Malaria, an age old disease proves hard to control

Tantri Yuliandini, The Jakarta Post, Jakarta

Hundreds of years ago, malaria was thought to be caused by harmful gasses from swamps (hence the name mal aria, Latin for bad air), and was greatly feared due to the high death toll it brought.

Today -- despite the fact that the actual cause, the anopheline mosquito, has been known for more than a century -- malaria remains one of the world's most problematic health issues, as it has tended to re-emerge time and again despite aggressive efforts to control the communicable disease.

World Health Organization (WHO) data show approximately 300 million people worldwide have been affected by malaria, and between 1 and 1.5 million people die from it every year.

While previously widespread, malaria is now mainly confined to Africa, Asia and Latin America where the problems of controlling the disease are aggravated by inadequate health structures and poor socioeconomic conditions.

In Indonesia, malaria is endemic to most areas, with the eastern part of the country being the most severely affected.

Around 100 million of its more than 200 million people are at risk of malaria and approximately 1.5 million cases are detected annually, according to WHO.

A massive effort by WHO to control malaria in 1950 succeeded in bringing down the estimated number of malaria cases from between 110 and 115 million to less than one million in the Southeast Asian region.

A similar effort in Indonesia during the 1960s, staged by the ministry of health, was so successful that Java and Bali have since been deemed relatively free of malaria.

However, since 1995 the number of malaria cases reported has been steadily increasing, especially in Central Java and Yogyakarta.

A massive outbreak of malaria occurred between 1998 and 1999 in some areas of South Sumatra, Yogyakarta, Central Java, Lampung and North Sumatra. Some 18,812 cases of malaria and 21 deaths were reported from the outbreak.

More recently, the communicable disease was reported to have killed 54 people in Banyumas, Central Java. Some 10,000 people were reported to have been infected by the disease in the region.

This came as a shock, as the ministry had been implementing its program called Gerakan Basmi Kembali Malaria (Rollback Malaria Program) since 1998.

The Director General of Communicable Diseases and Environmental Health at the Ministry of Health, Umar Fahmi Achmadi, told The Jakarta Post Monday that globally, the re- emergence of malaria was caused by an increase in the world's temperature, usually known as global warming, which had created an environment ideal for the breeding of the anopheline mosquito.

Malaria parasites are transmitted from one person to another by the female anopheline mosquito. The males do not transmit the disease as they feed only on plant juices.

Like all other mosquitoes, the anophelines breed in water, each species having its preferred breeding grounds, feeding patterns and resting places.

"The anophelines are known to breed faster and more aggressively in higher temperatures," Umar said.

There are about 380 known species of anopheline mosquito in the world, but only 60 or so are able to transmit the parasite.

"Out of the 380 species, at least 18 are found in Indonesia but we have not yet determined how many are able to transmit malaria parasites," he said.

Among the 18 species are Anopheline maculatus, An. sundaicus, An. aconitus, An. barbirostris, An. subpictus, An. balabacensis, An. koliensis and An. farauti.

Umar said the recent malaria outbreaks could also have been triggered by the population's high mobility, especially during the Muslim and Christmas holidays last month.

"People have been moving into and out of endemic areas to visit friends and relatives -- they are highly susceptible to malaria as they have not developed immunity to the disease."

People living in endemic regions where transmission is high can gradually develop immunity to malaria.

Malaria is caused by protozoan parasites of the genus Plasmodium. Four species of Plasmodium can produce the disease in its various forms, but one, the P. falciparum, is the most widespread and dangerous of the four, and if left untreated can lead to fatal cerebral malaria or a state of unrousable coma.

The situation has become even more complex over the last few years with the increase in resistance to the drugs normally used to combat the malaria parasites, especially chloroquine.

Umar said the increased resistance to drugs was being caused by the lack of discipline among people taking malaria medicine, the distribution of imitation drugs and the limited ability of some people to absorb the medicine.

"Patients tend to stop medication once they feel better. This doesn't eliminate the parasites wholly but only makes them woozy and in the long run makes them immune to the drugs."