The First Investigation of Tick Vectors and Tick-Borne Diseases in Extensively Managed Cattle in Alle District, Southwestern Ethiopia

A systematic review of ticks and tick-borne pathogens of cattle reared by smallholder farmers in South Africa

Ticks are important ectoparasites of domestic animals, wild animals and humans. They spread a variety of infective agents such as protozoans, viruses, and bacteria. Cattle reared by smallholder farmers are susceptible to ticks and tick-borne pathogens due to the type of production system practiced by the farmers. Hence, this review was focused on the occurrence of ticks and tick-borne pathogens in cattle reared by smallholder farmers in South Africa. The systematic search produced a total of 13,408 articles from four databases, and after screening processes, the review utilized 23 articles published between 1983 and 2023. A total of 26 tick species belonging to seven genera were identified in the reviewed articles, with Rhipicephalus (Boophilus) decoloratus and Rhipicephalus evertsi evertsi being the most frequently reported tick species in South Africa followed by Amblyomma hebreum, Rhipicephalus appendiculatus, Hyalomma marginatum rufipes, Rhipicephalus microplus, Rhipicephalus follis, Rhipicephalus gertrudae and Hyalomma truncatum. The most frequently reported tick-borne pathogens across the provinces included Babesia bigemina, Babesia bovis, and Anaplasma marginale, with Eastern Cape Province accounting for most of the records followed by KwaZulu-Natal and Mpumalanga Provinces. The findings of this review confirm that cattle reared by smallholder farmers harbour various ticks and tick-borne pathogens of veterinary, public health and economic importance, and regular monitoring of tick infestations in South Africa is recommended to avoid disease outbreaks.

Prevalence and tick loads in Nguni cattle reared in different environmental conditions across four provinces of South Africa

Background and Aim:

In tropical and subtropical countries, ixodid ticks are among livestock’s most economically important ectoparasites. Although Nguni cattle from South Africa have adapted to harsh environments, it is unknown whether they will be resistant to ticks, and the diseases carried by ticks under various climatic conditions. Therefore, this study aimed to compare tick load and estimate the prevalence of different tick species among Nguni cattle under different environmental conditions.

Materials and Methods:

Tick counts were conducted monthly under natural challenges over 2 years on 586 Nguni cattle located at ARC-Roodeplaat and Loskop farms (warmer climate), Mukhuthali Nguni Community and the University of Fort Hare farms (cooler climate). The generalized linear model procedure of the Statistical Analysis System was used to analyze the data. It fitted the location (farm), sex, year, month or season, and animal age as covariates.

Results:

The tick species (relative prevalence) observed were as follows: Amblyomma hebraeum (42%), Rhipicephalus evertsi (22%), Rhipicephalus (Boophilus) spp. (16%), Rhipicephalus appendiculatus (11%), Hyalomma marginatum (5%), and Rhipicephalus simus (4%). Tick infestation was significantly affected by location, season, year, month of the tick counting and age of the animal. Loskop farm had the highest tick count (m = 30.69) and showed the largest variation in tick count. Compared to the other seasons, higher tick counts were seen during the hot-dry (September–November) and hot-wet (December–February) seasons. A. hebraeum was the dominant tick species across all four farms, followed by R. evertsi. The perianal region (under the tail head), the perineum and the belly body locations were the most preferred tick attachment sites.

Conclusion:

These results provide useful information for developing appropriate control strategies for ticks and tick-borne diseases in these provinces of South Africa. Further work must investigate the feasibility of genetic improvement for tick resistance.

Babesiosis in cattle and ixodid tick distribution in Dasenech and Salamago Districts, southern Ethiopia

Babesiosis, caused by protozoan parasites of the genus Babesia, and ixodid ticks are considered to be one of the most important causes that result in significant economic losses in cattle production worldwide, including in Ethiopia. A cross-sectional study was undertaken in the Dasenech and Salamago Districts of South Omo zone Ethiopia to determine the prevalence and associated risk factors of babesia infection and ixodid ticks of cattle using Giemsa-stained thin and thick film techniques and morphological identification keys for babesia species and tick identification, respectively. Out of 470 examined cattle, 102 (21.7%) were infected by Babesiosis (15.53% Babesia bigemina and 6.17% Babesia bovis). A statistically significant association (p < 0.05) was observed between babesia infection and season and tick infestation. However, cattle that were infected with the Babesia parasite revealed a lower mean PCV value (21.49%) than noninfected cattle (28.29%) and showed a statistically significant (p < 0.05) difference with the occurrence of Babesia infection. The overall prevalence of ixodid ticks was 53.8% (253/470) and revealed a statistically significant association (p < 0.05) between the season and origin of the animal. However, no statistically significant association (p > 0.05) was observed between sex, age, and body condition score of the animal with the occurrence of ixodid tick. A total of 8040 adult ticks belonging to four tick genera, Amblyomma, Rhipicephalus (Boophilus), Hyalomma, and Rhipicephalus, were collected from various body parts and identified. The high prevalence of Babesia infection and ixodid ticks in cattle at the study sites requires seroprevalence and molecular studies to identify the predominant Babesia species and to detect Babesia in tick hemolymph for the identification of tick genera responsible for the occurrence of Babesia infection. Additionally, tailoring suitable and coordinated tick management methods using chemotherapy as well as strategic treatment to overt clinical cases of bovine babesiosis is critical.