A patient was treated for the tropical disease dengue fever in Croydon last week.

The rare case of the mosquito-borne virus, which causes fever and acute joints pain, was reported by Public Health England.

Medical practitioners are obliged to report suspected cases of dengue fever, as well as certain other infectious diseases, to authorities.

There were three cases of scarlet fever, one of malaria and one of food poisoning in Croydon in the week ending October 4.

Experts have also warned people to take precautions after ticks carrying Lyme disease were found in two south London parks.

Lyme is an infectious or parasitic disease that can be transmitted to humans by the bite of carrier tick. It is potentially fatal and there currently no vaccine available.

London School of Hygiene and Tropical Medicine found infected ticks in Richmond Park and ticks capable of passing on the infection Bushy Park, Hampton. 

Researchers found no evidence of the pests in Wimbledon Common or Hampton Court.

Dr James Logan said: "The overall risk of Lyme disease in London parks is very low, but precautions should be taken.

"Check yourself and your pets after frequenting parkland areas, and remove any ticks as quickly as possible using a tick removal tool. To minimise the risk stick to footpaths and wear an insect repellent."

Howard Carter, a bite protection expert, said: "The number of ticks is increasing all the time and quite dramatically.

"People really do need to be aware of the impact these things can have on health. If you are bitten it is not a little itch that goes away after a couple of days, it can be life-changing or even fatal."