VILAR, A. L. T.; http://lattes.cnpq.br/0417531152459249; VILAR, Ana Leticia Tôrres.
Abstract:
This study focused on estimating the herd-level and animal-level prevalences, and identifying herdlevel
spatial clustering and risk factors associated with herd-level prevalence for bovine
paratuberculosis in the State of Paraíba, Northeastern Brazil. The state was divided into three
sampling groups: sampling stratum 1 (mesoregion of Sertão), sampling stratum 2 (mesoregion of
Borborema), and sampling stratum 3 (mesoregions of Zona da Mata and Agreste). For each
sampling stratum, herd-level and animal-level prevalences were estimated by a two-stage sampling
survey. In the first stage, a pre-established number of herds (primary sampling units) were randomly
selected; in the second stage, a pre-established number of cows aged ≥ 24 months were randomly
selected (secondary sampling units). In total, 2504 animals were sampled from 480 herds.
Serological diagnosis of Mycobacterium avium subsp. paratuberculosis (MAP) infection was
performed by the indirect ELISA kits. A herd was deemed positive if it included at least one
positive animal in herds of up to 24 females, and two positive animals in herds with more than 24
females. The herd-level prevalence in the State of Paraíba was 34.5% (95% CI = 30.2–39.1%),
41.4% (95% CI = 34.0–49.1%) in Sertão, 26.6% (95% CI = 20.2–34.2%) in the region of
Borborema, and 30.5% (95% CI = 23.9–38.0%) in Agreste/Mata. The animal-level prevalence was
10.7% (95% CI = 7.3–15.4%) in the State of Paraíba, 9.4% (95% CI = 7.3–12.1%) in Sertão, 7.9%
(95% CI = 5.2–11.7%) in the region of Borborema and 13.9% (95% CI = 6.2––28.3%) in
Agreste/Mata. The frequency of seropositive animals per herd ranged from 6.7% to 100% (median
of 20%).The risk factors identified were as follows: Sertão region (OR = 1.9), more than 12 adult
animals in the herd (OR = 1.9), and not using maternity pens (OR = 1.7). Two significant clustering
of positive herds were detected in Northern part of Borborema mesoregion. Our findings suggest
that MAP herd-level seroprevalence in the State of Paraíba, Northeastern Brazil, is high, and
support the idea that the use of maternity pens will be important for preventing transmission of
MAP in the herds. As serological tests for MAP diagnosis are not widely available and are very
expensive, as well as replacement or maintenance of livestock by animal purchasing is common in
the region, it is concluded that prevention measures should be applied at herd level.