Impact of IRS: Four-years of entomological surveillance of the Indian Visceral Leishmaniases elimination programme.
Animals
Biological Assay
Female
Humans
India
/ epidemiology
Insect Control
/ methods
Insect Vectors
/ parasitology
Insecticide Resistance
Insecticides
/ administration & dosage
Leishmaniasis, Visceral
/ epidemiology
Phlebotomus
/ parasitology
Psychodidae
/ drug effects
Pyrethrins
/ administration & dosage
Journal
PLoS neglected tropical diseases
ISSN: 1935-2735
Titre abrégé: PLoS Negl Trop Dis
Pays: United States
ID NLM: 101291488
Informations de publication
Date de publication:
08 2021
08 2021
Historique:
received:
13
01
2021
accepted:
01
07
2021
revised:
19
08
2021
pubmed:
10
8
2021
medline:
17
11
2021
entrez:
9
8
2021
Statut:
epublish
Résumé
In 2005, Bangladesh, India and Nepal agreed to eliminate visceral leishmaniasis (VL) as a public health problem. The approach to this was through improved case detection and treatment, and controlling transmission by the sand fly vector Phlebotomus argentipes, with indoor residual spraying (IRS) of insecticide. Initially, India applied DDT with stirrup pumps for IRS, however, this did not reduce transmission. After 2015 onwards, the pyrethroid alpha-cypermethrin was applied with compression pumps, and entomological surveillance was initiated in 2016. Eight sentinel sites were established in the Indian states of Bihar, Jharkhand and West Bengal. IRS coverage was monitored by household survey, quality of insecticide application was measured by HPLC, presence and abundance of the VL vector was monitored by CDC light traps, insecticide resistance was measured with WHO diagnostic assays and case incidence was determined from the VL case register KAMIS. Complete treatment of houses with IRS increased across all sites from 57% in 2016 to 70% of houses in 2019, rising to >80% if partial house IRS coverage is included (except West Bengal). The quality of insecticide application has improved compared to previous studies, average doses of insecticide on filters papers ranged from 1.52 times the target dose of 25mg/m2 alpha-cypermethrin in 2019 to 1.67 times in 2018. Resistance to DDT has continued to increase, but the vector was not resistant to carbamates, organophosphates or pyrethroids. The annual and seasonal abundance of P. argentipes declined between 2016 to 2019 with an overall infection rate of 0.03%. This was associated with a decline in VL incidence for the blocks represented by the sentinel sites from 1.16 per 10,000 population in 2016 to 0.51 per 10,000 in 2019. Through effective case detection and management reducing the infection reservoirs for P. argentipes in the human population combined with IRS keeping P. argentipes abundance and infectivity low has reduced VL transmission. This combination of effective case management and vector control has now brought India within reach of the VL elimination targets.
Sections du résumé
BACKGROUND
In 2005, Bangladesh, India and Nepal agreed to eliminate visceral leishmaniasis (VL) as a public health problem. The approach to this was through improved case detection and treatment, and controlling transmission by the sand fly vector Phlebotomus argentipes, with indoor residual spraying (IRS) of insecticide. Initially, India applied DDT with stirrup pumps for IRS, however, this did not reduce transmission. After 2015 onwards, the pyrethroid alpha-cypermethrin was applied with compression pumps, and entomological surveillance was initiated in 2016.
METHODS
Eight sentinel sites were established in the Indian states of Bihar, Jharkhand and West Bengal. IRS coverage was monitored by household survey, quality of insecticide application was measured by HPLC, presence and abundance of the VL vector was monitored by CDC light traps, insecticide resistance was measured with WHO diagnostic assays and case incidence was determined from the VL case register KAMIS.
RESULTS
Complete treatment of houses with IRS increased across all sites from 57% in 2016 to 70% of houses in 2019, rising to >80% if partial house IRS coverage is included (except West Bengal). The quality of insecticide application has improved compared to previous studies, average doses of insecticide on filters papers ranged from 1.52 times the target dose of 25mg/m2 alpha-cypermethrin in 2019 to 1.67 times in 2018. Resistance to DDT has continued to increase, but the vector was not resistant to carbamates, organophosphates or pyrethroids. The annual and seasonal abundance of P. argentipes declined between 2016 to 2019 with an overall infection rate of 0.03%. This was associated with a decline in VL incidence for the blocks represented by the sentinel sites from 1.16 per 10,000 population in 2016 to 0.51 per 10,000 in 2019.
CONCLUSION
Through effective case detection and management reducing the infection reservoirs for P. argentipes in the human population combined with IRS keeping P. argentipes abundance and infectivity low has reduced VL transmission. This combination of effective case management and vector control has now brought India within reach of the VL elimination targets.
Identifiants
pubmed: 34370731
doi: 10.1371/journal.pntd.0009101
pii: PNTD-D-21-00042
pmc: PMC8376195
doi:
Substances chimiques
Insecticides
0
Pyrethrins
0
cypermethrin
1TR49121NP
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
e0009101Déclaration de conflit d'intérêts
The authors have declared that no competing interests exist.
Références
Trop Parasitol. 2014 Jan;4(1):10-9
pubmed: 24754021
Cien Saude Colet. 2011 Feb;16(2):575-90
pubmed: 21340333
PLoS Negl Trop Dis. 2017 Sep 5;11(9):e0005890
pubmed: 28873425
Proc Natl Acad Sci U S A. 2015 Jul 14;112(28):8573-8
pubmed: 26124110
J Trop Med. 2011;2011:876742
pubmed: 21811510
J Vector Borne Dis. 2008 Jun;45(2):105-11
pubmed: 18592839
PLoS Negl Trop Dis. 2011 Feb 08;5(2):e960
pubmed: 21347452
Trop Med Int Health. 2004 Aug;9(8):846-56
pubmed: 15303988
PLoS Negl Trop Dis. 2017 Apr 17;11(4):e0005504
pubmed: 28414744
PLoS Negl Trop Dis. 2019 Sep 16;13(9):e0007724
pubmed: 31525195
BMC Med. 2009 Oct 05;7:54
pubmed: 19804620
PLoS One. 2013 Apr 09;8(4):e61370
pubmed: 23585896
Gates Open Res. 2018 Feb 21;2:10
pubmed: 30234191
Lancet Microbe. 2021 Jan;2(1):e23-e31
pubmed: 33615281
PLoS Negl Trop Dis. 2014 Apr 24;8(4):e2810
pubmed: 24762676
Ann Trop Med Parasitol. 2001 Mar;95(2):197-202
pubmed: 11299126
Indian J Med Res. 2007 Nov;126(5):447-51
pubmed: 18160749
J Am Mosq Control Assoc. 1987 Jun;3(2):302-3
pubmed: 3333059
PLoS Negl Trop Dis. 2014 Aug 21;8(8):e3020
pubmed: 25144317
Indian J Med Res. 2006 Mar;123(3):331-44
pubmed: 16778314
J Commun Dis. 2001 Jun;33(2):102-9
pubmed: 12170928
Vector Borne Zoonotic Dis. 2012 Jun;12(6):467-72
pubmed: 22217179
BMC Infect Dis. 2013 Jan 18;13:21
pubmed: 23327548
Pestic Biochem Physiol. 2013 Jul 1;106(3):93-100
pubmed: 24019556
PLoS One. 2012;7(5):e35671
pubmed: 22693548
J Vector Ecol. 2011 Mar;36 Suppl 1:S106-17
pubmed: 21366762
Am J Trop Med Hyg. 2016 Mar;94(3):679-685
pubmed: 26811431
Parasit Vectors. 2013 Oct 18;6(1):302
pubmed: 24499561
Trop Med Int Health. 2008 Aug;13(8):1073-85
pubmed: 18564350
Parasit Vectors. 2013 Dec 13;6:354
pubmed: 24330760
PLoS Med. 2011 Jan 25;8(1):e1000412
pubmed: 21311585
Ann Trop Med Parasitol. 2011 Jan;105(1):31-5
pubmed: 21294947
J Vector Ecol. 2012 Jun;37(1):148-53
pubmed: 22548548
J Clin Microbiol. 2018 Jun 25;56(7):
pubmed: 29695527