Dynamics of natural infection by Babesia bovis and Babesia bigemina in dairy cattle from an enzootic instability area in Northeastern Brazil

Abstract

This study aimed to determine the dynamics of natural infection in the transmission of Babesia spp. to cattle in an enzootic instability area in Northeastern Brazil. Blood samples were collected from 30 calves located on two dairy farms to determine the packed cell volume (PCV) and the timing of the primo-infection using polymerase chain reaction (PCR) and their association with climatic factors and management practices. On Farm A, the determination of primo-infection was observed on average at 249.4 (±24.42) days of age for B. bigemina and at 252.6 (±17.07) days of age for B. bovis; there was no significant difference between the times of infection (P> 0.05). The infection coincided with a period of high rainfall in the region. On Farm B, primo-infection infection was not observed. There was no infection by Babesia spp. on Farm B due to the intensive use of acaricides that led to an absence of ticks. There was no significant difference between the average PCV of animals from Farms A and B (P> 0.05). The management practices on the properties, in addition to the weather conditions influenced the exposure of the animals to disease vectors and may have contributed to the maintenance of this enzootic area in Northeastern Brazil.

Epidemiological aspects of cattle tick fever in Brazil

“…These environmental conditions favor tick development; however, the incorrect use of acaricides causes variations in the seroprevalence between farms of this microregion. Enzootic instability for B. bovis and B. bigemina is observed in this region, with seroprevalences of 68.8% (139/202) and 52.5% (106/202), respectively; however, stability is observed for A. marginale with a seroprevalence of 89.1% (180/202) (Souza et al, 2013); in one of the herds used in this study, a tick fever outbreak occurred in 3-month-old calves at the beginning of the rainy season, with a morbidity of 13.3% (Souza et al, 2018). In the State of Piauí, in general, tick fever occurs because of high tick infestations at the end of the rainy season; both calves and adults can become sick, however, clinical signs are more intense in adults (Francisco Souza, Pernambuco Federal Rural University.…”

Chemoprophylaxis for babesiosis and anaplasmosis in cattle: case report

“…Existence of seasonal variations in cattle tick populations is an important factor that is associated with the occurrences of outbreaks. The largest part of Brazilian territory is considered of enzootic stability, without significant variations in tick populations throughout the year (Souza et al, 2018).…”

“…Cattle tick fever (CTF) is a complex of diseases affecting cattle worldwide (Gonçalves, 2000). CTF is cause by the Rickettsia Anaplasma marginale (bovine anaplasmosis) and the protozoa Babesia bovis and Babesia bigemina (bovine babesiosis) (Grau et al, 2013;Souza et al, 2018). The cattle tick Rhipicephalus microplus is the main vector involved with the transmission of CTF and is the only known vector for bovine babesiosis (Souza et al, 2018).…”

“…CTF is cause by the Rickettsia Anaplasma marginale (bovine anaplasmosis) and the protozoa Babesia bovis and Babesia bigemina (bovine babesiosis) (Grau et al, 2013;Souza et al, 2018). The cattle tick Rhipicephalus microplus is the main vector involved with the transmission of CTF and is the only known vector for bovine babesiosis (Souza et al, 2018). Bovine anaplasmosis can also be transmitted mechanically by hematophagous dipterans (Stomoxys calcitrans, tabanids and culicids), via iatrogenic and transplacental routes (Grau et al, 2013).…”

“…Geographical regions with significant annual variations in populations of R. microplus are more favorable for the occurrences of CTF outbreaks (Souza et al, 2018) when compared with regions in which the presence of this vector is stable (Brito et al, 2013). Cattle from enzootically unstable tick areas are more susceptible, since the absence of contact with the pathogens implies in the absence of immunity against the disease (Schild et al, 2008).…”