Molecular Identification of Encephalitozoon hellem from Companion Birds Kept in Pet Shops, Japan

Novel zoonotic Enterocytozoon and Encephalitozoon genotypes in domestic pigeons (Columba livia domestica) in Iran: Public health implications

To determine the occurrence of microsporidiosis in domestic pigeons in Iran, privately-owned pigeons presenting weight loss and diarrhea were tested through molecular and histopathological methods. Multiplex-PCR findings showed 57%, 30%, and 14% positivity for Enterocytozoon, Encephalitozoon, and mixed infection in the fecal samples, respectively. A novel Enterocytozoon bieneusi genotype, named IrnEb1, falling into zoonotic group 1 of E. bieneusi, and a novel genotype of Encephalitozoon hellem, named Irn2E, clustering as a sister taxon to genotype 2B were identified in pigeons for the first time using Sanger sequencing and phylogenetic analyses. Histopathological examination revealed the occurrence of non-suppurative enteritis, nephritis, pneumonia, hepatitis, and encephalitis associated with focal necrosis and inflammatory cell infiltration. Data shown herein present a high prevalence of microsporidiosis in pigeons in Iran. Considering that both detected microsporidian species are zoonotic parasites, these findings suggest that the infected pigeons could pose a risk to public health.

Prevalence of Encephalitozoon hellem among companion and exhibition birds in Japan

Microsporidia can cause infection in various animals and humans. To determine the recent prevalence of Encephalitozoon in companion birds in Japan, 364 bird feces and 16 conjunctival exudates, as well as 28 exhibition bird feces, were examined using polymerase chain reaction (PCR). Thirty-five (9.6%) feces and 2 (12.5%) conjunctival exudates from companion birds were PCR positive, and sequence analysis revealed that all detected organisms were Encephalitozoon hellem genotype 1A. The prevalence by region varied from 4.5% in the Shikoku region to 14.3% in the Chugoku region. By age, the prevalence in birds younger than 6 months of age was 13.3%. We also discuss the threat of human infection as a zoonotic disease.

The global epidemiology of Microsporidia infection in birds: A systematic review and meta-analysis

This study aimed to assess the global status and genetic diversity of Microsporidia infection in different birds. An online search was conducted in international databases from 1 January 1990 to 30 June 2022. A total of 34 articles (including 37 datasets) were included for the final meta-analysis. The pooled global prevalence of Microsporidia infection in birds was 14.6% (95% CI: 11.6-18.1). The highest prevalence of Microsporidia was found in wild waterfowl which was 54.5% (28.1-78.6). In terms of detection methods, the pooled prevalence was estimated to be 21.2% (95% CI: 12.1-34.4) and 13.4% (95% CI: 10.3-17.3) for using microscopic and molecular detection methods, respectively. Enterocytozoon bieneusi was the most common pathogen (24/31; 77.42% of the studies) according to PCR-based methods, and genotype D was the highest reported genotype (nine studies). In conclusion, designing strategies for the control and prevention of Microsporidia infection in birds should be recommended.