Two years after US$22 million in donor funds were pumped into malaria control along the Cambodia-Thailand border to fight off suspected resistance to treatment, health workers say the battle is not over.

“If you take your foot off the [accelerator] we can lose everything we have done in the past two to three years,” Steven Bjorge, anti-malaria team leader in Cambodia for the World Health Organization (WHO), told IRIN in February 2012.

The government reported 103,000 malaria infections and 151 deaths nationwide in 2010. A year later, 85,000 reported infections led to 93 deaths - a 38-percent decline in mortality.

When health workers screened more than 3,600 people for malaria in Pailin Province, near the Thai-Cambodia border, in May 2010, only two out of every 1,000 people tested positive for the fatal strain of malaria (falciparum) that had shown resistance to the recommended treatment, based on the drug artemisinin.

Villages in this province are in the zone hit by artemisinin resistance in earlier years.

Resurgence risk

Bjorge warned that any decline in vigilance could lead to resurgence. A recent analysis of “historical failures to maintain gains against [malaria]” identified 75 significant returns of the disease in 61 countries from the 1930s to the 2000s.

The authors of the analysis concluded that nine out of 10 such returns were due to weaker malaria control programs, brought about by funding problems in 54 percent of cases. Other causes included “purposeful cessation”, war, administrative problems, community non-cooperation, vector and drug resistance, population movements among humans as well as mosquitoes, and climate changes.

Elimination

The government has announced a goal of zero malaria cases by 2025, but is struggling to hang on to donor funds.

The Global Fund to Fight HIV/AIDS, Tuberculosis and Malaria pledged almost $80 million in two current grants to fight malaria in Cambodia, but government agencies were unable to collect some $20 million - 35 percent of one grant - due to “performance below the expectations”, said Andrew Hurst, a Global Fund spokesman.

“Grant signed amounts represent available fund ceilings and are not an entitlement,” he wrote in response to a query by IRIN about the undisbursed amount, which is still available but must be requested again.

Aid analysts warn that the Global Fund’s stricter reporting requirements after a funding squeeze may hobble emergency responses.

“There is also a danger that some risk-reduction measures primarily intended for high-risk countries will be applied to all countries, thereby increasing the administrative burden and slowing down the work in low-risk countries,” wrote Angela Kageni, a senior programme officer at Aidspan, the Kenya-based not-for-profit Global Fund watchdog.

The director of Cambodia’s Centre for Malaria Control said the centre cannot comment without a “final decision” from the Global Fund on an upcoming review of the country’s grant, scheduled to end in 2015. The next phase begins on 1 January 2013.

One challenge in reaching zero cases will be detecting asymptomatic incidents - when people have built up enough resistance to the parasite not to display symptoms but still carry the disease - said Didier Menard, chief of the molecular epidemiology unit at the Pasteur Institute in the capital, Phnom Penh.

Such people constitute a “hidden malaria parasite reservoir”, so when a mosquito bites them, and then bites someone else, the disease can be transmitted. But the test and the laboratory equipment required to detect such low parasite levels - polymerase chain reaction (PCR) - is expensive and not widely available or fool-proof, Menard noted.

Another challenge will be migrant workers infected with malaria - either domestic seasonal workers or those coming from a neighboring country - Bjorge pointed out. “A comprehensive intervention is hard with people who do not even live under a tent… [Our efforts] are trial and error right now.”

Some 35 percent of Cambodia’s population is constantly on the move, according to the most recent government estimate.

As a result, in recent decades malaria hotspots have shifted from rural areas to forested areas that attract seasonal migrants, Bjorge said. “Those will be the hardest to reach.”

(IRIN is a a service of the UN Office for the Coordination of Humanitarian Affairs This report does not necessarily reflect the views of the United Nations.)