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Fungi/Mycobacterium in Blood

See histoplasmosis (p.. 341), Mycobacterium tuberculosis (treat as pulmonary TB, p.. 326), Mycobacterium avium-intracellulare (p.. 321, 342)..

Parasites, Fungi, Unusual Organisms in CSF/Brain

Cysts/Mass Lesions in CSF/Brain

Subset	Pathogens	Preferred Therapy	Alternate Therapy
Cerebral	Nocardia sp..	Preferred IV Therapy:	Preferred PO Therapy
nocardiosis		TMP–SMX (TMP 5 mg/	TMP–SMX 1 DS tablet (PO)
		kg, SMX 15 mg/kg)	q12h × 6 months
		(IV) q6h until clinical	Alternate PO Therapy
		improvement, then (PO)
			Minocycline 100 mg (PO) q12h
		therapy
			× 6 months
		Alternate IV PO	or
		Therapy: Minocycline	Doxycycline 100 mg (PO) q12h
		or Doxycycline 100 mg	× 6 months
		(IV) q12h until clinical
		improvement, then
		(PO) therapy
Cryptococcal	Cryptococcus	See p.. 22
meningitis/	neoformans
cryptococcomas
Cerebral amebiasis	Entamoeba	Metronidazole 750 mg (PO) q8h × 10 days
	histolytica		or
		Tinidazole 800 mg (PO) q8h × 5 days
Primary amebic	Naegleria fowleri	See p.. 21
meningo-
encephalitis
Granulomatous	Acanthamoeba	See p.. 22
amebic encephalitis
Cerebral	Echinococcus	Surgical resection plus	Surgical resection plus
echinococcosis	granulosus or	Albendazole 400 mg*	Mebendazole 50 mg/kg (PO)
(hydatid cyst	multilocularis	(PO) q12h until cured	q24h until cured
disease)
Cerebral	Gnathostoma	Surgical resection	Albendazole 400 mg (PO) q12h
gnathostomiasis	spinigerum		× 3 weeks or Ivermectin 200
			mcg/kg/d × 2 days
Cerebral coenurosis	Taenia multiceps	Surgical resection

262 A n t i b i o t i c E s s e n t i a l s

Cysts/Mass Lesions in CSF/Brain (cont’d)

Subset	Pathogens	Preferred Therapy	Alternate Therapy
Neurocysticercosis	Taenia solium	Albendazole 400 mg*	Praziquantel 33 mg/kg
		(PO) q12h × 2 weeks	(PO) q8h × 1day, then 15 mg/
			kg (PO) q8h × 2–4 weeks ±
			cimetidine 400 mg (PO) q8h
			(to ↑ praziquantel levels)
Cerebral	Paragonimus	Praziquantel	Bithionol 50 mg/kg (PO) q48h
paragonimiasis	westermani	25 mg/kg	× 2 weeks
(lung fluke)		(PO) q8h × 2 days	or
			Tridabendazole 10 mg/kg (PO)
			q24h × 2 days
Cerebral	Toxoplasma	See pp.. 331–332
toxoplasmosis	gondii
Chagas’ disease	Trypanosoma	Nifurtimox 2 mg/kg	Benznidazole 3..5 mg/kg (PO)
(American	brucei cruzi	(PO) q6h × 4 months	q12h × 2 months
trypanosomiasis)

*If < 60 kg, give albendazole 7..5 mg/kg..

Cerebral Nocardiosis

Clinical Presentation:  CNS mass lesion resembling brain tumor/abscess.. Symptoms are highly variable, and result from local effects of granulomas/abscesses in CNS.. Up to 40% of patients with systemic nocardiosis have associated mass lesions in CNS..

Diagnostic Considerations:  Diagnosis by demonstrating Nocardia (gram positive, delicate, beaded, branching filaments) in brain biopsy specimens.. Notify laboratory for modified acid fast specimen staining/aerobic cultures if suspect Nocardia.. Nocardia are weakly acid-fast and aerobic..

Pitfalls:  Usually not limited to brain.. Look for Nocardia in skin, lungs or liver.. Use in-vitro susceptibility data to guide therapy for refractory cases.. IV regimens are recommended for critically ill patients.. HIV patients require life-long suppression with TMP–SMX..

Prognosis:  Related to health of host, degree of immunosuppression, and extent of lesions..

Cerebral Amebiasis (Entamoeba histolytica)

Clinical Presentation:  Rare cause of brain abscess.. Onset is frequently abrupt with rapid progression. . Suspect in patients with a history of amebiasis and altered mental status/focal neurologic signs.. If present, meningeal involvement resembles acute bacterial meningitis.. CT/MRI shows focal lesions..

Diagnostic Considerations:  Diagnosis by demonstrating E.. histolytica trophozoites in wet preps or by trichrome stain from aspirated brain lesions under CT guidance.. Worldwide distribution.. Mass lesions may be single or multiple, and more commonly involve the left hemisphere.. Most patients have concomitant liver ± lung abscesses..

Pitfalls:  Trophozoites/cysts in stool are not diagnostic of CNS disease.. E.. histolytica serology is often positive, but is nonspecific.. E.. histolytica trophozoites are not present in CSF..

Prognosis:  Related to size/location of CNS lesions..

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Primary Amebic Meningoencephalitis (Naegleria fowleri) (see p.. 23)

Granulomatous Amebic Encephalitis (Acanthamoeba) (see p.. 23)

Cerebral Echinococcosis (Echinococcus granulosus) Hydatid Cyst Disease

Clinical Presentation:  Most cysts are asymptomatic.. Mass lesions may cause seizures, cranial nerve abnormalities, other focal neurologic symptoms..

Diagnostic Considerations:  CT/MRI typically shows a single large cyst without edema or enhancement.. Multiple cysts are rare.. Diagnosis by demonstrating protoscolices in “hydatid sand”in cysts.. Usually associated with liver/lung hydatid cysts..

Pitfalls:  E.. granulosus serology lacks specificity..

Prognosis:  Related to size/location of CNS cysts.. CSF eosinophilia is not a feature of CNS involvement.. Treatment consists of surgical removal of total cyst after instilling cysticidal agent (hypertonic saline, iodophor, ethanol) into cyst plus albendazole..

Cerebral Echinococcosis (Echinococcus multilocularis) Hydatid Cyst Disease

Clinical Presentation:  Frequently associated with hydatid bone cysts (may cause spinal cord compression), liver/lung cysts.. Peripheral eosinophilia occurs in 50%, but eosinophils are not seen in the CSF.. Diagnostic Considerations:  E.. multilocularis ELISA is sensitive and specific..

Pitfalls:  Praziquantel is ineffective for CNS hydatid cyst disease.. Imaging studies suggest carcinoma/ sarcoma.. Diagnosis is frequently not made until brain biopsy..

Prognosis:  If treatment is effective, improvement of CNS lesions is evident in 8 weeks.. Brain/bone cysts are difficult to cure..

Cerebral Gnathostomiasis (Gnathostoma spinigerum)

Clinical Presentation:  Nausea, vomiting, increased salivation, skin flushing, pruritus, urticaria, and upper abdominal pain 1–6 days after exposure.. Cerebral form presents as eosinophilic meningitis with radiculomyeloencephalitis, with headache and severe sharp/shooting pains in extremities often followed by paraplegia and coma.. Any cranial nerve may be involved.. The most characteristic feature is changing/migratory neurological findings.. Intense peripheral eosinophilia occurs in 90% of patients.. CSF has eosinophilic pleocytosis and may have RBCs..

Diagnostic Considerations:  In cases with ocular involvement, the worm may be seen in the anterior chamber of eye.. Specific Gnathostoma serology of CSF is helpful in establishing the diagnosis.. Acquired from infected cat/dog feces.. Most cases occur in Southeast Asia also Central/South America (Mexico, Peru) and most recently in Africa (Botswana).. Few other CNS infections have both RBCs and eosinophils in the CSF..

Pitfalls:  Do not miss associated eye involvement or characteristic episodic non-pitting subcutaneous edema..

Prognosis:  Related to invasion of medulla/brainstem..

Cerebral Coenurosis (Taenia multiceps)

Clinical Presentation:  CNS mass lesion with seizures/cranial nerve abnormalities, often presenting as a posterior-fossa syndrome.. Common sites of CNS involvement include paraventricular and basal subarachnoid spaces.. Eosinophils not in CSF..

264	A n t i b i o t i c E s s e n t i a l s

Diagnostic Considerations:  Diagnosis by demonstrating protoscolices in brain cyst specimens. . Worldwide distribution.. Transmitted via dog feces..

Pitfalls:  Do not miss associated ocular lesions, which mimic intraocular neoplasms/granulomas.. Prognosis:  Related to size/extent of CNS lesions..

Neurocysticercosis (Taenia solium)

Clinical Presentation:  Chronic eosinophilic meningitis/mass lesions with seizures.. Hydrocephalus is common.. Spinal involvement may result in paraplegia.. Cerebral cysts are usually multiple..

Diagnostic Considerations:  CT/MRI shows multiple enhancing and non-enhancing unilocular cysts..

Diagnosis by specific T.. solium serology of serum/CSF or excision of cyst.. Neurocysticercosis is the most common CNS parasite.. Worldwide in distribution; most common in Eastern Europe, Asia, Latin America..

Pitfalls:  Cranial nerve abnormalities are uncommon..

Prognosis:  Related to extent/location of CNS lesions.. Adjunctive therapy includes corticosteroids, antiepileptics, and shunt for hydrocephalus..

Cerebral Paragonimiasis (Paragonimus westermani) Lung Fluke

Clinical Presentation:  Can resemble epilepsy, cerebral tumors, or brain embolism.. Primary focus of infection is pulmonary, with pleuritic chest pain, cough, and night sweats.. CNS findings are a manifestation of extrapulmonary (ectopic) organ involvement..

Diagnostic Considerations:  Diagnosis by demonstrating operculated eggs in sputum, pleural fluid, or feces.. Multiple sputum samples are needed to demonstrate P.. westermani eggs.. Charcot-Leyden crystals are seen in sputum.. Endemic in Far East, India, Africa, and Central/South America..

Pitfalls:  Extrapulmonary (ectopic) organ involvement (cerebral, subcutaneous, abdominal) is common.. Up to 20% of patients have normal chest x-rays..

Prognosis:  Related to size/location of CNS cysts and extent of lung involvement..

Cerebral Toxoplasmosis (T. gondii) (see pp.. 331–332)

Cerebral Cryptococcosis (C. neoformans) (see pp.. 329–330)

Chagas’ Disease (Trypanosoma brucei cruzi) American Trypanosomiasis

Clinical Presentation:  Acute unilateral periorbital cellulitis (Romaña’s sign) or regional adenopathy and edema of extremity at site of infected reduviid bug (Chagoma).. Chronic disease manifests as myocarditis/ heart block or megaesophagus, megaduodenum, megacolon.. Hepatosplenomegaly is common.. Overt CNS signs are frequently absent.. CNS Chagas’ disease typically have hypodense ring enhancing lesions with surrounding edema on head CT/MRI scans.. If meningoencephalitis develops, the prognosis is very poor.. In immunosuppressed patients (especially AIDS), recrudescence of disease occurs with development of T.. brucei cruzi brain abscesses..

Diagnostic Considerations:  Diagnosis in acute disease by demonstrating trypanosomes in wet prep of anticoagulated blood or stained buffy coat smears.. Amastigote forms present intracellularly in monocytes/histiocytes in Giemsa-stained smear of bone marrow/lymph node aspirate, or by xenodiagnosis.. Serology (mostly used for chronic disease) has limited value in endemic areas due to lack of specificity, but is useful in non-endemic areas.. Common in Central/South America.. Acquired from infected reduviid bugs, which infest mud/clay/stone parts of primitive dwellings. . Infection in humans occurs in areas containing reduviids that defecate during or immediately after a blood meal..