Response to back-to-back outbreaks of circulating vaccine-derived poliovirus type 2 in two nomadic pastoralist settlements in Oti Region, Ghana-2019.

BACKGROUND: The global switch from trivalent oral poliovirus vaccine (OPV) to bivalent OPV in April 2016 without corresponding co-administration of inactivated poliovirus vaccine (IPV) until June 2018, created a cohort of poliovirus type 2 naïve children with risk of developing vaccine-derived poliovirus type 2 (VDPV2). In November and December 2019, two cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) were confirmed in quick succession through Acute Flaccid Paralysis (AFP) surveillance in two nomadic pastoralist settlements in Oti Region. We investigated to determine the outbreak extent, identify risk factors and implement control and preventive measures. METHODS: We interviewed case-patients' families, abstracted immunization records, assessed AFP surveillance and conducted rapid OPV and IPV vaccination coverage surveys. Using AFP case definition of any child less than 15 years in the community with sudden onset of paralysis from July to November 2019 (in case-patient 1's district) and August to December 2019 (in case-patient 2's district), we conducted active case search. Stool samples from apparently healthy children and close contacts of the case-patients were collected and tested for poliovirus. We conducted environmental assessment of the community to identify potential risk factors. RESULTS: Case-patient 1 was an eight-year-old female who had taken two doses of OPV while case-patient 2 was an eight-month-old male who had taken three out of required four OPV doses in addition to IPV at seven months. Families of both case-patients had either travelled to or received visitors from areas with confirmed cVDPV2. Of all children surveyed, eight (29.6%) of 27 and three (18.8%) of 16 eligible children in communities of case-patient 1 and 2 respectively had received required four doses of OPV. No AFP case was found in both communities and surrounding settlements. Both communities had no source of potable water and toilet facilities. A stool sample from a contact of case-patient 1 tested positive for cVDPV2. CONCLUSION: Outbreaks of cVDPV2 occurred in insanitary, under-vaccinated nomadic pastoralist settlements in Oti Region. Three rounds of monovalent OPV vaccination campaigns for children under 5 years of age in the districts and region as well as countrywide IPV vaccination campaign for poliovirus type 2 naïve cohort were conducted.

Epidemiology of intussusception in infants less than one year of age in Ghana, 2012-2016.

INTRODUCTION: we examined the epidemiology, clinical and demographic characteristics of intussusception in Ghanaian infants. METHODS: active sentinel surveillance for pediatric intussusception was conducted at Komfo Anokye Teaching Hospital in Kumasi and Korle Bu Teaching Hospital in Accra. From March 2012 to December 2016, infants < 1 year of age who met the Brighton Collaboration level 1 diagnostic criteria for intussusception were enrolled. Data were collected through parental interviews and medical records abstraction. RESULTS: a total of 378 children < 1 year of age were enrolled. Median age at onset of intussusception was 27 weeks; only 12 cases (1%) occurred in infants < 12 weeks while most occurred in infants aged 22-34 weeks. Median time from symptom onset until referral to a tertiary hospital was 2 days (IQR: 1-4 days). Overall, 35% of infants were treated by enema, 33% had surgical reduction and 32% required surgical reduction and bowel resection. Median length of hospital stay was 5 days (IQR: 3-8 days) with most patients (95%) discharged home. Eleven (3%) infants died. Infants undergoing enema reduction were more likely than those treated surgically to present for treatment sooner after symptom onset (median 1 vs 3 days; p < 0.0001) and have shorter hospital stays (median 3 vs 7 days; p < 0.001). CONCLUSION: Ghanaian infants had a relatively low case fatality rate due to intussusception, with a substantial proportion of cases treated non-surgically. Early presentation for treatment, possibly enhanced by community-based health education programs and health information from various media platforms during the study period might contribute to both the low fatality rate and high number of successful non-surgical treatments in this population.

Detection of vaccine-derived poliovirus circulation by environmental surveillance in the absence of clinical cases.

BACKGROUND: On August 25, 2019, the Noguchi Memorial Institute for Medical Research notified the confirmation of a circulating-vaccine-derived poliovirus type-2 (cVDPV2) from the Agbogbloshie environmental surveillance (AES) site, in the Greater Accra Region. A field investigation of the outbreak was conducted to describe the results of epidemiological and laboratory investigations, and control efforts. METHODS: We conducted a descriptive investigation, records review, and active-case-search. Caregivers were interviewed on the vaccination status of their children; knowledge, attitude, and practices on polio prevention; water, sanitation and hygiene practices, and health-seeking behaviors. Stool from healthy children <5 y and sewage samples were taken for laboratory diagnosis. RESULTS: cVDPV2 genetically similar to the cVDPV2 diagnosed recently in the Northern Region of Ghana and Nigeria was identified. 2019 half-year coverage of OPV and IPV was 22%. Fully immunized children were 49% (29/59). Most health workers (70%) had a fair knowledge of polio and acute flaccid paralysis (AFP). Forty-six percent of care-givers admitted to using the large drain linked to the site where the cVDPV2 was isolated as their place of convenience and disposing of the fecal matter of their children. No AFP case was identified. Stool samples from 40 healthy children yielded non-polio enteroviruses while 75% (3/4) of the additional sewage samples yielded cVDPV2. CONCLUSION: cVDPV2 was isolated from the AES site. No AFP or poliovirus was identified from healthy children. There is a need to improve health workers' knowledge on AFP and to address the dire sanitation conditions in the Agbogbloshie market and its environs.

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.

Sustained impact of rotavirus vaccine introduction on rotavirus gastroenteritis hospitalizations in children <5 years of age, Ghana, 2009-2016.

INTRODUCTION: Ghana introduced monovalent rotavirus vaccine in April 2012. We sought to determine the long-term impact of routine rotavirus vaccination on rotavirus gastroenteritis hospitalizations in Ghana during the first 4 years following rotavirus vaccine introduction. METHODS: Active sentinel surveillance for acute gastroenteritis hospitalizations among children <5 years of age was conducted at two sites from July 2009 through June 2016. Stool specimens were collected from enrolled children and tested by enzyme immunoassay. Changes in the proportion of all-cause gastroenteritis hospitalizations due to rotavirus pre- (July 2009-June 2012) and post-vaccine introduction (July 2012-June 2016) were compared using chi-square test. RESULTS: The proportion of acute gastroenteritis hospitalizations due to rotavirus among children <5 years of age significantly declined by 42% from a pre-vaccine median of 50% (343/684) to a post-vaccine median of 29% (118/396) (p < 0.001). The age distribution of rotavirus hospitalizations shifted toward older ages with 64% (759/1197) of rotavirus hospitalizations occurring in children <12 months of age pre-vaccine introduction to 47% (212/453) occurring in children <12 months of age post-vaccine introduction (p < 0.001). DISCUSSION: The decline in rotavirus hospitalizations following rotavirus vaccine introduction have been sustained over the first 4 years of the vaccination program in Ghana. Continued vaccination against rotavirus will ensure that this burden remains low.

Rotavirus strain distribution in Ghana pre- and post- rotavirus vaccine introduction.

BACKGROUND: Ghana introduced the monovalent rotavirus vaccine (Rotarix) into its national paediatric vaccination programme in May2012. Vaccine introduction was initiated nationwide and achieved >85% coverage within a few months. Rotavirus strain distribution pre- and post-RV vaccine introduction is reported. METHODS: Stool samples were collected from diarrhoeic children <5 years of age hospitalized between 2009 and 2016 at sentinel sites across Ghana and analyzed for the presence of group A rotavirus by enzyme immunoassay. Rotavirus strains were characterized by RT-PCR and sequencing. RESULTS: A total of 1363 rotavirus EIA-positive samples were subjected to molecular characterization. These were made up of 823 (60.4%) and 540 (39.6%) samples from the pre- and post-vaccine periods respectively. Rotavirus VP7 genotypes G1, G2 and G3, and VP4 genotypes P[6] and P[8] constituted more than 65% of circulating G and P types in the pre-vaccine period. The common strains detected were G1P[8] (20%), G3P[6] (9.2%) and G2P[6] (4.9%). During the post-vaccine period, G12, G1 and G10 genotypes, constituted more than 65% of the VP7 genotypes whilst P[6] and P[8] made up more than 75% of the VP4 genotypes. The predominant circulating strains were G12P[8] (26%), G10P[6] (10%) G3P[6] (8.1%) and G1P[8] (8.0%). We also observed the emergence of the unusual rotavirus strain G9P[4] during this period. CONCLUSION: Rotavirus G1P[8], the major strain in circulation during the pre-vaccination era, was replaced by G12P[8] as the most predominant strain after vaccine introduction. This strain replacement could be temporary and unrelated to vaccine introduction since an increase in G12 was observed in countries yet to introduce the rotavirus vaccine in West Africa. A continuous surveillance programme in the post-vaccine era is necessary for the monitoring of circulating rotavirus strains and the detection of unusual/emerging genotypes.

Country Immunization Information System Assessments - Kenya, 2015 and Ghana, 2016.

The collection, analysis, and use of data to measure and improve immunization program performance are priorities for the World Health Organization (WHO), global partners, and national immunization programs (NIPs). High quality data are essential for evidence-based decision-making to support successful NIPs. Consistent recording and reporting practices, optimal access to and use of health information systems, and rigorous interpretation and use of data for decision-making are characteristics of high-quality immunization information systems. In 2015 and 2016, immunization information system assessments (IISAs) were conducted in Kenya and Ghana using a new WHO and CDC assessment methodology designed to identify root causes of immunization data quality problems and facilitate development of plans for improvement. Data quality challenges common to both countries included low confidence in facility-level target population data (Kenya = 50%, Ghana = 53%) and poor data concordance between child registers and facility tally sheets (Kenya = 0%, Ghana = 3%). In Kenya, systemic challenges included limited supportive supervision and lack of resources to access electronic reporting systems; in Ghana, challenges included a poorly defined subdistrict administrative level. Data quality improvement plans (DQIPs) based on assessment findings are being implemented in both countries. IISAs can help countries identify and address root causes of poor immunization data to provide a stronger evidence base for future investments in immunization programs.

Impact and Effectiveness of Monovalent Rotavirus Vaccine Against Severe Rotavirus Diarrhea in Ghana.

BACKGROUND: Ghana was among the first African nations to introduce monovalent rotavirus vaccine (RV1) into its childhood immunization schedule in April 2012. We aimed to assess the impact of vaccine introduction on rotavirus and acute gastroenteritis (AGE) hospitalizations and to estimate vaccine effectiveness (VE). METHODS: Using data from 2 teaching hospitals, monthly AGE and rotavirus admissions by age were examined 40 months before and 31 months after RV1 introduction using interrupted time-series analyses. From January 2013, we enrolled children <2 years of age who were eligible for RV1 from a total of 7 sentinel sites across the country. To estimate VE, we fit unconditional logistic regression models to calculate odds ratios of vaccination by rotavirus case-patient status, controlling for potential confounders. RESULTS: Vaccine coverage ranged from 95% to 100% for dose 1 and 93% to 100% for dose 2. In the first 3 years after vaccine introduction, the percentage of hospital admissions positive for rotavirus fell from 48% in the prevaccine period to 28% (49% adjusted rate reduction; 95% confidence interval [CI], 32%-63%) postvaccination among <5-year-olds. With high vaccine coverage, it was not possible to arrive at robust VE estimates; any-dose VE against rotavirus hospitalization was estimated at 60% (95% CI, -2% to 84%;P= .056). CONCLUSIONS: Results from the first 3 years following RV1 introduction suggest substantial reductions of pediatric diarrheal disease as a result of vaccination. Our VE estimate is consistent with the observed rotavirus decrease and with efficacy estimates from elsewhere in sub-Saharan Africa.

Decline in severe diarrhea hospitalizations after the introduction of rotavirus vaccination in Ghana: a prevalence study.

BACKGROUND: Almost all diarrhea deaths in young children occur in developing countries. Immunization against rotavirus, the leading cause of childhood severe dehydrating acute diarrhea may reduce the burden of severe diarrhea in developing countries. Ghana introduced rotavirus and pneumococcal vaccination in the national expanded program on immunization in May 2012. METHODS: Review of all-cause diarrheal hospitalization data for children aged 59 months and younger at 2 pediatric referral hospitals in southern Ghana from 2008 to 2014. The proportion of acute diarrhea (defined as 3 or more watery, non-bloody stools within 24 hours that has lasted for less than 7 days) cases caused by rotavirus was determined. Temporal trend and age group distribution of all-cause diarrhea and rotavirus gastroenteritis before and after introduction of the new vaccines were compared. RESULTS: Of the 5847 children hospitalized with all-cause diarrhea during the 74 months (January 2008 - February 2014), 3963 (67.8%) children were recruited for rotavirus surveillance and stool specimens were tested for rotavirus in 3160/3963 (79.7%). Median monthly hospitalization for all-cause diarrhea reduced from 84 [interquartile range (IQR) 62 - 105] during the 52 months pre-vaccination introduction to 46 (IQR 42 - 57) in the 22 months after implementation of vaccination. Significant decline in all-cause diarrhea hospitalization occurred in children aged 0 - 11 months: 56.3% (2711/4817) vs. 47.2% 486/1030 [p = 0.0001, 95% confidence interval (CI) 0.77 - 0.88] and there was significant reduction of rotavirus gastroenteritis hospitalization: 49.7% (1246/2505) vs. 27.8% (182/655) [p = 0.0001, 95% CI 0.32 - 0.47] before and after vaccine introduction respectively. CONCLUSIONS: Implementation of rotavirus vaccination program may have resulted in significant reduction of severe diarrhea hospitalization even though this observational study could not exclude the effect of other confounding factors. Continued surveillance is recommended to monitor the progress of this program.

Evaluation of AFP surveillance indicators in polio-free Ghana, 2009-2013.

BACKGROUND: Ghana recorded the last case of indigenous wild poliovirus in 1999 but suffered two more outbreaks in 2003 and 2008. Following the World Health Organization (WHO) guidelines, transmission was interrupted through high routine immunisation coverage with live-attenuated oral polio vaccine (OPV), effective acute flaccid paralysis (AFP) surveillance and supplementary immunisation activities (SIA). This article describes the results of a five-year surveillance of AFP in polio-free Ghana, evaluate the surveillance indicators and identify areas that need improvement. METHODS: We investigated 1345 cases of AFP from children aged less than 15 years reported to the Disease Surveillance Department from January 2009 to December 2013. Data on demographic characteristics, vaccination history, clinical presentation and virological investigation on stool specimens collected during investigation were analysed. RESULTS: Of the specimens analysed, 56% were from males and 76.3% were from children less than 5 years of age. Twenty-four percent of the children received up to 3 doses of OPV, 57% received at least 4 doses while the status of 19% was unknown. Core AFP surveillance indicators were partly met for non-polio AFP rate while the WHO target for stool adequacy and timeliness was exceeded over the period of study. All the cases were classified virologically, however no wild polio was found. Sixty-day follow-up was conducted for 56.3% of cases and 8.6% cases classified as compactible with polio. CONCLUSION: Both laboratory and epidemiological surveillance for AFP were efficient and many WHO targets were met. However, due to the risk of poliovirus importation prior to global eradication, longterm surveillance is required to provide a high degree of confidence in prevention of poliovirus infection in Ghana. Thus, efforts should be made to strengthen regional performance and to follow-up on all AFP cases in order to establish proper diagnoses for the causes of the AFP leading to proper care.