Epidemiology of measles in Blantyre, Malawi: analyses of passive surveillance data from 1996 to 1998

Abstract

SUMMARYMeasles surveillance data in Blantyre, Malawi were reviewed for 1996-8 to describe the epidemiology of infection and to estimate vaccine efficacy (VE) by the screening method. A total of 674 measles cases were reported to the Blantyre District Health Office during this period. Age distribution showed that 108 (16n1 %) of the cases were aged less than 1 year. The median age was 5 years. Eighty percent of the cases between 1 and 19 years had been previously vaccinated. VE was 68n6 % (95 % CI, 52n7-79n2) for children 12-23 months of age and 67n3 % (95 % CI, 48n3-79n3) for infants 9-11 months of age. Reasons for this low vaccine efficacy are discussed. Previous vaccination history was negatively associated with the risk for developing cough during measles infection (odds ratio (OR), 0n30 ; 95 % CI, 0n09-0n91), diarrhoea (OR, 0n64 ; CI, 0n44-0n95) and pneumonia (OR, 0n40 ; CI, 0n25-0n62). Logistic regression analysis showed that pneumonia in adults was negatively associated with vaccination history. The passive surveillance system for measles in Malawi was useful to describe the epidemiology of measles.

Lessons and Challenges for Measles Control from Unexpected Large Outbreak, Malawi

“…However, in our study the estimated effectiveness of the second dose was lower than expected; for children receiving the second measles vaccine dose through the 2008 SIA, vaccine effectiveness was 91%. Factors that can reduce vaccine protection include failure in the cold chain, interaction with maternal antibodies, waning immunity, and the HIV pandemic ( 23 ). The vaccine is less effective in HIV-infected children because of quick loss of protective antibodies after immunization ( 24 ).…”

Trends and Weekly and Seasonal Cycles in the Rate of Errors in the Clinical Management of Hospitalized Patients

“…Although seasonal patterns, or seasonality, have been observed in many areas of medicine (e.g., Anderak et al, 2000;Basta et al, 2011;Bound et al, 1989;Castilla et al, 1990;Eatough, 2002;Fitzpatrick et al, 1994;Kershenbaum et al, 2011;Ordookhani et al, 2010;Seretakis et al, 1997;Yamaguchi et al, 2002), the occurrence of seasonal variation in errors in the clinical care of hospitalized patients events has received less analysis, possibly due to the limited availability of sufficiently large or enduring data sets. One of the most widely studied sources of variability over the annual scale is associated with the academic year and the commencement of new graduate doctors working in health care facilities.…”

Placental malaria and immunity to infant measles

“…In Malawi between 1996 and 1998, 51% of infants with measles were less than 9 months of age and 17% less than 6 months. 5 Improved malaria control in pregnancy has substantial benefits for the mother and the baby, which may include a reduced risk of measles in early infancy. Studies of infant measles susceptibility in relation to placental malaria and maternal antibody transfer are warranted.…”