Unacceptably High Mortality Related to Measles Epidemics in Niger, Nigeria, and Chad

Abstract

BackgroundDespite the comprehensive World Health Organization (WHO)/United Nations Children's Fund (UNICEF) measles mortality–reduction strategy and the Measles Initiative, a partnership of international organizations supporting measles mortality reduction in Africa, certain high-burden countries continue to face recurrent epidemics. To our knowledge, few recent studies have documented measles mortality in sub-Saharan Africa. The objective of our study was to investigate measles mortality in three recent epidemics in Niamey (Niger), N'Djamena (Chad), and Adamawa State (Nigeria).Methods and FindingsWe conducted three exhaustive household retrospective mortality surveys in one neighbourhood of each of the three affected areas: Boukoki, Niamey, Niger (April 2004, n = 26,795); Moursal, N'Djamena, Chad (June 2005, n = 21,812); and Dong District, Adamawa State, Nigeria (April 2005, n = 16,249), where n is the total surveyed population in each of the respective areas. Study populations included all persons resident for at least 2 wk prior to the study, a duration encompassing the measles incubation period. Heads of households provided information on measles cases, clinical outcomes up to 30 d after rash onset, and health-seeking behaviour during the epidemic. Measles cases and deaths were ascertained using standard WHO surveillance-case definitions. Our main outcome measures were measles attack rates (ARs) and case fatality ratios (CFRs) by age group, and descriptions of measles complications and health-seeking behaviour. Measles ARs were the highest in children under 5 y old (under 5 y): 17.1% in Boukoki, 17.2% in Moursal, and 24.3% in Dong District. CFRs in under 5-y-olds were 4.6%, 4.0%, and 10.8% in Boukoki, Moursal, and Dong District, respectively. In all sites, more than half of measles cases in children aged under 5 y experienced acute respiratory infection and/or diarrhoea in the 30 d following rash onset. Of measles cases, it was reported that 85.7% (979/1,142) of patients visited a health-care facility within 30 d after rash onset in Boukoki, 73.5% (519/706) in Moursal, and 52.8% (603/1,142) in Dong District.ConclusionsChildren in these countries still face unacceptably high mortality from a completely preventable disease. While the successes of measles mortality–reduction strategies and progress observed in measles control in other countries of the region are laudable and evident, they should not overshadow the need for intensive efforts in countries that have just begun implementation of the WHO/UNICEF comprehensive strategy.

The dynamics of measles in sub-Saharan Africa

“…2c). Major outbreaks can quickly overwhelm local public health resources and result in high rates of childhood mortality 3 . Thus, to mitigate the potentially devastating effects of these outbreaks, both surveillance to detect epidemics, and the right balance between routine, supplementary and reactive control strategies are key to long-term measles control strategies in the region.…”

“…Global measles immunization programmes have focused on increasing routine vaccine coverage in young children through the World Health Organization (WHO) Expanded Programme on Immunization (EPI) 2 . EPI is reinforced by wide age range Supplementary Immunization Activities (SIAs) aimed at eliminating susceptible individuals who persist in the population beyond the age recommended for vaccination through routine health services 2,3 . Recent increases in vaccine distribution through the Measles Initiative, a partnership of WHO, UNICEF, the American Red Cross, the United Nations Foundation, and the US Centers for Disease Control, have led to an estimated 60% reduction in measles mortality worldwide relative to the global burden of mortality in 1999 (ref.…”

“…Routine single-dose measles vaccine distribution through EPI was initiated in 1987. Niger's first measles-only SIA, targeting all children aged 9 months to 14 yr, was conducted in 2004 and achieved an estimated coverage of 99% of the target population 3 . Before the SIA, measles outbreaks exhibited annual cycles at the national scale (Fig.…”

Wild-type measles virus infection of primary epithelial cells occurs via the basolateral surface without syncytium formation or release of infectious virus

“…Measles is a severe disease contributing to significant morbidity and mortality rates in many parts of the developing world (Grais et al, 2007). It is also of growing concern in some areas of the developed world where the vaccination rate has fallen below the level required to prevent periodic outbreaks of measles (Choi et al, 2008).…”

Outbreak response immunisation: the experience of Chad during recurrent measles epidemics in 2005 and 2010

“…VC surveys were conducted immediately after both campaigns using Lot Quality Assurance Sampling (LQAS). 6 Between January and April, 7822 cases were reported in 2005 and 8481 cases in 2010, corresponding to global attack rates of 64.6 per 10 000 population and 54.5 per 10 000 population, respectively (Figures 1 and 2 7,8 The city was divided into 25 non-overlapping lots based on administrative neighbourhoods with well known boundaries in 2005. In 2010, three additional lots were included in the survey to match the new administrative distribution of the city.…”