# Systematic misclassification of sylvatic dengue virus 2 (DENV-2) infections as “undetermined serotype”: implications in routine RT-qPCR surveillance

## TL;DR

Some dengue virus tests incorrectly classify a specific strain as unknown, which could be fixed by updating the tests to include this strain.

## Contribution

The paper highlights the misclassification of sylvatic DENV-2 and proposes updated molecular tools for accurate surveillance.

## Key findings

- Commercial dengue molecular serotyping assays misclassify sylvatic DENV-2 as 'undetermined serotype'.
- Updating molecular tools to include sylvatic DENV-2 could improve surveillance accuracy.
- Multiplex assays covering urban and sylvatic strains may better monitor dengue virus prevalence.

## Abstract

Recent findings by Suppiah et al. revealed DENV-2 positive samples misclassified as “Undetermined Serotype” when using commercial dengue molecular serotyping assays. This highlights the noninclusion and resulting misclassification of this viral strain as a dengue virus serotype using available molecular tools. Drawing parallels from the notification of the same assay failure against sylvatic DENV-2 strains in Senegal, West Africa, this correspondence advocates for updating the existing tools to account for this viral variant. Development of multiplex assays including both urban and sylvatic strains may enhance dengue virus surveillance and provide real time monitoring of the prevalence of sylvatic viral lineages among recorded dengue infections in surveillance data.