Parts of Cork have three times the rates of tuberculosis infection over other parts of the county due to different vaccination polices, a new study has claimed.
Researchers claim that regional variations in the incidence of tuberculosis in counties Cork and Kerry in the past two decades are linked to a policy of not vaccinating people in Cork City and north Cork for the disease. They found a higher incidence of TB in areas where the vaccination was not in use since 1972.
The research, led by a team from the Department of Infectious Diseases at Cork University Hospital, examined data on 550 confirmed cases of TB in Cork and Kerry between 2003 and 2016.
Although no longer considered a major health issue here, the report’s main author, Eileen Sweeney, a specialist registrar, said the prevention and treatment of TB, which is the ninth leading cause of death worldwide, remains a significant challenge internationally.
Three policies have existed over parts of Cork and Kerry since 1972 when the universal neonatal BCG vaccination was discontinued in Cork City and north Cork based on the low incidence of the disease. At the same time newborn babies were continued to be vaccinated in Kerry, while children aged 10-12 were vaccinated in south-west Cork.
Universal vaccination for TB was discontinued in Ireland in 2015 after a global shortage of the BCG vaccine. The study found the incidence of TB was highest in the unvaccinated region of Cork City and north Cork at 132 cases per 100,000 population over the 14-year period, while it was 56 cases per 100,000 with the neonatal vaccination programme in Co Kerry and just 44 per 100,000 in Cork south-west’s childhood vaccination programme.
Dr Sweeney said:
In 2017 it was estimated the incidence of TB in Ireland was 6.7 cases per 100,000 population. The study said the incidence of TB in the south of Ireland between 2003 and 2016 was consistently above that of the general Irish population.
“Cork stands out through the entire period of the study for above-average infection rates. We postulate that this is as a result of the variation in regional BCG vaccine policy,” Dr Sweeney said.
The BCG vaccine is the only one licensed for TB and is estimated to have overall efficacy against up to 80% of severe forms of TB in children, particularly meningitis.
Dr Sweeney said it was reported that some children from Cork City had gone to other areas to receive the BCG vaccine due to parental concern after local outbreaks. The Department of Health is considering policy on the BCG vaccine.