Fungi-Cestodes Deck Flashcards
1
Q
Giardiasis (Giardia lamblia)
A
- aka “Beaver Fever” and “Backpacker’s Bug”
- usually self-limited, normally commensual protozoa
- Small Intestine, watery diarrhea.
- Symptoms of GI infection + bloating, excessive gas, and burping (often sulfurous)
- Malabsorption, structural and chemical changes to brush border.
- Watery diarrhea
- IgA deficiency?
1
Q
Chagas Disease (American Trypanosomiasis)
A
- Rural areas of Mexico, Central America, and South America;
- Flagellate protozoan, insect born zoonosis (kissing bug).
- Bite => Invasion of macrophages / nodular ‘chagoma’
- lesion => dissemination
- Acute illness may kill via myocarditis / encephalitis
- Chronic illness involes GI dysfunction and autonomic nerve degeneration and cardiac failure–years to decades
1
Q
Ascariasis (Ascaris lumbricoides)
A
- ingestion of food contaminated with eggs
- most common helminthic infection in humans
- usually ASYMPTOMATIC
- penetrate small intestine and travel to lungs
- can cause obstruction of pancreatic or biliary ducts-pancreatitis, suppurative cholangitis, and liver abscesses.
- Ascaris pneumonia (rare): larvae fill alveolar airspaces
2
Q
Mucormycosis (Zygomycosis)
A
- Environmental fungi, cause severe necrotizing, invasive infections that begin in sinuses and lungs (spores are inhaled)
- Rhinocerebral: creates a black crust with friable/hemorrhagic underlying tissue - spreads to vessels and brain. Tx = surgery, amphotericin B, may be fatal
- Pulmonary: Usually fatal, looks like aspergillosis (sepsis and infarction)
- Subcutaneous zygomycosis: In the tropics, hard inflamm. mass (infects subcutaneous fat) on shoulder, trunk, buttock, thigh
2
Q
Leishmaniasis (Leishmania spp.)
A
- Via sandfly bite.
- proliferate in macrophages–amastigotes
- Tropic/Subtropic, overcrowding.
- Skin soars, may progress to disseminated disease, splenomegaly.
- immunocompromised-diffuse cutaneous leishmaniasis.
- mucocutaneous late complication: disfiguring larynx, nasopharynx, anus, vulva (highly damaging)
- kala azar=visceral leishmaniasis “black sickness”-viscera overwhelmed by build up of infected macrophages–disrupts organ architecture with sheets of parasitized macrophages.
- kala azar is fatal: Requires treatment if disseminated.
3
Q
Coccidioidomycosis “Valley fever” “Desert Fever”
A
- “Valley fever” “Desert Fever”
- Coccidioides immitis or Coccidioides posadasii
- Endemic in certain parts of Arizona, California, Nevada, New Mexico, Texas, Utah.
- Flu-like, maculopapular rash,
- Begins with pulmonary infection (granuloma-caseous)–nodules form in lung with hemoptysis, then disseminates, can cause meningitis in immunocompromised.
- usually after pulomary infection, appearance of eryhthema nodosum (IgG deposits-allergic reaction in fat underneath skin)
4
Q
Paracoccidioidomycosis (South American/Brazilian Blastomycosis)
A
- similar to coccidiodomycosis + blastomycosis
- chronic granulomatous infection (with purulent exudates) starting with lung involvement–dissemination in immunocompromised to skin, oropharynx, adrenals, and macrophages of lymphatic system.
- central + south america
- usually acute, self-limited and mild disease
4
Q
Clonorchiasis / Liver fluke (Clonorchis sinensis)
A
- Asia, Vietnam, Korea
- spread by ingesting inadequately cooked freshwater fish
- flat and transparent adult
- lethal due to complications: biliary obstruction, bacterial cholangitis, pancreatitis, cholangiocarcinoma
5
Q
African Trypanosomiasis (Trypanosoma brucei rhodesiense)
A
- Tetse fly
- Acute febrile progresses to life threatening meningoencephalitis-3 to 6 months
- Humans only reservoir of T. brucei
- evade immune system by altering glycoprotein antigen coat–genetically determined pattern (not mutation)
- Disruption of sleep, neurological problems.
- Fatal if untreated
7
Q
Candida (albicans)
A
- Usually superficial (deep infections uncommon and life threatening)
- Endogenous flora, most common precipitating factor = antibiotic use. Yeast converts to invasive hyphae or pseudohyphae form.
- Limited to mucocutaneous sites:
- Thrush = oral cavity, fuzzy white coat on tongue (maceration predisposes)
- Vulvovaginitis = thick white discharge, itchy (antibiotics, preg., diabetes, steroids)
- Sepsis and disseminated candidiasis = usually deadly (catheter, IV, dialysis)
- Endocarditis = large vegetations (IV drug use)
- Other surfaces include esophagitis, paronychia (nailbeds), diaper rash and intertrigo (opposed skin surfaces)
7
Q
Loiasis “African Eye Worm”
A
- Mango fly bite transmites loa loa (round worm), which travels to the conjunctiva, where it can be readily seen in patient.
- Does not cause blindness
- DO NOT give antifilarials–destructive inflammatory response (highly antigenic when worms dead).
- rarely lethal (sudden + diffuse cerebral ischemia)
- usually self limited with mild CNS involvement
7
Q
Schistosomiasis (Schistosoma mansoni, S. japonicum, S. haematobium)
A
- Most important human helminthic infection, very disabling.
- S. haematobium: Intense inflammatory response, damage to nearby tissue, usually Liver, GI, or bladder, where it causes granulomas and dysregulated growth (polyps in colon, sq cell carcinoma in bladder).
- Portal hypertension (Desposit egg in venules), esophageal varices (S. Mansoni +S. japonicum)
- Asexual reproduction in snail.
- Penetrates human skin as schistosomula.
- Lays eggs: These cause the inflammatory response.
- Diagnosed based on eggs in feces.
- Generally self-limited
8
Q
Trichinosis (Trichinella spiralis)
A
- Inadequatly cooked or encysted meat; PORK.
- Survives in human skeletal muscle, myositis (diaphragm, ocular muscles, tongue, intercostals, deltoids, gastrocnemius), calcifications
- Classic sign: periorbital edema, swelling around the eyes, which may be caused by vasculitis.
- Extreme eosinophilia (>50% of leukocytes)
- May have CNS or cardiac involvement
10
Q
Fascioliasis
A
- spread by eating contaminated vegetation (watercress) with cysts from sheep
- cysts liberate metacecariae that pass into peritoneal cavity–live in intrahepatic and extrahepatic bile ducts
- hepatic abscesses and granulomas
- induce hyperplasia of bile duct epithelium, portal and periductal fibrosis, and biliary obstruction
- Symptoms: eosinophilia, vomiting, acute gastric pain
- Fatal if untreated
- diagnosis: recovering eggs from stool or biliary tract
11
Q
Dermatophyte Infections (Microsporum, Epidermophyton and Trichophyton)
A
- obtain nutrients from keratin–common and benign
- Athlete’s foot or tinea pedis
- Ringworm of the body or tinea corpora
- Facial ringworm or tinea faciei
- Blackdot ringworm or tinea capitis
- Scalp ringworm or tinea capitis
- Ringworm of the hands or tinea manuum
- Ringworm of the nail, Onychomycosis, or tinea unguium
12
Q
Mycetoma
A
- chronic granulomatic + suppurative cutaneous disease-through breaks in the skin
- tropical workers–affect feet: MADURA FOOT
- disfiguring skin infection–abscesses that combine–large abscesses with ulceration–purulent discharge-white or black.
