CAPE TOWN, April 19 (Xinhua) -- South African health authorities on Thursday issued a malaria alert amid a rising risk of acquiring the disease both in and outside the country.

The total number of malaria cases has increased in three malaria-affected areas -- northeastern Limpopo, eastern Mpumalanga and northern KwaZulu-Natal, the National Institute for Communicable Diseases (NICD) said.

Some of the patients are likely to be travellers returning from neighboring countries, particularly Mozambique, the NICD said.

But the institute did not give the specific number of malaria cases.

With the recent Easter holidays and an upcoming weekend, a substantial proportion of the South African population have returned or will shortly return from malaria-endemic destinations, the NICD said.

Anyone who has been in a malaria risk area in the past 10 days to three weeks and who gets ill with flu-like symptoms should remember that malaria is a possibility and seek medical attention, which should include a malaria blood test, repeated if necessary, the institute said.

Travellers should tell healthcare workers about travel and possible exposure, as they may forget to ask, the institute said.

Using anti-mosquito measures (nets, repellents etc) and/or prophylactic medicines does not guarantee perfect protection from malaria, the institute cautioned.

It warned that delayed diagnosis of malaria often leads to more severe illness with the danger of serious complications or even death.

Symptoms of malaria include fever, chills, sweating, body pains, headache and extreme tiredness, which appear within 10-15 days after the infective mosquito bite.

This was the second malaria alert issued in South Africa since December 14 last year.

South Africa has pledged to eliminate malaria by 2018. Malaria in the country is seasonal, with transmission occurring between September and May in geographical areas of Limpopo, KwaZulu-Natal and Mpumalanga provinces.