A major outbreak of tuberculosis - which may turn out to be one of the biggest in the UK since the disease was brought under control in the 1980s - has been identified at a secondary school in Leicester.
Last night public health officials said 24 cases of TB have been confirmed, 20 of them children at Crown Hills community college and one a teacher. About 700 children, aged 11 to 14, have been screened and of those a further 60 look likely to have been infected with the disease.
"This is a major outbreak," said Gerry Bryant, specialist registrar in public health with Leicestershire health authority. "I'm not aware of a published outbreak of this size in a school. We believe it might be part of a larger community outbreak. It is very difficult to tell at this stage."
Dr Philip Monk, consultant on communicable disease control at the health authority, blamed the outbreak on a particularly virulent strain of the disease that is spreading rapidly.
Thousands of children may potentially have to be screened if it is thought the disease had spread. "We may be looking at six primary schools that feed into Crown Hills community college. That would be 2,000-2,500 pupils as a starting point. Then there are around 3,000 pupils from secondary schools," Dr Monk said.
It is highly unusual to get a significant number of cases in a school because generally, children tend to be infected not by each other but by very close contact with adults, usually members of their family.
There will certainly be more cases to come. Every child and teacher in the school will now be screened. Not every person who develops TB is infectious, but some of the Crown Hills children have proved to be so, and so the disease may well have spread within their families. All those infected have been given the standard course of antibiotic TB treatment, and the 60 who had strongly positive skin-prick tests, indicating likely infection, have been given a shorter course to keep the disease at bay.
The outbreak began when one child in year nine developed TB last August. Ninety-three per cent of the children at the school are of Asian origin and it is possible the child became infected on a visit to India, where TB is endemic. The second case, in October, involving a child in the same class, was discovered when the first child's close contacts were screened. When a third child in the class developed TB last month, it was decided to mount a major screening exercise.
For Gary Coleby, headteacher of the school in inner-city Leicester, the news of the rising numbers is a blow. Its Ofsted report before Christmas said it was one of the best urban schools in the country. And for three years running it has been one of the government's top 200 improving schools. Mr Coleby is trying hard to reassure everyone that it is business as usual.
"The original three children diagnosed have all been treated and are all back at school," he said. "The parents are concerned but they are being kept very closely informed about what is going on and they are involved in the process so they know what is happening. We do have a lot of parental support here and it is now paying dividends.
New strains
"The most important message is that there is no panic and the school is operating absolutely as normal, although with some disruption because of the screening."
Sixty years ago, this outbreak would have been a disaster and a tragedy, because TB was a regular killer, but the BCG vaccination, together with better drug treatment, surveillance and meticulous follow-up of all the contacts of anyone with the infection have made deaths unnecessary.
But nobody takes tuberculosis lightly. The number of cases in the country is rising among people who are born abroad or whose parents were. TB is killing millions in south-east Asia, Africa and eastern Europe - and is frequently the direct cause of death of those whose immune systems have been damaged by HIV.
But what alarms public health officials most is the onward march of new strains of TB which are resistant to the antibiotic drugs most used to treat the disease. Unless the disease can be brought under control elsewhere in the world, increasing numbers of multi drug-resistant TB (MDRTB) cases will arrive in the UK. They are hard - and expensive - to treat. The Crown Hills college outbreak is not MDRTB, but it has arrived from abroad and all the vigilance of the public health officials has not been able to prevent it.
The finger was immediately pointed at the absence of the BCG vaccination programme in schools. Many parents have voiced anxieties at the temporary halt to vaccinations two years ago which was caused by a shortage of vaccine.
Less than two weeks ago, on World TB Day, the government announced that the BCG vaccination programme for schoolchildren would be restarting. In London, which has more TB cases than anywhere else, vaccinations for 13-year-olds have already started again. There is a cohort of children who have been missed, some of whom may be about to leave school and, potentially, travel to countries where TB is endemic. Those, the government has said, will receive a catch-up vaccination in the summer. Government policy is that children born in TB endemic areas, or whose parents or grandparents were born there, should be vaccinated at birth. Those who come to live in the UK should be vaccinated on arrival.
The vast majority of Crown Hills' 1,200 pupils have been protected from TB, but unfortunately the BCG is only 60 to 70% effective and the strain that has hit the school appears to be particularly virulent.
Ironically, what has happened in Leicester underlines the limited usefulness of the schools vaccination programme, which is coming under review in a few years' time and which there may be moves to end.
"There has been discussion in the medical press about how much benefit is achieved by the schools programme," said John Watson, a consultant epidemiologist at the Public Health Laboratory Service. "You have to vaccinate an awful lot of children to prevent a single case of TB. It is not comparable to the childhood vaccination programmes against measles, for instance."
What is TB and how is it spread?
What kind of disease is tuberculosis?
Contagious, caused by a bacteria that attacks the lungs, although it can also target the lymph nodes, bones and occasionally the brain.
How common is it?
It used to be very common in the UK. Known as consumption in Victorian times, it claimed the lives of many poets and writers, notably Keats. There were 50,000 cases a year in the 1940s, which dropped to 5,000 in the late 80s, rising to just below 7,000 now. This is nothing compared to Africa, eastern Europe and south-east Asia. TB makes 8m people a year sick worldwide and kills 2m.
How is it spread?
Through the air, when sufferers cough, spit or sneeze. The sick used to be shut away in sanatoria to recover, or more often die, but current wisdom is that people do not catch it without prolonged close contact. Children, the elderly and the frail or immuno-compromised are at greatest risk. Before pasteurisation, TB could be contracted from milk from cows infected with bovine TB.
Does everybody who comes into contact with TB bacteria get the disease?
No. One third of all people are estimated to carry the bacteria, but only one out of 10 of them will develop TB.
What are the symptoms?
Fever and night sweats, coughing, losing weight and blood in the sputum are some of the main ones. Symptoms usually take months to appear.
Is it treatable?
Yes, thanks to antibiotics. Patients are given a six-month course of four drugs. It is vital to stick to the course, even when the symptoms disappear, or the bacteria lingering dormant in the body will mutate to become resistant to the drugs.
Is that a big problem?
The spread of multi drug-resistant TB (known as MDRTB) is extremely worrying. There are particularly serious problems in the former Soviet Union. The World Health Organisation says MDRTB threatens global control of the disease.
