Estudo epidemiológico da infecção por nematódeos broncopulmonares em ruminantes no estado de Pernambuco

Abstract

The present study provides epidemiological data on lungworm infection in ruminants in the state of Pernambuco, including the following aspects: 1) Epidemiological, morphological, and molecular data on the lungworm larva of a species of Protostrongylus from goats. Fecal samples from goats (n = 217) were analyzed by the Baermann technique and larvae were detected in 18.9% (41/217) of the samples. These larvae had a mean length of 339μm (±52.99μm) and a mean width of 18 μm (±1.46μm). Morphologically they were similar to Protostrongylus sp. and molecularly they revealed strong identity (98.7%) with Protostrongylus rufescens homologous sequences available in GenBank. 2) To provide a comprehensive overview of historical and current data published between January 1980 and December 2020 on lungworm infection of domestic ruminants in Brazil. In this period, 24 articles were published, being in cattle (n = 16), goats (n = 6), sheep (n = 1) and one study (n = 1) with goats and sheep. Overall, 12 studies were based on post-mortem examination only, five on detection of specimens in fecal samples, and seven were based on fecal analysis followed by post-mortem examination. Of all studies, 66.7% (n = 16) articles recorded Dictyocaulus viviparus, 4.2% (n = 1) Dictyocaulus filaria, 8.3% (n = 2) P. rufescens, 16.7% (n = 4) M. capillaris, and 4.2% (n = 1) co-infection by D. filaria and Muellerius capillaris. 3) To determine the prevalence of lungworms in ruminants from the semiarid region of northeastern Brazil. A total of 429 fecal samples were collected from cattle (n = 219), goats (n = 122) and sheep (n = 88) and analyzed by the Baermann technique. Cattle and sheep were negative. Larvae of Protostrongylus sp. were detected in 8.19% (10/122) of goats. They had an average length of 351μm (±29.06μm) and an average width of 19μm (±1.46μm). All infected goats were raised in a semi-intensive production system and did not exhibit any clinical signs suggestive of the infection by lungworms. 4) Lungworms infection in beef cattle herds reared in an important livestock production area in the northeastern region of Brazil. From September 2020 to August 2021, monthly fecal samples (n = 493) were collected from 46 beef cattle. Out of all animals assessed, lungworm larvae were detected in 8.7% (4/46). Animals did not present any clinical sign suggestive of the infection by lungworms parasites. Twenty larvae were retrieved, with the minimal number (n = 1) detected in October and December, and the maximum number (n = 13) in November. They presented a mean length of 363μm (± 28.65μm), mean width of 19 μm (±1.03μm) and were morphologically similar to Dictyocaulus sp.. Infection by these nematodes has been reported in the last four decades in Brazil, but most of the information was obtained from post-mortem examination. Finally, we report the occurrence of these parasites in cattle and goats in the northeastern region. Despite the absence of clinical signs in the animals in this study, sanitary measures are recommended to prevent infection by these nematodes and reduce the economic impact they can cause in livestock production.