Progress towards elimination of measles in Kenya, 2003-2016

Introduction: measles is targeted for elimination in the World Health Organization African Region by the year 2020. In 2011, Kenya was off track in attaining the 2012 pre-elimination goal. We describe the epidemiology of measles in Kenya and assess progress made towards elimination.Methods: we reviewed national case-based measles surveillance and immunization data from January 2003 to December 2016. A case was confirmed if serum was positive for anti-measles IgM antibody, was epidemiologically linked to a laboratory-confirmed case or clinically compatible. Data on case-patient demographics, vaccination status, and clinical outcome and measles containing vaccine (MCV) coverage were analyzed. We calculated measles surveillance indicators and incidence, using population estimates for the respective years.Results: the coverage of first dose MCV (MCV1) increased from 65% to 86% from 2003-2012, then declined to 75% in 2016. Coverage of second dose MCV (MCV2) remained < 50% since introduction in 2013. During 2003-2016, there were 26,188 suspected measles cases were reported, with 9043(35%) confirmed cases, and 165 deaths (case fatality rate, 1.8%). The non-measles febrile rash illness rate was consistently > 2/100,000 population, and "80% of the sub-national level investigated a case in 11 of the 14 years. National incidence ranged from 4 to 62/million in 2003-2006 and decreased to 3/million in 2016. The age specific incidence ranged from 1 to 364/million population and was highest among children aged < 1 year.Conclusion: Kenya has made progress towards measles elimination. However, this progress remains at risk and the recent declines in MCV1 coverage and the low uptake in MCV2 could reverse these gains

The Effort to Attain Measles Pre-elimination Targets by 2012 and to Eliminate Measles in the African Region by 2020

Reduction in measles mortality contributes significantly towards attaining the Millennium Development Goal 4 (MDG 4); which aims to reduce overall under-five childhood deaths by two thirds by 2015; compared with 1990 levels. Routine measles immunization coverage is a key indicator for measuring progress towards attainment of this goal. Implementation of measles mortality reduction strategies in the African Region has led to major achievements; notably a reduction of estimated measles deaths by 92between 2000 and 2008. Despite the progress made; renewed commitment by countries is required to attain the pre-elimination targets and subsequently reach the ultimate goal of measles elimination by 2020. Countries will need to strengthen their immunization systems through ensuring that quality immunization services reach the hard-to-reach populations in addition to scaling up implementation of proven approaches and strategies such as the Reaching-Every-District approach. Gaps in the mobilization of resources have had a negative impact on the ability of countries to attain and sustain a high level of routine immunization and supplemental immunization activities coverage. Countries will also need to adopt a stepwise approach towards achieving the measles elimination goal by 2020; beginning with the attainment by 2012 of the proposed pre-elimination targets

A low-cost; community-based measles outbreak investigation with follow-up action

An outbreak of measles in Kampala; Uganda; in 1990 raised concern about the effectiveness of the measles vaccine that was used. The Uganda EPI programme and the medical office of the Kampala City Council therefore conducted a community-based investigation; with door-to-door interviews in two selected communities. They revealed 68 measles cases ranging in age from 5 months to 12 years; the highest age-specific attack rate (32pc) was found in children aged 12 to 23 months. BCG immunization coverage was high (85pc); but measles immunization coverage was moderate (48pc). One community; served by a mobile clinic; presented a vaccine efficacy of only 55pc. Responses by mothers revealed that many had failed to have their children completely immunized because of a lack of information; and not because of difficulties in access to the service. In a follow-up; community leaders initiated monthly checking of immunization cards of both children and mothers. The low vaccine efficacy found in one of the communities resulted in a thorough assessment of the city's cold chain. This community-based approach proved to be cost-effective and practical for identifying the obstacles to effective immunization delivery

Measles epidemic in Harare, Zimbabwe, despite high measles immunization coverage rates

Despite rapidly increasing measles immunization coverage in Harare city, measles remains endemic, and regular outbreaks occur. The most recent occurred in 1988, when the measles immunization coverage was 83%. We have carried out a retrospective study of the clinical and epidemiological features of this outbreak to assess whether the present immunization policy needs to be changed. Of 4357 cases of measles seen at primary health care centres and hospitals in Harare during the outbreak, 1399 (32%) were severe or involved complications that required hospital admission. The peak incidence occurred among under-2-year-olds, followed by that among 5-7-year-olds. Poor nutritional status was significantly more frequent among children who were hospitalized and among those who died. A total of 59% of all cases aged 9-59 months had documented evidence of measles immunization. The most frequent complications, which occurred most often among under-5-year-olds, were diarrhoea with dehydration, pneumonia, laryngotracheobronchitis, and convulsions, which together affected 56% of hospitalized cases. The hospital case fatality rate was low (1.43%). In Harare, measles transmission remains a problem, despite high measles immunization coverage rates; the failure rate for the standard Schwarz measles vaccine also appears to be high. There is a need to reduce the number of measles cases among under-9-month-olds and young children. Further studies into alternative measles vaccines and schedules are required