Polio eradication and measles immunisation in Nigeria

Burden of measles in Nigeria: a five-year review of casebased surveillance data, 2012-2016

Introduction

measles is a vaccine preventable, highly transmissible viral infection that affects mostly children under five years. We reviewed surveillance data on measles from Nigeria over a five-year period to highlights its burden and make recommendations for improvements.

Methods

we conducted a secondary data analysis of measles specific Integrated Disease Surveillance and Response (IDSR) records of all states in Nigeria over a five-year period.

Results

a total of 131,732 cases were recorded between January 2012 and September 2016. Most cases 57,892 (43.95%) were recorded in 2013 while the least 11,061 (8.4%) were recorded in 2012. A total of 817 deaths were recorded, with a case fatality rate (CFR) of 0.62%. The highest CFR (1.43%) was recorded in 2012 while the least CFR (0.44%) was recorded in 2016. Only 8,916 (6.7%) cases were confirmed by laboratory tests. The trend of measles cases followed the same pattern throughout the years under review, with cases peaking at March, then gradually reducing to lowest level at June, which was maintained throughout the rest of the year. States in northern region of Nigeria recorded the highest attack rate (Yobe: 480.29 cases per 100,000 population, Sokoto: 284.63 cases per 100,000 population and Katsina: 246.07 cases per 100,000 population) compared to States in the southern region (Rivers: 11.72 cases per 100,000 population and Akwa Ibom: 13.59 cases per 100,000 population). Conversely, States in the southern region recorded the highest CFR (Ebonyi: 13.43% and Rivers: 3.27%).

Conclusion

measles infection remains a burden especially in the northern region of Nigeria. Although measles fatalities declined over the years, laboratory confirmation was sub-optimal. We recommended improvement on routine immunization and strengthening of regional laboratories diagnostic capacities, for successful eradication of measles from Nigeria.

Molecular detection of measles virus from children during a sporadic outbreak in two semi-urban areas in Nigeria

BACKGROUND

According to the World Health Organization (WHO), African region accounts for 36% of deaths caused by measles worldwide. Nigeria has, over the years, recorded the highest average annual measles incidence per 100,000 populations in Africa. Measles epidemics have consistently been reported in northern Nigeria, but not in the South; reports of reduced protective haemagglutination inhibition antibody titers among children in Ibadan, southern Nigeria was made. Investigation of the viral agent responsible for the disease outbreak among children presenting with rash in two semi urban areas in southern Nigeria was carried out to confirm the etiology of the disease.

METHODOLOGY

Twenty six throat swabs (TS), and nineteen urine samples were collected from twenty six children residing in Onireke and Sabo areas of Ibadan following the report of an outbreak of rashes among children. Active case finding with the support of community leaders was used to locate the affected children. Multiplex reverse transcriptase polymerase chain reaction (MRT-PCR), was used to identify the agent.

RESULTS

21 of the 26 children screened tested positive for measles virus, but none was positive for Rubella virus. There was significant association between measles infection, and households with higher number of persons.

CONCLUSION

Mass measles vaccination that targets overcrowded, rural and inaccessible areas is needed to increase herd immunity. Public health enlightenment on the benefits of vaccination is encouraged.

Measles virus strain diversity, Nigeria and Democratic Republic of the Congo

Differences in epidemiologic patterns are only partially explained by vaccination practices.

We investigated the genetic diversity of measles virus (MV) in Nigeria (2004–2005) and the Democratic Republic of the Congo (DRC) (2002–2006). Genotype B3 strains circulating in Kinshasa, DRC, in 2002–2003 were fully replaced by genotype B2 in 2004 at the end of the second Congo war. In Nigeria (2004–2005), two genetic clusters of genotype B3, both of which were most closely related to 1 variant from 1998, were identified. Longitudinal analysis of MV strain diversity in Nigeria suggested that only a few of the previously described 1997–1998 variants had continued to circulate, but this finding was concomitant with a rapid restoration of genetic diversity, probably caused by low vaccination coverage and high birth rates. In contrast, the relatively low genetic diversity of MV in DRC and the genotype replacement in Kinshasa reflect a notable improvement in local measles control.

Completeness of suspected measles reporting in a southern district of Nigeria

OBJECTIVE

To determine the completeness of reporting of suspected measles cases to a local health authority in southern Nigeria.

STUDY DESIGN

Retrospective.

METHODS

Suspected measles cases were identified in all 23 health facilities in Aniocha South Local Government Area (LGA) of Delta State, Southern Nigeria by retrospective review of the health facilities' registers and the LGA surveillance records between 1 January 2007 and 30 June 2008. A capture-recapture method was used to obtain an estimate of the total number of measles cases expected for the study area within the study period. The completeness of reporting was calculated as a ratio of the number of measles cases reported to the LGA by hospitals to the number of cases estimated by the capture-recapture method.

RESULTS

An estimate of 87 measles cases was obtained with the capture-recapture method. The overall completeness of reporting was 11.5% (95% confidence interval 8.1-19.6%).

CONCLUSION

The number of suspected measles cases seems to have been grossly under-reported in this area.

Inequitable childhood immunization uptake in Nigeria: a multilevel analysis of individual and contextual determinants

BACKGROUND

Immunization coverage in many parts of Nigeria is far from optimal, and far from equitable.Nigeria accounts for half of the deaths from Measles in Africa, the highest prevalence of circulating wild poliovirus in the world, and the country is among the ten countries in the world with vaccine coverage below 50 percent. Studies focusing on community-level determinants therefore have serious policy implications

METHODS

Multilevel multivariable regression analysis was used on a nationally-representative sample of women aged 15-49 years from the 2003 Nigeria Demographic and Health Survey. Multilevel regression analysis was performed with children (level 1) nested within mothers (level 2), who were in turn nested within communities (level 3).

RESULTS

Results show that the pattern of full immunization clusters within families and communities, and that socio-economic characteristics are important in explaining the differentials in full immunization among the children in the study. At the individual level, ethnicity, mothers' occupation, and mothers' household wealth were characteristics of the mothers associated with full immunization of the children. At the community level, the proportion of mothers that had hospital delivery was a determinant of full immunization status.

CONCLUSION

Significant community-level variation remaining after having controlled for child- and mother-level characteristics is indicative of a need for further research on community-levels factors, which would enable extensive tailoring of community-level interventions aimed at improving full immunization and other child health outcomes.

Measles control and the prospect of eradication

Remarkable progress has been made in reducing measles incidence and mortality as a consequence of implementing the measles mortality reduction strategy of the World Health Organization (WHO) and United Nations Children's Fund (UNICEF). The revised global measles mortality reduction goal set forth in the WHO-UNICEF Global Immunization Vision and Strategy for 2006–2015 is to reduce measles deaths by 90% by 2010 compared to the estimated 757,000 deaths in 2000. The possibility of measles eradication has been discussed for almost 40 years, and measles meets many of the criteria for eradication. Global measles eradication will face a number of challenges to achieving and sustaining high levels of vaccine coverage and population immunity, including population growth and demographic changes, conflict and political instability, and public perceptions of vaccine safety. To achieve the measles mortality reduction goal, continued progress needs to be made in delivering measles vaccines to the world's children.

Is the Expanded Programme on Immunisation the most appropriate delivery system for intermittent preventive treatment of malaria in West Africa?

OBJECTIVE

To investigate the coverage and equity of the Expanded Programme on Immunisation (EPI) and its effect on age schedule, seasonality of malaria risk, and linked intermittent preventive treatment (IPT) in West Africa.

METHOD

Secondary analyses of data from a trial of IPT in Ghana. The potential effectiveness and impact of EPI-linked IPT in West Africa was calculated using the coverage of Diptheria Pertussis Tetanus vaccination obtained from national surveys and the reported protective efficacies of IPT.

RESULTS

In West Africa, where the transmission of malaria is highly seasonal, only 10% of malaria episodes in infants would be averted with the current coverage of EPI.

CONCLUSION

In this setting, the EPI-linked IPT is not necessarily the most appropriate approach and alternative IPT schedules and delivery systems are needed.

Global measles elimination

Measles remains a leading vaccine-preventable cause of child mortality worldwide, particularly in sub-Saharan Africa where almost half of the estimated 454,000 measles deaths in 2004 occurred. However, great progress in measles control has been made in resource-poor countries through accelerated measles-control efforts. The global elimination of measles has been debated since measles vaccines were first licensed in the 1960's, and this debate is likely to be renewed if polio virus is eradicated. This review discusses the pathogenesis of measles and the likelihood of the worldwide elimination of this disease.