Muhammad Ali Pate

Implications of a Circulating Vaccine-Derived Poliovirus in Nigeria

BACKGROUND The largest recorded outbreak of a circulating vaccine-derived poliovirus (cVDPV), detected in Nigeria, provides a unique opportunity to analyze the pathogenicity of the virus, the clinical severity of the disease, and the effectiveness of control measures for cVDPVs as compared with wild-type poliovirus (WPV). METHODS We identified cases of acute flaccid paralysis associated with fecal excretion of type 2 cVDPV, type 1 WPV, or type 3 WPV reported in Nigeria through routine surveillance from January 1, 2005, through June 30, 2009. The clinical characteristics of these cases, the clinical attack rates for each virus, and the effectiveness of oral polio vaccines in preventing paralysis from each virus were compared. RESULTS No significant differences were found in the clinical severity of paralysis among the 278 cases of type 2 cVDPV, the 2323 cases of type 1 WPV, and the 1059 cases of type 3 WPV. The estimated average annual clinical attack rates of type 1 WPV, type 2 cVDPV, and type 3 WPV per 100,000 susceptible children under 5 years of age were 6.8 (95% confidence interval [CI], 5.9 to 7.7), 2.7 (95% CI, 1.9 to 3.6), and 4.0 (95% CI, 3.4 to 4.7), respectively. The estimated effectiveness of trivalent oral polio vaccine against paralysis from type 2 cVDPV was 38% (95% CI, 15 to 54%) per dose, which was substantially higher than that against paralysis from type 1 WPV (13%; 95% CI, 8 to 18%), or type 3 WPV (20%; 95% CI, 12 to 26%). The more frequent use of serotype 1 and serotype 3 monovalent oral polio vaccines has resulted in improvements in vaccine-induced population immunity against these serotypes and in declines in immunity to type 2 cVDPV. CONCLUSIONS The attack rate and severity of disease associated with the recent cVDPV identified in Nigeria are similar to those associated with WPV. International planning for the management of the risk of WPV, both before and after eradication, must include scenarios in which equally virulent and pathogenic cVDPVs could emerge.

Outbreak of Type 2 Vaccine-Derived Poliovirus in Nigeria: Emergence and Widespread Circulation in an Underimmunized Population

Wild poliovirus has remained endemic in northern Nigeria because of low coverage achieved in the routine immunization program and in supplementary immunization activities (SIAs). An outbreak of infection involving 315 cases of type 2 circulating vaccine-derived poliovirus (cVDPV2; >1% divergent from Sabin 2) occurred during July 2005–June 2010, a period when 23 of 34 SIAs used monovalent or bivalent oral poliovirus vaccine (OPV) lacking Sabin 2. In addition, 21 “pre-VDPV2” (0.5%–1.0% divergent) cases occurred during this period. Both cVDPV and pre-VDPV cases were clinically indistinguishable from cases due to wild poliovirus. The monthly incidence of cases increased sharply in early 2009, as more children aged without trivalent OPV SIAs. Cumulative state incidence of pre-VDPV2/cVDPV2 was correlated with low childhood immunization against poliovirus type 2 assessed by various means. Strengthened routine immunization programs in countries with suboptimal coverage and balanced use of OPV formulations in SIAs are necessary to minimize risks of VDPV emergence and circulation.

Human resources for maternal, newborn and child health: from measurement and planning to performance for improved health outcomes

BackgroundThere is increasing attention, globally and in countries, to monitoring and addressing the health systems and human resources inputs, processes and outputs that impede or facilitate progress towards achieving the Millennium Development Goals for maternal and child health. We reviewed the situation of human resources for health (HRH) in 68 low- and middle-income countries that together account for over 95% of all maternal and child deaths.MethodsWe collected and analysed cross-nationally comparable data on HRH availability, distribution, roles and functions from new and existing sources, and information from country reviews of HRH interventions that are associated with positive impacts on health services delivery and population health outcomes.ResultsFindings from 68 countries demonstrate availability of doctors, nurses and midwives is positively correlated with coverage of skilled birth attendance. Most (78%) of the target countries face acute shortages of highly skilled health personnel, and large variations persist within and across countries in workforce distribution, skills mix and skills utilization. Too few countries appropriately plan for, authorize and support nurses, midwives and community health workers to deliver essential maternal, newborn and child health-care interventions that could save lives.ConclusionsDespite certain limitations of the data and findings, we identify some key areas where governments, international partners and other stakeholders can target efforts to ensure a sufficient, equitably distributed and efficiently utilized health workforce to achieve MDGs 4 and 5.

A model for the adoption of ICT by health workers in Africa

PURPOSE To investigate the potential of information and communication technology (ICT) adoption among maternal and child health workers in rural Nigeria. METHODS A prospective, quantitative survey design was used to collect data from quasi-randomly selected clusters of 25 rural health facilities in 5 of the 36 states in Nigeria over a 2-month period from June to July 2010. A total of 200 maternal and child health workers were included in the survey, and the data were analyzed using a modified theory of acceptance model (TAM). RESULTS There was no significant difference between ICT knowledge and attitude scores across states. There were significant differences in perceived ease of use (P<.001) and perceived usefulness scores (P=.001) across states. Midwives reported higher scores on all the constructs but a lower score on endemic barriers (which is a more positive outcome). However, the differences were only statistically significant for perceived usefulness (P=.05) and endemic barriers (P<.001). Regression analysis revealed that there was no interaction between worker group and age. Older workers were likely to have lower scores on knowledge and attitude but higher scores on perceived ease of use and perceived usefulness. Lastly, we found that worker preference for ICT application in health varied across worker groups and conflicted with government/employer priorities. CONCLUSIONS Although the objective of this study was exploratory, the results provide insight into the intricacies involved in the deployment of ICT in low-resource settings. Use of an expanded TAM should be considered as a mandatory part of any pre-implementation study of ICT among health workers in sub-Saharan Africa.

Measles Resurgence Following a Nationwide Measles Vaccination Campaign in Nigeria, 2005–2008

INTRODUCTION From 1990 through 2008, routine immunization coverage of measles vaccine in Nigeria ranged from 35% to 70%. Nigeria conducted a nationwide measles vaccination campaign in 2 phases during 2005-2006 that targeted children aged 9 months to 14 years; in 2008, a nationwide follow-up campaign that targeted children aged 9 months to 4 years was conducted in 2 phases. Despite these efforts, measles cases continued to occur. METHODS This is a descriptive study that reviewed the measles immunization coverage data from administrative, World Health Organization, United Nations Childrens Fund, survey, and supplemental immunization activities data. Measles surveillance data were analyzed from case-based surveillance reports. RESULTS Confirmed measles cases increased from 383 in 2006 to 2542 in 2007 and to 9510 in 2008. Of the confirmed cases in 2008, 717 (30%) occurred in children <2 years of age, 1145 (48%) in children 2-4 years of age, and 354 (14%) were in children 5-14 years of age. In 2008, the measles case fatality rate was 1.2%. CONCLUSIONS Suboptimal routine coverage and the wide interval between the catch-up and follow-up campaigns likely led to an accumulation of children susceptible to measles.

Predictive spatial risk model of poliovirus to aid prioritization and hasten eradication in Nigeria

BackgroundOne of the challenges facing the Global Polio Eradication Initiative is efficiently directing limited resources, such as specially trained personnel, community outreach activities, and satellite vaccinator tracking, to the most at-risk areas to maximize the impact of interventions. A validated predictive model of wild poliovirus circulation would greatly inform prioritization efforts by accurately forecasting areas at greatest risk, thus enabling the greatest effect of program interventions.MethodsUsing Nigerian acute flaccid paralysis surveillance data from 2004-2013, we developed a spatial hierarchical Poisson hurdle model fitted within a Bayesian framework to study historical polio caseload patterns and forecast future circulation of type 1 and 3 wild poliovirus within districts in Nigeria. A Bayesian temporal smoothing model was applied to address data sparsity underlying estimates of covariates at the district level.ResultsWe find that calculated vaccine-derived population immunity is significantly negatively associated with the probability and number of wild poliovirus case(s) within a district. Recent case information is significantly positively associated with probability of a case, but not the number of cases. We used lagged indicators and coefficients from the fitted models to forecast reported cases in the subsequent six-month periods. Over the past three years, the average predictive ability is 86 ± 2% and 85 ± 4% for wild poliovirus type 1 and 3, respectively. Interestingly, the predictive accuracy of historical transmission patterns alone is equivalent (86 ± 2% and 84 ± 4% for type 1 and 3, respectively). We calculate uncertainty in risk ranking to inform assessments of changes in rank between time periods.ConclusionsThe model developed in this study successfully predicts districts at risk for future wild poliovirus cases in Nigeria. The highest predicted district risk was 12.8 WPV1 cases in 2006, while the lowest district risk was 0.001 WPV1 cases in 2013. Model results have been used to direct the allocation of many different interventions, including political and religious advocacy visits. This modeling approach could be applied to other vaccine preventable diseases for use in other control and elimination programs.

Conditional cash transfer schemes in Nigeria: potential gains for maternal and child health service uptake in a national pilot programme

BackgroundThis paper describes use of a Conditional Cash Transfer (CCT) programme to encourage use of critical MNCH services among rural women in Nigeria.MethodsThe CCT programme was first implemented as a pilot in 37 primary health care facilities (PHCs), in nine Nigerian states. The programme entitles women using these facilities up to N5,000 (approximately US

Prenatal care and basic emergency obstetric care services provided at primary healthcare facilities in rural Nigeria

30) if they attend antenatal care (ANC), skilled delivery, and postnatal care. There are 88 other PHCs from these nine states included in this study, which implemented a standard package of supply upgrades without the CCT. Data on monthly service uptake throughout the continuum of care was collected at 124 facilities during quarterly monitoring visits. An interrupted time series using segmented linear regression was applied to estimate separately the effects of the CCT programme and supply package on service uptake.ResultsFrom April 2013-March 2014, 20,133 women enrolled in the CCT. Sixty-four percent of beneficiaries returned at least once after registration, and 80% of women delivering with skilled attendance returned after delivery. The CCT intervention is associated with a statistically significant increase in the monthly number of women attending four or more ANC visits (increase of 15.12 visits per 100,000 catchment population, p < 0.01; 95% confidence interval 7.38 to 22.85), despite a negative level effect immediately after the intervention began (-45.53/100,000 catchment population; p < 0.05; 95% CI −82.71 to −8.36). A statistically significant increase was also observed in the monthly number of women receiving two or more Tetanus toxoid doses during pregnancy (21.65/100,000 catchment population; p < 0.01; 95% CI 9.23 to 34.08). Changes for other outcomes with the CCT intervention (number of women attending first ANC visit; number of deliveries with skilled attendance; number of neonates receiving OPV at birth) were not found to be statistically significant.ConclusionsThe results show that the CCT intervention is capable of significant effects on service uptake, although results for several outcomes of interest were inconclusive. Key lessons learnt from the pilot phase of implementation include a need to track beneficiary retention throughout the continuum of care as closely as possible, and avert loss to follow-up.

Survey of poliovirus antibodies in Kano, Northern Nigeria.

To assess the availability of prenatal care and basic emergency obstetric care services at primary healthcare (PHC) facilities in rural Nigeria.

Long shadow of fear in an epidemic: fearonomic effects of Ebola on the private sector in Nigeria

INTRODUCTION In 1988, the World Health Assembly resolved to eradicate poliomyelitis. Since then, much progress towards this goal has been made, but three countries including Nigeria remain polio-endemic as of end 2012. To assess the immunity level against poliomyelitis in young children in Northern Nigeria, we conducted a seroprevalence survey in the Kano Metropolitan Area (KMA) in May 2011. METHODS Parents or guardians of infants aged 6-9months or children aged 36-47months presenting to the outpatient department of Murtala Mohammad Specialist Hospital were approached for participation, screened for eligibility and were asked to provide informed consent. After that, a questionnaire was administered and blood was collected for neutralization assay. RESULTS A total of 327 subjects were enrolled. Of these, 313 (96%) met the study requirements and were analyzed (161 [51%] aged 6-9months and 152 [49%] aged 36-47months). Among subjects aged 6-9months, seroprevalence was 81% (95% confidence interval [CI] 75-87%) to poliovirus type 1, 76% (95% CI 68-81%) to poliovirus type 2, and 73% (95% CI 67-80%) to poliovirus type 3. Among subjects aged 36-47months, the seroprevalence was 91% (95% CI 86-95%) to poliovirus type 1, 87% (95% CI 82-92%) for poliovirus type 2, and 86% (95% CI 80-91%) to poliovirus type 3. Seroprevalence was associated with history of oral poliovirus vaccine (OPV) doses, maternal education and gender. CONCLUSIONS Seroprevalence is lower than required levels for poliovirus interruption in the KMA. Persistence of immunity gaps in the 36-47months group is a big concern. Since higher number of vaccine doses is associated with higher seroprevalence, it implies that failure-to-vaccinate and not vaccine failure accounts for the suboptimal seroprevalence. Intensified efforts are necessary to administer polio vaccines to all target children and surpass the threshold levels for herd immunity.