Research carried out in Thailand suggests the disease can suppress HIV to undetectable levels.

Scientists found that the virus count in the blood of people with Aids fell significantly after they suffered a bout of scrub typhus, a tropical disease spread by insects.

They are now working to see if disease has the same affect among people with HIV.

The discovery was made by a team of scientists from the joint US-Thai funded Armed Forces Institute of Medical Sciences.

Dr George Watt, one of the lead scientists, said the discovery was made "by accident".

"No other infectious disease has ever shown the effects of reducing HIV viral load.

"The scrub typhus-HIV link was completely unexpected, we were not looking for it.

"We were merely doing a general descriptive study of the relationship between HIV and tropical diseases when we came across this sudden discovery."

Further research

He warned, however, that further research was needed before the disease could be used as an effective treatment.

The scientists are extending their research to study a wider sample of HIV patients in an attempt to identify exactly what element of scrub typhus works to suppress the virus.

They believe that a microbial agent called Orientia tsutsugamushi which is part of the typhus virus may be responsible.

The scrub typhus-HIV link was completely unexpected, we were not looking for it

Dr George Watt, Armed Forces Institute of Medical Sciences

If successful, typhus could be used to provide a cheap alternative to the combination drug therapies which are currently available.

The vast majority of the 34m in the world who suffer from HIV or Aids cannot afford expensive combination drug treatments.

"If antibodies of scrub typhus were used to fight HIV it potentially could be a very inexpensive method."

He added: "We have to tell dying patients, 'Yes, there is treatment for HIV, but it's too expensive for you.' So there is tremendous motivation for the scrub typhus to work."

Scrub typhus is most common in east Asia and the western Pacific. It is transmitted via the bite of the larval trombiculid mite and while it can be fatal it can be treated with drugs if caught early.