scholarly journals Effect of Short-Term Heating on Bioefficacy of Deltamethrin-Coated Long-Lasting Insecticidal Nets

2021 ◽  
Author(s):  
Nakei Bubun ◽  
Timothy W. Freeman ◽  
Moses Laman ◽  
Stephan Karl
Keyword(s):  
Quality Assurance ◽  
Papua New Guinea ◽  
New Guinea ◽  
Short Term ◽  
Knock Down ◽  
Anopheles Mosquitoes ◽  
Long Lasting Insecticidal Nets

The authors recently reported that long-lasting insecticidal nets (LLINs) distributed in Papua New Guinea (PNG) between 2013 and 2019, exhibited severely diminished efficacy to knock down and kill susceptible Anopheles mosquitoes. This coincided with a rise in malaria observed in PNG since 2015. Here, the authors show that LLIN bioefficacy is increased by heating LLINs prior to WHO cone bioassays. Unused LLINs with low bioefficacy, delivered to PNG in 2019, were heated to 120°C for 5 minutes. Cone bioassays were performed before and at 1 hour, 7 days, and 30 days after heating. This led to a significant increase in 24-hour mortality (17–61%) and 60-minute knock down (31–72%). The effect was sustained over 30 days. Bioassays are crucial in quality assurance of LLIN products. Our findings indicate that bioefficacy of LLINs can be increased by heating. This may have implications for quality assurance procedures used to assess LLINs.

scholarly journals Effect of short-term heating on bioefficacy of deltamethrin-coated long-lasting insecticidal nets

2021 ◽  
Author(s):  
Nakei Bubun ◽  
Timothy W Freeman ◽  
Moses Laman ◽  
Stephan Karl
Keyword(s):  
Quality Assurance ◽  
Papua New Guinea ◽  
New Guinea ◽  
Short Term ◽  
Knock Down ◽  
Anopheles Mosquitoes ◽  
Long Lasting Insecticidal Nets

We recently reported that long-lasting insecticidal nets (LLINs) distributed in Papua New Guinea (PNG) between 2013 and 2019, exhibited severely diminished efficacy to knock down and kill susceptible Anopheles mosquitoes. This coincided with a rise in malaria observed in PNG since 2015. Here we show that LLIN bioefficacy is increased by heating LLINs prior to WHO cone bioassays. Unused LLINs with low bioefficacy, delivered to PNG in 2019, were heated to 120 degrees Celsius for 5 minutes. Cone bioassays were performed before and at 1 h, 7 days and 30 days after heating. This led to a significant increase in 24 h mortality (17% to 61%) and 60 min knock down (31% to 72%). The effect was sustained over 30 days. Bioassays are crucial in quality assurance of LLIN products. Our findings indicate that bioassay results can easily be manipulated. This may have implications for quality assurance procedures used to assess LLINs.

scholarly journals Changes in malaria burden and transmission in sentinel sites after the roll-out of long-lasting insecticidal nets in Papua New Guinea

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Manuel W. Hetzel ◽  
Lisa J. Reimer ◽  
Gibson Gideon ◽  
Gussy Koimbu ◽  
Céline Barnadas ◽  
...  
Keyword(s):  
Papua New Guinea ◽  
New Guinea ◽  
Malaria Burden ◽  
Long Lasting Insecticidal Nets ◽  
Roll Out

scholarly journals Probe-based multiplex qPCR identifies blood-meal hosts in Anopheles mosquitoes from Papua New Guinea

2020 ◽  
Author(s):  
John B Keven ◽  
Georgia Artzberger ◽  
Mary L. Gillies ◽  
Rex B. Mbewe ◽  
Edward D. Walker
Keyword(s):  
Papua New Guinea ◽  
Quantitative Pcr ◽  
Blood Meal ◽  
New Guinea ◽  
Molecular Probe ◽  
Conventional Pcr ◽  
Anopheles Mosquitoes ◽  
Mixed Blood ◽  
Host Blood ◽  
Blood Meals

Abstract Background: Determination of blood-meal hosts in blood-fed female Anopheles mosquitoes is important for evaluating vectorial capacity of vector populations and assessing effectiveness of vector control measures. Sensitive molecular methods are needed to detect traces of host blood in mosquito samples, to differentiate hosts, and to detect mixed host blood meals. This paper describes a molecular probe-based quantitative PCR for identifying blood-meal hosts in Anopheles malaria vectors from Papua New Guinea. Methods: TaqMan oligonucleotide probes targeting specific regions of mitochondrial or nuclear DNA of the three primary Anopheles blood-meal hosts, humans, pigs and dogs, were incorporated into a multiplex, quantitative PCR which was optimized for sensitivity and specificity. Results: Amplification of serially diluted DNA showed that the quantitative PCR detected as low as 10-5 ng/ml of host DNA. Application to field-collected, blood-fed Anopheles showed that the quantitative PCR identified the vertebrate hosts for 89% (335/375) of mosquitoes whereas only 55% (104/188) of blood-meal samples tested in a conventional PCR were identified. Of the 104 blood-fed Anopheles that were positive in both PCR methods, 16 (15.4%) were identified as mixed blood meals by the quantitative PCR whereas only 3 (2.9%) were mixed blood meals by the conventional PCR. Conclusions: The multiplex quantitative PCR described here is sensitive at detecting low DNA concentration and mixed host DNA in samples and useful for blood-meal analysis of field mosquitoes, in particular mixed-host blood meals.

How Political Commitments Influence Research

2018 ◽  
Author(s):  
Stuart Kirsch
Keyword(s):  
Environmental Impact ◽  
Nongovernmental Organizations ◽  
Papua New Guinea ◽  
New Guinea ◽  
The Other ◽  
Research Projects ◽  
Short Term ◽  
Challenges And Opportunities ◽  
Political Commitments

This chapter is based on long-term research with people affected by the Ok Tedi mine in Papua New Guinea, including involvement in a lawsuit seeking to halt its destructive environmental impact. It considers examples of ethnographic refusal, when anthropologists do not write about events that might harm their informants. It also examines relationships between engaged anthropologists and colleagues, lawyers and law, corporations, nongovernmental organizations, and communities. This chapter and the next address these questions in the context of long-term research projects, while the other examples in the book consider these issues in relation to short-term, problem-focused research, which have their own challenges and opportunities.

scholarly journals Aspects of the ecology of the kalubu bandicoot (Echymipera kalubu) and observations on Raffray’s bandicoot (Peroryctes raffrayanus), Eastern Highlands Province, Papua New Guinea

2014 ◽  
Vol 36 (1) ◽  
pp. 21 ◽  
Author(s):  
Richard J. Cuthbert ◽  
Matthew J. H. Denny
Keyword(s):  
Papua New Guinea ◽  
New Guinea ◽  
Home Range Size ◽  
Montane Forest ◽  
Home Ranges ◽  
Short Term ◽  
Disturbed Areas ◽  
The Family ◽  
Eastern Highlands ◽  
Density Rate

Bandicoots in the family Peroryctidae in New Guinea are widespread and relatively abundant, but little is known of their ecology. We present the first detailed study on the ecology of the kalubu bandicoot (Echymipera kalubu) and observations on Raffray’s bandicoot (Peroryctes raffrayanus), from mid-montane forest in Papua New Guinea. Both species were primarily nocturnal and utilised a range of habitats including those modified by human activity, although Raffray’s bandicoot was more frequently encountered in less disturbed areas. Male kalubu bandicoots were larger than females, with larger animals having larger short-term home ranges and evidence for intrasexual territoriality. Mean short-term home-range size was 2.8 ha (MCP, n = 10), with an estimated population density of ~85 animals km–2 in the study area. Female kalubu bandicoots attained sexual maturity at ~400 g and 67% of mature females were reproductively active with an average of 1.5 young per litter. Both species were hunted, but their density, rate of reproduction and use of modified habitats suggest that they were able to withstand current hunting levels.

Capture and immobilisation of cuscuses and ringtail possums in Papua New Guinea

2004 ◽  
Vol 31 (1) ◽  
pp. 101 ◽  
Author(s):  
Leonardo A. Salas ◽  
Suzette A. Stephens
Keyword(s):  
Body Weight ◽  
Papua New Guinea ◽  
New Guinea ◽  
Drug Dose ◽  
Short Term ◽  
Night Time ◽  
Unit Effort ◽  
Drug Doses ◽  
Ketamine Hcl

We evaluated two methods (daytime and night-time searches) for capturing montane possums, the dose of ketamine HCl needed for their short-term restraint, its influence in effect length and recovery length, the effect of body weight, and differences between species and sexes. Daytime searches required significantly more effort to find animals, and provided significantly fewer captured animals per unit effort, than night-time searches. Chances of capturing animals once detected were higher during daytime. Drug doses of 9–17 mg kg–1 immobilised animals within 1 min (±1.25, s.d.), effects lasted 19 min (±1.34), and recovery took an additional 28 min (±1.29). Significant effects on effect length and recovery were observed only for drug dose, but these are weak. We recommend finding animals before dawn, following them to their dens, and capturing them during daylight as the safest and most effective method for montane possums of New Guinea. For short-term restraint, a dose of 10 mg kg–1 ketamine HCl is sufficient.

scholarly journals Decreased bioefficacy of long-lasting insecticidal nets and the resurgence of malaria in Papua New Guinea

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Rebecca Vinit ◽  
Lincoln Timinao ◽  
Nakei Bubun ◽  
Michelle Katusele ◽  
Leanne J. Robinson ◽  
...  
Keyword(s):  
Papua New Guinea ◽  
New Guinea ◽  
Long Lasting Insecticidal Nets

scholarly journals Probe-based multiplex qPCR identifies blood-meal hosts in Anopheles mosquitoes from Papua New Guinea

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
John B. Keven ◽  
Georgia Artzberger ◽  
Mary L. Gillies ◽  
Rex B. Mbewe ◽  
Edward D. Walker
Keyword(s):  
Papua New Guinea ◽  
Blood Meal ◽  
New Guinea ◽  
Multiplex Qpcr ◽  
Anopheles Mosquitoes
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