Warning on new wave of foreign bugs

Britain's chief medical officer will this week issue a warning about the dangers of bringing back infectious diseases from abroad.

Sir Liam Donaldson will mark the start of the traditional time for winter holiday breaks with a major report on the mounting risk to public health in this country from diseases caught on overseas travel or brought here by foreign visitors. He is expected to call for more effective monitoring, a sharper response to outbreaks from abroad and raised awareness of the health risks when travelling abroad.

Holidaymakers travelling to Third World countries are increasingly being urged to have inoculations against a range of diseases, including cholera, malaria, tuberculosis, plague and yellow fever.

Tuberculosis is regarded as a serious and growing threat to health in Britain. Last April, more than 50 people – mostly secondary school students – were infected in Leicester in the worst outbreak of TB for 20 years. It was thought that because of the high Asian population of the school, the source could have been in India. It led to an extensive screening programme in schools in the city.

The CMO is also expected to raise concerns about a rise in sexually transmitted diseases, particularly among young people who may not be aware of the "safe sex" campaigns of the 1980s.

The row over the MMR jab is also adding to the problem of infectious diseases, with a measles epidemic more likely unless the Government can raise the percentage of children who are immunised.

The Prime Minister's attempt to allay fears about MMR has failed to reduce the demand for the alternative course of three separate injections for mumps, measles and rubella, said Sarah Dean, manager of a private health company, Direct Health 2000.

"It has gone berserk. This Blair thing has pushed it over the top. Demand has gone up 40 per cent."

Global warming has added to fears that Britain is becoming more susceptible to outbreaks of tropical diseases. Although malaria is not transmitted between humans, there are fears that warmer and wetter winters could lead to infected mosquitoes surviving in Britain.

A year ago, Sir Liam warned that malaria could be reintroduced by British travellers who catch the disease while abroad. The last outbreak in England was in Kent, when troops returning from the First World War with malaria were bitten by local mosquitoes, which then spread the disease.

The failure of some airlines to take sufficient precautions on passenger jets is another concern. Insects travelling on planes may have been responsible for cases of malaria in patients living close to airports. The Lords science and technology committee also recommended tougher action on air filters to tackle the spread of infectious diseases between passengers during flights.

Other more alarming but rare infections such as Ebola, present in Zaire and Sudan, are thought not likely to reach Britain, but more common diseases such as influenza may present a growing risk.

The communicable diseases surveillance unit is currently reporting a low incidence of flu in Britain, but the 1999 outbreak caused an estimated 20,000 deaths. Its main challenge is that it can mutate quickly, leaving humans with no immunity.

Serious outbreaks often lead to a winter crisis for the NHS and health ministers have promoted anti-flu vaccines to reduce the risk of services being disrupted.

Britain's seaports and airports have their own health authorities, which carry out health checks. There were calls during the Aids scares of the 1980s for routine monitoring of visitors from high-risk areas, but these were discounted as impracticable.