The Health Ministry has high hopes of eradicating malaria in the country, but says massive deforestation – which pushes parasite-carrying animals toward urban areas – has threatened its efforts to combat the disease.

Tjandra Yoga Aditama, the ministry's director general for disease control, said Indonesia was expected to be malaria-free by 2030, with the number of infections decreasing every year.

"In 2009 and last year, malaria elimination efforts posted good results," he said on Sunday in marking World Malaria Day, which falls on April 25 each year. "The number of infections continues to decrease in each province, although not at the same rate," he added.

There were 544,470 reported cases of the mosquito-borne disease last year, 900 of which were fatal, according to the ministry. The annual incidence of infection per 1,000 people also fell from 4.6 in 1990 to 1.96 last year.

The ministry said Jakarta became malaria-free last year, with Bali and Batam expected to follow suit this year. The government expects to wipe out malaria in Java, Aceh and the Riau Islands by 2015, and in Sumatra, Kalimantan, Sulawesi and West Nusa Tenggara by 2020.

However, Tjandra said the ministry was still concerned about the rise in infections from Plasmodium knowlesi, a potentially fatal malaria parasite commonly carried by long-tailed macaques and transmitted to humans through mosquito bites. Other malaria cases are caused by either Plasmodium falciparum or Plasmodium vivax, according to the ministry.

P. knowlesi is responsible for nearly half the malaria cases in the country and is particularly prevalent in Kalimantan, whose forests are inhabited by macaque populations.

The ministry said illegal logging and forest-clearing in the area had encroached on monkeys' habitats, forcing the animals out of the forest and toward human settlements.

Tjandra said this problem would likely cause the number of malaria cases to increase, hampering the government's eradication campaign. Unless promptly treated, P. knowlesi malaria can cause death within seven days, as well as serious organ complications in humans.

The ministry said another cause for concern was the possibility of a P. knowlesi outbreak due to climate change. Frequent flooding due to erratic weather patterns and environmental degradation increases the likelihood of the formation of stagnant pools where mosquitoes can breed, it said.

Despite these problems, Tjandra said the government was employing "all measures" to eradicate malaria by 2015 under the United Nations Millennium Development Goals.

The country's malaria-eradication program is aimed mainly at high-risk populations in areas such as Kalimantan. Tjandra said the program involved the distribution of rapid diagnostic test kits to local health centers, as well as the provision of drugs for malaria victims.

The Health Ministry has also launched the Gebrak Malaria campaign to improve health services in malaria-prone areas and educate residents about the importance of destroying mosquito larvae, he said.

Another effort involves requiring local health agencies to conduct routine insecticide spraying to kill mosquitoes and their larvae, and distribute mosquito nets to households, Tjandra said.

In December last year, the World Health Organization said countries around the world could prevent malaria deaths within five years through these preventive measures.

There were an estimated 81 million malaria cases worldwide last year, according to the WHO's 2010 World Malaria Report, with 117,704 recorded fatalities.