Integrated serological surveillance of acute febrile illness in the context of a lymphatic filariasis survey in Timor-Leste: a pilot study using dried blood spots.
Timor-Leste
dengue
dried blood spot
leptospirosis
scrub typhus
serological surveillance
Journal
Transactions of the Royal Society of Tropical Medicine and Hygiene
ISSN: 1878-3503
Titre abrégé: Trans R Soc Trop Med Hyg
Pays: England
ID NLM: 7506129
Informations de publication
Date de publication:
01 06 2022
01 06 2022
Historique:
received:
03
09
2021
revised:
04
10
2021
accepted:
13
10
2021
pubmed:
2
12
2021
medline:
3
6
2022
entrez:
1
12
2021
Statut:
ppublish
Résumé
Acute febrile illnesses (AFIs), including dengue, scrub typhus and leptospirosis, cause significant morbidity and mortality in Southeast Asia. Serological surveillance can be used to investigate the force and distribution of infections. Dried blood spot (DBS) samples are an attractive alternative to serum because they are easier to collect and transport and require less cold storage. We conducted a pilot study to determine the feasibility of integrating serological surveillance for dengue, scrub typhus and leptospirosis into a population-representative lymphatic filariasis seroprevalence survey in Timor-Leste using DBSs. A total of 272 DBSs were collected from healthy community participants. DBSs were analysed at the National Health Laboratory using commercially available enzyme-linked immunosorbent assays. To validate assays for DBSs, 20 anonymised serum samples of unknown serostatus were used to create dried serum spots (DSSs). These were analysed with optical densities compared with those of serum. Where low variance was observed (dengue assay) the published kit cut-offs for serum were applied to the analysis of DBSs. For the other assays (scrub typhus and leptospirosis), index values (IVs) were calculated and cut-offs were determined to be at 2 standard deviations (SDs) above the mean. Of the 272 samples analysed, 19 (7.0% [95% confidence interval {CI} 4.3 to 10.7]) were positive for dengue immunoglobulin G (IgG), 11 (4.0% [95% CI 2.1 to 7.1]) were positive for scrub typhus IgG and 16 (5.9% [95% CI 3.4 to 9.4%]) were positive for leptospira IgG. While dengue seroprevalence was lower than in nearby countries, results represent the first evidence of scrub typhus and leptospirosis transmission in Timor-Leste. Integrated programmes of serological surveillance could greatly improve our understanding of infectious disease epidemiology in remote areas and would incur minimal additional fieldwork costs. However, when planning such studies, the choice of assays, their validation for DBSs and the laboratory infrastructure and technical expertise at the proposed location of analysis must be considered.
Sections du résumé
BACKGROUND
Acute febrile illnesses (AFIs), including dengue, scrub typhus and leptospirosis, cause significant morbidity and mortality in Southeast Asia. Serological surveillance can be used to investigate the force and distribution of infections. Dried blood spot (DBS) samples are an attractive alternative to serum because they are easier to collect and transport and require less cold storage. We conducted a pilot study to determine the feasibility of integrating serological surveillance for dengue, scrub typhus and leptospirosis into a population-representative lymphatic filariasis seroprevalence survey in Timor-Leste using DBSs.
METHODS
A total of 272 DBSs were collected from healthy community participants. DBSs were analysed at the National Health Laboratory using commercially available enzyme-linked immunosorbent assays. To validate assays for DBSs, 20 anonymised serum samples of unknown serostatus were used to create dried serum spots (DSSs). These were analysed with optical densities compared with those of serum. Where low variance was observed (dengue assay) the published kit cut-offs for serum were applied to the analysis of DBSs. For the other assays (scrub typhus and leptospirosis), index values (IVs) were calculated and cut-offs were determined to be at 2 standard deviations (SDs) above the mean.
RESULTS
Of the 272 samples analysed, 19 (7.0% [95% confidence interval {CI} 4.3 to 10.7]) were positive for dengue immunoglobulin G (IgG), 11 (4.0% [95% CI 2.1 to 7.1]) were positive for scrub typhus IgG and 16 (5.9% [95% CI 3.4 to 9.4%]) were positive for leptospira IgG.
CONCLUSIONS
While dengue seroprevalence was lower than in nearby countries, results represent the first evidence of scrub typhus and leptospirosis transmission in Timor-Leste. Integrated programmes of serological surveillance could greatly improve our understanding of infectious disease epidemiology in remote areas and would incur minimal additional fieldwork costs. However, when planning such studies, the choice of assays, their validation for DBSs and the laboratory infrastructure and technical expertise at the proposed location of analysis must be considered.
Identifiants
pubmed: 34850241
pii: 6444888
doi: 10.1093/trstmh/trab164
pmc: PMC9157677
doi:
Substances chimiques
Immunoglobulin G
0
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
531-537Subventions
Organisme : World Health Organization
ID : 001
Pays : International
Informations de copyright
© The Author(s) 2021. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.
Références
Am J Trop Med Hyg. 2012 Jul;87(1):165-170
pubmed: 22764309
J Clin Microbiol. 2007 Mar;45(3):887-90
pubmed: 17229857
Am J Trop Med Hyg. 2019 Dec;101(6):1265-1271
pubmed: 31628737
Am J Trop Med Hyg. 2017 Dec;97(6):1682-1685
pubmed: 29016321
Lancet Glob Health. 2013 Jul;1(1):e46-54
pubmed: 24748368
Int J Environ Res Public Health. 2020 Sep 09;17(18):
pubmed: 32917033
BMC Med. 2020 Sep 21;18(1):299
pubmed: 32951591
Bull World Health Organ. 2016 Nov 01;94(11):817-825A
pubmed: 27821884
Am J Trop Med Hyg. 2014 Feb;90(2):195-210
pubmed: 24366501
Clin Diagn Lab Immunol. 2002 Nov;9(6):1235-9
pubmed: 12414755
PLoS One. 2020 Nov 30;15(11):e0242889
pubmed: 33253280
BMC Infect Dis. 2019 Jul 4;19(1):577
pubmed: 31272417
PLoS Negl Trop Dis. 2010 Dec 07;4(12):e909
pubmed: 21151880
PLoS One. 2017 Jun 29;12(6):e0180560
pubmed: 28662144
Mem Inst Oswaldo Cruz. 2016 Jul 4;111(8):501-4
pubmed: 27384081
BMC Public Health. 2016 Aug 18;16(1):824
pubmed: 27538986
Eur J Epidemiol. 2001;17(7):601-8
pubmed: 12086073
BMC Res Notes. 2011 Jun 29;4:216
pubmed: 21714858
Int J Environ Res Public Health. 2020 Dec 07;17(23):
pubmed: 33297445
J Travel Med. 2019 Dec 23;26(8):
pubmed: 31616949
Am J Trop Med Hyg. 2014 May;90(5):892-896
pubmed: 24615123
BMC Infect Dis. 2006 Jan 25;6:13
pubmed: 16436203
Clin Microbiol Infect. 2010 May;16(5):447-51
pubmed: 19778303
Lancet. 2018 May 12;391(10133):1927-1938
pubmed: 29550029
PLoS Negl Trop Dis. 2018 Jul 16;12(7):e0006533
pubmed: 30011271
PLoS Negl Trop Dis. 2021 Jun 28;15(6):e0009457
pubmed: 34181665
Lancet Infect Dis. 2021 Apr;21(4):529-536
pubmed: 33212068
J Clin Pathol. 1999 Sep;52(9):633-9
pubmed: 10655983
Transfus Med Rev. 2019 Jan;33(1):35-42
pubmed: 30471867
Clin Microbiol Infect. 2021 Jun;27(6):904-908
pubmed: 32866651
J Infect Dis. 2015 Feb 15;211(4):590-9
pubmed: 25336728
Parasit Vectors. 2018 Jan 4;11(1):9
pubmed: 29301546
PLoS Negl Trop Dis. 2020 May 12;14(5):e0008289
pubmed: 32396575
Elife. 2018 Aug 14;7:
pubmed: 30103854
J Trop Med. 2020 May 25;2020:1019238
pubmed: 32536945
Am J Trop Med Hyg. 2021 Jan;104(1):130-135
pubmed: 33146119
Malar J. 2020 Mar 4;19(1):104
pubmed: 32127001
PLoS Negl Trop Dis. 2017 Sep 25;11(9):e0005838
pubmed: 28945755