Seroprevalence and Risk Factors of Bovine Herpesvirus 1 Infection in Cattle Herds in the State of Paraná, Brazil

Abstract

Epidemiological data describing bovine herpesvirus 1 (BoHV-1) infection in Brazilian cattle herds are scarce. A cross-sectional study was conducted in the state of Paraná between December 2001 and July 2002 with the objective of estimating the apparent prevalence of BoHV-1-seropositive herds and animals and identifying the potential risk factors for infection in farms with breeding animals in the state of Paraná in Southern Brazil. The state was divided into seven regions based on the livestock production dynamics of the different areas. Sampling was performed in two stages. Initially, herds were randomly selected, followed by a random selection of animals within the selected herds. Blood samples were collected from 14803 females, aged ≥24 months, from 2018 BoHV-1 non-vaccinated herds. Serum samples were tested for antibodies against BoHV-1 using an indirect enzyme-linked immunosorbent assay (ELISA). The apparent prevalence of seropositivity in the herds and animals in Paraná was 71.3% (95% CI: 69.3-73.3) and 59.0% (95% CI: 56.2-61.8), respectively. Multiple logistic regression analysis revealed that risk factors associated with the presence of the infection were as follows: beef herds [OR = 1.58 (1.12-2.23)], natural service [OR = 1.48 (1.02-2.14)], purchase of animals [OR = 1.90 (1.52-2.37)], pasture rental [OR = 2.24 (1.51-3.33)], existence of calving pens [OR = 1.56 (1.20-2.03)] and records of abortion in the last 12 months [OR = 1.45 (1.08-1.95)]. These results indicate that BoHV-1 infection is widespread in the state of Paraná.

Histophilus somni is a potential threat to beef cattle feedlots in Brazil

“…Since we have identified H. somni associated with several clinical manifestations in cattle (Headley and others 2013, Headley and others 2014b), it is likely that this pathogen might have been present in cattle herds from Brazil but probably underdiagnosed. The identification of BoHV-1 in one of these steers during this study is not surprising, since this virus is endemic in most cattle herds of Paraná State (Dias and others 2013), and might have been one of the stressors responsible for the development of the respiratory disease at this feedlot. Consequently, BoHV-1 might have been the primary infectious disease at this herd, with H. somni being a secondary disease pathogen, while the recovery or not of viral DNA from other animals with respiratory distress would have been directly related to the phase of the viral infection at the time of sampling.…”

Occurrence of Bovine Viral Diarrhea (BVDV) and Bovine Infectious Rhinotracheitis (IBR) Virus Infections in Buffaloes in Pernambuco state - Brazil

“…The differences between the results of this study with those carried out in other country regions can be justified by the differences between the hygienic-sanitary management of the herds, age of the animals, reproductive management type [5], production systems, size of the herds [18]. Besides each region's climatic characteristics, geographic factors, exploration type and population sampled [10] are different.…”

“…In the association analysis between the serological status and the hygienic-sanitary and reproductive management aspects, a higher frequency of positive animals was observed in the herds that adopted an extensive breeding system (P < 0.001); this may occur due to a low control of reproductive diseases, when compared to dairy farming, and may occur because of the agent's introduction into free properties [5]. Another hypothesis, would be the possible contact with neighboring herds, facilitating direct contact with infected animals or the indirect contamination by contaminated water and food [7].…”

“…In relation to the type of herd, an association was observed for open herds (P = 0.029); this variable was identified as a risk factor in cattle raised in the Paraná state [5]. This association can be attributed to other variables, such as if the animals were purchased at agricultural fairs or not [34].…”

Coxiella burnetii associated with BVDV (Bovine Viral Diarrhea Virus), BoHV (Bovine Herpesvirus), Leptospira spp., Neospora caninum, Toxoplasma gondii and Trypanosoma vivax in reproductive disorders in cattle

“…in herds (FÁVERO et al, 2017). While prevalence rates ranging from 22.2% to 85.4% (FLORES et al, 2013;QUINCOZES et al, 2007;ALMEIDA et al, 2013) have been reported for BVDV, seropositivity rates between 18% and 90% were found for BoHV-1 in non-vaccinated herds in different geographic regions of Brazil (LOVATO et al, 1995;TAKIUCHI et al, 2001;DIAS et al, 2013). The Leptospira spp.…”