Frequência, aspectos parasitológicos e morfológicos da infecção por Angiostrongylus cantonensis (Chen, 1935) (Nematoda, Angiostrongylidae) em roedores sinantrópicos no estado de Pernambuco

Abstract

Angiostrongylus cantonensis is a zoonotic nematode that has terrestrial rodents and mollusks as the main hosts. Several species of mammals and birds are susceptible to accidental infection, and A. cantonensis infection is the main cause of eosinophilic meningitis in humans. The introduction and rapid dissemination of mollusks of the Achatina fulica species has increased the risk of transmission of A. cantonensis, since the mollusk is its main intermediate host, even in Brazil, where several areas are vulnerable to the introduction of the parasite and data on epidemiology. In Pernambuco there is no data on the presence of naturally infected rodents. The objective of this work was to evaluate the frequency, distribution, structural, morphological, parasitological, ultrastructural and molecular characterization of A. cantonensis in naturally infected rodents in the different mesoregions of the state of Pernambuco. For the study, 94 rodents of the Rattus norvegicus (norway rat) and R. rattus (black rat) species were collected from 13 municipalities distributed in four mesoregions of the State of Pernambuco, with and without human cases of Eosinophilic Meningitis. Euthanasia, necropsy and analysis of the thoracic organs of the rodents and collection of helminths found in the cardiopulmonary block, using light and electronic microscopy, and Polymerase Chain Reaction (PCR) were performed. A macroscopic and histopathological analysis of lung lesions was carried out, after which a morphological evaluation of the parasites found in the pulmonary arteries of the rodent was performed to identify the parasites. The evaluation of the pulmonary exudate was performed on the presence of eggs and L1 larvae; for the molecular diagnosis, the PCR technique was used and with the aid of transmission electron microscopy, the ultrastructural evaluation of the enterocytes of the digestive tract of A. cantonensis was carried out. The frequency of 29.78% of norway rats infected by A. cantonensis was observed. In the histological study of the lungs it was observed subacute to chronic pneumonitis, besides pulmonary fibrosis and presence of eggs and larvae of the parasite in the lung tissue. PCR revealed 1134 bp fragments compatible with the genus Angiostrongylus and transmission electron microscopy revealed ultrastructures of the enterocytes and intestinal epithelium of the parasite. This is the first report of natural infection of R. norvegicus by A. cantonensis in urban areas, indicating the risk of infection to the human population in the areas of the state of Pernambuco, northeastern Brazil, where the presence of the parasite was detected.