A study of the mass administration of anti-malarial drugs in two provinces of Cambodia has shown the challenges that surface during such interventions, including the spread of “rumours” among villagers, which can decrease participation, new research shows.

According to the study published late last month in the Malaria Journal, a clear understanding of the dynamics within communities where anti-malarial drugs are being introduced is critical.

“Only if the majority [of] community members are convinced that participating in the campaign is to their benefit – whether health, financial, social or political – can the people overcome their own concerns and the dissuasive messages of others,” the authors wrote.

Huy Rekol, head of the National Center for Parasitology, Entomology and Malaria Control, said his staff had not encountered these types of problems while conducting two pilot projects of mass administrations in Preah Vihear and Battambang, the two provinces studied.

“People were very happy,” he said, though he added education was required regularly.

According to the study, in Preah Vihear, adverse reactions to the drugs led to changes in attitudes toward the intervention, exacerbated by “rumours suggesting that the anti-malarial was different from that used [given]" by the village malaria workers.

In Battambang, the mass administration took place during the rainy season, coinciding with cold and influenza-like illnesses, which some villagers attributed to the anti-malarial drugs, resulting in an estimated 10 percent decrease in participation, according to the study.

In Preah Vihear, “news of adverse events spread through the villages and staff described them as a major reason why coverage declined”.

Villagers in both provinces were concerned about the campaign because of the widely reported HIV outbreak that swept through Battambang’s Roka commune in 2014, when an unlicensed doctor spread the virus to nearly 300 villagers by using tainted needles.

“Staff in Battambang described this as a challenge during community engagement but it was not described as a reason for non-participation amongst villagers,” the study reads. “In Preah Vihear, however, it was mentioned by villagers as a reason not to participate.”

Meanwhile, there was an approximately 60 percent increase in the number of malaria cases in Cambodia last year compared to 2016, though Rekol wasn’t able to provide the specific figures. The increase may be related to a longer than usual rainy season, the movement of people, and the quality of mosquito nets – distributed in the last two years – starting to deteriorate, he said. He said some 1.7 million to 2 million nets should be distributed this year.

Luciano Tuseo, head of the malaria program at the World Health Organization (WHO) Cambodia, said he was not able to comment on the specifics of this study.

“However, WHO recommended that focalized anti-malaria [mass drug administrations] may be considered as a component of malaria elimination efforts in [the] Greater Mekong Sub region in area[s] with good access [to] treatment, vector control and surveillance,” he said in an email. “This require[s] extensive community engagement to achieve a high level of community acceptance and participation.”