Another case of malaria reported

Eighth case, a foreign worker, on Jurong Island brings total infections since May to 22
Salma Khalik, Straits Times 8 Jul 09;

MALARIA is still spreading, despite intense efforts to get rid of mosquitoes and their breeding sites.

Jurong Island has seen its eighth case, bringing the total number of infections in Singapore since early May to 22.

The latest victim is another foreigner, a 24-year-old who works on a construction site along Jurong Island Highway. He lives on the mainland in Soon Lee Road, where there are no known malaria cases.

He fell ill on June 20, 10 days after the previous victim on the island, another foreign construction worker, did.

Both have since recovered and have been discharged from hospital.

The Ministry of Health said it informed the National Environment Agency (NEA) of this latest case on June 25, two days after it was notified by the patient's doctor.

The current outbreak has also hit 14 people in another cluster in the north - in the Mandai/Sungei Kadut area.

All but two are foreign workers.

Malaria parasites are carried by female Anopheles mosquitoes, which need to feed on blood to reproduce.

When a mosquito bites an infected person, it picks up the parasite from his blood, and passes it to the person it next feeds on. Anopheles mosquitoes are most active at dawn and dusk.

The recent infection surfaced despite the ongoing intensive fogging and search-and-destroy efforts on Jurong Island and in the Mandai/Sungei Kadut areas to prevent the disease from gaining a foothold.

This outbreak of local cases is possibly the country's largest since it was declared malaria-free in 1982. Five people fell ill in the last outbreak in 2007, and 13 contracted the disease the year before.

Singapore also gets between 100 and 300 imported cases a year. Malaria is a 'notifiable disease', which makes it mandatory for doctors to report cases they see to the Health Ministry within 24 hours to minimise spread.

Once malaria becomes endemic like dengue, it will be difficult to eradicate, since it is impossible to rid the nation of all mosquitoes.

The only way to fight it then would be to quarantine the infected, so they do not get bitten again by Anopheles mosquitoes and pass the parasite along. This should break the chain of infection.

People who come down with the illness suffer fever, headache, chills and vomiting spells about 10 to 15 days after being bitten.

The parasites have been known to lie dormant in the body for up to a year. Left untreated, they can cause red blood cells to burst, leading to seizures and sometimes death.

But malaria is eminently curable.

An outbreak is considered over if no new cases surface for 30 days. The Mandai/Sungei Kadut cluster, for example, will get the all-clear if no more cases surface by the end of this week.

The last victim there was sick on June 11.

Another malaria case in Sungei Kadut-Mandai Estate area
Pearl Forss, Channel NewsAsia 26 Jul 09;

SINGAPORE: One more person has contracted malaria in the Sungei Kadut-Mandai Estate area, bringing the total number of cases in this cluster to 16.

The latest person is a 21-year-old foreign construction worker who previously lived in Mandai Estate.

He has no travel history and no history of malaria prior to entry to Singapore. His illness started on June 30.

The last time anyone else contracted malaria in this cluster was on July 1. So far, 14 foreigners and two locals are affected in this cluster.

The National Environment Agency (NEA) and stakeholders, such as dormitory operators, are continuing with vector control operations in the Sungei Sungei Kadut-Mandai Estate area.

This includes oiling and Bti misting to destroy mosquito breedings, with chemical fogging and residual spraying to kill adult mosquitoes.

The construction site and dormitory operators have also equipped their workers with mosquito repellent as a precautionary measure.

No new breedings have been found since June 27, and NEA says the vector control operations will continue. No other new cluster has been reported.

There are no new cases at Jurong Island and the total number of cases in this cluster remains at seven. The cases are all male foreigners aged 25 to 46, and the onset dates of the cases in this cluster ranged from May 3 to June 10.

- CNA/yt