Related Experiment Videos
A school microepidemic of tuberculosis
C P Bredin1, M Godfrey, J McKiernan
1Department of Respiratory Medicine, St Finbarr's and Regional Hospitals, Cork, Ireland.
Thorax
|December 1, 1991
Summary
Microepidemics of tuberculosis (TB) can occur even in low-incidence areas. This study found that teenagers vaccinated with neonatal BCG can still develop active TB, emphasizing the need for ongoing surveillance.
Area of Science:
- Epidemiology
- Infectious Diseases
- Public Health
Background:
- Microepidemics of tuberculosis (TB) remain a concern in low-incidence countries.
- Neonatal BCG vaccination was discontinued in Cork city in 1972, leaving most students unvaccinated or vaccinated in infancy.
Purpose of the Study:
- To describe a microepidemic of tuberculosis in a secondary school.
- To assess the risk of active tuberculosis in teenagers previously vaccinated with BCG.
Main Methods:
- A retrospective study of a tuberculosis microepidemic in a secondary school (604 girls) in Cork city, Ireland (1986-1990).
- Contact tracing and tuberculin testing (Heaf test) were performed.
- Chemoprophylaxis with rifampicin and isoniazid was administered to 75 tuberculin-positive individuals.
Main Results:
- Six active cases and 75 tuberculin-positive cases of tuberculosis were identified among 604 students.
- Four of the six active cases had received neonatal BCG vaccination.
- None of the 75 treated individuals developed active tuberculosis during the four-year follow-up, but a sibling of the probable index case developed active TB.
Conclusions:
- Neonatal BCG vaccination does not guarantee lifelong protection against tuberculosis.
- Teenagers who received neonatal BCG can still develop active tuberculosis.
- Ongoing surveillance for tuberculosis is crucial, even in populations with a history of BCG vaccination.