Pertussis in Lao PDR: Seroprevalence and disease

Int J Infect Dis. 2020 Jun;95:282-287. doi: 10.1016/j.ijid.2020.03.074. Epub 2020 Apr 8.

Abstract

Objectives: Pertussis is a debilitating vaccine-preventable infection. The aim of this study was to determine susceptibility and exposure to pertussis in Lao PDR in different age groups and subpopulations.

Methods: A total 3072 serum samples were obtained from different cohorts: children with documented vaccination, pre-schoolers, schoolchildren, blood donors, healthcare workers (HCWs), and pregnant women and paired cord blood. Samples were tested for anti-pertussis toxin IgG antibodies. A history of Bordetella pertussis exposure was defined according to antibody titres. Four hundred and seventy-five throat swabs and nasopharyngeal aspirates were analysed by PCR for the presence of B. pertussis in symptomatic children at the Children's Hospital in Vientiane.

Results: Overall pertussis seroprevalence was 57.5%. The prevalence of titres indicating acute infection or recent vaccination or infection/vaccination within the last 12 months ranged from 7.4% (100/1356) in adults to 21.4% (25/117) in pre-schoolers (age 1-5 years). B. pertussis was detected in 1.05% (5/475) of children with respiratory symptoms in Vientiane Capital.

Conclusions: It is suggested that routine childhood vaccination, in particular outreach, as well as vaccination of HCWs should be strengthened. A childhood booster and vaccination of pregnant mothers should be considered. There is also a need to improve reporting and to introduce pertussis testing in at least one central facility.

Keywords: Bordetella pertussis; Lao PDR; Seroprevalence; Vaccine immunogenicity; Vaccine-preventable infection.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibodies, Bacterial / blood
  • Bordetella pertussis* / immunology
  • Child
  • Child, Preschool
  • Cohort Studies
  • Female
  • Fetal Blood
  • Health Personnel
  • Humans
  • Immunization, Secondary
  • Infant
  • Infant, Newborn
  • Laos / epidemiology
  • Male
  • Middle Aged
  • Pertussis Vaccine / administration & dosage
  • Pertussis Vaccine / immunology
  • Pregnancy
  • Prevalence
  • Seroepidemiologic Studies
  • Whooping Cough / epidemiology*
  • Whooping Cough / prevention & control
  • Young Adult

Substances

  • Antibodies, Bacterial
  • Pertussis Vaccine