Tick burden and acquisition of immunity to Theileria parva by Tarime cattle in comparison to Sukuma cattle under different tick control regimes in the Lake Zone of Tanzania

Abstract

This study was conducted to determine tick burden and immunological parameters of resistance to East Coast fever (ECF) in Tarime and Sukuma cattle. Tick load, packed cell volume (PCV), Theileria parva (T. parva) specific antibody percent positivity (PP), and prevalence of T. parva parasites were studied in relation to dipping regime, strains, and season. A total of 50 experimental cattle were included in this study. Tick load was determined by whole body counts, antibody percent positivity was determined by the polymorphic immunodominant molecule (PIM)-based T. parva enzyme-linked immunosorbent assay (ELISA), and prevalence of T. parva parasites was detected by a nested polymerase chain reaction (PCR) based on the p104 gene. Dipping frequency on tick burden showed no statistically significant differences when cattle of either strain were dipped either once every 2 or 3 weeks in the dry and wet seasons. However, Tarime cattle had higher (p<0.05) tick count than Sukuma cattle and non dipped groups maintained high tick infestation throughout the experimental period. The PCV values were within the physiological range, although this parameter was lower in Tarime cattle (p<0.05). All cattle regardless of strain were seropositive, although Tarime cattle maintained higher PP compared to Sukuma by 15%. Conversely, the prevalence of T. parva parasites was lower in Tarime (38%) compared to Sukuma cattle (38.5%), but the difference was not significant (p>0.05). During the study period, 20% (5/25) of Sukuma cattle contracted ECF, but none of the Tarime cattle showed clinical signs for the disease. The differences between the two strains shown in terms of PP and T. parva parasite prevalence may indicate the ability of individual cattle to resist tick infestation and ECF infection under natural challenge. Higher antibody levels but lower parasite prevalence attained by Tarime cattle, suggests inherent ability of Tarime cattle to resist clinical development of ECF infection, but to remain as T. parva carriers.

The Bovine Major Histocompatibility Complex and Its Role in Tick and Tick-borne Disease Resistance and Immune Responsiveness in Bos Indicus and their Crosses with Bos Taurus in Sub-Saharan Africa: A Review

“…A cohort study done in Tanzania assessed natural tick infestation on Zebu cattle in Tanzania based on geographical locations, animals were dipped once every two to three weeks to control the tick challenge. Results revealed that more animals (P < 0.05) were infested with ticks in Tarime district (96.1 %) than in Serengeti (61.7 %) suggesting that Serengeti Zebu herds exhibited high resistance to ticks than Tarime Zebu herds (Laisser et al, 2016). The Nguni breed of South Africa is one of the most researched Sanga breeds.…”

“…The crosses between Horro (Zebu) and Jersey cattle in Ethiopia have also been reported to exhibit a high degree of tick resistance (Irvin et al, 1996). In another study, acquired immunity against Theileiria parva was demonstrated in two Tanzanian indigenous cattle breeds (Tarime and Sukuma cattle) in the Lake zone (Laisser et al, 2016). In Kenya, Zebu cattle from an East Coast Fever (ECF) endemic area were reported to have a better ability to control the course of the ECF disease and recover in a shorter period than Friesian (B. taurus) cattle (Ndungu et al, 2005).…”