Eosinophilic enteritis caused by Angiostrongylus costaricensis: occurrence at the northernmost border of the main endemic area in South America

Abstract

Abdominal angiostrongyliasis (AA) is endemic in Southern Brazil. Few cases have been reported in other countries in South America. The eosinophilic ileocolitis typical of AA has also been detected in southeastern Brazil, including one patient from the State of Espirito Santo (ES). We aimed to investigate a possible northern limit for the occurrence of AA in Brazil and raise awareness and improve the diagnosis of this zoonotic infection. A retrospective survey was conducted using the database from the pathology service of a University Hospital in ES. A prospective study was also conducted to identify blood eosinophilia, a marker for AA, in samples analyzed in clinical laboratories in Santa Maria de Jetibá (SMJ) and Ibatiba (IBA), between October 2021 and June 2022. Cases with eosinophilic lesions in the gastrointestinal tract and/ or liver were identified. Of 12,284 reports, 53 cases with moderate to severe eosinophilia were submitted to detailed microscopic evaluation. No case of suspected or confirmed AA was detected. In total, 684/17,228 (3.97%) and 1,025/17,832 (5.75%) cases in IBA and SMJ, respectively, had eosinophil counts > 7%. Serological (Dot-ELISA) results were positive for 2/10 index and 7/14 secondary cases. Possibly active Angiostrongylus costaricensis transmission occurs in ES, at the northern limit of the most important endemic area in Brazil and South America. Increased awareness among health personnel and systematic prospective surveillance are needed for the optimized diagnosis and management of AA cases in southeastern Brazil and other less known transmission areas in South America.

KEY WORDS: Abdominal angiostrongyliasis; eosinophilic gastroenteritis; eosinophilic ileocolitis; eosinophilic hepatitis; eosinophilia.