Bacteremia (multiple pathogens) | Fever, chills, shock | Blood culture | Broad-spectrum antibiotics | Use prior culture results to guide empiric therapy |
Pneumonia (multiple pathogens) | Fever, cough, dyspnea | Radiograph, blood culture, viral studies | Broad-spectrum antibiotics | Evaluation for both bacterial and viral pathogens is important |
C. difficile | Fever, painful diarrhea with blood and mucus | Stool toxin assay | Metronidazole; oral vancomycin as 2nd line | Up to one-third of infants are asymptomatically colonized |
M. tuberculosis (TB) | Fever, chills, cough, weight loss; night sweats and hemoptysis are uncommon in children | Culture, PCR, tuberculin skin test, IGRA | Isoniazid, rifampin, pyrazinamide, ethambutol | Children infrequently are culture positive; index of suspicion must be high to make the diagnosis |
Nontuberculous mycobacteria (NTM) | Can cause pulmonary, skin/soft tissue, lymphadenopathy, and disseminated disease | Culture | Varies by species | Differentiating colonization from disease can be challenging |
Nocardia | Lymphocutaneous disease in normal hosts; pulmonary, CNS, and skin disease seen in immunocompromised children | Culture; bacteria are variably acid-fast | Trimethoprim-sulfamethoxazole; add amikacin for CNS or other life-threatening disease | Need to ask lab to hold cultures for several weeks to allow this indolent pathogen to be isolated |
Aspergillus | Pulmonary, sinus, CNS, or skin involvement with associated thromboses | Culture, silver stain of biopsy specimen | Amphotericin | Can see halo sign on chest CT |
Coccidioidomycosis | Fever, chest pain, dyspnea, weight loss; skin findings and arthralgia may be only signs in children | Serology, culture | Amphotericin | Travel history is important: in the United States, endemic in the Southwest |
Cryptococcus | Indolent meningitic symptoms; skeletal and skin nodules can be seen | Serum and CSF antigen; culture | Amphotericin + flucytosine | Can have minimal CSF pleocytosis |
Histoplasmosis | Fever, chest pain, dyspnea, weight loss, erythema nodosum | Serology, culture, urinary antigen | Amphotericin | Antigen testing insensitive for pulmonary histoplasmosis in immunocompromised persons |
Pneumocystis jirovecii | Subacute presentation with fever, nonproductive cough, dyspnea; hypoxemia often noted | Silver stain; CXR | Trimethoprim-sulfamethoxazole | LDH often very elevated; CXR shows diffuse reticulonodular pattern |
Adenovirus | Hemorrhagic cystitis, pneumonia, hepatitis, conjunctivitis, colitis | Viral culture; rapid assays have poor sensitivity | Cidofovir for disseminated disease | Virus can be shed for months after initial infection |
BK virus | UTI symptoms, hemorrhagic cystitis | PCR | Supportive | Can be associated with chronic renal failure |
Cytomegalovirus (CMV) | Pneumonia, colitis, retinitis, hepatitis | PCR, antigenemia, serology | Ganciclovir | Like all herpes viruses, CMV can reactivate after periods of latency |
Epstein–Barr virus (EBV) | Fever, influenza-like illness, Guillian–Barré, meningoencephalitis, PTLD, hemophagocytic syndrome | PCR, serology | Supportive | Very elevated ferritin can be seen with PTLD; can see primary or reactivation infection |
Herpes simplex virus (HSV) | Severe dermatologic findings, eczema herpeticum; disseminated HSV less common | Culture, PCR | Acyclovir | Varied CNS presentations seen: meningoencephalitis, Bell palsy, ascending myelitis |
Influenza | More severe symptoms than influenza in normal hosts | Viral culture, rapid assays, PCR | Oseltamivir | Higher rates of hospitalization seen in children with malignancies and hemoglobinopathies |
Parvovirus | Fever, rash; aplastic crisis, occasionally with involvement of other cell lineages | Serology | Supportive | Can cause crisis in children with hemoglobinopathies |
Varicella zoster virus (VZV) | Can see hemorrhagic VZV or reactivation as shingles | Direct fluorescent antibody (DFA) testing | Acyclovir (not as effective for VZV as for HSV) | Atypical presentations of chicken pox seen in immunocompromised children |
Babesiosis | Fever, chills, headache, malaise, pallor (mimics malaria) | Maltese cross on peripheral smear | Quinine + clindamycin | Overwhelming parasitemia seen in asplenic patients |
Cryptosporidium | Nonbloody, watery diarrhea (lasts weeks), abdominal pain, weight loss; pulmonary, biliary tract, and disseminated disease can be seen in the immunocompromised | Stool antigen testing | Nitazoxanide | Shedding can be intermittent, requiring collection of several stool specimens |
Giardia | Watery nonbloody diarrhea, abdominal pain and distension, flatulence | Stool antigen testing | Nitazoxanide | More common in persons with humoral immunodeficiencies |
Malaria | Fever, chills, headache, malaise, pallor | Thick, thin peripheral smears | Quinine + clindamycin | P. falciparum has higher morbidity/mortality than other plasmodial species. |
Strongyloides | Pulmonary infiltrates, sepsis, meningitis (from translocation of Gram-negative enterics across the gut) | Visualization of larvae in the stool; serologies cross-react with filariae | Ivermectin or thiabendazole | Eosinophilia seen during tissue migration phase; auto-inoculation seen in immunocompromised hosts |
Toxoplasmosis | Encephalitis, pneumonia, disseminated disease | Serology | Pyrimethamine + sulfadiazine | IgM response poor in immunocompromised patients |