Point of Care Significance 6/10

Discarded Malaria Rapid Tests Repurposed for Arbovirus Surveillance in Haiti

Researchers extracted nucleic acids from discarded malaria rapid diagnostic test cassettes collected from febrile patients in Haiti (2021-2023) and detected DENV-3 in 68 samples from 2023, confirmed by NGS sequencing with high similarity to Caribbean strains. No alphavirus or Oropouche virus was detected. The approach demonstrates that discarded RDTs can serve as a practical surveillance tool for arbovirus detection in settings where conventional surveillance is disrupted.

The original study

Characterization of arbovirus infections in patients within Haiti by screening discarded malaria rapid diagnostic test cassettes.

Authors
Matulis GA, Smith HP, Hall G, Katich RS, Delp KL, Douglas CE, et al.
Journal
PLoS neglected tropical diseases
PMID
41860982
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Original abstract

BACKGROUND: Arboviruses represent a diverse group of pathogens transmitted by arthropod vectors. Within Haiti, arboviruses responsible for previous outbreaks include dengue virus, Zika virus, and chikungunya virus. Recent security concerns within Haiti have interrupted broader surveillance efforts, creating challenges for public health agencies tasked with monitoring for vector-borne diseases. In this study, we aimed to better understand circulating arboviruses within Haiti using nucleic acids stored in discarded malaria rapid diagnostic tests (RDTs). METHODOLOGY/PRINCIPAL FINDINGS: RDTs were collected between 2021-2023 from febrile patients presenting to health care centers throughout the Sud and Ouest Departments of Haiti. Test strips were removed from the RDT cassettes, and total nucleic acid was extracted. Samples were initially tested for sample integrity using a human RNase P real-time PCR assay, followed by a flavivirus spp. real-time PCR assay. A total of 52 RDTs tested positive by the flavivirus spp. assay, and an additional 21 were indeterminant. Testing all flavivirus spp. positive and indeterminant samples with a DENV quadraplex assay resulted in 68 samples testing positive for DENV-3. All samples testing positive for DENV-3 were collected in 2023. NGS sequencing and subsequent phylogenetic analysis demonstrated high sequence similarity to sequences published from the Caribbean region between 2022-2023. A subset of the flavivirus negative RDTs were tested using alphavirus spp. (n = 517) and Oropouche virus (n = 293) real-time RT-PCR assays. No samples tested positive using either the alphavirus spp. (0/517) or Oropouche virus (0/293) assays. CONCLUSIONS/SIGNIFICANCE: These results demonstrate the context-specific utility of discarded malaria RDTs for remote arbovirus surveillance among febrile patients, with potential for viral characterization. The exclusive finding of DENV-3 within these samples is concordant with the DENV-3 outbreak that was observed throughout the Americas in 2023. As political insecurity continues within Haiti, malarial RDTs represent an important tool for high level surveillance of novel public health threats.