Susceptibility of field-collected Phlebotomus argentipes (Diptera: Psychodidae) sand flies from Bangladesh and Nepal to different insecticides

Chowdhury, Rajib Nayan; Das, Murari Lal; Chowdhury, Vashkar; Roy, Lalita; Faria, Shyla; Priyanka, Jyoti; Akter, Sakila; Maheswary, Narayan Prosad; Khan, Rajaul Karim; Argaw, Daniel; Kroeger, Axel

doi:10.1186/s13071-018-2913-6

Cited by 20 publications

(18 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Field trials in Bangladesh, India and Nepal have shown high entomological efficacy of IRS with pyrethroids, alpha-cypermethrin or deltamethrin against P. argentipes [16][17][18][19]. Similarly, IRS with alpha-cypermethrin in Morocco brought about a significant reduction in the density of P. sergenti sandflies [20].…”

Section: Discussionmentioning

confidence: 99%

Insecticide susceptibility of Phlebotomus argentipes sandflies, vectors of visceral leishmaniasis in India

Dinesh

Hassan

Kumar

et al. 2021

Tropical Med Int Health

View full text Add to dashboard Cite

objectives Indoor residual spraying (IRS) with insecticides is the main vector control intervention for the elimination of visceral leishmaniasis in India. After a change in IRS policy in 2015 due to widespread resistance of Phlebotomus argentipes to DDT, IRS with DDT was replaced with alphacypermethrin IRS in 2016. The objective of the present study was to evaluate the susceptibility of P. argentipes to DDT and its alternatives, namely malathion and pirimiphos-methyl (organophosphates); alpha-cypermethrin, deltamethrin, lambda-cyhalothrin and permethrin (pyrethroids), and bendiocarb and propoxur (carbamates), in support of visceral leishmaniasis elimination in India.methods Phlebotomus argentipes sandflies were collected from the visceral-leishmaniasis endemic states of Bihar, Jharkhand and West Bengal. In the WHO tube tests, the phenotypic susceptibility of F1, 2-day old, non-blood fed females were determined against filter papers impregnated with DDT 4%, malathion 5%, pirimiphos-methyl 0.25%, alpha-cypermethrin 0.05%, deltamethrin 0.05%, lambda-cyhalothrin 0.05%, permethrin 0.75%, bendiocarb 0.1% and propoxur 0.1%, which were sourced from Universiti Sains Malaysia. The knockdown of sandflies after 1-h exposure and mortality at 24 h after the 1-h exposure period were scored.results Mean mortality of P. argentipes 24 h after exposure in tube tests was 22.6% for DDT and ≥ 98% for other insecticide-impregnated papers tested.conclusion Phlebotomus argentipes continues to be highly resistant to DDT with no reversal of resistance after DDT's withdrawal from IRS. P. argentipes was fully susceptible to pyrethroid, organophosphate and carbamate insecticides tested. Regular monitoring is warranted for insecticide resistance management in sandfly vectors.

show abstract

Section: Discussionmentioning

confidence: 99%

Insecticide susceptibility of Phlebotomus argentipes sandflies, vectors of visceral leishmaniasis in India

Dinesh

Hassan

Kumar

et al. 2021

Tropical Med Int Health

View full text Add to dashboard Cite

show abstract

“…In 2009, bioassays conducted in four villages from Eastern Nepal revealed the presence of DDT resistance in one of the four populations of P. argentipes , as well as possible resistance to deltamethrin 0.05%, thereby providing an early sign of development of selection pressure against pyrethroids [10]. Bioassays in three districts of Eastern Nepal in 2015 and 2016, on the other hand showed susceptible vector populations at 60 min exposure to alpha-cypermethrin 0.05% and deltamethrin 0.05% [12], which is contrary to the results obtained in our study.…”

Section: Discussionmentioning

confidence: 99%

“…argentipes populations [10] provided a clue for possible cross-resistance to pyrethroids due to involvement of knockdown resistance (kdr) mutations in a common para-type voltage-gated sodium channel (vgsc) target site gene in nerve cells [11]. Early signs of pyrethroid resistance were observed in the Eastern part of Nepal and also in some Indian areas bordering the country [11,12]. Systematic monitoring of insecticide resistance is considered a key component of VL surveillance.…”

Section: Introductionmentioning

confidence: 99%

Status of susceptibility of the visceral leishmaniasis vector,Phlebotomus argentipes(Diptera: Psychodidae: Phlebotominae), to insecticides used for vector control in Nepal

Roy

Uranw

Cloots

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

BackgroundVisceral leishmaniasis (VL) is targeted for elimination as a public health problem in Nepal by 2023. For nearly three decades, the core vector control intervention in Nepal has been indoor residual spraying (IRS) with pyrethroids. Considering the long-term use of pyrethroids and possible development of resistance of the vector Phlebotomus argentipes sand flies, we monitored susceptibility status of their field populations to the insecticides of different classes, in villages with and without IRS activities in recent years.Methodology/Principal findingsSand flies were collected from villages with and without IRS in five VL endemic districts from August 2019 to November 2020. The WHO susceptibility test procedure was adopted using filter papers impregnated at the discriminating concentrations of insecticides of the following classes: pyrethroids (alpha-cypermethrin 0.05%, deltamethrin 0.05% and lambda-cyhalothrin 0.05%), carbamates (bendiocarb 0.1%) and organophosphates (malathion 5%). Pyrethroid resistance intensity bioassays with papers impregnated with 5× of the discriminating concentrations, piperonyl butoxide (PBO) synergist-pyrethroid bioassays and DDT cross resistance bioassays were also performed. In the IRS villages, the vector sand flies were resistant (mortality rate <90%) to alpha-cypermethrin and possibly resistant (mortality rate 90–97%) to deltamethrin and lambda-cyhalothrin, while susceptibility to these insecticides was variable in the non-IRS villages. The vector was fully susceptible to bendiocarb and malathion in all villages. A delayed knockdown time (KDT50) with pyrethroids was observed in all villages. The pyrethroid resistance intensity was low, and the susceptibility improved at 5× of the discriminating concentrations. Enhanced pyrethroid susceptibility after pre-exposure to PBO and the DDT-pyrethroid cross-resistance were evident.Conclusions/SignificanceOur investigation showed that P. argentipes sand flies have emerged with pyrethroid resistance, suggesting the need to switch to alternative classes of insecticides such as organophosphates for IRS. We strongly recommend for the regular and systematic monitoring of insecticide resistance in sand flies to optimize the efficiency of vector control interventions to sustain VL elimination efforts in Nepal.Author summaryVisceral leishmaniasis (VL), transmitted by P. argentipes sand flies, is endemic in South-East Asian countries such as Bangladesh, India and Nepal, and is on the verge of elimination as a public health problem in Nepal by 2023. As part of the WHO Global Vector Control Response, entomological surveillance including insecticide resistance monitoring is one of the four main pillars of this strategy. In the early 1990s, the historical use of DDT for sand fly vector control was replaced with deltamethrin or alpha-cypermethrin, which have now been in use for almost three decades in Nepal. Suspecting that this long-term use of pyrethroids might have selected resistance in sand fly populations which would jeopardize control efforts, we conducted the first comprehensive survey to generate contemporary evidence of insecticide resistance in Nepal. For this, we performed WHO susceptibility tests in five VL endemic districts and found strong evidence of pyrethroid resistance in vector populations from the areas receiving IRS. Resistance mechanisms involved would probably be kdr mutations and monooxygenase. This study also endorses regular insecticide resistance monitoring to inform evidence-based decisions on insecticide use for vector control and to maintain the effectiveness of vector control measures as a core intervention in the fight against VL.

show abstract

“…It later appeared that one of the batches of Miltefosine supplied by the national programme was a fake drug with no active substance [31], so we may consider that the effect of case management was minimal during that period. Similarly, no sand fly control activities were conducted by the government up to early 2012 [8, 12] since banned of DDT in 1997 [32], as the registration process of deltamethrin for sand fly control took a long time [13]. However, in 2013 the national programme distributed two pieces of LLIN to each patient who had completed VL treatment between 2009 and 2011 [8].…”

Section: Discussionmentioning

confidence: 99%

Effect of insecticide-treated bed nets on visceral leishmaniasis incidence in Bangladesh. A retrospective cohort analysis

Chowdhury

Faria

et al. 2019

PLoS Negl Trop Dis

Self Cite

View full text Add to dashboard Cite

BackgroundVisceral leishmaniasis (VL) is a parasitic disease, transmitted by the sand fly species Phlebotomus argentipes in the Indian sub-continent. Effective vector control is highly desirable to reduce vector density and human and vector contact in the endemic communities with the aim to curtail disease transmission. We evaluated the effect of long lasting insecticide treated bed nets (LLIN) and bed nets impregnated with slow-release insecticide tablet K-O TAB 1-2-3 (jointly insecticide-treated nets or ITN) on VL incidence in a highly endemic sub-district (upazila) in Bangladesh.MethodsSeveral distributions of LLIN or K-O TAB 1-2-3 for self-impregnation of bed nets at home took place in Fulbaria upazila, Mymensigh district from 2004 to 2008 under three research projects, respectively funded by CDC, Atlanta, USA (2004) and WHO-TDR, Geneva, Switzerland (2006 & 2008). We included all households (n = 8142) in the 20 villages that had benefited in the past from one of these interventions (1295 donated LLIN and 11,918 local bed nets impregnated with K-O TAB 1-2-3) in the “exposed cohort”. We recruited a “non-exposed cohort” in villages with contemporaneously similar incidence rates who had not received such vector control interventions (7729 HHs from nine villages). In both cohorts, we visited all families house to house and ascertained any VL cases for the 3 year period before and after the intervention. We evaluated the incidence rate (IR) of VL in both cohorts as primary endpoint, applying the difference-in-differences method.ResultsThe study identified 1011 VL cases (IR 140.47/10,000 per year [py]) before the intervention, of which 534 and 477 cases in the intervention and control areas respectively. The IR was 144.13/10,000 py (534/37050) and 136.59/10,000 py (477/34923) in the intervention and control areas respectively, with no significant difference (p = 0.3901) before the intervention. After the intervention, a total of 555 cases (IR 77.11/10,000 py) were identified of which 178 (IR 48.04/10,000 py) in the intervention and 377 (107.95/10,000 py) in the control area. The intervention area had a significant lower IR than the control area during follow up, rate difference = –59.91, p<0.0001. The IR during follow up was significantly reduced by 96.09/10,000 py in the intervention area (p<0.0001) and 28.63/10,000 py in control area (p<0.0001) compared to baseline. There was a strong and significant overall effect of the ITN intervention, δ = –67.45, p <0.0001. Sex (OR = 1.36, p<0.0001) and age (OR = 0.99, p<0.0001) also had a significant effect on VL incidence. Male had a higher risk of VL than female and one year increase in age decreased the likelihood of VL by about 0.92%. Two third of the VL incidence occurred in the age range 2 to 30 years (median age of VL patients was 17 years).ConclusionVL incidence rate was significantly lower in the ITN intervention cohort compared to control in Bangladesh. Some bias due to more intense screen-and-treat activities or other interventions in the intervention area cannot b...

show abstract

Susceptibility of field-collected Phlebotomus argentipes (Diptera: Psychodidae) sand flies from Bangladesh and Nepal to different insecticides

Cited by 20 publications

References 9 publications

Insecticide susceptibility of Phlebotomus argentipes sandflies, vectors of visceral leishmaniasis in India

Insecticide susceptibility of Phlebotomus argentipes sandflies, vectors of visceral leishmaniasis in India

Status of susceptibility of the visceral leishmaniasis vector,Phlebotomus argentipes(Diptera: Psychodidae: Phlebotominae), to insecticides used for vector control in Nepal

Effect of insecticide-treated bed nets on visceral leishmaniasis incidence in Bangladesh. A retrospective cohort analysis

Contact Info

Product

Resources

About