Impact of rotavirus vaccine introduction in Abidjan, Côte d'Ivoire.

Côte d'Ivoire introduced rotavirus vaccine in March 2017. Rotavirus surveillance is conducted at Centre Hospitalier Universitaire de Yopougon in Abidjan, the capital city. Children <5 years of age are enrolled in rotavirus surveillance if admitted to the hospital with acute gastroenteritis. We used sentinel surveillance data from 2014 through mid-2019 to compare trends in rotavirus pediatric gastroenteritis hospitalizations before and after rotavirus vaccine introduction. We used Poisson regression to analyze changes in rotavirus prevalence, adjusting for calendar month and accounting for total monthly admissions; January 2014 - December 2016 was considered "pre-vaccine," and January 2017 - June 2019 was considered "post-vaccine." Age distribution and severity were compared between periods using the Mann-Whitney U test. Rotavirus-positive admissions declined 51% (95% CI: 28%-67%), from 31.5% pre-vaccine to 14.9% afterward. The median age of rotavirus-positive children increased from 7 months (interquartile range [IQR]: 5-11) in the pre-vaccine period to 11 months (IQR: 7-18, p = .005) in the post-vaccine period. The median severity score decreased from 11 to 9 (p = .008) among all children, and from 12 pre- to 10.5 post-vaccine (p = .35) among rotavirus-positive children. Our findings suggest that rotavirus vaccine introduction contributed to reduced rotavirus hospitalization in Abidjan and possibly more broadly.

Impact of Rotavirus Vaccine Introduction on Rotavirus Hospitalizations Among Children Under 5 Years of Age-World Health Organization African Region, 2008-2018.

BACKGROUND: Rotavirus is the leading cause of acute gastroenteritis (AGE) among children worldwide. Prior to rotavirus vaccine introduction, over one third of AGE hospitalizations in Africa were due to rotavirus. We describe the impact of rotavirus vaccines using data from the African Rotavirus Surveillance Network (ARSN). METHODS: For descriptive analysis, we included all sites reporting to ARSN for any length of time between 2008 and 2018. For vaccine impact analysis, continuous surveillance throughout the year was required to minimize potential bias due to enrollment of partial seasons and sites had to report a minimum of 100 AGE cases per year. We report the proportion of rotavirus AGE cases by year relative to vaccine introduction, and the relative reduction in the proportion of rotavirus AGE cases reported following vaccine introduction. RESULTS: From 2008 to 2018, 97 366 prospectively enrolled hospitalized children <5 years of age met the case definition for AGE, and 34.1% tested positive for rotavirus. Among countries that had introduced rotavirus vaccine, the proportion of hospitalized AGE cases positive for rotavirus declined from 39.2% in the prevaccine period to 25.3% in the postvaccine period, a 35.5% (95% confidence interval [CI]: 33.7-37.3) decline. No declines were observed among countries that had not introduced the vaccine over the 11-year period. CONCLUSIONS: Rotavirus vaccine introduction led to large and consistent declines in the proportion of hospitalized AGE cases that are positive for rotavirus. To maximize the public health benefit of these vaccines, efforts to introduce rotavirus vaccines in the remaining countries in the region and to improve coverage should continue.

Polio Data Quality Improvement in the African Region.

The polio Eradication Initiative (PEI) is one of the most important public health interventions in Africa. Quality data is necessary to monitor activities and key performance indicators and access year by year progress made. This process has been possible with a solid polio health information system that has been consolidated over the years. This study describes the whole process to have data for decision making. The main components are the data flow, the role of the different levels, data capture and tools, standards and codes, the data cleaning process, the integration of data from various sources, the introduction of innovative technologies, feedback and information products and capacity building. The results show the improvement in the timeliness of reporting data to the next level, the availability of quality data for analysis to monitor key surveillance performance indicators, the output of the data cleaning exercise pointing out data quality gaps, the integration of data from various sources to produce meaningful outputs and feedback for information dissemination. From the review of the process, it is observed an improvement in the quality of polio data resulting from a well-defined information system with standardized tools and Standard Operating Procedures (SOPs) and the introduction of innovative technologies. However, there is room for improvement; for example, multiple data entries from the field to the surveillance unit and the laboratory. Innovative technologies are implemented for the time being in areas hard to reach due to the high cost of the investment. A strong information system has been put in place from the community level to the global level with a link between surveillance, laboratory and immunization coverage data. To maintain standards in Polio Information system, there is need for continuous training of the staff on areas of surveillance, information systems, data analysis and information sharing. The use of innovative technologies on web-based system and mobile devices with validation rules and information check will avoid multiple entries.

The performance of routine immunization in selected African countries during the first six months of the COVID-19 pandemic.

INTRODUCTION: following the declaration of the COVID-19 pandemic on 11 March 2020, countries started implementing strict control measures, health workers were re-deployed and health facilities re-purposed to assist COVID-19 control efforts. These measures, along with the public concerns of getting COVID-19, led to a decline in the utilization of regular health services including immunization. METHODS: we reviewed the administrative routine immunization data from 15 African countries for the period from January 2018 to June 2020 to analyze the trends in the monthly number of children vaccinated with specific antigens, and compare the changes in the first three months of the COVID-19 pandemic. RESULTS: thirteen of the 15 countries showed a decline in the monthly average number of vaccine doses provided, with 6 countries having more than 10% decline. Nine countries had a lower monthly mean of recipients of first dose measles vaccination in the second quarter of 2020 as compared to the first quarter. Guinea, Nigeria, Ghana, Angola, Gabon, and South Sudan experienced a drop in the monthly number of children vaccinated for DPT3 and/or MCV1 of greater than 2 standard deviations at some point in the second quarter of 2020 as compared to the mean for the months January-June of 2018 and 2019. CONCLUSION: countries with lower immunization coverage in the pre-COVID period experienced larger declines in the number of children vaccinated immediately after the COVID-19 pandemic was declared. Prolonged and significant reduction in the number of children vaccinated poses a serious risk for outbreaks such as measles. Countries should monitor coverage trends at national and subnational levels, and undertake catch-up vaccination activities to ensure that children who have missed scheduled vaccines receive them at the earliest possible time.

Hospital-based Surveillance for Pediatric Bacterial Meningitis in the Era of the 13-Valent Pneumococcal Conjugate Vaccine in Ghana.

BACKGROUND: Global surveillance for vaccine preventable invasive bacterial diseases has been set up by the World Health Organization to provide disease burden data to support decisions on introducing pneumococcal conjugate vaccine (PCV). We present data from 2010 to 2016 collected at the 2 sentinel sites in Ghana. METHODS: Data were collected from children <5 years of age presenting at the 2 major teaching hospitals with clinical signs of meningitis. Cerebrospinal fluid specimens were collected and tested first at the sentinel site laboratory with conventional microbiology methods and subsequently with molecular analysis, at the World Health Organization Regional Reference Laboratory housed at the Medical Research Council Unit The Gambia, for identification of Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, the 3 most common bacteria causing meningitis. RESULTS: There were 4008 suspected cases of meningitis during the surveillance period, of which 31 (0.8%) were laboratory confirmed. Suspected meningitis cases decreased from 923 in 2010 to 219 in 2016. Of 3817 patients with available outcome data, 226 (5.9%) died. S. pneumoniae was the most common bacterial pathogen, accounting for 68.5% of confirmed cases (50 of 73). H. influenzae and N. meningitidis accounted for 6.8% (5 of 73) and 21.9% (16 of 73), respectively. The proportion of pneumococcal vaccine serotypes causing meningitis decreased from 81.3% (13 of 16) before the introduction of 13-valent PCV (2010-2012) to 40.0% (8 of 20) after its introduction (2013-2016). CONCLUSIONS: Cases of suspected meningitis decreased among children <5 years of age between 2010 and 2016, with declines in the proportion of vaccine-type pneumococcal meningitis after the introduction of 13-valent PCV in Ghana.

Etiology of Pediatric Bacterial Meningitis Pre- and Post-PCV13 Introduction Among Children Under 5 Years Old in Lomé, Togo.

BACKGROUND: Pediatric bacterial meningitis (PBM) causes severe morbidity and mortality within Togo. Thus, as a member of the World Health Organization coordinated Invasive Bacterial Vaccine Preventable Diseases network, Togo conducts surveillance targeting Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis (meningococcus), and Haemophilus influenzae, at a sentinel hospital within the capital city, Lomé, in the southernmost Maritime region. METHODS: Cerebrospinal fluid was collected from children <5 years with suspected PBM admitted to the Sylvanus Olympio Teaching Hospital. Phenotypic detection of pneumococcus, meningococcus, and H. influenzae was confirmed through microbiological techniques. Samples were shipped to the Regional Reference Laboratory to corroborate results by species-specific polymerase chain reaction. RESULTS: Overall, 3644 suspected PBM cases were reported, and 98 cases (2.7%: 98/3644) were confirmed bacterial meningitis. Pneumococcus was responsible for most infections (67.3%: 66/98), followed by H. influenzae (23.5%: 23/98) and meningococcus (9.2%: 9/98). The number of pneumococcal meningitis cases decreased by 88.1% (52/59) postvaccine introduction with 59 cases from July 2010 to June 2014 and 7 cases from July 2014 to June 2016. However, 5 cases caused by nonvaccine serotypes were observed. Fewer PBM cases caused by vaccine serotypes were observed in infants <1 year compared to children 2-5 years. CONCLUSIONS: Routine surveillance showed that PCV13 vaccination is effective in preventing pneumococcal meningitis among children <5 years of age in the Maritime region. This complements the MenAfriVac vaccination against meningococcal serogroup A to prevent meningitis outbreaks in the northern region of Togo. Continued surveillance is vital for estimating the prevalence of PBM, determining vaccine impact, and anticipating epidemics in Togo.

Etiology of Bacterial Meningitis Among Children <5 Years Old in Côte d'Ivoire: Findings of Hospital-based Surveillance Before and After Pneumococcal Conjugate Vaccine Introduction.

BACKGROUND: Bacterial meningitis remains a major disease affecting children in Côte d'Ivoire. Thus, with support from the World Health Organization (WHO), Côte d'Ivoire has implemented pediatric bacterial meningitis (PBM) surveillance at 2 sentinel hospitals in Abidjan, targeting the main causes of PBM: Streptococcus pneumoniae (pneumococcus), Haemophilus influenzae, and Neisseria meningitidis (meningococcus). Herein we describe the epidemiological characteristics of PBM observed in Côte d'Ivoire during 2010-2016. METHODS: Cerebrospinal fluid (CSF) was collected from children aged <5 years admitted to the Abobo General Hospital or University Hospital Center Yopougon with suspected meningitis. Microbiology and polymerase chain reaction (PCR) techniques were used to detect the presence of pathogens in CSF. Where possible, serotyping/grouping was performed to determine the specific causative agents. RESULTS: Overall, 2762 cases of suspected meningitis were reported, with CSF from 39.2% (1083/2762) of patients analyzed at the WHO regional reference laboratory in The Gambia. In total, 82 (3.0% [82/2762]) CSF samples were positive for bacterial meningitis. Pneumococcus was the main pathogen responsible for PBM, accounting for 69.5% (52/82) of positive cases. Pneumococcal conjugate vaccine serotypes 5, 18C, 19F, and 6A/B were identified post-vaccine introduction. Emergence of H. influenzae nontypeable meningitis was observed after H. influenzae type b vaccine introduction. CONCLUSIONS: Despite widespread use and high coverage of conjugate vaccines, pneumococcal vaccine serotypes and H. influenzae type b remain associated with bacterial meningitis among children aged <5 years in Côte d'Ivoire. This reinforces the need for enhanced surveillance for vaccine-preventable diseases to determine the prevalence of bacterial meningitis and vaccine impact across the country.

Pediatric Bacterial Meningitis Surveillance in Niger: Increased Importance of Neisseria meningitidis Serogroup C, and a Decrease in Streptococcus pneumoniae Following 13-Valent Pneumococcal Conjugate Vaccine Introduction.

BACKGROUND: Meningitis is endemic in Niger. Haemophilus influenzae type b (Hib) vaccine and the 13-valent pneumococcal conjugate vaccine (PCV13) were introduced in 2008 and 2014, respectively. Vaccination campaign against Neisseria meningitidis serogroup A was carried out in 2010-2011. We evaluated changes in pathogen distribution using data from hospital-based surveillance in Niger from 2010 through 2016. METHODS: Cerebrospinal fluid (CSF) specimens from children <5 years old with suspected meningitis were tested to detect vaccine-preventable bacterial pathogens. Confirmatory identification and serotyping/grouping of Streptococcus pneumoniae, N. meningitidis, and H. influenzae were done. Antimicrobial susceptibility testing and whole genome sequencing were performed on S. pneumoniae isolates. RESULTS: The surveillance included 2580 patients with suspected meningitis, of whom 80.8% (2085/2580) had CSF collected. Bacterial meningitis was confirmed in 273 patients: 48% (131/273) was N. meningitidis, 45% (123/273) S. pneumoniae, and 7% (19/273) H. influenzae. Streptococcus pneumoniae meningitis decreased from 34 in 2014, to 16 in 2016. PCV13 serotypes made up 88% (7/8) of S. pneumoniae meningitis prevaccination and 20% (5/20) postvaccination. Neisseria meningitidis serogroup C (NmC) was responsible for 59% (10/17) of serogrouped N. meningitidis meningitis. Hib caused 67% (2/3) of the H. influenzae meningitis isolates serotyped. Penicillin resistance was found in 16% (4/25) of S. pneumoniae isolates. Sequence type 217 was the most common lineage among S. pneumoniae isolates. CONCLUSIONS: Neisseria meningitidis and S. pneumoniae remain important causes of meningitis in children in Niger. The decline in the numbers of S. pneumoniae meningitis post-PCV13 is encouraging and should continue to be monitored. NmC is the predominant serogroup causing N. meningitidis meningitis.

Epidemiology of Ebola virus disease transmission among health care workers in Sierra Leone, May to December 2014: a retrospective descriptive study.

BACKGROUND: Anecdotal evidence suggests that much of the continuing infection of health care workers (HCWs) with Ebola virus during the current outbreak in Sierra Leone has occurred in settings other than Ebola isolation units, and it is likely that some proportion of acquisition by HCWs occurs outside the workplace. There is a critical need to define more precisely the pathways of Ebola infection among HCWs, to optimise measures for reducing risk during current and future outbreaks. METHODS: We conducted a retrospective descriptive study of Ebola acquisition among health workers in Sierra Leone during May-December 2014. The data used were obtained mainly from the national Ebola database, a cross-sectional survey conducted through administration of a structured questionnaire to infected HCWs, and key informant interviews of select health stakeholders. RESULTS: A total of 293 HCWs comprising 277 (95 %) confirmed, 6 (2 %) probable, and 10 (3 %) suspected cases of infection with Ebola virus were enrolled in the study from nine districts of the country. Over half of infected HCWs (153) were nurses; others included laboratory staff (19, 6.5 %), doctors (9, 3.1 %), cleaners and porters (9, 3.1 %), Community Health Officers (8, 2.7 %), and pharmacists (2, 0.7 %). HCW infections were mainly reported from the Western Area (24.9 %), Kailahun (18.4 %), Kenema (17.7 %), and Bombali (13.3 %) districts. Almost half of the infected HCWs (120, 47.4 %) believed that their exposure occurred in a hospital setting. Others believed that they were exposed in the home (48, 19 %), at health centres (45, 17.8 %), or at other types of health facilities (13, 5.1 %). Only 27 (10.7 %) of all HCW infections were associated with Ebola virus disease (EVD) isolation units. Over half (60 %, 150) of infected HCWs said they had been trained in infection prevention and control prior to their infection, whereas 34 % (85) reported that they had not been so trained. CONCLUSIONS: This study demonstrated the perception that most HCW infections are associated with general health care and home settings and not with dedicated EVD settings, which should provide substantial reassurance to HCWs that measures in place at dedicated EVD facilities generally provide substantial protection when fully adhered to.

Surveillance for Diseases Targeted by new Vaccines: Progress; Challenges and Way Forward

Thirteen years ago; WHO-AFRO proposed the establishment of a sentinel disease surveillance network as part of efforts to improve surveillance for invasive bacterial diseases (IBD) including paediatric pneumonia and meningitis and rotavirus diarrhoea in all Member States as part of surveillance for vaccine-preventable diseases and in line with the regional strategy integrated disease surveillance and response (IDSR). This was prompted by the eminent availability of new and prospective vaccines against Haemophilus influenzae type b (Hib); Streptococcus pneumoniae (S. pneum); Neisseria meningitides (Nm) and rotavirus vaccines. The Regional Office for Africa developed guidelines and tools and standardized methodology; including cases definitions to be used to recruit eligible cases. This article outlines the challenges and results of this initiative to date and aims for the future

The performance of routine immunization in selected African countries during the first six months of the COVID-19 pandemic

Introduction: following the declaration of the COVID-19 pandemic on 11 March 2020, countries started implementing strict control measures, health workers were re-deployed and health facilities re-purposed to assist COVID-19 control efforts. These measures, along with the public concerns of getting COVID-19, led to a decline in the utilization of regular health services including immunization.Methods: we reviewed the administrative routine immunization data from 15 African countries for the period from January 2018 to June 2020 to analyze the trends in the monthly number of children vaccinated with specific antigens, and compare the changes in the first three months of the COVID-19 pandemic.Results: thirteen of the 15 countries showed a decline in the monthly average number of vaccine doses provided, with 6 countries having more than 10% decline. Nine countries had a lower monthly mean of recipients of first dose measles vaccination in the second quarter of 2020 as compared to the first quarter. Guinea, Nigeria, Ghana, Angola, Gabon, and South Sudan experienced a drop in the monthly number of children vaccinated for DPT3 and/ or MCV1 of greater than 2 standard deviations at some point in the second quarter of 2020 as compared to the mean for the months January-June of 2018 and 2019.Conclusion: countries with lower immunization coverage in the pre-COVID period experienced larger declines in the number of children vaccinated immediately after the COVID-19 pandemic was declared. Prolonged and significant reduction in the number of children vaccinated poses a serious risk for outbreaks such as measles. Countries should monitor coverage trends at national and subnational levels, and undertake catch-up vaccination activities to ensure that children who have missed scheduled vaccines receive them at the earliest possible time