BUGS DRUG 3 Flashcards
Picornoviridae
4 genera
Subgroups
\+ sense ssRNA, nonenveloped, icosohedral
Genera
1)Enterovirus (intestinal and lymphoid infection) fecal oral spread
- Poliovirus
-Cocksackie A and B
- Echovirus
2) Rhinovirus
3) Hepatovirus
4) parechovirus
Poliovirus
Infects:
- Peyers patches and tonsils (fecal oral spread and resp secretions)
- motor neurons (paralytic poliomyelitis)
- risk paralysis increases as one gets older
- primarily anterior horn, some presynaptic destruction (no sensory)
Disease course: mild illness -> +- aseptic meningitis -> +- paralytic poliomyelitis
Vaccine:
- salk: formalin-killed injected, IgG made. No paralytic polio assoc.
- Sabin: Attenuated. Oral, spread to contacts. IgA and IgG made. Occasionally paralytic polio virulance is picked up, should NOT be used in immunocompromised.
Most common cause of aseptic meningitis in the USA
Enteroviruses .
=cocksackie A/B, echovirus, new enteroviridae
Cocksackie A
Mild illness: Attack rate near 100%!
- Herpangina: fever, sore throat, small red based vesicles back of throat
- Hand, foot, mouth: mild illness, malaise, fever, oral vesicles, small tender lesions hands, feet, buttocks.(Enterovirus 71 can also cause)
Cocksackie B
Pleurodynia: Fever, headache, lower pleuritic pain
-Cock B = 50% of viral myocarditis/pericarditis. Can be mild->severe. Worse when younger. 10% progress to dilated cardiomyopathy, the rest recovers.
Common cold offenders
rhinovirus and coronaviridae
Famousness of coronaviridae
Common cold + SARS.
SARS
fever, myalgia, chills - >dry cough -> severe resp involvement -> ARDS
Enterovirus considerations
Different serotypes cause different clinical manifestations.
-Aseptic meningitis, hemorrhagic conjunctivitis, MOST COMMON cause of fever/rash (exanthums) in children summer/fall.
Enteroviurs 71 -> Hand foot mouth
HAV
more mild hepatitis. Vaccine available
Pinworm (Enterobius vermicularis)
Most common Helminth infection in the USA
- fecal/oral transmission
- larvae hatch in small intestine
- mature in cecum
- lay eggs in perianal area
Mild Symptoms:
- asymptomatic
- allergy to secretions/pruritis + 2ndary bacterial infection w/fatigue
- granuloma’s in vagina
- rare penetration of bowel wall and migration
Tx; Mebendazole (vermox)
whipworm
Appears whiplike
-eggs require soil to mature and become infectious
Symptoms
- asymptomatic
- anemia
- abdominal pain
- dysentery
- growth retardation if severe infection >200 worms
Tx; Mebendazole (vermox)
Ascaris Lumbricoides
1billion infected, huge 30cm.
Tropics and southern mountainous USA
Life cycle: Egg ingested -> hatch in duodenum -> penetrate intestinal wall into BV’s -> liver/heart/pulmonary circulation -> grow/molt in alveoli -> crawl up/coughed/swallowed (3mo after ingestion) ->mate/lay eggs in intestines
Symptoms:
- pneumonitis
- intestinal obstruction
- migration to bile duct/pancreas/liver
- malnutrition in children
Dx:Eggs in stool
Tx; Mebendazole (Vermox)
hookworm
BLOOD SUCKERS
Some Southeastern USA prevalence
Life Cycle:
Larvae hatch/mature in stool -> penetrate human skin as FILARIFORM LARVAE -> lung -> trachea ->swallowed/mature and attach to intestinal wall (suck blood and eat protein) and mate-> live 5-18yrs depending on species
Symptoms:
- Asymptomatic unless high worm burden
- anemia/protein deficiency if poor nutrition and/or high worm burden
Tx; Mebendazole
nematode is what?
roundworm
platyhelminthe is what?
flatworm
intestinal nematode is what?
Nematode that matures into adult in human intestinal tract
Ingested roundworms
EAT these Enterobius vermicularis (pinworm) Ascaris Lumbricoides (giant roundworm) Trichuris Trichiura (whipworm)
Cutaneous invasion roundworms
invade your feet through SANd
Strongyloides Stercoralis Ancylostoma duodenale (hookworm) Necator americanus (hookworm)
Strongyloides Stercoralis
Penetrate skin -> lungs -> cough/swallow
**Eggs are not passed in stool, filariform larvae hatch in SAME host
THUS
a) Autoinfection
b) Direct cycle (passed out in stool to new host)
c) Indirect (passed into stool and mature to male/female ->reproduce -> filariform hatch)
**dissemination and severe autoinfection in immunosuppressed patients.
Dx; larvae in feces (no eggs as noted)
Tx; albendazole
Drug for all intestinal nematodes
Mebendazole/albendazole/thiabendazole -> paralyze worms and pass them out of stool
Dimorphic systemic mycoses
Histolplasmosis capsulatum, blastomyces, coccidiodomycosis
