Overview Snapshot A 24-year-old man presents to his primary care physician with fever, headache, sore throat, and myalgias. He reports his symptoms began a few days ago and believes it is from a "cold." Social history is significant for having multiple male partners. He does not consistently use condoms. His last sexual encounter was 2 months ago. Physical exam is significant for cervical lymphadenopathy. An HIV-1/2 antigen/antibody combination immunoassay is positive for p24 antigen and an elevated HIV viral load. HIV-1/2 antibody differentiation immunoassay shows that he is solely HIV-1 reactive. Introduction Human immunodeficiency virus (HIV), an RNA retrovirus, can result in login to view 7 more bullets Pathogenesis login to view 13 more bullets HIV structure login to view 26 more bullets Diagnosis login to view 6 more bullets Opportunistic Infections Based on CD4+ Cell Count Cell Count (cells/mm3) Pathogen & Disease(s) < 500/mm3 Candida albicans oral thrush Bartonella henselae bacillary angiomatosis Epstein–Barr virus (EBV) oral hairy leukoplakia HHV-8 Kaposi sarcoma HPV squamous cell carcinoma of theanus and cervix < 200/mm3 Pneumocystis jirovecii pneumonia Reactivation of the JC virus progressive multifocal leukoencephalopathy Histoplasma capsulatum nonspecific symptoms such as fever, weight loss, and cough along with oval yeast cells within macrophages < 100/mm3 Candida albicans esophagitis Aspergillus fumigatus hemoptysis and pleurisy Mycobacterium avium-intracellulare and mycobacterium avium complex nonspecific findings such asfever, weight loss, and night sweats Toxoplasma gondii brain abscesses that can appear as ring-enhancing lesions on MRI Cryptococcus neoformans meningitis Cryptosporidium species watery diarrhea Epstein–Barr virus (EBV) B-cell lymphoma Cytomegalovirus retinitis esophagitis colitis encephalitis pneumonitis