Validity of measles mortality data using hospital registers and community surveys.

BACKGROUND: Case-fatality rates (CFR) for measles cases have previously been reported to be higher in hospital than in community studies. METHODS: Data on measles morbidity and mortality obtained in community investigations of measles outbreaks in two rural districts in Kenya were compared to data from the same time period on measles morbidity and mortality in children hospitalized with measles in the respective district hospitals. RESULTS: The CFR were found to be considerably lower in the respective district hospitals, 1.7 and 2.1%, than in the community surveys, 8.0% and 9.4%, respectively (relative risk [RR] 0.17, 95% confidence interval [CI] 0.10-0.30, and RR = 0.20, 95% CI: 0.05-0.81). CONCLUSIONS: Hospital-based studies of the CFR in measles infection are not representative of measles mortality in the community. It may be misleading to use hospital data in measles control surveillance systems. Further studies are needed of the mortality after discharge of hospitalized measles cases.

Measles in infants: a review of studies on incidence, vaccine efficacy and mortality in east Africa.

Control of measles in developing countries is complicated by high incidence and mortality among infants. Hospital-based and community-based studies from East Africa were reviewed with respect to the reported incidence and mortality of measles and vaccine efficacy/seroconversion rates after the administration of measles vaccine to infants. The studies reviewed confirm that measles is particularly severe in infants, and some indicate that vaccination before 9 months with standard vaccine could be effective and have beneficial effects for children aged 6-9 months, while other studies refute this finding. Due to the high incidence and mortality of measles in infants, alternative control strategies are essential to reduce measles mortality. Further studies are needed on the effects of a two-dose schedule vaccinating at 6 and 9 months, which in mathematical modelling shows considerable benefit. Improved management of measles cases, including the administration of vitamin A could be considered as a complementary strategy for reducing measles mortality, especially in infants.

Neonatal tetanus mortality in coastal Kenya: a community survey.

In a house-to-house survey in Kilifi District, Kenya, mothers of 2556 liveborn children were interviewed about neonatal mortality, especially from neonatal tetanus (NNT). The crude birth rate was 60.5 per 1000 population, the neonatal mortality rate 21.1 and the NNT mortality rate 3.1 per 1000 livebirths. The neonatal and NNT mortality rates were higher in boys than in girls. Neonatal tetanus was not associated with mother's age, parity, or history of previous child death. The majority of the children (72%) were adequately protected at birth against NNT; in those with documented protection NNT mortality was 0, in those with undocumented protection 1.2 and in other children 8.5 per 1000 livebirths. Other risk factors for NNT included home delivery, untrained assistance during delivery, unhygienic cord cutting and application of potentially infectious substances on the umbilical stump. The survey indicates that over the past decade the surveyed area has greatly reduced neonatal and NNT mortality. Possible strategies for accelerated NNT control have been identified by the survey.

Child mortality impact of a measles outbreak in a partially vaccinated rural African community.

In spite of a measles vaccination coverage of 58%, 33% of 60 infant and child deaths were attributed to measles in a rural area of Kenya in 1988. Among 252 measles cases, there were 20 acute and 5 late deaths which may have been caused by the measles. Median age at infection was 44 months, with 16% of cases below 1 year of age. The highest age-specific attack rates (43% and 41%) were in unvaccinated children 6-11 months and 1-2-year-olds. The overall case fatality rate for children below 5 years was 12.6%, for unvaccinated children below 5, 16.2% and among children below 9 months, 24%. Children in homes with several cases had a higher case fatality ratio than had isolated cases, although not significantly so (RR 1.93, 95% CI 0.71-5.24). The median age of the children who died was 12 months. Overall vaccine efficacy was 62% for children 1-4 years. Our findings suggest that the measles vaccination coverage must be raised considerably in order to reduce mortality rates, and that alternative ways to project infants are needed.

Severe measles outbreak in western Kenya.

During a measles outbreak investigation in Siaya district clustering of many measles cases were found to be an important determinant for measles mortality. A high proportion of cases were under one year of age. Case fatality rates were higher than previously reported from Kenya, particularly among infants. Vaccine efficacy was 18%. Alternative ways of protecting infants are discussed.

A cluster survey of mortality due to neonatal tetanus in Kenya.

Three house-to-house surveys were conducted in three different districts in Kenya, using a cluster survey technique for estimation of neonatal tetanus death rates. The results showed neonatal death rates of 10, 16 and 23 per 1000 livebirths and neonatal tetanus death rates of 6, 11 and 16 per 1000 livebirths respectively. A recall method based on interviews with women attending antenatal clinics gave much lower rates. The community surveys indicate a total neonatal tetanus death rate of 8 per 1000 livebirths and it is estimated that each year between 8000 and 12,000 children die in Kenya from this preventable disease.

PIP: The incidence of neonatal tetanus mortality was determined in Kenya by household surveys randomly selected by 2-stage cluster sampling in 3 districts. The districts were Tana, a poor pastoral area, and Meru and Kisii districts, both farming areas with literacy and health levels around the Kenyan average. Interviews were conducted by teams of 3 including a locally trained person, usually a student nurse, a guide and a representative of the village elders. Live neonates delivered during the previous 12-month period ending 1 month before survey were recorded until 70 births were reached in each cluster. Respondents were asked if a child had died during the 1st month, was born alive, did suck but stopped when it became ill, had fever, convulsions, became stiff or had tetanus (local name). The neonatal death rates ranged from 10-23 per 1000 live births. Neonatal tetanus mortality ranged from 6-16 per 1000 live births. Neonatal tetanus death rates were 14.1 for home deliveries and 4.3 for deliveries in health clinics. Tetanus deaths occurred between Days 6 and 12, while other neonatal deaths took place on Day 1. Tetanus accounted for nearly 70% of all neonatal deaths. These figures are lower than those reported for Ivory Coast, Malawi and rural India, but higher than data for urban Egypt. If these areas are representative of Kenya as a whole, then 8000-12,000 tetanus deaths occur among newborns in the country.