Publications by authors named "Ali Djibo"
Investigating persistent measles dynamics in Niger and associations with rainfall.
J R Soc Interface
August 2020
Measles is a major cause of child mortality in sub-Saharan Africa. Current immunization strategies achieve low coverage in areas where transmission drivers differ substantially from those in high-income countries. A better understanding of measles transmission in areas with measles persistence will increase vaccination coverage and reduce ongoing transmission.
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- - The text discusses rising meningococcal meningitis cases in the "African meningitis belt" and highlights the late timing of current reactive vaccination campaigns, leading to limited vaccine availability and a recommendation for using ciprofloxacin as preventive treatment for household contacts of infected individuals.
- - A cluster-randomized trial is set to take place in Niger, where villages will be assigned to one of three groups: standard care, household prophylaxis, or village-wide prophylaxis, aiming to compare the incidence of meningitis during the epidemic.
- - The trial will monitor the effectiveness of treatments after the first reported case in a village, along with assessing potential antibiotic resistance, involving a sample size adjustment based on initial data collected.
Background: Each year, rotavirus gastroenteritis is responsible for about 37% of deaths from diarrhea among children younger than 5 years of age worldwide, with a disproportionate effect in sub-Saharan Africa.
Methods: We conducted a randomized, placebo-controlled trial in Niger to evaluate the efficacy of a live, oral bovine rotavirus pentavalent vaccine (BRV-PV, Serum Institute of India) to prevent severe rotavirus gastroenteritis. Healthy infants received three doses of the vaccine or placebo at 6, 10, and 14 weeks of age.
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- In low-income areas, vaccination campaigns often struggle to hit their targets due to a lack of accurate data on the size and distribution of the population.
- The use of satellite imagery in urban Niger revealed that vaccination coverage was overestimated because campaign planners didn't account for both resident numbers and seasonal migration patterns.
- By combining satellite data with measles case reports, researchers developed a model that suggests vaccination efforts could be significantly improved if population fluctuations are considered during campaign planning.
We describe clinical symptoms, case-fatality rates, and prevalence of sequelae during an outbreak of Neisseria meningitidis serogroup C infection in a rural district of Niger. During home visits, we established that household contacts of reported case-patients were at higher risk for developing meningitis than the general population.
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- The study examines the costs of strengthening bacterial meningitis surveillance in Chad and Niger following the introduction of a serogroup A meningococcal conjugate vaccine.
- Data was collected through interviews and financial reviews, revealing that Niger had a more advanced surveillance system compared to Chad, reflected in the higher costs of US$ 1,951,562 and US$ 338,056, respectively.
- Key expenses were identified as laboratory investigations and personnel resources, with Niger needing significantly more funds for upgrades to reach desired standards than Chad.
Knowledge of rotavirus epidemiology is necessary to make informed decisions about vaccine introduction and to evaluate vaccine impact. During April 2010-March 2012, rotavirus surveillance was conducted among 9,745 children <5 years of age in 14 hospitals/health centers in Niger, where rotavirus vaccine has not been introduced. Study participants had acute watery diarrhea and moderate to severe dehydration, and 20% of the children were enrolled in a nutrition program.
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- Malnutrition is a significant issue in the Sahel region, and this study focuses on understanding the types of infections in hospitalized children with complicated severe acute malnutrition (SAM) in Maradi, Niger.
- The study included clinical examinations and various lab cultures for 311 children, uncovering that gastroenteritis and respiratory infections were the most common diagnoses, with a concerning 9% mortality rate mostly due to sepsis.
- The findings highlight a disconnect between clinical signs and actual infections, emphasizing the need for updated international guidelines on using broad-spectrum antibiotics in treating complicated SAM based on recent data.
Objective: Since many of the world's vaccine supply chains contain multiple levels, the question remains of whether removing a level could bring efficiencies.
Methods: We utilized HERMES to generate a detailed discrete-event simulation model of Niger's vaccine supply chain and compared the current four-tier (central, regional, district, and integrated health center levels) with a modified three-tier structure (removing the regional level). Different scenarios explored various accompanying shipping policies and frequencies.
Given the characteristic age-prevalence curve of Schistosoma infection, preventive chemotherapy with praziquantel is primarily targeted at school-aged children, whilst, in highly endemic areas, other high-risk groups might be included for regular treatment. Nevertheless, schistosomiasis can affect children well before they reach school-age, but this population group is usually excluded from preventive chemotherapy. We assessed the safety and efficacy of praziquantel syrup (Epiquantel®) in preschool-aged children in three villages of Niger.
View Article and Find Full Text PDFThe aim of this study was to assess the efficacy and safety of two closely spaced doses of praziquantel (PZQ) against Schistosoma haematobium and S. mansoni infection in school-aged children, and to characterise re-infection patterns over a 12-month period. The study was carried out in five villages in western Niger: Falmado, Seberi and Libore (single S.
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- The study explores how making different WHO Expanded Program on Immunizations (EPI) vaccines thermostable affects the vaccine cold chain, using a simulation model of Niger's vaccine supply chain.
- Results showed that any thermostable vaccine improved overall vaccine availability and reduced cold storage and transport issues, with the pentavalent vaccine having the most significant positive impact.
- The conclusion emphasizes that even a single thermostable vaccine can alleviate supply chain challenges and underscores the importance of further developing such vaccines beyond just reducing reliance on refrigeration.
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- In 2008, Africa had a staggering 94% of global cholera cases, and while the WHO recommends vaccinations, their use in Sub-Saharan Africa is still limited.
- An evaluation of cholera surveillance in Maradi, Niger, showed that the data collected from 2006-2009 was reliable enough to identify high-risk areas for targeted vaccination.
- The study identified two impoverished neighborhoods in Maradi that, despite being only 1% of the population, accounted for 21% of cholera cases, suggesting a need for focused cholera vaccination efforts there.
Article Synopsis
- - In 2004, Niger launched a control program for schistosomiasis and soil-transmitted helminths, providing 4.3 million treatments to children and adults within two years, primarily through schools and community efforts.
- - A 2006 study analyzed the economic costs of this program, revealing a total cost of $456,718, with treatment costs at $0.58 per person; school-based treatment averaged $0.76 and community distribution $0.46.
- - The effectiveness and costs of treatment approaches vary significantly by region, necessitating a careful analysis of distribution methods and economic impacts in order to optimize future program design.
Background: Many countries, such as Niger, are considering changing their vaccine vial size presentation and may want to evaluate the subsequent impact on their supply chains, the series of steps required to get vaccines from their manufacturers to patients. The measles vaccine is particularly important in Niger, a country prone to measles outbreaks.
Methods: We developed a detailed discrete event simulation model of the vaccine supply chain representing every vaccine, storage location, refrigerator, freezer, and transport device (e.
Background: Diarrhea remains the second leading cause of death in children under 5 years of age in sub-Saharan Africa. Health care seeking behavior for diarrhea varies by context and has important implications for developing appropriate care strategies and estimating burden of disease. The objective of this study was to determine the proportion of children under five with diarrhea who consulted at a health structure in order to identify the appropriate health care levels to set up surveillance of severe diarrheal diseases.
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- The study aimed to compare the effects of two types of nutritional supplementation (RUSFs and RUTFs) on wasting, stunting, and mortality in children aged 6 to 36 months in Maradi, Niger.
- Out of 1645 children, those receiving RUSFs showed significant reductions in wasting and severe wasting in villages with prior preventive interventions but not in those without prior help.
- Overall, the RUSF strategy also led to a 19% reduction in stunting compared to RUTFs, highlighting that previous nutritional support influences the effectiveness of these supplementation strategies.
Article Synopsis
- Seasonally driven cycles of incidence for directly transmitted pathogens, like measles, are common but not well understood, especially regarding their relationship to environmental factors like rainfall.
- In Niger, measles outbreaks consistently start in the dry season and decline with the onset of rains, showing that transmission rates fluctuate inversely with rainfall patterns.
- The study finds that larger, urban populations experience greater seasonal fluctuations in transmission, driven by human density and agricultural cycles, leading to local extinctions of measles rather than acting as permanent reservoirs.
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- - The study compares the effectiveness of ready-to-use therapeutic food (RUTF) and a corn/soy-blend (CSB) pre-mix for treating moderate acute malnutrition (MAM) in children in Niger, finding that RUTF significantly outperforms CSB in recovery rates.
- - Children receiving RUTF showed a higher recovery rate (79.1%) compared to those on the CSB pre-mix (64.4%), as well as greater average weight gain and shorter treatment duration.
- - The findings suggest that using RUTF in supplementary feeding programs may enhance treatment efficacy and quality, leading to less need for hospital transfers and better overall outcomes for children with MAM.
The burden of schistosomiasis in infants and preschool-aged children and their mothers is poorly known. We carried out a cross-sectional epidemiological survey in two villages in Niger: Falmado is endemic for Schistosoma haematobium only, whereas a mixed S. haematobium-S.
View Article and Find Full Text PDFBackground: In 2006, the Médecins sans Frontières nutritional program in the region of Maradi (Niger) included 68,001 children 6-59 months of age with either moderate or severe malnutrition, according to the NCHS reference (weight-for-height<80% of the NCHS median, and/or mid-upper arm circumference<110 mm for children taller than 65 cm and/or presence of bipedal edema). Our objective was to identify baseline risk factors for death among children diagnosed with severe malnutrition using the newly introduced WHO growth standards. As the release of WHO growth standards changed the definition of severe malnutrition, which now includes many children formerly identified as moderately malnourished with the NCHS reference, studying this new category of children is crucial.
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- The study assesses the impact of distributing ready-to-use therapeutic foods (RUTF) on the nutritional health of children aged 6 to 60 months in Niger by comparing two groups: one receiving RUTF and another not receiving it.
- A cluster randomized trial was conducted in 12 villages, with 6 villages receiving monthly RUTF packets and 6 serving as the control group with no intervention.
- Results indicated an improvement in the nutritional status of children in the RUTF group, shown by an increase in their weight-for-height z score and a decrease in rates of wasting over an 8-month follow-up period.
Article Synopsis
- Vaccination has largely reduced measles in many parts of the world, but it still poses a significant threat in high birth rate countries like those in the Sahel, particularly Niger.
- Measles epidemics in Niger are irregular and influenced by seasonal transmission patterns, leading to unpredictable and large-scale outbreaks despite some vaccine coverage.
- These findings highlight the need for effective control strategies focusing on both managing susceptible populations and reducing the impact of sporadic major outbreaks.
Low measles vaccination coverage (VC) leads to recurrent epidemics in many African countries. We describe VC before and after late reinforcement of vaccination activities during a measles epidemic in Niamey, Niger (2003-2004) assessed by Lot Quality Assurance Sampling (LQAS). Neighborhoods of Niamey were grouped into 46 lots based on geographic proximity and population homogeneity.
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