Doctors say nationwide TB immunisation no longer required
‘Threat of infection from immigrants is low’ - study
Matthew Vella Doctors studying the incidence rates of tuberculosis (TB) in Malta have proposed that the school vaccination programme should be discontinued, because the island satisfies international safety criteria.
Malta has a long-standing surveillance programme for TB, and since the early 1950s has carried out mass immunisation of schoolchildren aged 11-13 years, free of charge.
According to a study by doctors on the frontline of immunisation and chest disease, Malta now has one of the lowest incident rates of TB in Europe, and a lower annual risk infection rate than in the UK.
The Maltese study says the island’s native-born population has one of the lowest TB incidences in Western Europe: less than 15 per 100,000 person/year, in spite of the influx of immigrants from high-incidence zones in Africa.
“The likelihood of native children coming into contact with infectious TB in irregular migrants, high-risk population, and becoming infected is unlikely,” the doctors say.
“Malta satisfies the criteria proposed by the International Union against Tuberculosis and Lung Disease (IUATLD) to consider discontinuation of the routine mass vaccination programme, and in turn it may no longer be reasonable or even safe to encourage routing school vaccinations for the Malta-born, 11 to 12-year-old population.”
Instead, the doctors propose vaccinating non-Maltese children at an early age and to strengthen immunisation for immigrants coming from high-TB and high-HIV prevalence areas. Irregular immigrants are screened for TB and infectious diseases upon arrival.
The incidence of TB in children aged under 11 has declined by 4.3% since 1979, and after 2000 no cases were reported. “These favourable findings indicate very low levels of ongoing TB infection in the community.”
“Directly observed treatment, short-course chemotherapy, treatment outcome monitoring, good pharmaceutical services and consistent political support have helped to achieve World Health Organisation targets. The absence of local drug-resistant TB is a good indicator of adequate local treatment… there have been no notifications of TB in Malta-born children for at least eight years.”
The doctors add that the mass immunisation should also be reconsidered due to the risk of serious adverse reactions from the vaccine itself. “Although the vaccine is known to be extremely safe… Malta can expect at least one to two children developing a serious local adverse reaction each year… it would seem that the incidence of TB is now much less than the adverse reactions expected from the vaccine.”
The study was conducted by doctors Brian Farrugia, from Mater Dei’s chest clinic, Victoria Farrugia Sant Angelo, head of school health services and immunisation, and Joseph Cacciottolo from the University of Malta’s department of medicine.
In the early 1950s, major trials were set up by the British Medical Research Council to determine the efficacy of routine vaccination with the Bacille Calmette-Guérin (BCG).
The vaccine had a protective efficacy of 75-80% lasting 10-15 years and was recommended as a routine procedure for tuberculin-negative adolescents.
At that time TB was commonest amongst those aged 15 to 29 years.
It was thought reasonable to vaccinate all tuberculin negative schoolchildren between the ages of 11-13 years to provide protection. Malta, then a British colony, followed suit.
In 2002, the Malta Tuberculosis Working Group called for the reconsideration of the school programme, but it was decided at the time to continue the vaccination programme mainly because of uncertainties resulting from the influx of irregular migrants from high TB incidence areas.
Tuberculosis – causes and treatment
TB is a serious, slowly developing, bacterial infection caused by the bacterium Mycobacterium tuberculosis. TB most commonly affects the lungs but can affect almost any part of the body. It can be spread when someone with the infection coughs, sneezes or talks and another person breathes in the bacteria. However, prolonged contact is usually needed to become infected.
Some people develop a minor infection which then settles as their immune system fights it, and evidence is only found later incidentally as a scar on a chest X ray. Whilst for others active TB flares up many years after this initial infection. If the initial infection isn’t fought off, it can progress to serious ongoing infection a few weeks after the first contact.
Symptoms Initially, there may be no symptoms. When symptoms develop they will vary depending which part of the body is affected but commonly include:
A persistent cough, usually for more than three weeks – it may be dry to start with and progress to blood-streaked sputum
Night sweats for weeks or months
Weight loss
Fatigue
High temperature
Shortness of breath
Causes and risk factors It’s estimated that a third of the world’s population is infected with the bacteria that causes TB. Each year about 9 million people develop the disease and up to nearly 2 million people worldwide are killed by it. People at greater risk of developing it include:
Children and older people
Smokers
Those living in overcrowded conditions
Those who have a poor diet
People with HIV
The homeless
Those who have a weakened immune system because of other medical conditions, such as diabetes, or because of other medical therapy, such as immuno-suppressant medication
Treatment and recovery TB is difficult to treat – normal antibiotics do not kill TB bacteria. Combinations of several special antibiotics treat the infection in the majority of cases. These must be taken for long periods, usually at least six months, to avoid becoming ill with TB again and developing a drug-resistant form of the disease. Even with treatment, some people develop long-term complications from infection.
Travellers to countries where TB is prevalent are at greater risk. A vaccine is available, which is offered to those at high risk of contracting the disease. Check with your doctor whether your travel plans put you at risk of TB and discuss possible vaccination.
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