Cryptosporidium: A Comprehensive Review of Epidemiology, Pathogenesis, and the Advancing Frontier of Molecular Diagnostics

AbstractThe protozoan parasite Cryptosporidium is globally recognized as a critical etiological agent of diarrheal disease,particularly the moderate-to-severe form (MSD) affecting young children across the world. While typically causing atransient, self-limiting illness in healthy hosts, the infection is notorious for causing prolonged, chronic, andpotentially fatal disease in immunocompromised populations, such as those with HIV/AIDS. The parasite is efficientlytransmitted through the fecal-oral route, frequently causing zoonotic or waterborne epidemics due to its oocysts’inherent resistance to chlorine disinfection. The traditional diagnostic reliance on low-sensitivity microscopy is nowbeing actively replaced by more precise molecular techniques. This comprehensive review synthesizes the currentepidemiological landscape, elucidates the parasitic life cycle and pathogenic mechanisms, and provides a criticalassessment of diagnostic progress, highlighting the transformative roles of contemporary molecular technologies,including Polymerase Chain Reaction (PCR), Next-Generation Sequencing (NGS), and CRISPR-Cas9.