International Journal of Environmental and Biological Sciences Articles Publishing terms and rules Vol. 1 No. 3 (2026): Third Issue - July 2026 2026-07-31

Experimental Evaluation of the Mechanical Transfer of Rotavirus A RNA by Female Culex molestus Mosquitoes Rotavirus A RNA and Female Culex molestus Mosquitoes

  • Rusul Abdulnabi Wali
  • Rafid Abbas Ali
  • Saif Jabbar Yasir

01Abstract

Background: Rotavirus A is a major cause of acute gastroenteritis, particularly in children and primarily transmitted via the fecal-oral route, but it can also survive and spread indirectly through contaminated surfaces, materials, and water. Despite widespread interest in the role of insects in the mechanical transmission of enteric infectious agents, regarding the potential contribution of mosquitoes, the information on rotavirus A RNA mechanical transfer remains limited successful detection, and studies on this topic are scarce. Aim: This study aimed to evaluated the mechanical transfer of rotavirus RNA by Culex molestus mosquito’s female and the effect of exposure duration on transfer under controlled laboratory conditions. Materials and Methods: The study included 75 fecal samples that underwent initial screening for rotavirus antigen using a rapid immunoassay. Molecular detection of viral RNA was then performed using RT-qPCR targeting NSP3 gene. Mosquitoes Female were divided into independent experimental groups and exposed to positive fecal sources for 1, 4, and 24 hours. mosquitoes were transferred to molecularly negative fecal medium., and the mosquitoes were allowed contact with the medium for 8 hours. Ct values, viral loads, and recovery rates were compared among exposure groups. Results: Rapid testing showed positive results in 75 samples, while RT- qPCR confirmed the presence of rotavirus RNA in 41 samples, with a molecular positivity r ate of 54.7%.


Mechanical transfer testing revealed the successful detection of rotavirus RNA in the receiving media after all exposure durations, while all negative controls remained RT-qPCR negative. The mean Ct gradually decreased from 0.41 ± 35.84 after 1 hour to 0.36 ± 31.72 after 4 hours, and then to 0.28 ± 27.48 after 24 hours. Concurrently, the estimated viral load increased from 10¹×1.1 to 10²×1.7 and then to 10³×3.3 copies/µL, respectively. The percentage of molecular recovery also increased from 0.11% after 1 hour to 1.7% after 4 hours, and then to 33.0% after 24 hours. Analysis of variance showed a highly significant effect of exposure duration on Ct values ​​(P < 0.001). Correlation analysis showed a strong inverse relationship between exposure duration and Ct values ​​(r = −0.923, P < 0.001). Similarly, the relationship between baseline and post-transfer Ct values ​​showed a strong positive correlation (r = 0.94, P < 0.001). Conclusion: The current study provides experimental evidence for the ability of female Culex molestus mosquitoes. The results also showed that the amount of viral genetic material transferred was related to the duration of mosquito exposure to the contaminated source, with longer exposure resulting in lower Ct values ​​and higher estimated viral load and molecular recovery rates. The findings suggest that the viral load in the original source may be an additional factor influencing recovery efficiency after transfer. However, the results demonstrate the transfer of viral RNA but not the transfer of live, infectious viral particles. These findings should be interpreted as evidence of mechanical transfer of viral RNA rather than evidence of vector competence or biological transmission. This was among the first controlled experimental studies investigating the mechanical transfer of rotavirus A RNA by Culex molestus mosquitoes.

Keywords Rotavirus A Mechanical transmission Culex molestus Mosquitoes RT-qPCR Viral RNA Ct value Duration of exposure Molecular recovery

02Authors

Rusul Abdulnabi Wali
Department of Biology, College of Education for Pure Sciences, University of Karbala, Karbala, Iraq
Rafid Abbas Ali
Department of Biology, College of Education for Pure Sciences, University of Karbala, Karbala, Iraq
Saif Jabbar Yasir
Department of Medical Microbiology, College of Medicine, University of Kufa, Najaf, Iraq.

03Article Details

Section
Articles Publishing terms and rules
Pages
221-250
Published
2026-07-31

How to Cite

Experimental Evaluation of the Mechanical Transfer of Rotavirus A RNA by Female Culex molestus Mosquitoes: Rotavirus A RNA and Female Culex molestus Mosquitoes. (2026). International Journal of Environmental and Biological Sciences, 1(3), 221-250. https://doi.org/10.63939/mabp5w93

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