FIRST AID FOR THE USMLE FINAL TEST
2026 QUESTIONS WITH CORRECT
ANSWERS GRADED A+
◍ DNA viruses are the HHAPPPPy viruses.
Answer: Hepadna, Herpes, Adeno, Pox, Parvo, Papilloma, Polyoma
◍ New infiltrate on CXR, increased sputum production; sweet odor possible;
mechanical ventilation, endotracheal intubation.
Answer: Late onset: P. aeruginosa, Klebsiella, Acinetobacter, S. aureus
◍ Rash on hands and feet, what organism?.
Answer: Coxsackie A virus, Treponema pallidum, Rickettsia rickettsii
◍ Osteomyelitis IV drug abuse.
Answer: Pseudomonas, Candida, S. aureus are most common
◍ Erythema, induration, tenderness, drainage from access sitesIntravascular
catheter.
Answer: -S. aureus (including MRSA)S. epidermidis (long
term)Enterobacter
◍ Scarlet fever.
Answer: Blanching Scarlet rash with sandpaper-like texture, strawberry
tongue, circumoral pallor, subsequent desquamation in setting of Group A
strep pharyngitis (erythrogenic toxin +)
◍ Pertussis toxin.
Answer: Bordetella pertussis exotoxinInhibits phagocytic
abilityOveractivates adenylate cyclase (increasing cAMP) by disabling Gi,
impairing phagocytosis to permit survival of microbeWhooping
cough—child coughs on expiration and "whoops" on inspiration (toxin may
, not actually be a cause of cough; can cause "100-day cough" in adults)
◍ What are you most likely to contract from a HUMAN Bite?.
Answer: Anaerobes StreptococciEikenella corrodens (Clenched-fist injury,
Bite that occurred during a "fist fight")
◍ Bunyaviruses virology.
Answer: -RNA-Enveloped -SS circular 3 segments-HelicalCalifornia
encephalitisSandfly/Rift Valley feversCrimean-Congo hemorrhagic
feverHantavirus—hemorrhagic fever, pneumonia
◍ 3 CNS protozoa infections.
Answer: 1. Toxoplasmosis 2. Naeglera fowleri 3. Trypanosoma brucei
◍ Pilus/Fimbria on bacteria is composed of what? What is the function?.
Answer: Composition: GlycoproteinFunction: Mediate adherence of bacteria
to cell surface, sex plus during conjugation.
◍ Oval-shaped vesicles on palms and soles; vesicles and ulcers in oral mucosa.
Answer: Coxsackievirus type A (hand-foot-mouth disease)
◍ EBV infects B cells through ____..
Answer: CD21
◍ Parvovirus virology.
Answer: -DNA-Naked -SS and linear (smallest DNA virus)-B19
virus—aplastic crises in sickle cell disease, "slapped cheeks" rash in
children (erythema infectiosum, or fifth disease)-RBC destruction in fetus
leads to hydrops fetalis and death, in adults leads to pure RBC aplasia and
rheumatoid arthritis-like symptoms
◍ Exotoxin toxicity.
Answer: High (fatal dose on the order of 1 μg)
◍ Pelvic inflammatory disease.
Answer: Top bugs: Chlamydia trachomatis (subacute, often
undiagnosed)Neisseria gonorrhoeae (acute). C. trachomatis—most common
bacterial STI in the United States. Cervical motion tenderness (chandelier
, sign), purulent cervical discharge (see picture A). -PID may include
salpingitis, endometritis, hydrosalpinx, and tubo-ovarian abscess.Salpingitis
is a risk factor for ectopic pregnancy, infertility, chronic pelvic pain, and
adhesions.Can lead to Fitz-Hugh-Curtis syndrome— infection of the liver
capsule and "violin string" adhesions of peritoneum to liver (see picture B).
◍ EHEC (toxin, mechanism, and presentation).
Answer: Also called STEC (Shiga toxin-producingE. coli). O157:H7 is most
common serotype in U.S.Often transmitted via undercooked meat, raw leafy
vegetables.Shiga-like toxin causes hemolytic-uremic syndrome:Triad of
anemia, thrombocytopenia, and acute renal failure due to micro thrombi
forming on damaged endothelium --> mechanical hemolysis (with
schistocytes on peripheral blood smear), platelet consumption, and
decreased renal blood flow.-Dysentery (toxin alone causes necrosis
andinflammation).-Does not ferment sorbitol (distinguishes EHECfrom
other E. coli).
◍ 72-hr cycle (quartan) fever.
Answer: P. malariae malariae
◍ Capsule will be composed of what on bacteria? What is the benefit of a
capsule?.
Answer: Function: Protects against phagocytosisComposition: Organized,
discrete polysaccharide layer (except Bacillus anthracis, which contains
d-glutamate)
◍ Pseudomembranous colitis; caused by antibiotics; occasionally bloody
diarrhea.
Answer: C. difficile
◍ Trichomonas vaginalis diagnosis.
Answer: Trophozoites (motile) (see picture) on wet mount; "strawberry
cervix"
◍ Treatment for chlamydiae infections.
Answer: Azithromycin (favored because one-time treatment) or
, doxycycline.
◍ Endotoxin vaccines.
Answer: No toxoids formed and no vaccine available
◍ When performing a thoracentesis, where should the needle be placed with
regard to the ribs/intercostal space and why?.
Answer: When performing a thoracentesis, where should the needle be
placed with regard to the ribs/intercostal space and why?- should be placed
SUPERIOR to the rib- the vessels run on the inferior portion of each rib in
the costal groove (superior to inferior = VAN --> vein, artery, nerve)
◍ Portal hypertension.
Answer: Schistosoma mansoni, Schistosoma japonicum
◍ Dog or cat bite, what organism?.
Answer: Pasteurella multocida
◍ Echinococcus granulosus.
Answer: Cestode - tapewormTransmitted via ingestion of eggs from dog
feces. Sheep are an intermediate host Causes hydatid cysts (see picture D) in
liver , causing anaphylaxis if antigens released (hydatid cyst injected with
ethanol or hypertonic saline to kill daughter cysts before
removal)Treatment: albendazole
◍ Taenia solium.
Answer: Cestode - tapewormTransmission: ingestion of larvae encysted in
undercooked pork, and ingestion of eggs contaminated in human fecesPork
ingested infection causes intestinal infection treated by praziquantelEgg
ingestion infection causes cysticercosis, neurocysticercosis (see picture B)
treated with praziquantel; albendazole for neurocysticercosis
◍ Trypanosoma brucei diagnosis.
Answer: Trypomastigote in Blood smear (see picture)
◍ Lactose fermenting enterics special culture requirements.
Answer: MacConkey agar - fermentation produces acid, causing colonies to
2026 QUESTIONS WITH CORRECT
ANSWERS GRADED A+
◍ DNA viruses are the HHAPPPPy viruses.
Answer: Hepadna, Herpes, Adeno, Pox, Parvo, Papilloma, Polyoma
◍ New infiltrate on CXR, increased sputum production; sweet odor possible;
mechanical ventilation, endotracheal intubation.
Answer: Late onset: P. aeruginosa, Klebsiella, Acinetobacter, S. aureus
◍ Rash on hands and feet, what organism?.
Answer: Coxsackie A virus, Treponema pallidum, Rickettsia rickettsii
◍ Osteomyelitis IV drug abuse.
Answer: Pseudomonas, Candida, S. aureus are most common
◍ Erythema, induration, tenderness, drainage from access sitesIntravascular
catheter.
Answer: -S. aureus (including MRSA)S. epidermidis (long
term)Enterobacter
◍ Scarlet fever.
Answer: Blanching Scarlet rash with sandpaper-like texture, strawberry
tongue, circumoral pallor, subsequent desquamation in setting of Group A
strep pharyngitis (erythrogenic toxin +)
◍ Pertussis toxin.
Answer: Bordetella pertussis exotoxinInhibits phagocytic
abilityOveractivates adenylate cyclase (increasing cAMP) by disabling Gi,
impairing phagocytosis to permit survival of microbeWhooping
cough—child coughs on expiration and "whoops" on inspiration (toxin may
, not actually be a cause of cough; can cause "100-day cough" in adults)
◍ What are you most likely to contract from a HUMAN Bite?.
Answer: Anaerobes StreptococciEikenella corrodens (Clenched-fist injury,
Bite that occurred during a "fist fight")
◍ Bunyaviruses virology.
Answer: -RNA-Enveloped -SS circular 3 segments-HelicalCalifornia
encephalitisSandfly/Rift Valley feversCrimean-Congo hemorrhagic
feverHantavirus—hemorrhagic fever, pneumonia
◍ 3 CNS protozoa infections.
Answer: 1. Toxoplasmosis 2. Naeglera fowleri 3. Trypanosoma brucei
◍ Pilus/Fimbria on bacteria is composed of what? What is the function?.
Answer: Composition: GlycoproteinFunction: Mediate adherence of bacteria
to cell surface, sex plus during conjugation.
◍ Oval-shaped vesicles on palms and soles; vesicles and ulcers in oral mucosa.
Answer: Coxsackievirus type A (hand-foot-mouth disease)
◍ EBV infects B cells through ____..
Answer: CD21
◍ Parvovirus virology.
Answer: -DNA-Naked -SS and linear (smallest DNA virus)-B19
virus—aplastic crises in sickle cell disease, "slapped cheeks" rash in
children (erythema infectiosum, or fifth disease)-RBC destruction in fetus
leads to hydrops fetalis and death, in adults leads to pure RBC aplasia and
rheumatoid arthritis-like symptoms
◍ Exotoxin toxicity.
Answer: High (fatal dose on the order of 1 μg)
◍ Pelvic inflammatory disease.
Answer: Top bugs: Chlamydia trachomatis (subacute, often
undiagnosed)Neisseria gonorrhoeae (acute). C. trachomatis—most common
bacterial STI in the United States. Cervical motion tenderness (chandelier
, sign), purulent cervical discharge (see picture A). -PID may include
salpingitis, endometritis, hydrosalpinx, and tubo-ovarian abscess.Salpingitis
is a risk factor for ectopic pregnancy, infertility, chronic pelvic pain, and
adhesions.Can lead to Fitz-Hugh-Curtis syndrome— infection of the liver
capsule and "violin string" adhesions of peritoneum to liver (see picture B).
◍ EHEC (toxin, mechanism, and presentation).
Answer: Also called STEC (Shiga toxin-producingE. coli). O157:H7 is most
common serotype in U.S.Often transmitted via undercooked meat, raw leafy
vegetables.Shiga-like toxin causes hemolytic-uremic syndrome:Triad of
anemia, thrombocytopenia, and acute renal failure due to micro thrombi
forming on damaged endothelium --> mechanical hemolysis (with
schistocytes on peripheral blood smear), platelet consumption, and
decreased renal blood flow.-Dysentery (toxin alone causes necrosis
andinflammation).-Does not ferment sorbitol (distinguishes EHECfrom
other E. coli).
◍ 72-hr cycle (quartan) fever.
Answer: P. malariae malariae
◍ Capsule will be composed of what on bacteria? What is the benefit of a
capsule?.
Answer: Function: Protects against phagocytosisComposition: Organized,
discrete polysaccharide layer (except Bacillus anthracis, which contains
d-glutamate)
◍ Pseudomembranous colitis; caused by antibiotics; occasionally bloody
diarrhea.
Answer: C. difficile
◍ Trichomonas vaginalis diagnosis.
Answer: Trophozoites (motile) (see picture) on wet mount; "strawberry
cervix"
◍ Treatment for chlamydiae infections.
Answer: Azithromycin (favored because one-time treatment) or
, doxycycline.
◍ Endotoxin vaccines.
Answer: No toxoids formed and no vaccine available
◍ When performing a thoracentesis, where should the needle be placed with
regard to the ribs/intercostal space and why?.
Answer: When performing a thoracentesis, where should the needle be
placed with regard to the ribs/intercostal space and why?- should be placed
SUPERIOR to the rib- the vessels run on the inferior portion of each rib in
the costal groove (superior to inferior = VAN --> vein, artery, nerve)
◍ Portal hypertension.
Answer: Schistosoma mansoni, Schistosoma japonicum
◍ Dog or cat bite, what organism?.
Answer: Pasteurella multocida
◍ Echinococcus granulosus.
Answer: Cestode - tapewormTransmitted via ingestion of eggs from dog
feces. Sheep are an intermediate host Causes hydatid cysts (see picture D) in
liver , causing anaphylaxis if antigens released (hydatid cyst injected with
ethanol or hypertonic saline to kill daughter cysts before
removal)Treatment: albendazole
◍ Taenia solium.
Answer: Cestode - tapewormTransmission: ingestion of larvae encysted in
undercooked pork, and ingestion of eggs contaminated in human fecesPork
ingested infection causes intestinal infection treated by praziquantelEgg
ingestion infection causes cysticercosis, neurocysticercosis (see picture B)
treated with praziquantel; albendazole for neurocysticercosis
◍ Trypanosoma brucei diagnosis.
Answer: Trypomastigote in Blood smear (see picture)
◍ Lactose fermenting enterics special culture requirements.
Answer: MacConkey agar - fermentation produces acid, causing colonies to
