is the most promising source of data for impact measurement of health, poverty, and equity-related issues. It will facilitate subtle monitoring and surveillance activities, fostering a truly systemic approach by inclusion of all stake holders on the basis of the existing but constantly evolving system.

This analysis of constraints to scaling-up health-related interventions in Chad shows that emphasis has to be put on systemic approaches which address absorptive capacity, on removal of structural constraints, and on efficient and equitable production of health services. In the production of services the development of infrastructure must not exceed the development of human resources. If the millennium development goals are to be achieved, major investments in basic and in-service training and in management skills are crucially needed. In addition, the study shows the importance of promoting health services which actively seek to fulfil community demands and those of disadvantaged groups. Copyright # 2003 John Wiley & Sons, Ltd.

BACKGROUND In response to the 2011 and 2012 polio epidemic in Chad, Chad's Ministry of Public Health, with support from Global Polio Eradication Initiative partners, took steps to increase vaccination coverage of nomadic children with targeted polio campaigns. This article describes the strategies we used to vaccinate nomads in 3 districts of Chad. METHODS Our targeted interventions involved using mobile vaccination teams, recruiting local nomads to identify settlements, using social mobilization, and offering vaccinations to children, women, and animals. RESULTS Vaccination coverage of nomadic children 0-59 months of age increased, particularly among those never before vaccinated against polio. These increases occurred mostly in the intervention districts of Dourbali, from 2956 to 8164 vaccinated children, and Kyabe, from 7319 to 15 868. The number of first-time vaccinated nomadic children also increased the most in these districts, from 60 to 131 in Dourbali and from 1302 to 2973 in Kyabe. Coverage in the Massaguet district was only 37.7%. CONCLUSIONS Our success was probably due to (1) appointment of staff to oversee implementation, (2) engagement of the national government and its partners, (3) participation of nomadic community leaders, (4) intersectoral collaboration between human and animal health services, and (5) flexibility and capacity of vaccinators to vaccinate when and where nomads were available.

International audience; For over 100 years, large epidemics of meningococcal meningitis have occurred every few years in areas of the African Sahel and sub-Sahel known as the African meningitis belt. Until recently, the main approach to the control of these epidemics has been reactive vaccination with a polysaccharide vaccine after an outbreak has reached a defined threshold and provision of easy access to effective treatment but this approach has not prevented the occurrence of new epidemics. Meningococcal conjugate vaccines, which can prevent meningococcal carriage and thus interrupt transmission, may be more effective than polysaccharide vaccines at preventing epidemics. Because the majority of African epidemics have been caused by serogroup A meningococci, a serogroup A polysaccharide/tetanus toxoid protein conjugate vaccine (PsA-TT) has recently been developed. Results from an initial evaluation of the impact of this vaccine on meningococcal disease and meningococcal carriage in Burkina Faso have been encouraging. To review how the research agenda for meningococcal disease in Africa has been changed by the advent of PsA-TT and to define a new set of research priorities for study of meningococcal infection in Africa, a meeting of 41 scientists was held in Dakar, Senegal on April 24th and 25th 2012. The research recommendations developed during the course of this meeting are presented in this paper. The need for enhanced surveillance for meningitis in defined populations with good diagnostic facilities in African countries at risk of epidemics was identified as the highest priority. This is needed to determine the duration of protection against serogroup A meningococcal disease provided by PsA-TT and to determine the risk of disease and carriage caused by meningococci of other serogroups. Other research areas given high priority included identification and validation of serological correlates of protection against meningococcal disease and carriage, development of improved methods for detecting carriage and epidemiological studies aimed at determining the reasons underlying the peculiar epidemiology of meningococcal disease in the African meningitis belt. Minutes and working papers from the meeting are provided in supplementary tables and some of the presentations made at the meeting are available on the MenAfriCar consortium website (www.menafricar.org) and on the web site of the Centers for Disease Control (www.cdc.gov).Conference report - Dakar discussion group on priorities for research on epidemic meningococcal disease in Africa

A meningococcal serogroup A polysaccharide/tetanus toxoid conjugate vaccine (PsA-TT) (MenAfriVac#x2122;) is being deployed in countries of the African meningitis belt. Experience with other polysaccharide/protein conjugate vaccines has shown that an important part of their success has been their ability to prevent the acquisition of pharyngeal carriage and hence to stop transmission and induce herd immunity. If PsA-TT is to achieve the goal of preventing epidemics, it must be able to prevent the acquisition of pharyngeal carriage as well as invasive meningococcal disease and whether PsA-TT can prevent pharyngeal carriage needs to be determined. To address this issue, a consortium (the African Meningococcal Carriage (MenAfriCar) consortium) was established in 2009 to investigate the pattern of meningococcal carriage in countries of the African meningitis belt prior to and after the introduction of PsA-TT. This article describes how the consortium was established, its objectives and the standardised field and laboratory methods that were used to achieve these objectives. The experience of the MenAfriCar consortium will help in planning future studies on the epidemiology of meningococcal carriage in countries of the African meningitis belt and elsewhere. Un vaccin conjugué contenant un polysaccharide du sérogroupe A méningococcique et une anatoxine du tétanos (PsA-TT) (MenAfriVac™) est en cours de déploiement dans les pays de la ceinture africaine de la méningite. L’ expérience avec d’ autres vaccins conjugués polysaccharide/protéine a montré qu’ une partie importante de leur succès a été leur capacité à empêcher l’ acquisition du portage pharyngé et donc à arrêter la transmission et à induire une immunité de group. Si PsA-TT doit d’ atteindre l’ objectif de prévenir les épidémies, il devrait être en mesure d’ empêcher l’ acquisition du portage pharyngé ainsi que la méningococcie invasive et le fait que PsA-TT puisse empêcher le portage pharyngé devrait être déterminé. Pour résoudre ce problème, le consortium MenAfriCar (Consortium Africain du Portage Méningococcique) a été établi en 2009 pour étudier le mode de portage du méningocoque dans les pays de la ceinture africaine de la méningite avant et après l’ introduction de PsA-TT. Cet article décrit comment le consortium a été établi, ses objectifs et les méthodes de laboratoire et de terrain standardisées qui ont été utilisées pour atteindre ces objectifs. L’ expérience du consortium MenAfriCar aidera à planifier les futures études sur l’ épidémiologie du portage du méningocoque dans les pays de la ceinture africaine de la méningite et d’ ailleurs. Se está utilizando una vacuna meningocócica conjugada (MenAfriVac™) de polisacárido del serogrupo A / tétano toxoide (PsA-TT) en países del cinturón Africano de meningitis. Las experiencias obtenidas con otras vacunas conjugadas polisacárido/proteína han demostrado que una parte importante de su éxito se debe a su habilidad para prevenir la colonización faríngea de los portadores, acabando por lo tanto con la transmisión, y a la de inducir la protección de rebaño. Si PsA-TT ha de cumplir el objetivo de prevenir epidemias, debe ser capaz de prevenir el estado de portador faríngeo, al igual que la enfermedad invasiva por meningococo, y para ello es necesario determinar si la PsA-TT puede prevenir la colonización faríngea. Con el fin de abordar esta cuestión se estableció un consorcio africano en el 2009 - el MenAfriCar (African Meningococcal Carriage Consortium) – para investigar los patrones del estado de portador de meningococo en países del cinturón Africano de la meningitis, antes y después de la introducción de PsA-TT. Este artículo describe como se estableció el consorcio, sus objetivos y los métodos estandarizados de campo y de laboratorio que se utilizaron para alcanzarlos. La experiencia del consorcio MenAfriCar ayudará en la planificación de estudios futuros sobre la epidemiología del estado de portador de meningococo, tanto en países del cinturón Africano de la meningitis como en otros lugares del mundo.