Infectious - Internal Medicine Flashcards
[Diagnose]
20/M painful penile rash on his penis. Multiple vesicular lesions on an erythematous base present.
Dx: Genital Herpes
Etiology: HSV Type 2
Initial Test: Tzank smear
Accurate Test: Detect virus, viral antigen, viral DNA in scraping from lesions
[Diagnose]
20/M non-painful rash on his penis. PE: non-tender ulcerated nodule
Dx: Primary syphilis Etiology: T. pallidum Most infectious state: secondary syphilis Accurate Test: Dark Field microscopy Tx: single dose penicillin IM
[Diagnose]
20/M painful penile rash on his penis. Multiple vesicular lesions on an erythematous base present.
What will you see in Tzank Smear?
giant cells or intranuclear inclusions
What is the drug of choice for HSV encephalitis and neonatal herpes?
IV acyclovir
[Diagnose]
20/M with a previous history of non-painful ulcerated penile nodule 2 weeks ago. Now has widely distributed macular rash on palms and soles; presence of condyloma lata
Dx: Secondary syphilis Etiology: T. pallidum Most infectious state: secondary syphilis Accurate Test: RPR/VDRL or FTA ABS Tx: single dose penicillin IM
[Diagnose]
20/M with a previous history of non-painful ulcerated penile nodule, macular rash on palms and soles and presence of condyloma lata.
Years later, patient has tabes dorsalis, gummas, Argyll-Robertson pupil
Dx: Tertiary syphilis
Etiology: T. pallidum
Most infectious state: secondary syphilis
Accurate Test: RPR/VDRL or FTA ABS or Lumbar punction
Tx: single dose penicillin IM
If patient with syphilis is allergic with penicillin, what is the alternative drug?
Doxycycline
Compare chance vs chancroid in terms of etiology
Chancre = T. pallidum Chancroid = H. ducreyi
Compare chance vs chancroid in terms of presence of pain
Chancre = painless Chancroid = painful
[Diagnose]
26/F yellowish vaginal discharge and dysuria. history of unprotected sex.
yellow mucopurulent discharge from the cervical os.
Dx: Mucupurulent cervicitis
Etiology: N. gonorrhea or chlamydia trachomatis
Initial test: Gram staining
Accurate test: NAAT or culture
Tx: single dose regimen for gonorrhea + treat chlamydia
What is the single best test for both chlamydia and gonorrhea
Nucelic acid amplification test
what is the therapy for both gonorrhea + chlamydial infection?
(Neisseria)
1. Ceftriaxine 250mg IM SD OR Cefixime 400mg PO SD
PLUS
(Chlamydia)
2. Doxycycline 100mg PO BID x 7days OR Azithromycin 1g PO SD
- Ceftriaxine 250mg IM SD OR Cefixime 400mg PO SD
PLUS
- Doxycycline 100mg PO BID x 7days OR Azithromycin 1g PO SD
In the regimen above, which covers for chlamydial infection?
Azithromycin or Doxycycline
In chlamydial treatment, which is contraindicated in pregnancy?
Doxycycline
[Diagnose]
20/F, lower abdominal pain, tenderness, fever. (+) leukocytosis and cervical motion tenderness
Dx: PID Next step: Pregnancy test Initial test: cervical culture or NAAT Accurate test: laparoscopy Tx: Ceftriaxone IM + 14days Doxycycline + 14 days metronidazole
[Diagnose]
20/F vulvar itching/irritation
white clumped discharge
Dx: Vulvovaginal Candidiasis
Etiology: C. albicans
Tx: Fluconazole 150mg PO SD
[Diagnose]
20/F vulvar itching, produse white/yellow homogenous discharge.
Dx: Trichomonal vaginitis
Etiology: T. vaginalis
Tx: Metronidazole 2g PO SD OR Metronizadole 500mg BID PO x 7 days
[Diagnose]
20/F fishy odor with 10% KOH, slightly increased vaginal discharge
presence of vaginal epithelial cells with cocobacillary organisms giving a granular apperance
Dx: Bacterial vaginosis
Etiology: Gardnerella vaginalis
Tx: Metronidazole 500mg BID PO x 7 days
Treat the asymptomatic partner
“Clue cells”
[Diagnose]
18/M with loose bowel stools 6 hours after eating potato and egg salad.
(+) Nausea, vomiting, crampy bdominal pain
Dx: Bacterial food poisoning
Etiology: S. aureus
Next step: hydrate
what is the marker of fecal leukocytes that is more sensitive and is available in latex agglutination and ELISA formats?
Fecal lactoferin
[Diagnose]
Watery diarrhea;
Stool findings - no fecal leukocytes, no increase in fecal lactoferrin
Dx: non-inflammatory
Location: Proximal small bowel
[Diagnose]
dysentery;
Stool findings - fecal PMN; substantial increase in fecal lactoferrin
Dx: inflammatory (invasion or cytotoxin)
Location: Colon or distal small bowel
[Diagnose]
Enteric feve
Stool findings: fecal mononuclear leukocytes
Dx: penetrating
Etiologies: S. typhi, Y. enterocolitica
[Dx: bacterial etiology food poisoning]
6 hours PTC, nausea, vomiting diarrhea
Ham, poultry, potato, mayonnaise, egg salad intake
Etiology: S. aureus
[Dx: bacterial etiology food poisoning]
6 hours PTC, nausea, vomiting diarrhea
Fried rice intake
Etiology: B. cereus
[Dx: bacterial etiology food poisoning]
8 hours PTC, abdominal crapms, diarrhea, no vomiting
beef, poultry, legumes, gravies intake
Etiology: C. perfringes
[Dx: bacterial etiology food poisoning]
8 hours PTC, abdominal crapms, diarrhea, no vomiting
cereals, dried beans intake
Etiology: B. cereus
[Dx: bacterial etiology food poisoning]
20 hours PTC, watery diarrhea
shellfish and water intake
Etiology: V. cholerae
[Dx: bacterial etiology food poisoning]
20 hours PTC, watery diarrhea
salad, cheese, meat, water intake
ETEC
[Dx: bacterial etiology food poisoning]
20 hours PTC, bloody diarrhea
ground beef, raw milk, salami, raw vegetables intake
EHEC
[Dx: bacterial etiology food poisoning]
20 hours PTC, inflammatory diarrhea
poultry, egg, dairy intake
Salmonella spp
[Dx: bacterial etiology food poisoning]
20 hours PTC, inflammatory diarrhea
poultry + raw milk intake
C. jejuni
[Dx: bacterial etiology food poisoning]
20 hours PTC, dysentery
potato, egg salad, lettuce and raw vegetables intake
Shigella spp
[Dx: bacterial etiology food poisoning]
20 hours PTC, dysentery
mollusk, crustacean intake
V. parahaemolyticus
[Diagnose]
18M with 2 day history of loose bowel stools, initially non bloody now bloody, after eating burgers, fries, spaghetti.
PE: stable VS, dry mouth abdominal pain, low grade fever
Labs: anemia and thrombocytopenia
Dx: Hemorrhagic colitis t/c HUS
Etiology: E. coli 0157:H7
Toxin: shiga toxin
What are the component sof hemolytic uremic syndrome
Acute renal failure
microangiopathy hemolytic anemia
Thrombocytopenia
[E. coli pathotype: defining molecular trait]
HUS, industrialized country,
Lambda-like Stx1 or Stx2 encoding bacteriophage
Etiology: EHEC/STED/ST-EAEC
Trait: Shiga toxin
[E. coli pathotype: defining molecular trait]
Travelers to developing country; virulence plasmids
Etiology: ETEC
Trait: Heat stable and labile enterotoxins, colonization factor
[E. coli pathotype: defining molecular trait]
watery or persistent diarrhea; young children and neonates
Presence of adherence factor plasmid
Etiology: EPEC
Trait: attaching and effacing lesion of intestinal epithelium
[E. coli pathotype: defining molecular trait]
dysentery; developing country, virulence plasmid
Etiology: EIEC
Trait: invasion of colonic epithelial cells
[E. coli pathotype: defining molecular trait]
acute and persistent diarrhea, travelers diarrhea; both in developing and developed countries
Etiology: EAEC
Trait: aggregative/diffuse adherence; virulence factors regulated by AggR
[Diagnose]
40M fever, right sided abdominal pain/RUQ pain, no jaundice noted liver abscess on workup
anchovy paste on needle aspiration
Dx: Amebic liver abscess
Etiology: E. histolytica
Most common type of infection related to the pathogen: asymtomatic cyst passage
What is the definitive diagnosis of amebic colitis?
demonstration of hematophagous trophozoites of E. histolytica
How will you differentiate liver vs pyogenic abscess?
- Age: Pyogenic are older people
2. Gram staining and culture is the most important
What is the pathologic finding in intestinal amebiasis?
classic flask-shaped ulcer
What are the earliest colonic lesions of intestinal amebiasis?
microulcerations of the mucosa of the cecum, sigmoid, rectum
What will be your treatment regiment for asymptomatic carriers of amebiasis
- Iodoquinol (luminal) OR paramomycin
What will be your treatment regiment for acute colitis due to amebiasis?
- Iodoquinol (luminal)
2. paramomycin + Metronidazole 750mg PO x 5-10 dyas or Tinidazole
What will be your treatment regiment for amebic liver abscess?
- Iodoquinol (luminal)
2. paramomycin + Metronidazole 750mg PO x 5-10 dyas or Ornidazole
What is the most common cause of death due to parasitic infection worldwide?
malaria
What is the second most common cause of death due to parasitic infection worldwide?
E. hystolitica
{Diagnose]
30/M with 5-day history of fever and abdominal pain. Ha a history of travel to a developing country.
PE: Faint salmon-colored, maculopapular rash on the trunk (rose spots on trunk and chest)
Dx: Typhoid fever
Etiology: S. typhi or paratyphi
Accurate test: Blood culture
Tx: Ciprofloxacin
What is the most common manifestation of salmonella infection?
Enterocolitis
In S. typhi, when will you see the relative bradycardia?
at the peak of high fever
GI bleeding and intestinal perforation in salmonella typhi infection is due to?
Hyperplasia, ulceration and necrosis of the ileocecal peyers patches at the initial site of salmonella infiltration
In salmonella culture, which source has the greatest sensitivity?
bone marrow
Where will you obtain your culture?
Abdominal pain, constipation, positive typhi dot
1st to 2nd week of illness
blood
Where will you obtain your culture?
Abdominal pain, constipation, positive typhi dot, gradual increase of temp
3rd week of illness
stool
In typhoid fever, the patient ‘s temp is rapidly rising/spiking, where will you get your culture?
blood
A typhoid patient developed nausea, vomiting, diarrhea at onset with low grade fever
stool
24/M waded on flood waters, developed fever, body aches, conjunctival suffusion and abdominal pain, jaundice with no UO
PE: 120/70, clear breath sounds, crea at 3mg/dL
Dx: leptospirosis Next step: hydrate with pNSS gold standard: culture and isolation First line abx mild : Doxycycline First line abx severe: penicillin G
Leptospira are able to survive in non immune host since they evade complement-mediated killing by means of ____
binding factor H
a strong inhibitor of the complement system
[phase of leptospirosis]
fever, 3-10 days
negative antibody
where will you get the culture?
Stage: Acute leptospiremic phase
Culture source: blood
Leptospires present in: blood
In acute leptospiremic phase, week 1,
Leptospire location:
Antibody titer:
Leptospire present in: Blood
Antibody titer: negative
In acute leptospiremic phase, week 2,
Leptospire location:
Antibody titer:
leptospire present in: CSF
Antibody titer: slightly increased
In leptospirosis convalescent stage,
Leptospire location:
Antibody titer:
Leptospire present in: urine
Antibody titer: high
What are the criteria for for leptospirosis?
- Residing in flooded area or has high risk exposure
- Acute febrile illness of at least 2 days
- At least 2 of the following:
C JOHAM
Calf tenderness, conjunctival suffusion, chills, Jaundice, Oliguria, Abdominal pain, Myalgia
At what phase of lepstosprirosis where dark field microscopy or IF is important?
Leptospiremic phase (1st 7 to 10 days)
__ is the test that has the highest yield during leptospiremic phase before the appearance of antibodies
PCR
Indirect detection of leptospirosis via Microagglutination test is confirmatory of there is ___ rise in titer
4 fold rise
Specific IgM rapid test for leptospirosis is sensitive and highly specific if take within ___ days
less than 7 days
What electrolyte is uniquely associated with leptospiral nephropathy?
magnesium
What is the first line treatment for mild cases of leptospirosis?
Doxycycline 100mg BOD PO
What is the first line treatment for severe cases of leptospirosis?
Penicillin G 1.5M units q68 IV for 7 days
What is the treatment of choice for pulmonary hemorrhage in leptospirosis?
bolus methylprednisolone within first 12 hours of onset
[leptospirosis prophylaxis]
Low risk
Doxycycline 100mg 2 caps SD
[leptospirosis prophylaxis]
moderate risk
Doxycycline 100mg 2 caps OD x 3-5 days
[leptospirosis prophylaxis]
high risk and continuous exposure
Doxycycline 100mg 2 caps once weekly until end of exposure
[Diagnose]
32/M fever, chills, diaphoresis. History of palawan trip.
enlarged liver and spleen
Dx: Malaria
Accurate test: Thick and thin blood smear
what is the infective stage during asexual cycle of malaria?
sporozoites
what are the dormant forms responsible for relapse?
hypnozoites
Plasmodium species capable of relapse
P. vivax
P. ovale
[Classify the species]
Malignant tertian
P. falciparum
[Classify the species]
benign tertian
P. vivax, P. ovale
[Classify the species]
benign quartan
P. malaria
What are the fatal complication of falciparum malaria?
- cerebral malaria
- malaria hyperpyrexia
- blackwater fever
[malaria]
The fever spikes after 48-72 hours coincides with
rupture of RBC
[malaria treatment according to WHO]
Uncomplicated falciparum
ACT for 3 days
[malaria treatment according to WHO]
severe falciparum malariaN
- Artesunanate IV/IM day 1
- ACT for 3 days
- Primaquine
[malaria treatment according to WHO]
Non-falciparum malaria
- ACT or chlorquine
2. Primaquine for 14 days for eradication of hypnozoites
[malaria treatment according to WHO]
pregnancy (1st trimester)
- Uncomplicated Falciparum: Quinine + Clindamycin (7 days)
2. Non-falciparum: quinine
[malaria treatment according to WHO]
prophylaxis
take antimalarial drugs 2 days to 2 weeks before departure; continue for 4 weeks after
[diagnose]
20/M. 3 days fever, body pains, abdominal pain and gum bleeding. Tourniquet test positive. Leukopenia and elevated Hct
Dx: Dengue fever with warning sign (gum bleeding)
Earliest CBC abnormality: decrease in total WBC
What are the factors that increases the susceptibility to severe dengue?
- <12 years old
- Female sex
- Had previous dengue virus followed by dengue virus 2
What is protective from severe dengue?
Malnutrition
What are the dengue warning signs?
LIC-PALM
- Lethargy
- Increase in Hct
- Clinical fluid accumulation
- Persistent vomiting
- Abdominal pain or tenderness
- Liver enlargement >2cm
- Mucosal bleed
What are the criteria for severe dengue?
- AST/ALT >/ 1000
- Impaired consciousness
- Shock
- Fluid accumulation with respiratory distress
[Phase of dengue]
non-specific signs and symptoms, tourniquet test, mucosal bleed, decreased WBC
Febrile phase (Day 2-7)
[Phase of dengue]
Defervescence, progressive leukopenia, rapid decrease in PC and increase Hct
Fluid accumulation
shock, organ impairment, DICm hemorrhage
critical phase (Day 3-7)
What is a physical examination sign of dengue recovery?
“herman’s rash”
isles of white in the sea of red
NS 1 antigen can be positve as early as ____
1 day after symptom
Dengue IgM is detected in the first ___ days of illness
first 5 days
What are the signs of plasma leakage in Dengue?
- Rising hematocrit
- Effusion or ascites
- Shock (decreased pulse pressure)
[Diagnosis]
26/M from Samar Isles. Weight liss, abdominal enlargement and coffee ground vomiting. Hepatosplenomegaly.
fecalysis: egg with small hook-like spine
Dx: Schistosomiasis
Etiology: Schistosoma japonicum
Infective stage: cercarial skin penetration
Tx: Praziquantel
What is the most important of the neglected tropical diseases?
Schistosomiasis
Itchy maculopapular rash masnifesting 2 or 3 days after skin invasion of schistosoma
Swimmers itch
Cercarial dermatitis
Katayama syndrome is also equivalent to ___
Acute schistosomiasis
[Schistosomiasis]
Occurs 4-8 weeks after skin invasion, fever, hepatosplenomegaly, high degree of eosinophilia
Acute schistosomiasis
[Schistosomiasis]
begin few months after infection, colicky abdominal pain, bloody diarrhea, anemia, hepatosplenomegaly, portal hypertension, esophageal varices
chronic schistosomiasis
[Schistosomiasis]
egg induced granulomatous response lead to severe periportal fibrosis. It is also called
Symmers clay pipestem fibrosis
[Schistosomiasis]
Which lobe of the liver initially enlarges in hepatosplenic schistosomiasis?
left lobe
What is the most severe complication of hepatosplenic schistosomiasis?
Hematemesis
[Schistosomiasis]
What is the standard diagnostic method to diagnose schistosomiasis?
Detect schistosome egg in stool
[Diagnosis]
19/M sustained punctured wound after he step in a nail. Presents one week later with sore throat, difficulty talking and opening his mouth
Dx: Tetanus
Etiology: C. tetani
Toxin responsible: Tetanospasmin
Common site of infection: superficial abrasion to the limbs
What muscles are affected first: muscles of the face and jaw
What is the preferred treatment: metronidazole
What is the most common cause of death in tetanus?
Respiratory failure
What is the preferred antibiotic treatment for tetanus?
Metronidazole
Alternative: penicillin
Where is the most common infection site of tetanus infection in adults?
superficial abrasion
[HIV phase]
fever, skin rash, pharyngitis, myalgia
sudden onset of mononucleosis-like illness
Acute HIV syndrome
[HIV phase]
active virus replication
Asymptomatic Stage
[HIV]
Constitutional signs and symptoms start to appear in what CD4 level?
CD4 <200 dL
What is the hallmark of HIV?
profound immunodeficiency from progressive deficiency of helper T cells
What is the best predictor of long-term clinical outcome in HIV infection?
plasma viral load
What is the best predictor of short-term risk of developing and opportunistic infection?
CD4 lymphocyte count
What is the most common neurologic syndrome in AIDS?
AIDS dementia complex
What is the mean survival time from onset of severe AIDS dementia complex?
less than 6 months
What is the most common opportunistic infection affecting AIDS patient?
Pneumocystis pneumonia
Tx: TMP-SMX
The definitive dianosis of PCP pneumonia is by the use of what stain?
Giemsa or silver stain
When to start antiretroviral treatment?
CD4 <350 or presence of AIDS defining illness or symptomatic regardless of CD4
What is the regiment in treating HIV?
2 NRTI
1 NNRTI
What is the first line NRTI?
Zidovudine (AZT) + Lamivudine (3TC)
What is the first line NNRTI?
Nevirapine
What is the most common diagnosis of FUO among the neoplasms?
Malignant lymphoma
What is the most common implicated infectious organism in FUO?
TB
