Neutralizing based seroprevalence study of Toscana virus in livestock from Algeria.

Overview

• This study investigated the presence of Toscana virus (TOSV) neutralizing antibodies in various livestock species in Algeria to better understand the virus’s circulation and potential animal reservoirs in the region.

Introduction to Toscana Virus

• Toscana virus (TOSV) is a pathogen transmitted by sandflies and belongs to the Phlebovirus genus within the Phenuiviridae family.
• It is an emerging health threat in North Africa, especially in northern Algeria, where people exposed to sandflies have shown infections.
• Previous studies identified TOSV exposure mainly in dogs, with around 4.56% of tested dogs having neutralizing antibodies against TOSV.
• However, data on TOSV in other domestic animals was lacking, motivating this study to assess livestock exposure.

Study Objectives

• To evaluate the seroprevalence of TOSV neutralizing antibodies in multiple species of livestock: cattle, sheep, goats, rabbits, and horses.
• To identify geographic distribution and risk factors associated with TOSV exposure in these animals across various regions in Algeria.
• To assess the possible role of livestock in the natural transmission cycle of TOSV.

Methodology

• A total of 221 serum samples were collected from livestock during 2017.
• The samples came from 11 different governorates across northern and northeastern Algeria, including Blida, Medea, Algiers, Tipaza, Ain Defla, Tissemsilt, Setif, Mila, Tizi Ouzou, and Jijel.
• The species tested included:
  • Cattle (82 samples)
  • Sheep (64 samples)
  • Horses (20 samples)
  • Goats (30 samples)
  • Rabbits (number not specified)
• Neutralizing antibody testing was performed to detect prior exposure to TOSV.

Key Findings

• Seroprevalence rates of TOSV antibodies were:
  • 14.6% in cattle
  • 17.18% in sheep
  • 15% in horses
  • 3.33% in goats
  • No positive cases in rabbits
• Positive samples were predominantly from northern-central Algeria, including regions where TOSV presence was previously undocumented.
• The origin of samples had a statistically significant relationship with seroprevalence (p < 0.01), indicating certain areas had higher exposure risks.
• Females were more likely to be seropositive, with an odds ratio (OR) of 4.09, suggesting gender-related differences in exposure or susceptibility.
• The potential involvement of livestock in the TOSV transmission cycle was supported by statistical significance (p = 0.00731).

Implications and Conclusions

• This study provides further evidence that TOSV circulates widely among livestock in Algeria, expanding knowledge beyond previous findings in dogs.
• Livestock species such as cattle, sheep, horses, and goats may play a role in maintaining or amplifying the virus in nature.
• Understanding the role of livestock could help clarify how sandfly-borne phleboviruses persist in the environment and impact human health.
• These findings highlight the importance of including multiple animal species when studying arbovirus ecology and epidemiology.
• Further research is recommended to elucidate the precise mechanisms of livestock involvement in TOSV transmission and to assess the public health risks.