By Nick Triggle
BBC Health reporter
At the moment immigrants are targeted for TB screening at airports
The immigration debate has taken a new turn with Tories announcing they would tighten health checks on immigrants coming to the UK.
Tory leader Michael Howard said foreigners from outside the EU will be tested for tuberculosis if they are coming for more than 6 months.
Those who want to settle for the long-term will be required to undergo testing for other conditions such as HIV/Aids.
The proposals have reignited the debate about health tourism.
Traditionally, the focus has been on people coming into the UK purely to use the NHS and leaving - a practice which is estimated to cost the health service up to £200m a year.
But the cases that have been highlighted have tended to be people who are not applying to stay in the UK and as such would not be included under the Tories' plans.
Instead, the Tories want to make sure people applying to live and work in the UK are not going to be a burden on the health service.
Rates of TB have increased in the UK by 25% in the last 10 years with more than 7,000 being diagnosed each year - two thirds of which were people who were born abroad, according to Health Protection Agency figures.
HIV and TB
Three quarters of heterosexuals with HIV in the UK were infected in Africa
Two thirds of people with TB are born abroad, although it is possible they contracted TB in the UK
TB has increased by 25% in the last 10 years - 7,000 people are diagnosed with it each year
Doctors have put the rise down to population movement.
Dr John-Moore-Gillon, of the British Lung Foundation, said: "TB is increasing on a global basis and we have global population mobility like we never seen before.
"London like many other big cosmopolitan cities is acting as a mirror to what is going on in the rest of the world."
HPA research also suggested 75% of people diagnosed with heterosexually-acquired HIV in the UK in 2003 are thought to have been infected in Africa.
But experts remain doubtful whether the Tories' measures will really have an impact.
Danny Sriskandarajah, a senior researcher at the Institute of Public Policy Research, said there were problems with the Tory proposals, which involve the testing of people for TB in their country of origin.
"The issue with compulsory screening before arrival is that TB or its symptoms could develop afterwards. Screening is ineffective."
The plans for HIV have also attracted criticism.
Deborah Jack, chief executive of the National Aids Trust, said screening was unlikely to have an impact.
"There is no evidence of HIV health tourism. These proposals are going to be expensive and rather than solving public health problems they could cause them by forcing HIV underground and increasing stigma association with it."
And she said people with HIV were not just a burden on society.
"They bring a lot to the economy. It is very simplistic to say these people will cost a lot and contribute nothing."
Lisa Power, of the Terence Higgins Trust, accused the Tories of "pandering to prejudice".
"It won't do anything for public health. If the Tories were serious about addressing the issue, they would be talking about improving sex education and access to clinics."
But Mr Howard said it was clear immigrants were bringing disease into the UK.
At the moment officials target people for TB screening at airports and ports who they believe are ill.
About 100 cases of TB are found each year from 185,000 checks at Heathrow and Gatwick airports.
Mr Howard said: "We think it is important we safeguard the good standards of public health people enjoy.
"And you protect the NHS by stopping some people coming in."
Immigration Minister Des Browne said the government did not have plans to screen immigrants for HIV but acknowledged TB was an issue.
"We recognise that this is an important and difficult issue.
"It is a highly infectious disease and we require people to be treated before there are given entry clearance."