Journal Article > CommentaryAbstract
Int Health. 2014 May 6; Volume 6 (Issue 1); DOI:10.1093/inthealth/ihu005
Grais RF, Adamou HO
Int Health. 2014 May 6; Volume 6 (Issue 1); DOI:10.1093/inthealth/ihu005
Conference Material > Poster
Guardiola M, Skidmore J, Kituyi M, Sagrado MJ, Tembo K
MSF Paediatric Days 2024. 2024 May 3; DOI:10.57740/esTV2iD
Journal Article > ResearchFull Text
Emerg Infect Dis. 2014 April 1; Volume 20 (Issue 4); DOI:10.3201/eid2004.131328
Page AL, Jusot V, Mamaty AA, Adamou L, Kaplon J, et al.
Emerg Infect Dis. 2014 April 1; Volume 20 (Issue 4); DOI:10.3201/eid2004.131328
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. Of the 9,745 children, 30.6% were rotavirus positive. Genotyping of a subset of positive samples showed a variety of genotypes during the first year, although G2P[4] predominated. G12 genotypes, including G12P[8], which has emerged as a predominant strain in western Africa, represented >80% of isolates during the second year. Hospitalization and death rates and severe dehydration among rotavirus case-patients did not differ during the 2 years. The emergence of G12P[8] warrants close attention to the characteristics of associated epidemics and possible prevention measures.
Journal Article > Meta-AnalysisFull Text
Confl Health. 2019 November 21; Volume 13 (Issue 1); DOI:10.1186/s13031-019-0232-y
Robinson E, Crispino V, Ouabo A, Iballa F, Kremer R, et al.
Confl Health. 2019 November 21; Volume 13 (Issue 1); DOI:10.1186/s13031-019-0232-y
BACKGROUND
During humanitarian crises, health information systems are often lacking and surveys are a valuable tool to assess the health needs of affected populations. In 2013, a mortality and health survey undertaken by Médecins Sans Frontières (MSF) in the conflict affected Walikale territory of North Kivu, Democratic Republic of the Congo (DRC), indicated mortality rates exceeding humanitarian crisis thresholds and a high burden of mortality and morbidity due to malaria. In late 2017, after a period of relative stability, MSF reassessed the health status of the population through a second survey to guide ongoing operations.
METHODS
A two-stage cluster survey, selecting villages using probability proportional to size and households using random walk procedures, was conducted. Household members were interviewed on morbidity and mortality, healthcare use, vaccination status, and bednet availability.
RESULTS
The sample included 5711 persons in 794 households. The crude mortality rate (CMR) and under-five mortality rate (U5MR) were 0.98 per 10,000 persons/day (95% confidence interval (CI) 0.78–1.2) and 1.3 per 10,000 persons/day (95% CI): 0.82–2.0), respectively. The most frequently reported causes of death were fever/malaria (31%), diarrhoea (15%) and respiratory infections (8%). In 89% of households at least one person was reported as falling ill in the previous 2 weeks, and 58% sought healthcare. Cost was the main barrier amongst 58% of those who did not seek healthcare. Coverage of measles-containing-vaccine was 62% in under-fives. Sufficient bednet coverage (1 bednet/2 people) was reported from 17% of households.
CONCLUSION
The second survey illustrates that although mortality is now just below crisis thresholds, the area still experiences excess mortality and has substantial health needs. The study results have supported the further expansion of integrated community case management to improve access to care for malaria, diarrhoea and respiratory infections. Such surveys are important to orient operations to the health needs of the population being served and also highlight the ongoing vulnerability of populations after humanitarian crises.
During humanitarian crises, health information systems are often lacking and surveys are a valuable tool to assess the health needs of affected populations. In 2013, a mortality and health survey undertaken by Médecins Sans Frontières (MSF) in the conflict affected Walikale territory of North Kivu, Democratic Republic of the Congo (DRC), indicated mortality rates exceeding humanitarian crisis thresholds and a high burden of mortality and morbidity due to malaria. In late 2017, after a period of relative stability, MSF reassessed the health status of the population through a second survey to guide ongoing operations.
METHODS
A two-stage cluster survey, selecting villages using probability proportional to size and households using random walk procedures, was conducted. Household members were interviewed on morbidity and mortality, healthcare use, vaccination status, and bednet availability.
RESULTS
The sample included 5711 persons in 794 households. The crude mortality rate (CMR) and under-five mortality rate (U5MR) were 0.98 per 10,000 persons/day (95% confidence interval (CI) 0.78–1.2) and 1.3 per 10,000 persons/day (95% CI): 0.82–2.0), respectively. The most frequently reported causes of death were fever/malaria (31%), diarrhoea (15%) and respiratory infections (8%). In 89% of households at least one person was reported as falling ill in the previous 2 weeks, and 58% sought healthcare. Cost was the main barrier amongst 58% of those who did not seek healthcare. Coverage of measles-containing-vaccine was 62% in under-fives. Sufficient bednet coverage (1 bednet/2 people) was reported from 17% of households.
CONCLUSION
The second survey illustrates that although mortality is now just below crisis thresholds, the area still experiences excess mortality and has substantial health needs. The study results have supported the further expansion of integrated community case management to improve access to care for malaria, diarrhoea and respiratory infections. Such surveys are important to orient operations to the health needs of the population being served and also highlight the ongoing vulnerability of populations after humanitarian crises.
Journal Article > ReviewFull Text
Lancet Infect Dis. 2009 September 1; Volume 9 (Issue 9); 567-576.; DOI:10.1016/S1473-3099(09)70179-3
Sanchez-Padilla E, Guerin PJ, Steele AD, Luquero FJ
Lancet Infect Dis. 2009 September 1; Volume 9 (Issue 9); 567-576.; DOI:10.1016/S1473-3099(09)70179-3
Two new rotavirus vaccines have recently been licensed in many countries. However, their efficacy has only been shown against certain serotypes commonly circulating in Europe, North America, and Latin America, but thought to be globally important. To assess the potential impact of these vaccines in sub-Saharan Africa, where rotavirus mortality is high, knowledge of prevalent types is essential because an effective rotavirus vaccine is needed to protect against prevailing serotypes in the community. We did two systematic reviews and two meta-analyses of the most recent published data on the burden of rotavirus disease in children aged under 5 years and rotavirus serotypes circulating in countries in sub-Saharan Africa. Eligible studies were selected from PubMed/Medline, Cochrane Library, EmBase, LILACS, Academic Search Premier, Biological Abstracts, ISI Web of Science, and the African Index Medicus. Depending on the heterogeneity, DerSimonian-Laird random-effects or fixed-effects models were used for meta-analyses. Geographical variability in rotavirus burden within countries in sub-Saharan Africa is substantial, and most countries lack information on rotavirus epidemiology. We estimated that annual mortality for this region was 243.3 (95% CI 187.6-301.7) deaths per 100,000 under 5 years (ie, a total of 300,000 children die of rotavirus infection in this region each year). The most common G type detected was G1 (34.9%), followed by G2 (9.1%), and G3 (8.6%). The most common P types detected were P[8] (35.5%) and P[6] (27.5%). Accurate information should be collected from surveillance based on standardised methods in these countries to obtain comparable data on the burden of disease and the circulating strains to assess the potential impact of vaccine introduction.
Journal Article > ResearchFull Text
BMC Research Notes. 2017 October 23; Volume 10 (Issue 1); DOI:10.1186/s13104-017-2832-1
Lagare A, Moumouni A, Kaplon J, Langendorf C, Pothier P, et al.
BMC Research Notes. 2017 October 23; Volume 10 (Issue 1); DOI:10.1186/s13104-017-2832-1
We conducted a parallel evaluation of the diagnostic accuracy of VIKIA® Rota-Adeno, a rapid diagnostic test (RDT) and Premier™ Rotaclone® an enzyme immunoassay (EIA) using reverse transcription polymerase chain reaction (RT-PCR) as the reference standard. The study was part of a rotavirus surveillance project in Niger.
Journal Article > ResearchFull Text
N Engl J Med. 2017 March 23; Volume 376 (Issue 12); 1121-1130.; DOI:10.1056/NEJMoa1609462
Isanaka S, Guindo O, Langendorf C, Matar Seck A, Plikaytis BD, et al.
N Engl J Med. 2017 March 23; Volume 376 (Issue 12); 1121-1130.; DOI:10.1056/NEJMoa1609462
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. Episodes of gastroenteritis were assessed through active and passive surveillance and were graded on the basis of the score on the Vesikari scale (which ranges from 0 to 20, with higher scores indicating more severe disease). The primary end point was the efficacy of three doses of vaccine as compared with placebo against a first episode of laboratory-confirmed severe rotavirus gastroenteritis (Vesikari score, ≥11) beginning 28 days after dose 3.
RESULTS
Among the 3508 infants who were included in the per-protocol efficacy analysis, there were 31 cases of severe rotavirus gastroenteritis in the vaccine group and 87 cases in the placebo group (2.14 and 6.44 cases per 100 person-years, respectively), for a vaccine efficacy of 66.7% (95% confidence interval [CI], 49.9 to 77.9). Similar efficacy was seen in the intention-to-treat analyses, which showed a vaccine efficacy of 69.1% (95% CI, 55.0 to 78.7). There was no significant between-group difference in the risk of adverse events, which were reported in 68.7% of the infants in the vaccine group and in 67.2% of those in the placebo group, or in the risk of serious adverse events (in 8.3% in the vaccine group and in 9.1% in the placebo group); there were 27 deaths in the vaccine group and 22 in the placebo group. None of the infants had confirmed intussusception.
CONCLUSIONS
Three doses of BRV-PV, an oral rotavirus vaccine, had an efficacy of 66.7% against severe rotavirus gastroenteritis among infants in Niger. (Funded by Médecins sans Frontières Operational Center and the Kavli Foundation; ClinicalTrials.gov number, NCT02145000 .).
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. Episodes of gastroenteritis were assessed through active and passive surveillance and were graded on the basis of the score on the Vesikari scale (which ranges from 0 to 20, with higher scores indicating more severe disease). The primary end point was the efficacy of three doses of vaccine as compared with placebo against a first episode of laboratory-confirmed severe rotavirus gastroenteritis (Vesikari score, ≥11) beginning 28 days after dose 3.
RESULTS
Among the 3508 infants who were included in the per-protocol efficacy analysis, there were 31 cases of severe rotavirus gastroenteritis in the vaccine group and 87 cases in the placebo group (2.14 and 6.44 cases per 100 person-years, respectively), for a vaccine efficacy of 66.7% (95% confidence interval [CI], 49.9 to 77.9). Similar efficacy was seen in the intention-to-treat analyses, which showed a vaccine efficacy of 69.1% (95% CI, 55.0 to 78.7). There was no significant between-group difference in the risk of adverse events, which were reported in 68.7% of the infants in the vaccine group and in 67.2% of those in the placebo group, or in the risk of serious adverse events (in 8.3% in the vaccine group and in 9.1% in the placebo group); there were 27 deaths in the vaccine group and 22 in the placebo group. None of the infants had confirmed intussusception.
CONCLUSIONS
Three doses of BRV-PV, an oral rotavirus vaccine, had an efficacy of 66.7% against severe rotavirus gastroenteritis among infants in Niger. (Funded by Médecins sans Frontières Operational Center and the Kavli Foundation; ClinicalTrials.gov number, NCT02145000 .).
Journal Article > ResearchFull Text
Vaccine. 2020 December 3; Volume 38; DOI:10.1016/j.vaccine.2020.10.079
Hitchings MD, Cummings DAT, Grais RF, Isanaka S
Vaccine. 2020 December 3; Volume 38; DOI:10.1016/j.vaccine.2020.10.079
Analysis of immunogenicity data is a critical component of vaccine development, providing a biological basis to support any observed protection from vaccination. Conventional methods for analyzing immunogenicity data use either post-vaccination titer or change in titer, often defined as a binary variable using a threshold. These methods are simple to implement but can be limited especially in populations experiencing natural exposure to the pathogen. A mixture model can overcome the limitations of the conventional approaches by jointly modeling the probability of an immune response and the level of the immune marker among those who respond. We apply a mixture model to analyze the immunogenicity of an oral, pentavalent rotavirus vaccine in a cohort of children enrolled into a placebo-controlled vaccine efficacy trial in Niger. Among children with undetectable immunoglobulin A (IgA) at baseline, vaccinated children had 5.2-fold (95% credible interval (CrI) 3.7, 8.3) higher odds of having an IgA response than placebo children, but the mean log IgA among vaccinated responders was 0.9-log lower (95% CrI 0.6, 1.3) than among placebo responders. This result implies that the IgA response generated by vaccination is weaker than that generated by natural infection. Multivariate logistic regression of seroconversion defined by ≥ 3-fold rise in IgA similarly found increased seroconversion among vaccinated children, but could not demonstrate lower IgA among those who seroresponded. In addition, we found that the vaccine was less immunogenic among children with detectable IgA pre-vaccination, and that pre-vaccination infant serum IgG and mother’s breast milk IgA modified the vaccine immunogenicity. Increased maternal antibodies were associated with weaker IgA response in placebo and vaccinated children, with the association being stronger among vaccinated children. The mixture model is a powerful and flexible method for analyzing immunogenicity data and identifying modifiers of vaccine response and independent predictors of immune response.
Journal Article > CommentaryFull Text
Bull World Health Organ. 2012 September 1; Volume 90 (Issue 9); 635-635A.; DOI:10.2471/BLT.12.109504
Isanaka S, Schaefer MM, Vasset B, Baron E, Grais RF
Bull World Health Organ. 2012 September 1; Volume 90 (Issue 9); 635-635A.; DOI:10.2471/BLT.12.109504
Journal Article > ResearchFull Text
Vaccine. 2018 May 8; Volume 36 (Issue 25); 3674-3680.; DOI:10.1016/j.vaccine.2018.05.023
Coldiron ME, Guindo O, Makarimi R, Soumana I, Matar Seck A, et al.
Vaccine. 2018 May 8; Volume 36 (Issue 25); 3674-3680.; DOI:10.1016/j.vaccine.2018.05.023
BACKGROUND
Rotavirus remains a major cause of diarrhea among children under 5 years of age. The efficacy of RotaSIIL, a pentavalent rotavirus vaccine, was shown in an event-driven trial in Niger. We describe the two-year safety follow-up of this trial.
METHODS
Follow-up of safety outcomes began upon administration of the first dose of RotaSIIL or placebo. Adverse events were followed until 28 days after the third dose, and serious adverse events were followed until 2 years of age. Suspected cases of intussusception were evaluated at first point of contact and then referred to hospital for surgical evaluation. Causes of death were obtained by chart review and verbal autopsy. Passive surveillance was carried out in health centers. Community health workers carried out active surveillance in villages. Between-group differences were evaluated using the chi-squared test and Fisher's exact test.
RESULTS
A total of 4092 children were randomized, and 4086 received at least one dose of RotaSIIL or placebo, constituting the intention-to-treat population, who accrued a total of 7385 child-years of follow-up time. At two years of follow-up, 58 (2.8%) participants who received RotaSIIL and 49 (2.4%) participants who received placebo had died (p = 0.38). Most deaths were due to infectious causes common to the study area. One participant had confirmed intussusception, 542 days after receiving the third dose of RotaSIIL. A total of 395 (19.3%) participants receiving RotaSIIL and 419 (20.5%) participants receiving placebo experienced any serious adverse event (p = 0.36). Most serious adverse events were hospitalizations due to infection (malaria, lower respiratory tract infection and gastroenteritis) or marasmus. Overall, 1474 (72.1%) participants receiving RotaSIIL and 1456 (71.1%) participants receiving placebo had at least one adverse event (p = 0.49) in the follow-up period.
CONCLUSIONS
At two years of follow-up, RotaSIIL was found to be safe.
Rotavirus remains a major cause of diarrhea among children under 5 years of age. The efficacy of RotaSIIL, a pentavalent rotavirus vaccine, was shown in an event-driven trial in Niger. We describe the two-year safety follow-up of this trial.
METHODS
Follow-up of safety outcomes began upon administration of the first dose of RotaSIIL or placebo. Adverse events were followed until 28 days after the third dose, and serious adverse events were followed until 2 years of age. Suspected cases of intussusception were evaluated at first point of contact and then referred to hospital for surgical evaluation. Causes of death were obtained by chart review and verbal autopsy. Passive surveillance was carried out in health centers. Community health workers carried out active surveillance in villages. Between-group differences were evaluated using the chi-squared test and Fisher's exact test.
RESULTS
A total of 4092 children were randomized, and 4086 received at least one dose of RotaSIIL or placebo, constituting the intention-to-treat population, who accrued a total of 7385 child-years of follow-up time. At two years of follow-up, 58 (2.8%) participants who received RotaSIIL and 49 (2.4%) participants who received placebo had died (p = 0.38). Most deaths were due to infectious causes common to the study area. One participant had confirmed intussusception, 542 days after receiving the third dose of RotaSIIL. A total of 395 (19.3%) participants receiving RotaSIIL and 419 (20.5%) participants receiving placebo experienced any serious adverse event (p = 0.36). Most serious adverse events were hospitalizations due to infection (malaria, lower respiratory tract infection and gastroenteritis) or marasmus. Overall, 1474 (72.1%) participants receiving RotaSIIL and 1456 (71.1%) participants receiving placebo had at least one adverse event (p = 0.49) in the follow-up period.
CONCLUSIONS
At two years of follow-up, RotaSIIL was found to be safe.