Bacterial Infections |
Bartonella, ssp. henselae and quintana | -
FUO, bacillary angiomatosis, endocarditis, osteomyelitis, splenitis | CD4 count <100 cells/mm3 Elevated antibody titer to organism Histopathology or PCR | Bacillary angiomatosis, peliosis, bacteremia, and osteomyelitis: Endocarditis: -
Doxycycline 100 mg IV every 12 hours; PLUS -
Gentamycin 1 mg/kg IV every 8 hours for 2 weeks, then -
Doxycycline 100 mg by mouth twice daily for 3 months. |
Syphilis: Etiology is the spirochete Treponema pallidum. While not necessarily an opportunistic infection, there has been a resurgence in the United States in recent years. | -
HIV coinfection can alter the clinical presentation in every stage. -
Primary syphilis: Painless chancre at the site of inoculation. -
Secondary syphilis: Almost any rash, adenopathy, malaise, headache. -
Latent syphilis: -
○ Early: Absence of symptoms, but + RPR and treponemal specific confirmatory assay within 12 months of a previously negative RPR -
○ Late/Unknown duration: Asymptomatic and + RPR and treponemal specific confirmatory assay over 12 months beyond a previously negative RPR -
Neurosyphilis: -
○ Can occur at any stage of syphilis and manifest in varied clinical presentations, such as cranial nerve dysfunction, stroke, meningitis, acute or chronic change in mental status, loss of vibration sense, and auditory or ophthalmic abnormalities. It is important to note that asymptomatic neurosyphilis may be more common in HIV-infected individuals | -
Dark-field microscopy, where available, can detect treponemes in primary syphilis. -
Non-treponemal specific screening tests: -
○ Venereal Disease Research Laboratory (VDRL) -
○ Rapid plasma regain (RPR) -
○ Enzyme-linked Assays (EIA) -
RPR allows for the assessment of titer levels -
Treponemal specific confirmatory tests: -
FTA-ABS: Generally remains positive after one episode of syphilis | -
Primary, secondary, and early-latent syphilis: -
Late-latent or syphilis of unknown duration: -
Neurosyphilis: |
Mycobacterial Infections |
Mycobacterium tuberculosis | -
Pulmonary: Cough, fever, night sweats, weight loss -
Extrapulmonary: Blood (miliary), cardiac, joint, bone, skin, kidney, CNS, eye, and abdomen can be initial sites and increasing immunosuppression increases likelihood of extrapulmonary presentation. | | |
Mycobacterium avium intracellulare (MAI): Decreased incidence in post-HAART ear. | -
In patients with AIDS who are not on ART, MAC disease typically is a disseminated, multi-organ infection. Early symptoms may be minimal and can precede detectable mycobacteremia by several weeks. Symptoms include fever, night sweats, weight loss, fatigue, diarrhea, and abdominal pain. | -
CD4 counts <50 copies/mm3 -
+ Blood culture or culture from site. May use culture of normally sterile site, e.g., bone marrow or lymph node + AFB stain of blood, sputum, or stool (confirmation needs to be made with culture or PCR testing) Susceptibility testing to azithromycin and clarithromycin is recommended | |
Viral Infections |
Cytomegalovirus (CMV): Acquisition of infection is common. | -
More common with CD4 count <50 cells/mm3 -
Retinitis is the most common manifestation of the disease. Usually unilateral, but can be bilateral: floaters, scotamata, or peripheral visual loss is common. -
Extra-ocular disease: Can affect GI, lung, liver, kidney, sinuses, or CNS -
Symptoms often nonspecific: Fever, weight loss, odynophagia, or profuse bloody diarrhea. -
Pneumonitis is very uncommon | -
More common at CD4 <50 cells/mm3 -
CMV can be isolated in cell culture from blood leukocytes, urine, or tissue -
Positive blood buffy-coat culture -
DNA PCR of blood, fluid, or tissue | -
CMV retinitis: -
Induction therapy: For immediate sight-threatening lesions (adjacent to the optic nerve or fovea): -
Preferred systemic induction therapy: -
Valganciclovir 900 mg orally twice daily for 14–21 days -
For peripheral lesions: -
Chronic maintenance (secondary prophylaxis): -
CMV esophagitis or colitis: -
Ganciclovir 5 mg/kg IV every 12 hours; may switch to valganciclovir 900 mg orally twice daily once the patient can tolerate oral therapy -
Duration: 21–42 days or until symptoms have resolved -
Maintenance therapy is usually not necessary, but should be considered after relapses. -
Histologically confirmed CMV pneumonia: -
CMV neurological disease: -
Note: Treatment should be initiated promptly. -
The optimal duration of therapy and the role of oral valganciclovir have not been established for pulmonary or CNS CMV. |
Jackson Canyon (JC) virus: The causative agent of Progressive Multifocal Leukodystrophy (PML); causes a demyelinating disease of the CNS. | -
Usually insidious in onset. May present with focal neurologic deficits, cognitive dysfunction, visual disturbances, paralysis, ataxia, or aphasia. | -
PML is generally associated with profound immunosuppression, i.e., CD4 count <100–200 cells/mm3. -
MRI of white matter will reveal: -
Deceased signal on T1 images -
Increased signal on T2 and FLAIR sequences -
Presence of JC virus in CNS by PCR in conjunction with MRI findings -
Brain biopsy is gold standard with specificity of 100%, but carries significant risk. | |
Fungal Infections |
Aspergillosis: Rare in the post-HAART era, but significantly lethal in pre-HAART era. Most common spp. causing infection are A. fumingatus, followed by A. flavus | -
Invasive pulmonary aspergillosis is the most common presentation: Fever, cough, dyspnea, pleuritic pain, necrotizing pneumonia -
Other presentations include: Tracheobronchitis, CNS disease, skin, sinus disease | -
Profound immunosuppression (<100 CD4 cells/mm3) associated with higher risk -
Blood cultures generally not helpful -
CXR or CT scan for pulmonary involvement -
Fungal histology/culture of suspected site -
BAL galactomannan is very specific | |
Candida Mucocutaneous Infections: Candida ssp. are the most common fungal infections in HIV-infected adolescents and young adults. | | | |
| -
Esophageal candidiasis presents with odynophagia, retrosternal pain. -
Vulvovaginal candidiasis: Presents similarly to HIV-uninfected women with a white, cottage-cheese-like vaginal discharge and vaginal itching. | | |
Coccidioidomycosis: Etiology is attributed to two species, C. immitis and C. posadasii. C. immitis is confined to California while C. posadasii is more widely distributed throughout the Southwest, Mexico, and Latin America. | -
Pulmonary: -
Fever, malaise, and chest pain. -
Cough and hemoptysis is a rare presentation -
Meningitis: -
Disseminated disease: | -
Tissue histology that shows spherules containing endospores are diagnostic -
Blood cultures and CSF cultures are rarely positive -
Sputum cultures often positive. -
A coccidioidomycosis-specific antigen is available for urine and serum and is useful in making the diagnosis | -
Mild disease (e.g., focal pneumonia): -
Severe, non-CNS infection, or disseminated disease: -
Meningeal infection: -
Chronic suppressive therapy: |
Cryptococcosis: Generally caused by Cyrptococcus neoformans, but occasionally by C. gattii (in Australia, subtropical regions, and the Pacific Northwest). | | -
Cryptococcal antigen in serum, CSF, or other body fluid is effective for rapid diagnosis -
CSF analysis: -
Culture of blood, CSF, and sputum | -
CNS disease: -
Acute therapy (2-week induction) is followed by consolidation therapy. -
Consolidation therapy: For minimum of 8 weeks followed by maintenance therapy. -
Maintenance therapy: -
Non-CNS, extrapulmonary, and diffuse pulmonary disease: -
Non-CNS with mild to moderate symptoms and focal pulmonary infiltrates: |
Histoplasmosis: Etiology is inhalation of microconidia of Histoplasmosis capsulatum. Most highly endemic in the Ohio and Mississippi river valleys, Puerto Rico, and Latin America. | | -
Histoplasma antigen in blood or urine is sensitive for rapid diagnosis of acute pulmonary disease and disseminated disease -
Culture is often invasive and slow to grow organism -
EIA probes can detect infection in serum, sputum, and CSF | |
| -
CNS disease: -
Fever -
Headache -
Focal deficits -
GI disease: -
Diarrhea -
Abdominal pain -
Weight loss -
Pulmonary disease: -
Cough -
Fever -
Pleuritic chest pain | | -
Less severe disseminated disease: -
Induction and maintenance therapy: -
Meningitis: -
Induction therapy (4–6 weeks): -
Maintenance therapy: -
Itraconazole 200 mg orally twice daily for ≥1 year and until resolution of abnormal CSF findings |
Pneumocystis Pneumonia (PCP): Etiology is Pneumocystis jiroveci. The organisms are found worldwide in lungs of humans. | -
Pneumonia: -
Often subacute onset -
Fever -
Cough (nonproductive) -
Tachypnea -
Dyspnea | -
CD4 counts are generally <200 cells/mm3 or % <14%. -
Hypoxia is hallmark -
LDH is nonspecific, but often elevated -
Chest x-ray classically shows bilateral diffuse interstitial infiltrates described as “ground glass” in appearance. But, can be normal. -
Stains of sputum (obtained through induced mechanism, bronchoaveolar lavage) include silver stain, toluidine blue, and Wright stain may be used -
Direct fluorescent antibody stains may also be used. | -
Trimethoprim-Sulfamethoxazole (TMP-SMX) TMP 15–20 mg/kg/day IV or orally divided every 8 hours. -
Duration of treatment is 21 days followed by suppressive therapy. -
In severe disease, corticosteroids reduce morbidity and mortality |
Parasitic Infections |
Cryptosporidiosis/Microsporidiosis: Cryptosporidium spp. are ubiquitous protozoal parasites. Microspora spp. are intracellular spore-forming protozoa. | -
Cryptosporidiosis: -
Microsporidiosis: | -
Cryptosporidiosis: -
EIA is preferred -
Cannot be cultured -
Microsporidiosis: | -
Cryptosporidiosis: -
Microsporidiosis: -
Effective HAART treatment -
Albendazole 7.5 mg/kg (max 400 mg/dose) orally twice daily may be used for disseminated, but not ocular infection for microsporidia other than E. bienuesi. |
Toxoplasmosis: Etiology is Toxoplasma gondii. Prevalence of serum antibodies varies through the United States and the world. Disease is primarily due to reactivation of latent cysts. | | -
CT or MRI with contrast will show ring-enhancing lesions in the gray matter of the cortex or basal ganglia. Edema is often present. -
IgG antibodies are uniformly present. -
Stereotactic CT-guided brain biopsy is the only definitive diagnostic tool. -
Detection of Toxoplasma gondii by PCR in CSF is very specific, but has low sensitivity. | -
Treatment of acute infection: -
Pyrimethamine 200 mg orally 1 time, followed by weight-based therapy: -
If <60 kg, pyrimethamine 50 mg orally once daily + sulfadiazine 1000 mg orally every 6 hours + leucovorin 10–25 mg orally once daily -
If ≥60 kg, pyrimethamine 75 mg orally once daily + sulfadiazine 1500 mg orally every 6 hours + leucovorin 10–25 mg orally once daily -
Leucovorin dose can be increased to 50 mg daily or twice daily. -
Duration for acute therapy: -
Chronic maintenance therapy: |