Limits...
Olyset Duo® (a pyriproxyfen and permethrin mixture net): an experimental hut trial against pyrethroid resistant Anopheles gambiae and Culex quinquefasciatus in Southern Benin.

Ngufor C, N'guessan R, Fagbohoun J, Odjo A, Malone D, Akogbeto M, Rowland M - PLoS ONE (2014)

Bottom Line: LNs containing a mixture of pyriproxyfen and pyrethroid could provide personal protection through the pyrethroid component and reduce vector abundance in the next generation through the sterilizing effect of pyriproxyfen.Olyset Duo was more protective than Olyset Net in the huts against wild pyrethroid resistant Cx. quinquefasciatus although mortality rates of this species did not differ significantly between Olyset Net and Olyset Duo.Olyset Duo was superior to Olyset Net in terms of personal protection and killing of pyrethroid resistant An. gambiae, and sterilized surviving blood-fed mosquitoes.

View Article: PubMed Central - PubMed

Affiliation: London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom; Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin; Pan African Malaria Vector Research Consortium (PAMVERC), London, United Kingdom.

ABSTRACT

Background: Alternative compounds which can complement pyrethroids on long-lasting insecticidal nets (LN) in the control of pyrethroid resistant malaria vectors are urgently needed. Pyriproxyfen (PPF), an insect growth regulator, reduces the fecundity and fertility of adult female mosquitoes. LNs containing a mixture of pyriproxyfen and pyrethroid could provide personal protection through the pyrethroid component and reduce vector abundance in the next generation through the sterilizing effect of pyriproxyfen.

Method: The efficacy of Olyset Duo, a newly developed mixture LN containing pyriproxyfen and permethrin, was evaluated in experimental huts in southern Benin against pyrethroid resistant Anopheles gambiae and Culex quinquefasciatus. Comparison was made with Olyset Net® (permethrin alone) and a LN with pyriproxyfen alone (PPF LN). Laboratory tunnel tests were performed to substantiate the findings in the experimental huts.

Results: Overall mortality of wild pyrethroid resistant An. gambiae s.s. was significantly higher with Olyset Duo than with Olyset Net (50% vs. 27%, P = 0.01). Olyset DUO was more protective than Olyset Net (71% vs. 3%, P<0.001). The oviposition rate of surviving blood-fed An. gambiae from the control hut was 37% whereas none of those from Olyset Duo and PPF LN huts laid eggs. The tunnel test results were consistent with the experimental hut results. Olyset Duo was more protective than Olyset Net in the huts against wild pyrethroid resistant Cx. quinquefasciatus although mortality rates of this species did not differ significantly between Olyset Net and Olyset Duo. There was no sterilizing effect on surviving blood-fed Cx. quinquefasciatus with the PPF-treated nets.

Conclusion: Olyset Duo was superior to Olyset Net in terms of personal protection and killing of pyrethroid resistant An. gambiae, and sterilized surviving blood-fed mosquitoes. Mixing pyrethroid and pyriproxyfen on a LN shows potential for malaria control and management of pyrethroid resistant vectors by preventing further selection of pyrethroid resistant phenotypes.

Show MeSH

Related in: MedlinePlus

Mortality and bloodfeeding rates of pyrethroid resistant Anopheles gambiae in experimental huts.Percentage mortality (lighter shade) and bloodfeeding (darker shade) of pyrethroid resistant An. gambiae in experimental huts in Akron. For each response parameter (mortality or bloodfeeding), values for histograms sharing the same letter label are not significantly different (P>0.05). Error bars represent 95% confidence intervals.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3974762&req=5

pone-0093603-g001: Mortality and bloodfeeding rates of pyrethroid resistant Anopheles gambiae in experimental huts.Percentage mortality (lighter shade) and bloodfeeding (darker shade) of pyrethroid resistant An. gambiae in experimental huts in Akron. For each response parameter (mortality or bloodfeeding), values for histograms sharing the same letter label are not significantly different (P>0.05). Error bars represent 95% confidence intervals.

Mentions: Blood feeding and mortality: A total of 303 An. gambiae were collected from the experimental huts during the trial. The numbers entering each of the treated huts per night were higher than in the control, hence there was no evidence of a deterrent effect on An. gambiae with any of the treatments (Table 2). The proportion exiting from huts with control nets (31%) did not differ significantly from that with PPF LN (29%; P = 0.72) (Table 2). Exiting rates were much higher from huts with Olyset Duo (52%) and Olyset Net (56%) which might be attributed to the excito-repellent property of permethrin in both nets. Percentage blood-fed with the PPF LN (59%) did not differ significantly from the control net (53%, P = 0.44) or Olyset Net (45%, P = 0.07) (Figure 1). The lowest blood-feeding rate was achieved with Olyset Duo (13%). Olyset Duo also provided significantly higher levels personal protection (71%) than Olyset Net (3%, P<0.001) and PPF LN (0%, P<0.001) (Table 3). Lower proportions of mosquitoes were collected from inside the permethrin treated nets (Olyset Net: 11% and Olyset Duo: 4%) than from the PPF LN (35%, P<0.001) or control nets (39%, P<0.001) (Table 3). The proportion collected from inside Olyset Net (11%) did not differ significantly from that from Olyset Duo (4%, P = 0.07). Mortality with PPF LN (21%) was higher than the control net (8%, P = 0.03) but did not differ significantly from Olyset Net (27%, P = 0.24) (Figure 1). Much higher mortality rates were achieved with Olyset Duo than with Olyset Net (50% vs 27%; P = 0.01) and PPF LN (50% vs 21% P<0.001). Olyset Duo induced a higher overall killing effect on An. gambiae than did Olyset Net (48% vs 27%, P<0.05) (Table 4).


Olyset Duo® (a pyriproxyfen and permethrin mixture net): an experimental hut trial against pyrethroid resistant Anopheles gambiae and Culex quinquefasciatus in Southern Benin.

Ngufor C, N'guessan R, Fagbohoun J, Odjo A, Malone D, Akogbeto M, Rowland M - PLoS ONE (2014)

Mortality and bloodfeeding rates of pyrethroid resistant Anopheles gambiae in experimental huts.Percentage mortality (lighter shade) and bloodfeeding (darker shade) of pyrethroid resistant An. gambiae in experimental huts in Akron. For each response parameter (mortality or bloodfeeding), values for histograms sharing the same letter label are not significantly different (P>0.05). Error bars represent 95% confidence intervals.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3974762&req=5

pone-0093603-g001: Mortality and bloodfeeding rates of pyrethroid resistant Anopheles gambiae in experimental huts.Percentage mortality (lighter shade) and bloodfeeding (darker shade) of pyrethroid resistant An. gambiae in experimental huts in Akron. For each response parameter (mortality or bloodfeeding), values for histograms sharing the same letter label are not significantly different (P>0.05). Error bars represent 95% confidence intervals.
Mentions: Blood feeding and mortality: A total of 303 An. gambiae were collected from the experimental huts during the trial. The numbers entering each of the treated huts per night were higher than in the control, hence there was no evidence of a deterrent effect on An. gambiae with any of the treatments (Table 2). The proportion exiting from huts with control nets (31%) did not differ significantly from that with PPF LN (29%; P = 0.72) (Table 2). Exiting rates were much higher from huts with Olyset Duo (52%) and Olyset Net (56%) which might be attributed to the excito-repellent property of permethrin in both nets. Percentage blood-fed with the PPF LN (59%) did not differ significantly from the control net (53%, P = 0.44) or Olyset Net (45%, P = 0.07) (Figure 1). The lowest blood-feeding rate was achieved with Olyset Duo (13%). Olyset Duo also provided significantly higher levels personal protection (71%) than Olyset Net (3%, P<0.001) and PPF LN (0%, P<0.001) (Table 3). Lower proportions of mosquitoes were collected from inside the permethrin treated nets (Olyset Net: 11% and Olyset Duo: 4%) than from the PPF LN (35%, P<0.001) or control nets (39%, P<0.001) (Table 3). The proportion collected from inside Olyset Net (11%) did not differ significantly from that from Olyset Duo (4%, P = 0.07). Mortality with PPF LN (21%) was higher than the control net (8%, P = 0.03) but did not differ significantly from Olyset Net (27%, P = 0.24) (Figure 1). Much higher mortality rates were achieved with Olyset Duo than with Olyset Net (50% vs 27%; P = 0.01) and PPF LN (50% vs 21% P<0.001). Olyset Duo induced a higher overall killing effect on An. gambiae than did Olyset Net (48% vs 27%, P<0.05) (Table 4).

Bottom Line: LNs containing a mixture of pyriproxyfen and pyrethroid could provide personal protection through the pyrethroid component and reduce vector abundance in the next generation through the sterilizing effect of pyriproxyfen.Olyset Duo was more protective than Olyset Net in the huts against wild pyrethroid resistant Cx. quinquefasciatus although mortality rates of this species did not differ significantly between Olyset Net and Olyset Duo.Olyset Duo was superior to Olyset Net in terms of personal protection and killing of pyrethroid resistant An. gambiae, and sterilized surviving blood-fed mosquitoes.

View Article: PubMed Central - PubMed

Affiliation: London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom; Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin; Pan African Malaria Vector Research Consortium (PAMVERC), London, United Kingdom.

ABSTRACT

Background: Alternative compounds which can complement pyrethroids on long-lasting insecticidal nets (LN) in the control of pyrethroid resistant malaria vectors are urgently needed. Pyriproxyfen (PPF), an insect growth regulator, reduces the fecundity and fertility of adult female mosquitoes. LNs containing a mixture of pyriproxyfen and pyrethroid could provide personal protection through the pyrethroid component and reduce vector abundance in the next generation through the sterilizing effect of pyriproxyfen.

Method: The efficacy of Olyset Duo, a newly developed mixture LN containing pyriproxyfen and permethrin, was evaluated in experimental huts in southern Benin against pyrethroid resistant Anopheles gambiae and Culex quinquefasciatus. Comparison was made with Olyset Net® (permethrin alone) and a LN with pyriproxyfen alone (PPF LN). Laboratory tunnel tests were performed to substantiate the findings in the experimental huts.

Results: Overall mortality of wild pyrethroid resistant An. gambiae s.s. was significantly higher with Olyset Duo than with Olyset Net (50% vs. 27%, P = 0.01). Olyset DUO was more protective than Olyset Net (71% vs. 3%, P<0.001). The oviposition rate of surviving blood-fed An. gambiae from the control hut was 37% whereas none of those from Olyset Duo and PPF LN huts laid eggs. The tunnel test results were consistent with the experimental hut results. Olyset Duo was more protective than Olyset Net in the huts against wild pyrethroid resistant Cx. quinquefasciatus although mortality rates of this species did not differ significantly between Olyset Net and Olyset Duo. There was no sterilizing effect on surviving blood-fed Cx. quinquefasciatus with the PPF-treated nets.

Conclusion: Olyset Duo was superior to Olyset Net in terms of personal protection and killing of pyrethroid resistant An. gambiae, and sterilized surviving blood-fed mosquitoes. Mixing pyrethroid and pyriproxyfen on a LN shows potential for malaria control and management of pyrethroid resistant vectors by preventing further selection of pyrethroid resistant phenotypes.

Show MeSH
Related in: MedlinePlus