Epidemiological exploration of fleas and molecular identification of flea-borne viruses in Egyptian small ruminants

Abstract

The study aimed to investigate molecularly the presence of flea-borne viruses in infested small ruminants with fleas. It was carried out in Egypt's Northern West Coast (NWC) and South Sinai Governorate (SSG). Three specific primers were used targeting genes, ORF103 (for Capripoxvirus and Lumpy skin disease virus), NS3 (for Bluetongue virus), and Rdrp (for Coronavirus), followed by gene sequencing and phylogenetic analyses. The results revealed that 78.94% of sheep and 65.63% of goats were infested in the NWC area, whereas 49.76% of sheep and 77.8% of goats were infested in the SSG region. Sheep were preferable hosts for flea infestations (58.9%) to goats (41.1%) in the two studied areas. Sex and age of the animals had no effects on the infestation rate (p > 0.05). The season and site of infestation on animals were significantly different between the two areas (p < 0.05). Ctenocephalides felis predominated in NWC and Ctenocephalides canis in SSG, and males of both flea species were more prevalent than females. Molecular analysis of flea DNA revealed the presence of Capripoxvirus in all tested samples, while other viral infections were absent. Gene sequencing identified three isolates as sheeppox viruses, and one as goatpox virus. The findings suggest that Capripoxvirus is adapted to fleas and may be transmitted to animals through infestation. This underscores the need for ongoing surveillance of other pathogens in different regions of Egypt.

Keywords: Capripoxvirus; Coronavirus; Egypt; Fleas; Genotyping; Lumpy skin disease.

Figure 1

Google Map of Egypt shows the surveyed areas where samples were collected.

Figure 2

A descriptive comparison chart, created using the multi-layer column chart feature in the KUTOOLS program for Excel, illustrates the rate of flea infestation (%) among animals in two investigated sites: the Northern West Coast (NWC) and the South Sinai Governorate (SSG).

Figure 3

A descriptive comparison chart, created using the multi-layer column chart feature in the KUTOOLS program for Excel, illustrates the rate of flea infestation (%) among animals according to age and sex in two investigated sites: the Northern West Coast (NWC) and the South Sinai Governorate (SSG).

Figure 4

Shows the microscopical identification of fleas sp. during the study.

Figure 5

A descriptive comparison chart, created using the multi-layer column chart feature in the KUTOOLS program for Excel, illustrates the frequency rate of the fleas (%) collected during the study according to the species of fleas, site of infection (S&H Sexual organs and Head, N&V Neck and Ventral, L&T Legs and Tail), sex of the fleas and the season of collection in two investigated sites: the Northern West Coast (NWC) and the South Sinai Governorate (SSG).

Figure 6

PCR-based assays targeting the ORF103, NS3, and Rdrp genes for detecting Capripox, Bluetongue, and Coronaviruses, respectively. L: 100-bp DNA ladder; lanes 1, 2, 3, and 4 correspond to the examined flea-DNA samples. Lanes P and N represent positive and negative controls, respectively.

Figure 7

A phylogenetic tree was constructed in MEGA 6.0 using the neighbor-joining method for the analysis of the ORF103 gene for sheep and goat Capripox viruses. The accession numbers obtained in this study are colored.