Characterizing Environmental Surveillance Sites in Nigeria and Their Sensitivity to Detect Poliovirus and Other Enteroviruses.

BACKGROUND: Environmental surveillance (ES) for poliovirus is increasingly important for polio eradication, often detecting circulating virus before paralytic cases are reported. The sensitivity of ES depends on appropriate selection of sampling sites, which is difficult in low-income countries with informal sewage networks. METHODS: We measured ES site and sample characteristics in Nigeria during June 2018-May 2019, including sewage physicochemical properties, using a water-quality probe, flow volume, catchment population, and local facilities such as hospitals, schools, and transit hubs. We used mixed-effects logistic regression and machine learning (random forests) to investigate their association with enterovirus isolation (poliovirus and nonpolio enteroviruses) as an indicator of surveillance sensitivity. RESULTS: Four quarterly visits were made to 78 ES sites in 21 states of Nigeria, and ES site characteristic data were matched to 1345 samples with an average enterovirus prevalence among sites of 68% (range, 9%-100%). A larger estimated catchment population, high total dissolved solids, and higher pH were associated with enterovirus detection. A random forests model predicted "good" sites (enterovirus prevalence >70%) from measured site characteristics with out-of-sample sensitivity and specificity of 75%. CONCLUSIONS: Simple measurement of sewage properties and catchment population estimation could improve ES site selection and increase surveillance sensitivity.

Pediatric Bacterial Meningitis Surveillance in Nigeria From 2010 to 2016, Prior to and During the Phased Introduction of the 10-Valent Pneumococcal Conjugate Vaccine.

BACKGROUND: Historically, Nigeria has experienced large bacterial meningitis outbreaks with high mortality in children. Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis (meningococcus), and Haemophilus influenzae are major causes of this invasive disease. In collaboration with the World Health Organization, we conducted longitudinal surveillance in sentinel hospitals within Nigeria to establish the burden of pediatric bacterial meningitis (PBM). METHODS: From 2010 to 2016, cerebrospinal fluid was collected from children <5 years of age, admitted to 5 sentinel hospitals in 5 Nigerian states. Microbiological and latex agglutination techniques were performed to detect the presence of pneumococcus, meningococcus, and H. influenzae. Species-specific polymerase chain reaction and serotyping/grouping were conducted to determine specific causative agents of PBM. RESULTS: A total of 5134 children with suspected meningitis were enrolled at the participating hospitals; of these 153 (2.9%) were confirmed PBM cases. The mortality rate for those infected was 15.0% (23/153). The dominant pathogen was pneumococcus (46.4%: 71/153) followed by meningococcus (34.6%: 53/153) and H. influenzae (19.0%: 29/153). Nearly half the pneumococcal meningitis cases successfully serotyped (46.4%: 13/28) were caused by serotypes that are included in the 10-valent pneumococcal conjugate vaccine. The most prevalent meningococcal and H. influenzae strains were serogroup W and serotype b, respectively. CONCLUSIONS: Vaccine-type bacterial meningitis continues to be common among children <5 years in Nigeria. Challenges with vaccine introduction and coverage may explain some of these finding. Continued surveillance is needed to determine the distribution of serotypes/groups of meningeal pathogens across Nigeria and help inform and sustain vaccination policies in the country.

Prevalence and characteristics of rotavirus acute gastroenteritis among under-five children in ahmadu bello university teaching hospital, Zaria, Nigeria.

Background: Rotavirus infection is a significant cause of gastroenteritis in developing countries and, in severe cases even leads to death. The impact of rotavirus vaccine introduction in reducing the rotavirus disease burden in children was well known. The study was aimed to determine the prevalence and clinical characteristics of rotavirus gastroenteritis before the introduction of rotavirus vaccine into Nigeria's routine immunization program. Materials and Methods: We conducted a cross-sectional hospital-based study involving 735 children aged 0-59 months with acute gastroenteritis hospitalized at the Ahmadu Bello University Teaching Hospital Zaria from September 2017 to August 2020. Relevant sociodemographic and clinical data were obtained and entered into the World Health Organization standardized case investigation forms. Stool specimens were tested for rotavirus Group A antigen using the ProSpecT™ Rotavirus Microplate Assay by Thermoscientific Oxoid Microbiology UK. Results: One hundred and fifty-three stool samples tested positive for rotavirus giving a prevalence of 20.8%. One hundred and two (66.7%) children with rotavirus gastroenteritis were infants. There were 87 males and 66 females with M: F ratio of 1.3:1. Only 30 (19.6%) children with rotavirus-associated diarrhea presented with severe dehydration. The presence of vomiting was significantly associated with rotavirus diarrhea (P = 0.001). More cases of rotavirus diarrhea occurred in September through February. None of the studied children were vaccinated against rotavirus. Conclusion: The prevalence of rotavirus diarrhea remains high in this study. Infants were recognized as a high-risk group, and none of them were vaccinated against rotavirus and this underscores the urgent need for implementing the rotavirus vaccine in the national vaccination program to reduce the disease burden in the country.

Résumé L'infection à rotavirus est une cause importante de gastro-entérite dans les pays en développement et, dans les cas graves, entraîne même la mort. L'impact de l'introduction du vaccin antirotavirus pour réduire le fardeau de la maladie à rotavirus chez les enfants était bien connue. L'étude visait à déterminer la prévalence et les caractéristiques cliniques de la gastro-entérite à rotavirus avant l'introduction du vaccin antirotavirus dans le programme de vaccination systématique du Nigéria. Matériels et méthodesNous avons mené une étude hospitalière transversale portant sur 735 enfants âgés de 0 à 59 mois atteints de gastro-entérite aiguë. hospitalisé à l'hôpital universitaire Ahmadu Bello Zaria de septembre 2017 à août 2020. Données sociodémographiques et cliniques pertinentes les données ont été obtenues et saisies dans les formulaires normalisés d'investigation de cas de l'Organisation mondiale de la santé. Des échantillons de selles ont été testés pour le rotavirus Antigène du groupe A utilisant le test sur microplaque ProSpecT™ Rotavirus par Thermoscientific Oxoid Microbiology UK. Résultatscent cinquante trois les échantillons de selles ont été testés positifs pour le rotavirus donnant une prévalence de 20,8 %. Cent deux (66,7 %) enfants atteints de gastro-entérite à rotavirus ont été nourrissons. Il y avait 87 hommes et 66 femmes avec un rapport M:F de 1,3:1. Seuls 30 (19,6 %) enfants atteints de diarrhée à rotavirus ont présenté déshydratation sévère. La présence de vomissements était significativement associée à la diarrhée à rotavirus (P = 0,001). Plus de cas de diarrhée à rotavirus se sont produits de septembre à février. Aucun des enfants étudiés n'a été vacciné contre le rotavirus. ConclusionLa prévalence de la diarrhée à rotavirus reste élevé dans cette étude. Les nourrissons ont été reconnus comme un groupe à haut risque et aucun d'entre eux n'a été vacciné contre le rotavirus, ce qui souligne la nécessité urgente de mettre en œuvre le vaccin antirotavirus dans le programme national de vaccination afin de réduire la charge de morbidité dans le pays. Mots-clésGastro-entérite aiguë, diarrhée à rotavirus, vaccin à rotavirus, Zaria.

Adverse events following immunization: Findings from 2017/2018 measles vaccination campaign, Nigeria AEFI reporting in 2017/2018 measles vaccination campaign.

INTRODUCTION: An Adverse event following immunization (AEFI) is an untoward medical occurrence following immunization and which may not have a necessary causal relationship with the usage of a vaccine. The World Health Organization categories AEFI into two; serious and non-serious. An AEFI is considered serious if it is life-threatening, requires inpatient hospitalization or results in death. The measles vaccine is safe and effective however because it is a live-attenuated injectable vaccine it is more prone to AEFI as compared to non-injectable vaccines when given in large numbers over a short period as is the nature of measles mass vaccination campaigns (MVC). This article describes Nigeria's experience on AEFI reporting during the 2017/2018 Measles vaccination campaign (MVC). METHODS: We reviewed various materials which included the Open Data Kit (ODK) which is an open source smartphone-based data collecting tool, operations room reports, measles campaign tally sheets, AEFI line listing forms, the post measles campaign coverage survey report and the report of the AEFI national expert committee review of the 2017/2018 Nigeria measles MVC. RESULTS: A total of 6,214 suspected cases of AEFI were line listed from all 36 states and the Federal Capital Territory(FCT) during the 2017/2018 MVC with Fever(38%) and pain at injection site the (30%)most common reports. Overall, 99.7% AEFIs were reported to be non-serious AEFIs, with almost all cases resolved fully with no long-term sequalae.. The national incidence of suspected AEFI per 100,000 population was 16.3 with subnational incidence highest in Kebbi state (101.3/100,000) and lowest in Bayelsa state (0.8/100,000). CONCLUSION: Adequate AEFI reporting, Investigation and management remains important in managing the risk of a disruption of mass campaigns. The deployment of supervisors during campaign may play an important role in improving the identification and reporting of suspected AEFI. Further inquiries about AEFIs during the post campaign coverage evaluation also played a role in improving AEFI reporting and documentation. The real-time, on the spot, follow up by the national operations team helped with decision making and intervention including AEFI investigations and assessments.