Pulmonary cryptosporidiosis in simian immunodeficiency virus-infected rhesus macaques

Area of Science:

• Veterinary Pathology
• Infectious Diseases
• Primate Models

Background:

• Cryptosporidiosis is a common gastrointestinal opportunistic infection in human and nonhuman primates with Acquired Immunodeficiency Syndrome (AIDS).
• Pulmonary cryptosporidiosis has not been previously documented in nonhuman primate models.

Observation:

• Two macaques experimentally infected with simian immunodeficiency virus (SIV) exhibited lesions in multiple organs, including the lungs, trachea, bile ducts, pancreas, and intestines.
• Pulmonary lesions were characterized by moderate to severe bronchopneumonia attributed to cryptosporidiosis.

Findings:

• Oval Cryptosporidium spp. organisms (2-4 microm) were identified within the cytoplasm of alveolar macrophages and multinucleated giant cells in lung tissues.
• Multinucleated giant cells tested positive for SIV using in situ hybridization, suggesting a link between SIV infection and the observed pathology.
• These findings represent the first documented cases of pulmonary parenchymal cryptosporidiosis in SIV-infected macaques.

Implications:

• This study expands the known spectrum of opportunistic infections in SIV-infected macaques.
• It highlights the potential for pulmonary cryptosporidiosis in immunocompromised nonhuman primates.
• The findings contribute to understanding the pathogenesis of opportunistic infections in primate models of AIDS.