 |
|
|
|
The Diagnosis of Opportunistic Infections |
This area is under development. Please excuse the incomplete areas.
| Direct links | ||
| OI | Diagnosis | Treatment |
| Pneumocystis carinii pneumonia (PCP) | Dx | Tx |
| Toxoplasma gondii encephalitis | Dx | Tx |
| Cryptococcus neoformans | Dx | Tx |
| cytomegalovirus infection | Dx | Tx |
| histoplasmosis | Dx | Tx |
| aspergillosis | Dx | Tx |
| cryptosporidiosis | Dx | Tx |
| nocardiosis | Dx | Tx |
| coccidioidomycosis | Dx | Tx |
| acyclovir-resistant herpes simplex | Dx | Tx |
| severe refractory human papilloma virus (HPV) | Dx | Tx |
| progressive multifocal leukoencephalopathy (PML) | Dx | Tx |
| late stage Pseudomonas aeruginosa pneumonia | Dx | Tx |
Blue links are under development and are not working.
| Pneumocystis carinii pneumonia (PCP) | |
|
Clinical presentation: in many
cases the clinical scenario is diagnostic Known HIV infection or known/suspected risk factors for HIV CD4 < 200, usually < 100 Any combination of the following: Insidious onset of symptoms Cough, usually nonproductive or minimally productive, especially associated with inspiration Fever Progressive dyspnea or dyspnea on exertion Weight loss and anorexia Oral candidiasis Previous history of PCP Nonadherent to prophylaxis for PCP Elevated HIV viral load LDH usually elevated |
|
| Chest x-ray | Bilateral diffuse alveolar and interstitial infiltrates or any variety of patterns: normal, patchy alveolar, rarely cavitary |
| Pulse oximeter | Technique: perform pulse oximetry at rest
and with exercise (rapid walking) Reduced O2 saturation on room air or decreasing O2 saturation on room air with exercise |
| Arterial blood gas | Increased alveolar-arterial oxygen gradient |
| Induced sputum for Pneumocystis carinii smear | Technique: performed after good oral hygiene
obtained and optimally induced by trained respiratory technician with
normal saline aerosol Comment: This technique is fairly sensitive (as sensitive as bronchoalveolar lavage?) and very specific for PCP |
| Fiberoptic bronchoscopy with bronchoalveolar lavage | Technique: Fluid sent for Pneumocystis
carinii examination as well as microbiologic studies for acid fast
bacilli (AFB), fungi, and virus (especially CMV) Studies for cytopathology should also be considered. Comment: This is the optimal examination due to the possibility of concomitant pathogens in persons with severe disease |
| Toxoplasma gondii encephalitis |
|
Clinical presentation Known HIV infection or suspected/known risk factors for HIV
CD4 count < 100 Fever Altered mental status Focal neurologic deficits |
| Toxoplasma gondii IgG antibodies |
| Computerized tomography (CT) of brain with and without intravenous contrast |
| Magnetic resonance imaging (MRI) of brain with and without intravenous contrast |
| Cerebrospinal fluid (CSF) analysis |
| Positron emission tomography |
| Brain biopsy |
| Cryptococcus neoformans infections (cryptococcosis) |
|
Clinical presentation Known HIV infection or suspected/known risk factors for HIV
CD4 count < 100 Cough, usually nonproductive Dyspnea or dyspnea on exertion Altered mentation Seizures Focal neurologic deficits including decreased visual acuity, hearing loss |
| Chest x-ray |
| Computerized tomography (CT) of brain with and without intravenous contrast |
| Magnetic resonance imaging (MRI) of brain with and without intravenous contrast |
| Cerebrospinal fluid (CSF) analysis including India ink and fungal cultures |
| Cryptococcal antigen detection from blood and CSF |
| Fungal smears and cultures of blood, sputum |
| cytomegalovirus (CMV) infections |
|
Clinical presentation Known HIV infection or suspected/known risk factors for HIV CD4 count < 100, usually < 50 Any combination of the following: Fever Cough, usually nonproductive Dyspnea or dyspnea on exertion Loss of visual acuity, unilateral or bilateral Abnormal retinal exam Floaters in visual field Headache Focal neurologic deficits |
| Chest x-ray |
| Shell vial cultures of bronchoalveolar lavage, urine |
| CMV antigen (blood) assay |
| Tissue cytopathology - bronchoalveolar lavage, lung biopsy, GI tract biopsy, liver biopsy, etc. |
| histoplasmosis (Histoplasma capsulatum infection) |
|
Clinical presentation Known HIV infection or suspected/known risk factors for HIV CD4 count < 100, usually < 50 Any combination of the following: Fever Cough, usually nonproductive Dyspnea, or dyspnea on exertion Mucosal ulcerations (usually painless): mouth, rectum, genital tract Papular skin rash Diarrhea Splenomegaly |
| Direct buffy coat smear for fungi |
| Blood cultures for fungi |
| Urine histoplasma antigen |
| Bone marrow examination with fungal smears, fungal cultures, histopathology including special tissue stains for fungi |
| Smear and culture of mucosal ulcers |
| Biopsy of skin lesions with smears and cultures for fungi and histopathology including special tissue stains for fungi |
| Fiberoptic bronchoscopy with bronchoalveolar lavage |
| aspergillosis |
|
Clinical presentation Known or suspected advanced HIV infection History of IVDU or history of environmental exposure (hay, etc.) CD4 count < 100 Pulmonary nodules or cavitary lesion Intracranial perivascular infection or abscess |
| Aspergillus urine antigen |
| Biopsy material for fungal smears and cultures is the gold standard for sensitivity and specificity. |
| cryptosporidiosis |
|
Clinical presentation Known HIV infection or suspected/known risk factors for HIV CD4 count < 100, usually < 50 Diarrhea, usually voluminous and watery Any combination of the following: Abdominal cramps Nausea and vomiting Weight loss, possibly rapid Right upper quadrant abdominal pain and tenderness |
| Modified acid fast stain of the stool |
| Endoscopic aspiration of duodenum and/or biliary tree for cryptosporidiosis |
| acyclovir-resistant herpes simplex |
|
Clinical presentation Known or suspected advanced HIV infection CD4 usually < 200 and uncontrolled HIV viral load History of recurrent herpes simplex infection History of long term suppressive therapy with acyclovir Nonhealing ulcerative disease in area of previously acyclovir responsive herpes simplex |
| Viral culture for herpes simplex |
| Assay for thymidine kinase in isolated HSV |
| Lack of response to high dose acyclovir (800 mg po 5 times per day) is a low technology but effective approach to diagnosis |
| progressive multifocal leukoencephalopathy (PML) |
|
Clinical presentation Known or suspected advanced HIV infection CD4 usually < 100 and uncontrolled HIV viral load Focal neurologic deficits without other explanation |
| Magnetic resonance imaging (MRI) of brain with and without intravenous contrast |
| CSF analysis including JC virus PCR |
| Brain biopsy with cytopathology |
| Pseudomonas aeruginosa pneumonia (late stage AIDS) |
|
Clinical presentation Known or suspected advanced HIV infection CD4 <50 Multiple hospitalizations and extensive antibiotic exposure Malnutrition Cough productive of purulent sputum High fevers and rigors |
| CXR with bilateral lobular infiltrates |
| Sputum gram stain (large numbers of gram negative bacilli and WBCs) and culture (growing the organism obviously) |
| Blood cultures are often diagnostic also |
| CBC which reveals relative or absolute leukocytosis with a shift to immature forms |
| Antibiotic resistance may develop while on therapy |
Updated 12.18.2005
Under construction.
