Pooled versus individual sand fly PCR: insights into vector-related seasonal and reproductive drivers of Leishmania infection
Acta Tropica, vol.280, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 280
- Publication Date: 2026
- Doi Number: 10.1016/j.actatropica.2026.108165
- Journal Name: Acta Tropica
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, EMBASE, Geobase, MEDLINE, Zoological Record, Academic Search Ultimate (EBSCO)
- Keywords: Gravid, Leishmania, Phlebotomus, Pooled PCR, Seasonality, Surveillance
- Hacettepe University Affiliated: Yes
Abstract
Understanding temporal patterns of Leishmania infection in sand fly populations is essential for assessing transmission risk and improving surveillance and control in endemic regions. This study investigated infection dynamics in natural populations of Phlebotomus perniciosus and Phlebotomus ariasi, two established vectors of Leishmania infantum in the western Mediterranean and evaluated the utility of pooled sampling for vector surveillance. Sand flies were tested for Leishmania infection using a TaqMan real-time kinetoplast PCR either individually or in pools. Infection rates from pooled samples were estimated using maximum likelihood methods and analyzed alongside individual infection data using mixed-effects regression models to assess the influence of seasonality and female reproductive status on infection probability. Both individual and pooled analyses showed similar seasonal trends. Infection probability peaked in late summer, likely reflecting high parasite prevalence in reservoir hosts, and was highest in gravid females, suggesting cumulative parasite acquisition as sand flies age and complete successive gonotrophic cycles. Individual testing, although more resource-intensive, provided additional resolution by revealing species-specific patterns, with P. ariasi exhibiting higher infection rates than P. perniciosus, offering a deeper understanding of parasite circulation and species-specific infection patterns. We conclude that pooled sampling combined with appropriate statistical modelling can reliably capture seasonal infection patterns. Integrating reproductive status indicators with molecular surveillance represents a novel approach to refine transmission risk assessments and support more targeted and effective vector monitoring strategies in Leishmaniosis-endemic regions.