Infestation measured by Aedes aegypti larval surveys as an indication of future dengue epidemics: an evaluation for Brazil.
Aedes aegypti
dengue
house index
rapid larval survey
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 07 2020
01 07 2020
Historique:
received:
14
09
2019
revised:
08
03
2020
accepted:
13
03
2020
pubmed:
30
4
2020
medline:
25
6
2021
entrez:
30
4
2020
Statut:
ppublish
Résumé
Aedes aegypti rapid larval surveys are mandatory in Brazil. Here, we retrospectively examined whether the house index estimated by larval surveys served as a useful tool in anticipating epidemics within Brazilian municipalities from 2009-2015. We used correlation indices and classification analysis stratified by year, region, population size and time after the national larval survey. We found no association between the house index and the proportion of municipalities experiencing an epidemic. The sensitivity of a high score house index in predicting an epidemic was 7.20% (95% CI 6.22 to 8.33%) for all years combined. The positive predictive value of a high score house index to predict a 'true epidemic' was 38.96%, lower than the negative predictive values of a low score house index for predicting 'no epidemic' (56.96%). The highest overall sensitivity was observed in the North region (20.15%; 95% CI 17.14 to 23.53%). The sensitivity of a high score house index demonstrated a monotonic decrease with increasing time from larval collection. Larval surveys are surveillance tools with the potential to risk-stratify and guide dengue control programs towards judicious resource allocation. However, the national rapid larval survey performed in Brazil, in its present form, consistently underpredicts dengue epidemics.
Sections du résumé
BACKGROUND
Aedes aegypti rapid larval surveys are mandatory in Brazil. Here, we retrospectively examined whether the house index estimated by larval surveys served as a useful tool in anticipating epidemics within Brazilian municipalities from 2009-2015.
METHODS
We used correlation indices and classification analysis stratified by year, region, population size and time after the national larval survey.
RESULTS
We found no association between the house index and the proportion of municipalities experiencing an epidemic. The sensitivity of a high score house index in predicting an epidemic was 7.20% (95% CI 6.22 to 8.33%) for all years combined. The positive predictive value of a high score house index to predict a 'true epidemic' was 38.96%, lower than the negative predictive values of a low score house index for predicting 'no epidemic' (56.96%). The highest overall sensitivity was observed in the North region (20.15%; 95% CI 17.14 to 23.53%). The sensitivity of a high score house index demonstrated a monotonic decrease with increasing time from larval collection.
CONCLUSIONS
Larval surveys are surveillance tools with the potential to risk-stratify and guide dengue control programs towards judicious resource allocation. However, the national rapid larval survey performed in Brazil, in its present form, consistently underpredicts dengue epidemics.
Identifiants
pubmed: 32346740
pii: 5826585
doi: 10.1093/trstmh/traa021
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
506-512Informations de copyright
© The Author(s) 2020. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.