Long lasting insecticidal nets in Papua New Guinea
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PNGIMR has been conducting research for the last 45 years on malaria epidemiology, treatment and prevention and entomology to inform policy at the National Department of Health. Today, we are proud to celebrate one of those research activities and the scientist behind the research that has national and global implications.

Bed nets, also known as long lasting insecticidal nets or LLINs, are the most important tool used in PNG to prevent people from getting malaria. Scientific Officer Nakei Bubun monitors the quality of LLINs at PNGIMR’s entomology laboratory.

Ms Bubun graduated from the University of Papua New Guinea with a Bachelor’s Degree of Science and has been working with the entomology unit in Madang for more than a year. Her job is to do cone bioassays, the methodrecommended by the World Health Organization to assess the bioefficacy of nets treated with insecticide formulations.The work involves placing mosquitoes on a piece of LLIN and recording how many of them are knocked down and killed.

To do accurate cone bioassays, scientists need steady hands and patience. In the laboratory Ms Bubun carefully transfers five mosquitoes into each of four cones attached to a piece of LLIN. She repeats this five times on five different pieces of a LLIN, until she has 100 mosquitoes in 20 cones. After the mosquitoes have been on a piece of LLIN for three minutes, they are taken out of the cones and put in holding cups. After 60 minutes she counts the number of mosquitoes in the cups that are knocked down.After 24 hours she counts how many mosquitoes in the cups are dead. LLINs should show a 24 hours mortality rate of greater or equal to 80 percent or 60 minutes knockdown of at least 90 percent.

“My work is important for malaria control in PNG. I believe finding the best quality LLIN will definitely help to control the mosquitoes transmitting malaria and hence help reducing malaria in PNG,” she said.

In an earlier studyPNGIMR’s entomology team found that PermaNet 2.0,the LLINs previously distributed in PNG and elsewhere in the world, did not meet WHO standards.The entomology team published the results of these tests in 2020; their research led to the National Malaria Control Program bringing different LLINs into PNG.

PNG is now receiving new bed net brands such as SafeNet, Interceptor and Royal Sentry. Ms Bubun and colleagues are testing all these brands. Her work has helped to secure more funding to expand the bed net testing studies. This new study, with partners from James Cook University, is called the TAUNAM study, short for ‘Testing Quality and Understanding Effectiveness of Mosquito Nets Against Malaria in PNG’.

Ms Bubun said, “I would like to thank PMGIMR for the opportunity to do this research. I would also like to express my special thanks to the entomology lab team in Madang for their continuous backing of my work and Drs Stephan Karl and Moses Laman, who gave me this wonderful project to begin with and who have been very supportive throughout my work.”

PNGIMR is grateful for funding from the Global Fund and Australian Health and Medical Research Council (NHMRC)to conduct this important work in support of the National Malaria Control Program.