Scholarlink

Background <p>Phlebotomine sand flies transmit a wide range of human and veterinary pathogens, including <i>Leishmania</i> spp. and Toscana virus (TOSV). Both pathogens co-circulate extensively in the Mediterranean basin and may share hosts and vectors, raising the possibility of mixed infections with epidemiological relevance. While previous studies have suggested interactions between TOSV and <i>Leishmania</i> in mammalian hosts and in vitro systems, evidence from natural vectors is still lacking. Understanding these interactions is essential for predicting transmission outcomes in areas of pathogen overlap.</p> Methods <p>We investigated coinfection dynamics of TOSV and <i>Leishmania infantum</i> in their natural vector, <i>Phlebotomus tobbi</i>. Female sand flies were experimentally challenged with both pathogens through blood feeding. We measured infection rates, dissemination rates, and infection intensity levels at days 4 and 8 postinfection (p.i.) and compared the coinfected groups with the control harboring a single infection.</p> Results <p>At day 4 (D4) p.i., the coinfection resulted in significant suppression of both pathogens: TOSV infection rates decreased, as did <i>L. infantum</i> infection rates. However, neither infection intensity nor viral dissemination showed significant differences between groups. By day 8 (D8) p.i., <i>L. infantum</i> maintained a negative effect on TOSV infection, while TOSV did not alter <i>L. infantum</i> development. Dissemination and parasite load remained unaffected.</p> Conclusions <p>Our findings suggest competitive interactions between TOSV and <i>L. infantum</i> in sand flies, providing the first experimental indication of pathogen–pathogen interference within a natural vector. Such competition likely contributes to the rarity of coinfected sand flies in field surveys and highlights the importance of considering vector-level interactions when assessing transmission risks in endemic regions.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Negative interactions between Toscana virus and Leishmania infantum limit coinfection in sand flies

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年2月12日

查看全文
  • Marketa Stejskalova,
  • Nikola Polanska,
  • Sophie Desloire,
  • Maxime Ratinier,
  • Petr Volf,
  • Magdalena Jancarova

摘要

Background

Phlebotomine sand flies transmit a wide range of human and veterinary pathogens, including Leishmania spp. and Toscana virus (TOSV). Both pathogens co-circulate extensively in the Mediterranean basin and may share hosts and vectors, raising the possibility of mixed infections with epidemiological relevance. While previous studies have suggested interactions between TOSV and Leishmania in mammalian hosts and in vitro systems, evidence from natural vectors is still lacking. Understanding these interactions is essential for predicting transmission outcomes in areas of pathogen overlap.

Methods

We investigated coinfection dynamics of TOSV and Leishmania infantum in their natural vector, Phlebotomus tobbi. Female sand flies were experimentally challenged with both pathogens through blood feeding. We measured infection rates, dissemination rates, and infection intensity levels at days 4 and 8 postinfection (p.i.) and compared the coinfected groups with the control harboring a single infection.

Results

At day 4 (D4) p.i., the coinfection resulted in significant suppression of both pathogens: TOSV infection rates decreased, as did L. infantum infection rates. However, neither infection intensity nor viral dissemination showed significant differences between groups. By day 8 (D8) p.i., L. infantum maintained a negative effect on TOSV infection, while TOSV did not alter L. infantum development. Dissemination and parasite load remained unaffected.

Conclusions

Our findings suggest competitive interactions between TOSV and L. infantum in sand flies, providing the first experimental indication of pathogen–pathogen interference within a natural vector. Such competition likely contributes to the rarity of coinfected sand flies in field surveys and highlights the importance of considering vector-level interactions when assessing transmission risks in endemic regions.

Graphical Abstract