title: Measles sero-surveillance during mass immunisation campaign in Malawi.
abstract: OBJECTIVE
  To determine age-specific measles antibody prevalence and serological response to vaccination during the first mass campaign against measles in Malawi.
  
  
  METHODS
  Cross-sectional study using a questionnaire and a serological particle agglutination (PA) test.
  
  
  METHODS
  Two health centres in Salima district, central Malawi during the national measles immunisation week, 1998.
  
  
  METHODS
  Two hundred forty six under-five year old children.
  
  
  RESULTS
  Seventy four per cent of enrolled children (95% confidence interval, 69-80%) were measles PA antibody positive at the vaccination. The antibody positive rate was 17.4% in children aged 8-12 months and gradually increased up to 90% by four years-old, while the age-specific geometric mean titers (GMTs) in 48-59 months-old group were significantly lower than those in 24-35 months-old group, suggesting antibody waning after previous vaccination (p = 0.0047). Two hundred and thirty follow up specimens were obtained eight weeks after the vaccination. The sero-conversion rate was 100% in 58 children sero-negative at the vaccination and the GMTs in 172 children seropositive at the vaccination were significantly increased (p < 0.001).
  
  
  CONCLUSIONS
  These results indicated that the first national measles immunisation campaign successfully immunised the enrolled children or gave a booster response of antibody levels. It was also confirmed that the PA test was easy to perform and most suitable for the field condition in developing countries.
authors.affiliation: Community Health Sciences Unit, Ministry of Health and Population, Private Bag 65, Lilongwe, Malawi.
authors.forename: M
authors.initials: M
authors.lastname: Takechi
authors.forename: M
authors.initials: M
authors.lastname: Matsuo
authors.forename: D
authors.initials: D
authors.lastname: Butao
authors.forename: I L
authors.initials: IL
authors.lastname: Zungu
authors.forename: I
authors.initials: I
authors.lastname: Chakanika
authors.forename: J
authors.initials: J
authors.lastname: Michongwe
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D003906:Developing Countries; D005260:Female; D006801:Humans; D007109:Immunity / Q000502:physiology; D017589:Immunization Programs / Q000458:organization & administration*; D007115:Immunization Schedule; D007223:Infant; D008295:Malawi; D008297:Male; D032541:Mass Vaccination; D008457:Measles / Q000276:immunology* / Q000517:prevention & control*; D008458:Measles Vaccine / Q000008:administration & dosage*; D011336:Probability; D012680:Sensitivity and Specificity; D012698:Serologic Tests; D011795:Surveys and Questionnaires
chemical_list: D000914:Antibodies, Viral; D008458:Measles Vaccine