Infectious Diseases

A 38-year-old male, HBsAg(+) for 5 years, with recurrent ALT elevations over the past 2 years (resolved after treatment). For the past 2 months, he reports fatigue and poor appetite. Exam: no scleral icterus, no palmar erythema or spider angiomas, liver palpable 1 cm below costal margin, spleen palpable laterally. ALT 420 IU/L, TbiL 20 μmol/L, HBsAg(+). The most likely diagnosis is:

For a suspected Class A infectious disease patient before definitive diagnosis, they should be placed in a designated location for

A 28-year-old male farmer presents with fever, headache, and poor appetite for 4 days after harvest, and reduced urine output for 2 days. He is diagnosed with epidemic hemorrhagic fever. On day 2 of hospitalization, he develops anuria, worsening edema, restlessness, dyspnea, and cough. Examination reveals orthopnea, jugular vein distension, heart rate 140/min, gallop rhythm, extensive bilateral rales, and BP 186/94 mmHg. Laboratory tests show BUN 60 mmol/L and Cr 430 μmol/L. The mechanism underlying these symptoms and signs is:

An 18-year-old male presented with diarrhea yesterday, passing 5-6 loose stools. Today, the stools became mucopurulent, occurring every 2 hours with small volume, accompanied by tenesmus. Physical examination: soft abdomen, tenderness in the left lower quadrant, and hyperactive bowel sounds. Laboratory tests: WBC 14.6×10⁹/L (neutrophils 86%), stool microscopy showed RBCs 20/HP, WBCs covering the entire field, and macrophages 0-1/HP. Multiple similar diarrhea cases were reported in his class this week. Clinical diagnosis: bacillary dysentery. Which of the following measures is NOT immediately required?

A 35-year-old male official developed fever, headache, and myalgia 5 days after returning from flood relief work in a rural area, followed by oliguria, dark urine, and epistaxis, leading to hospitalization. Examination: temperature 39.6°C, marked scleral icterus, liver enlarged 2 fingerbreadths below the costal margin with tenderness, non-palpable spleen, and inguinal lymphadenopathy. Laboratory tests: total bilirubin 214 μmol/L, ALT 200 U/L, HBsAg(+), urinary protein (+++), hematuria (RBCs covering the field), Widal test 'O' 1:40, 'H' 1:320, and serum agglutination test 1:400. The diagnosis is:

A 31-year-old female presents with persistent high fever, right lower abdominal pain, and diarrhea for 1 week (onset: August 2). Stools occur 3-4 times daily, with mucus and occasional fresh blood. Physical exam: temperature 40°C, heart rate 92/min, lungs clear, 3-4 red rashes on the chest, soft abdomen, mild tenderness in the right lower quadrant, liver 2 cm below the costal margin, spleen palpable 1 cm below the costal margin. Laboratory tests: WBC 4.2×10⁹/L (Neutrophils 60%, Lymphocytes 36%, Monocytes 4%), stool microscopy shows WBC 2-4/HP, RBC 0-2/HP, stool culture negative. The most likely diagnosis is:

A 43-year-old male presented with fever for 3 days accompanied by headache and general malaise. He visited a hospital on August 9 and was treated for upper respiratory infection without improvement. His temperature continued to rise, and he was hospitalized on day 10 of illness. Physical examination: temperature 40.2°C, somnolence, HR 100 bpm, soft S1, liver palpable 2 cm below the costal margin with soft consistency, spleen palpable 1 cm below the costal margin, mild abdominal distension. Laboratory tests: WBC 4.0×10⁹/L (N 68%, L 32%), ALT 160 U/L, anti-HBc (+), HAV-IgM (-), EKG showed myocardial damage. Widal test results: 'O' 1:80, 'H' 1:160. The most likely diagnosis is:

An 8-year-old male presents with persistent high fever for 12 days, accompanied by diarrhea (3-5 times/day) and vague right lower abdominal pain. Physical exam: liver palpable 2 cm below the costal margin, spleen palpable 1.5 cm below the costal margin. Laboratory tests: WBC 2.5×10⁹/L (band neutrophils 10%, segmented neutrophils 60%, lymphocytes 30%), stool shows few WBCs and pus cells, ALT 100 U/L, total serum bilirubin 48 μmol/L, anti-HBs positive, Widal test (O 1:160, H 1:160), Leptospira agglutination test 1:200, urinary protein (+), urobilinogen (+), urinary bilirubin (-). The most likely diagnosis is:

Diarrhea caused by cholera

A 22-year-old male farmer was admitted with watery diarrhea for 1 day. No fever or tenesmus since onset. Stool contained small fecal matter, >10 times/day, no abdominal pain. After 3 hours, projectile vomiting occurred and was continuous. Clinical diagnosis: cholera. Which stage of the clinical course is this patient in?

A 26-year-old woman presents with 1 week of fever, fatigue, poor appetite, nausea, vomiting, and dark urine. Over the past 2 days, fever subsided but jaundice rapidly worsened with somnolence. Lab results: ALT 660 IU/L, AST 450 IU/L, total bilirubin 250 μmol/L. Which of the following tests would be most valuable for further diagnosis?

Pathological features of chronic active hepatitis

A 20-year-old male presents with fatigue and poor appetite for 5 days, dark urine for 3 days. Physical examination reveals icteric sclera, liver palpable 1 cm below the costal margin, spleen not palpable. ALT is 1250 U/L, anti-HBs (+), anti-HAV IgM (+). He had a history of 'acute icteric hepatitis' 3 years ago, now fully recovered. The most likely diagnosis is:

A 25-year-old male presents with anorexia, fatigue, nausea and vomiting for 1 week. Laboratory tests show: total bilirubin (TBil) 46 μmol/L, ALT 200 U/L, HAV-IgM(+), HAV-IgG(+), HBsAg(+), HBeAg(+), anti-HBc(+). The diagnosis is:

A 39-year-old male office worker, previously found to be HBsAg(+) (1:256) with normal ALT during a physical exam 2 years ago, remained stable on follow-up. Presented with fever, fatigue, poor appetite, and dark urine for 1 week. Laboratory tests: total bilirubin (TBil) 51 μmol/L, ALT 260 U/L, HAV-IgM(+), HBsAg(+). The diagnosis is:

A 24-year-old male developed icteric hepatitis B 3 months ago. For the past week, he has had fever and bleeding from skin and mucous membranes. Lab findings: hemoglobin 70 g/L, RBC 2.5×10¹²/L, WBC 1.5×10⁹/L (differential: neutrophils 0.2, lymphocytes 0.78, monocytes 0.02), reticulocytes 0.001. Bone marrow smear shows significant reduction in erythroid, myeloid, and megakaryocytic series, with lymphocytes 0.74. The most likely diagnosis is:

A 20-year-old male farmer was admitted in early January with a 5-day history of sudden onset chills, high fever (39.5°C), myalgia, nausea, vomiting, and passing 200ml of bloody urine. Physical examination showed periorbital edema, conjunctival and chest skin congestion, petechiae in the axilla, and a 1cm×2cm bruise at the injection site on the buttock. Lab results: Hemoglobin 160g/L, RBC 5.1x10¹²/L, WBC 64×10⁹/L (blast cells 12%, band cells 15%, neutrophils 43%, lymphocytes 30%), platelets 80×10⁹/L. The most likely diagnosis is:

On day 6 of hemorrhagic fever with renal syndrome, a patient has a daily urine output of only 80ml, BP of 176/110 mmHg, bounding pulse, facial edema, engorged superficial veins, and scattered rales at both lung bases. Which of the following treatment measures should be taken for this patient?

A 5-year-old girl was admitted on February 10 with fever, headache, vomiting for 4 days, and restlessness for 1 day. Examination: temperature 39.3°C, pulse 123/min, restlessness, neck stiffness, multiple petechiae on the abdomen, Kernig's sign (+), Brudzinski's sign (-). CBC: WBC 17×10⁹/L (N 89%). CSF: pressure 312mmH₂O, cell count 2.4×10¹²/L (N 95%), protein 1.65g/L, glucose 1.5mmol/L, chloride 89mmol/L. The most likely diagnosis is:

A 16-year-old male presents with fever for 1 day and abdominal pain, diarrhea for half a day on October 20. He has had over 10 episodes of bloody mucopurulent diarrhea, T 39.4°C, BP 110/70 mmHg, and left lower abdominal tenderness. The primary diagnosis to consider is:

A 56-year-old woman ate contaminated fruit yesterday and developed fever, abdominal pain, and diarrhea at night. The stool contained pus and blood, was scanty, and occurred more than 10 times a day, accompanied by tenesmus. Physical examination: temperature 39.5°C, normal blood pressure (BP), clear consciousness, no abnormalities in heart or lungs, tenderness in the left lower abdomen without rebound tenderness, white blood cell (WBC) count 18×10⁹/L (N0.85), stool microscopy showing red blood cells (RBC) (++), and pus cells (+++). What is the most important pathogenesis of this type of bacillary dysentery?

A 28-year-old woman. One year ago, she experienced left-sided abdominal pain accompanied by diarrhea, with 4-5 bowel movements per day, loose stools containing mucus and small amounts of pus/blood, but no fever, poor appetite, or vomiting. She self-administered furazolidone for 3 days, and symptoms resolved after discontinuation. Since then, bowel frequency increases with cold exposure or dietary indiscretion. This time, symptoms recurred after exertion. Stool microscopy: WBC 10-15/HP, RBC 5-6/HP. The most likely diagnosis is:

A 41-year-old male presents with fever for 2 weeks and right upper quadrant and right flank pain for 1 week. Physical exam: bulging right upper quadrant, liver 3 cm below the costal margin with tenderness on percussion and palpation. Ultrasound shows a 5 cm × 4 cm fluid level in the lower part of the right lobe of the liver. History of chronic diarrhea 1 month ago. Diagnosis: amoebic liver abscess. Which of the following treatments is incorrect?

A 40-year-old male farmer presents with sudden onset of chills and fever for 4 days, accompanied by headache and generalized myalgia (most prominent in the gastrocnemius muscle). He visited in mid-August and was treated for 'common cold' without improvement. After 3 days, he developed petechiae, ecchymoses, and icteric sclera, prompting hospitalization. Examination: temperature 39.4°C, icteric sclera, inguinal lymphadenopathy, liver 2 cm below the costal margin, and marked tenderness in the gastrocnemius muscle. Lab results: WBC 25.2×10⁹/L (neutrophils 80%), platelets 25×10⁹/L, urinary protein (++), urinary RBC 20–30/HP, and total bilirubin 53.2 μmol/L. What is the most likely diagnosis?

A 45-year-old male with chronic schistosomiasis for 10 years presents with hepatomegaly (liver 1.5 cm below costal margin, 4 finger-breadths below xiphoid), splenomegaly reaching umbilical level, positive serum anti-Schistosoma japonicum antibody, and elevated ALT (100 U/L) without jaundice. The most effective treatment for the pathogen is:

A 28-year-old male presents with 5 days of fever accompanied by poor appetite, fatigue, abdominal pain, distension, and diarrhea. He self-medicated with antipyretics, co-trimoxazole, and chloramphenicol, but the fever persisted. On day 10 of illness, he was hospitalized. Examination: temperature 39.8°C, heart rate 92 bpm, spleen palpable 1 cm below the costal margin (soft consistency), blood culture (negative). Typhoid fever is highly suspected clinically. Which test should be performed next for definitive diagnosis?

A 40-year-old male fisherman, residing in a schistosomiasis endemic area with a habit of drinking untreated water, presents with 3 weeks of continuous high fever (40°C, remittent type), abdominal distension, and 2-3 mucoid stools daily. Physical exam reveals liver 2 cm below the costal margin and spleen 1 cm below the costal margin. Lab results show WBC count 3.0×10⁹/L (neutrophils 55%, lymphocytes 45%), eosinophil count zero, and cough. The most likely diagnosis is:

A 22-year-old male presented on August 10 with half a day of diarrhea (20+ episodes, watery stools), 5-6 episodes of vomiting, no fever or abdominal pain, oliguria, normal body temperature, BP 70/50 mmHg (10.8/6.7 kPa), sunken eyes, and dry mouth/tongue. Laboratory tests: Hb 160g/L, WBC 10.1×10⁹/L. The most likely diagnosis is:

A 34-year-old male farmer presents with frequent diarrhea and vomiting for 1 day (approximately 20 episodes), watery stools, calf muscle cramps, and no significant abdominal pain. Examination shows clear consciousness, signs of severe dehydration, BP 60/40 mmHg, plasma specific gravity 1.035, hematocrit 60%, WBC 18×10⁹/L, and stool microscopy with 0-2 WBC/HP. Stool suspension and smear tests suggest a preliminary diagnosis of paracholera. What is the most common gastrointestinal symptom pattern in cholera and paracholera?

A 42-year-old male presents with vomiting and diarrhea for 2 days, and confusion and restlessness for half a day. On examination: BP 110/70 mmHg, delirium, moderate scleral icterus, multiple spider angiomas on the neck, no abnormalities in heart and lungs, soft abdomen, liver not palpable below the costal margin, spleen 3 cm below the costal margin, ecchymosis at the puncture site of the upper limb. Hb 90g/L, WBC 3.2×10⁹/L, blood glucose 7.0 mmol/L, glycosuria (+), ketonuria (-), urine microscopy (-). The most likely diagnosis is:

A 45-year-old male with a 17-year history of chronic hepatitis B reports decreased stamina, occasional abdominal distension, and weight loss over the past year. One week ago, he developed diarrhea and abdominal pain after consuming contaminated food. Diarrhea improved with medication, but fever, severe abdominal pain, distension, yellow urine, and markedly decreased urine output occurred in the last 3 days. On admission: alert but agitated and talkative, chronic liver disease facies, mild icterus of the sclera, prominent palmar erythema, spider angiomas, no abnormalities in heart and lungs; abdominal distension, tenderness in the lower abdomen, mild rebound tenderness, positive ascites sign. Emergency labs: WBC 9.8×10⁹/L (neutrophils 89%), K⁺ 3.4 mmol/L, Na⁺ 137 mmol/L, Cl^- 98 mmol/L, blood ammonia 96 μmol/L. The primary basis for diagnosing hepatorenal syndrome (HRS) is:

A 21-year-old male presents with fatigue, poor appetite, nausea, and right upper quadrant discomfort for 4 days. No history of hepatitis. Physical examination shows icteric sclera and a tender, moderately firm liver palpable 2 cm below the costal margin. Suspecting hepatitis, which test should be ordered first?

A 28-year-old male farmer presented on October 30 with high fever, headache, low back pain, vomiting, and diarrhea, with continuous fever for 4 days and one episode of epistaxis. After taking paracetamol, the fever subsided, but dizziness, oliguria, and painful urination developed. Lab results: WBC count 18×10⁹/L (neutrophils 60%, atypical monocytes 12%, lymphocytes 23%), platelets 50×10⁹/L, and membranous substances in urine. The diagnosis is:

A 28-year-old male farmer presented with fever for 5 days accompanied by petechiae, transferred from a rural hospital to Zhongshan Hospital of Shanghai Medical University in November 1993. Physical examination: temperature 38°C, BP 70/50 mmHg, marked facial and periorbital congestion, conjunctival edema and congestion, cord-like petechiae in the axilla, and significant percussion tenderness in the kidney area. Epidemic hemorrhagic fever (EHF) was suspected. Which of the following is most helpful for confirming the diagnosis?

A 40-year-old male farmer presents with fever, headache, and diarrhea for 3 days, visiting on November 10. Physical exam: temperature 39°C, BP 50/30 mmHg, apathy, facial flushing, conjunctival congestion and edema, extensive fine petechiae in both axillae, no hepatosplenomegaly. Laboratory tests: WBC 32×10⁹/L, Hb 160 g/L, platelets 34×10⁹/L, urinary protein (+++), stool microscopy shows WBC 5-8/HP. Which lab test is most appropriate for diagnosis?

A 40-year-old male farmer presents with irregular fever for 3 days, accompanied by headache, low back pain, and blurred vision. Physical examination shows facial and upper chest congestion, conjunctival edema, petechiae, and scattered pin-sized petechiae in the axilla and back. Blood pressure is 90/60 mmHg. Due to similar cases in the village, he is transferred to a city hospital with a suspected diagnosis of epidemic hemorrhagic fever (febrile phase). The primary cause of bleeding at this stage is:

A 31-year-old male farmer was admitted on December 10 with fever and low back pain for 4 days, plus facial edema and oliguria for 2 days. Physical exam: temperature 38°C, BP 130/75 mmHg, facial congestion with edema, conjunctival edema, and petechiae in axillae. Laboratory tests: WBC 15×10⁹/L, platelets (PLT) 31×10⁹/L, atypical lymphocytes on blood smear, urinary protein (+++). A diagnosis of oliguric phase of epidemic hemorrhagic fever was made. Which of the following about epidemic hemorrhagic fever is INCORRECT?

A 40-year-old male presents with fever for 3 days accompanied by abdominal pain and diarrhea, passing stool over 20 times daily with small volume, containing mucus and pus/blood. Stool microscopy shows red blood cells (++), white blood cells (++), and mucus (++). A diagnosis of acute bacillary dysentery is made. Which segment of the intestine is primarily affected by the pathological changes in this disease?

An 18-year-old male presents with fever, abdominal pain, and diarrhea (10+ times/day), initially loose stools progressing to mucopurulent bloody stool with tenesmus. Stool microscopy shows WBC 15-20/HP and RBC 5-10/HP. The patient is diagnosed with acute bacillary dysentery. What is the pathogenesis?

A 17-year-old male patient ate street barbecue 2 days ago. Today he developed cold intolerance, fever, abdominal pain, diarrhea (5-6 times/day with mucus), and tenesmus. Physical exam: temperature 39°C, soft abdomen, left lower quadrant tenderness without rebound tenderness, active bowel sounds. The most clinically significant test is:

A 26-year-old male farmer presents with 5 days of fever and cold intolerance, followed by headache and 2 episodes of vomiting in the past day. Admitted on August 15. T39.6°C, conjunctival congestion, neck stiffness, inguinal lymphadenopathy with tenderness, gastrocnemius tenderness, and urinary protein (++). The diagnosis should be:

A 26-year-old male presents with sudden onset fever, cold intolerance, headache, and myalgia for 3 days after harvesting rice. Physical exam: temperature 38.6°C, conjunctival congestion, heart rate 90/min, clear lungs. Initially treated as 'upper respiratory infection' but symptoms persisted. Laboratory tests: WBC 21.6×10⁹/L (neutrophils 90%), seroagglutination test titer 1:400. Diagnosed with leptospirosis. What is the clinical type in this case?

A 23-year-old male farmer presents with 5 days of fever, chills, myalgia, nausea and vomiting, red-colored urine, and oliguria (100-200ml/day). Physical exam shows periorbital edema, conjunctival edema and hemorrhage, petechiae on the back and axilla, and ecchymoses on the upper arm. Lab results: Hb 180g/L, WBC 60×10⁹/L, platelets 34×10⁹/L, blood smear shows 12% blast cells and 20% atypical lymphocytes, urinalysis reveals RBCs full field and protein (+++). The most likely diagnosis is:

A 30-year-old male fisherman is admitted on September 10 with high fever, myalgia for 3 days, and hemoptysis for 1 day. Examination: temperature 39.2°C, BP 100/60 mmHg, mild irritability, conjunctival congestion, rales on lung auscultation, liver 2 cm below the costal margin. Laboratory tests: WBC 18.5×10⁹/L, serum agglutination-lysis test 1:400(+). Which drug is the first choice for pathogen treatment?

A 29-year-old male presents with 3 days of fever, headache, fatigue, decreased appetite, calf pain while walking, and cough. Physical examination: temperature 39.8°C, flushed face, conjunctival congestion, normal vision, bilateral inguinal lymphadenopathy, marked tenderness of the gastrocnemius muscle, no meningeal signs or pathological reflexes. Liver palpable 1.5 cm below the costal margin. White blood cell (WBC) count 12.7×10⁹/L (neutrophils 74%, lymphocytes 21%, eosinophils 3%, monocytes 2%). The patient frequently worked in rice paddies prior to symptom onset. Which laboratory test is most meaningful for diagnosis?

A 36-year-old male farmer presents with persistent high fever for 1 week, progressing to chills, high fever, body aches, lumbar muscle pain, conjunctival congestion, proteinuria (+++), inguinal lymph nodes the size of broad beans. From day 5 of illness, he develops persistent cough with hemoptysis, shortness of breath, gurgling phlegm in the throat, heart rate of 110 bpm, and cyanosis of the lips. The most likely diagnosis is:

An 18-year-old male was admitted with persistent fever for 1 week accompanied by fatigue and anorexia. Physical examination: temperature 39.4°C, pulse 92/min, liver palpable 2 cm below the costal margin, spleen palpable 1 cm below the costal margin. Laboratory tests: WBC 4.0×10⁹/L, neutrophils 62%, lymphocytes 35%, monocytes 3%. Blood culture grew Salmonella typhi. After 5 days of chloramphenicol treatment, the temperature normalized. On day 18 of illness, the patient passed melena (~50g). Which of the following is most relevant for the diagnosis and prognosis of typhoid fever?

A 26-year-old male with a habit of drinking untreated water presents with persistent high fever (40°C) for 3 weeks, accompanied by abdominal distension. Physical exam: T 39.3°C, P 104 bpm, lethargy, soft/flat abdomen, liver and spleen palpable at the costal margin. Laboratory tests: WBC 3.4×10⁹/L (neutrophils 51%, lymphocytes 49%). Widal test shows 'O' agglutination 1:160 (+) and 'H' agglutination 1:320 (+). The most likely diagnosis is:

A 20-year-old female presents with sudden onset diarrhea for 4 hours. Watery stools, over 10 episodes, large volume, and vomiting 3 times (initially gastric contents, later watery). Exam: temp 35.7°C, conscious but irritable, sunken eyes, dry cracked lips, heart rate 130/min, soft abdomen with no tenderness, BP 46/20 mmHg. The most urgent treatment is:

A 35-year-old male was found to be HBsAg(+) 3 years ago with no usual discomfort. To determine the presence of hepatitis B, the patient visited the outpatient clinic. [Hypothetical scenario] Abnormal findings were detected during the outpatient examination, leading to hospitalization. Liver biopsy revealed piecemeal necrosis, destruction of the limiting plate, and passive septum formation. The pathological diagnosis is:

A 42-year-old male presents to the emergency department with 2 days of vomiting and diarrhea, and half a day of confusion and restlessness. Examination: BP 110/70 mmHg, clouding of consciousness, moderate scleral icterus, multiple spider angiomas on the neck, no abnormalities in heart and lungs, soft abdomen, liver not palpable below the costal margin, spleen 3 cm below the costal margin, ecchymosis at the puncture site of the upper limb. Hb 90g/L, WBC 3.2×10⁹/L, blood glucose 7.0 mmol/L, glycosuria (+), ketonuria (-), urine microscopy (-). The most valuable auxiliary test for diagnosing hepatic encephalopathy is:

A 45-year-old male with a 17-year history of chronic hepatitis B reports decreased stamina, occasional abdominal distension, and weight loss over the past year. One week ago, he developed diarrhea and abdominal pain after consuming contaminated food. While diarrhea improved with medication, he developed fever, severe abdominal pain, distension, yellow urine, and markedly decreased urine output over the past 3 days. On admission: alert and oriented but agitated and talkative, chronic liver disease facies, mild icterus of the sclera, prominent liver palms, spider angiomas, no abnormalities in heart and lungs; abdominal distension, tenderness in the lower abdomen, mild rebound tenderness, positive ascites sign. Emergency labs: CBC: WBC 9.8×10⁹/L, neutrophils 89%; electrolytes: K⁺ 3.4 mmol/L, Na⁺ 137 mmol/L, Cl^- 98 mmol/L; blood ammonia 96 μmol/L. Which of the following treatments is inappropriate?

A 21-year-old male presents with fatigue, poor appetite, nausea, and right upper quadrant discomfort for 4 days. No history of hepatitis. Physical exam reveals icteric sclera and a tender, mid-firm liver palpable 2 cm below the costal margin. Suspected hepatitis with ALT 2460 U/L confirms acute viral hepatitis. The most critical treatment measure at this stage is:

A 32-year-old woman presents with 4 days of generalized myalgia and fever after harvesting rice, accompanied by cough, abdominal pain, and one episode of hemoptysis (50-60ml). Examination: temperature 39.2°C, pallor, conjunctival congestion, heart rate 140/min with gallop rhythm, bilateral lung rales/crackles, and gastrocnemius tenderness. A diagnosis of leptospirosis is suspected. The primary reservoirs of leptospirosis are:

A 28-year-old male farmer presents with fever for 5 days and petechiae, transferred from a rural hospital to Zhongshan Hospital of Shanghai Medical University in November 1993. Physical exam: temperature 38°C, BP 70/50 mmHg, marked facial and periorbital congestion, conjunctival edema and congestion, cord-like petechiae in the axilla, and significant renal tenderness. Suspected diagnosis: epidemic hemorrhagic fever. The patient has entered the hypotensive phase. Which of the following is NOT a typical laboratory finding in this phase?

A 28-year-old male farmer presents with fever, headache, and poor appetite for 4 days after harvest, and reduced urine output for 2 days. He is diagnosed with epidemic hemorrhagic fever. On day 2 of hospitalization, he develops anuria, worsening edema, restlessness, dyspnea, and cough. Examination reveals orthopnea, jugular vein distension, heart rate 140/min, gallop rhythm, extensive bilateral rales, and BP 186/94 mmHg. Laboratory tests show BUN 60 mmol/L and Cr 430 μmol/L. The most effective treatment at this stage is:

A 23-year-old male farmer presents with 5 days of fever, chills, myalgia, nausea and vomiting, red-colored urine, and oliguria (100-200ml/day). Physical exam shows periorbital edema, conjunctival edema and hemorrhage, petechiae on the back and axilla, and ecchymoses on the upper arm. Lab results: Hb 180g/L, WBC 60×10⁹/L, platelets 34×10⁹/L, blood smear shows 12% blast cells and 20% atypical lymphocytes, urinalysis reveals RBCs full field and protein (+++). On day 3, he develops sudden right-sided hemiplegia, aphasia, and seizures. By day 4, he is comatose with no response to orbital compression, unequal pupils, right Babinski sign (+), and BP 160/110 mmHg. The most likely diagnosis is:

A 40-year-old male farmer presents with fever, headache, and diarrhea for 3 days on November 10. Physical exam: temperature 39°C, BP 50/30 mmHg, apathy, facial flushing, conjunctival congestion and edema, and extensive petechiae in both axillae. No hepatosplenomegaly. Lab results: WBC 32×10⁹/L, Hb 160g/L, platelets 34×10⁹/L, urinary protein (+++), stool microscopy shows WBC 5-8/HPF. Which of the following is the most critical and urgent intervention?

In winter, a 42-year-old male presented to the emergency department with fever, headache, and low back pain for 3 days, with a temperature of 40-40.6°C. Examination revealed: BP 70/40 mmHg, pulse 110 beats/min, facial flushing, conjunctival congestion and edema, palatal petechiae and reticular congestion, scattered petechiae on the chest and axilla, no abnormalities in heart and lungs, and positive renal percussion tenderness. The most likely diagnosis is:

A 31-year-old male farmer was admitted on December 10 with fever and low back pain for 4 days, along with facial edema and oliguria for 2 days. Physical exam: temperature 38°C, BP 130/75 mmHg, facial congestion and edema, conjunctival edema, and petechiae in the axilla. Laboratory tests: WBC 15×10⁹/L, platelets (PLT) 31×10⁹/L, atypical lymphocytes on blood smear, urinary protein (+++). Diagnosed with oliguric phase of epidemic hemorrhagic fever. The most urgent treatment for this patient is:

A 40-year-old male presents with fever for 3 days accompanied by abdominal pain and diarrhea, passing stool over 20 times per day with scant volume, mucus, and pus/blood. Stool microscopy shows red blood cells (++), white blood cells (++), and mucus (++). A diagnosis of acute bacillary dysentery is made. The typical symptoms of abdominal pain, diarrhea, and pus/blood in stool are caused by:

A 25-year-old woman presented to the clinic 1 week ago with fever, abdominal pain, and diarrhea (20+ episodes/day of bloody mucoid stools, scant volume, with tenesmus). She was treated for acute bacillary dysentery with oral antibiotics for 5 days with symptom improvement. Yesterday, after eating spoiled fruit, she developed recurrent abdominal pain, diarrhea (10+ episodes/day), and tenesmus. Which test is most definitive for diagnosing bacillary dysentery?

A 48-year-old male presents with diarrhea for 2 days, passing loose yellow stools with small amounts of mucus 10+ times daily, accompanied by mild left lower abdominal pain and tenesmus. Physical examination reveals only mild left lower abdominal tenderness and active bowel sounds. Suspected acute bacillary dysentery (ordinary type) is confirmed, and the patient is hospitalized for isolation. What is the criterion for discontinuing isolation?

An 18-year-old male presents with fever, abdominal pain, and diarrhea (10+ times/day) for 2 days. Initially loose stools progressed to mucopurulent bloody stools with tenesmus. Stool exam shows WBC 15-20/HPF and RBC 5-10/HPF. After 3 days of antibiotic therapy, symptoms improved but treatment was discontinued prematurely. What is the likely consequence?

For a 32-year-old female with persistent fever for 10 days, headache, poor appetite, and 3-4 bowel movements daily, treated with chloramphenicol and SMZcO without improvement, Widal test shows 'O' 1:160 and 'H' 1:320. Clinically diagnosed with typhoid fever, which method confirms the etiology?

An 18-year-old male presented with diarrhea (5-6 loose stools yesterday) progressing to mucopurulent stools every 2 hours today, scant volume, accompanied by tenesmus. Physical exam: soft abdomen, left lower quadrant tenderness, hyperactive bowel sounds. Laboratory tests: WBC 14.6×10⁹/L (86% neutrophils), stool microscopy shows RBCs 20/HPF, WBCs covering entire field, macrophages 0-1/HPF. Multiple similar diarrhea cases in class this week. Clinical diagnosis: bacillary dysentery. Which intestinal site has the most severe pathological changes?

A 17-year-old male patient ate grilled skewers from a roadside stall 2 days ago. Today, he developed chills, fever, abdominal pain, diarrhea, and tenesmus, with 5-6 bowel movements per day containing mucus. Physical examination: temperature 39°C, soft abdomen, tenderness in the left lower quadrant without rebound tenderness, active bowel sounds. Stool examination revealed mucopurulent stool, with WBC 10-15/HPF and occasional RBCs. Acute bacillary dysentery is suspected. Which of the following statements about this disease is incorrect?

A 26-year-old male farmer presents with 5 days of fever and chills, followed by headache and vomiting twice in 1 day. Admitted on August 15, his temperature is 39.6°C with conjunctival congestion, neck stiffness, inguinal lymphadenopathy with tenderness, gastrocnemius tenderness, and urinary protein (++). Which test is most helpful for diagnosis?

A 26-year-old male presents with sudden onset of fever, chills, headache, and generalized myalgia for 3 days after harvesting rice. Physical exam: temperature 38.6°C, conjunctival congestion, heart rate 90 bpm, clear lungs. Initially treated as "upper respiratory infection" but symptoms persisted. Laboratory tests: WBC 21.6×10⁹/L (neutrophils 90%), microscopic agglutination test titer 1:400. Diagnosed with leptospirosis. The main clinical manifestations of leptospirosis are:

A 29-year-old male presents with 3 days of fever, headache, fatigue, decreased appetite, calf pain while walking, and cough. Physical exam: temperature 39.8°C, flushed face, conjunctival congestion, normal vision, bilateral inguinal lymphadenopathy, marked tenderness in gastrocnemius muscles, no meningeal signs or pathological reflexes. Liver palpable 1.5 cm below costal margin. WBC 12.7×10⁹/L (N 74%, L 21%, EOS 3%, M 2%). Frequently worked in rice paddies prior to illness. The drug of choice is:

A 28-year-old male presents with 5 days of fever accompanied by poor appetite, fatigue, abdominal pain, distension, and diarrhea. Despite self-medication with antipyretics, co-trimoxazole, and chloramphenicol, the fever persists. He was hospitalized on day 10 of illness. Examination reveals a temperature of 39.8°C, heart rate of 92 bpm, and spleen palpable 1 cm below the costal margin (soft consistency). Blood culture is negative. Which of the following statements about typhoid fever is incorrect?

An 18-year-old male was admitted with persistent fever for 1 week accompanied by fatigue and anorexia. Physical examination: temperature 39.4°C, pulse 92/min, liver palpable 2 cm below the costal margin, spleen palpable 1 cm below the costal margin. Laboratory tests: WBC 4.0×10⁹/L, neutrophils 62%, lymphocytes 35%, monocytes 3%. Blood culture grew Salmonella typhi. After 5 days of chloramphenicol treatment, the fever subsided. On day 18 of illness, he passed 50g of melena. The period when typhoid fever is most contagious is:

A 40-year-old male fisherman, residing in a schistosomiasis endemic area with a habit of drinking untreated water, presents with persistent high fever (40°C, remittent type) for 3 weeks, abdominal distension, and mucoid stools (2-3 times/day). Physical examination reveals liver 2 cm below the costal margin, spleen 1 cm below the costal margin, WBC count 3.0×10⁹/L (neutrophils 55%, lymphocytes 45%, eosinophil count zero), and cough. Right lower abdominal guarding and loss of liver dullness are noted. What is the most urgent management?

A 22-year-old male presented on August 10 with half a day of diarrhea (20+ episodes of watery stools), 5-6 episodes of vomiting, no fever or abdominal pain, oliguria, normal body temperature, BP 70/50 mmHg (10.8/6.7 kPa), sunken eyes, and dry mouth/tongue. Laboratory tests: Hb 160g/L, WBC 10.1×10⁹/L. The most critical treatment is:

A 34-year-old male patient developed symptoms on July 5 and presented with frequent diarrhea and vomiting for 1 day. Stools were watery with no significant abdominal pain. Physical examination: BP 70/40 mmHg, clear consciousness, obvious signs of dehydration. The dehydration caused by cholera vomiting and diarrhea belongs to:

A 40-year-old male presents with fever for 3 days accompanied by abdominal pain and diarrhea, passing stool over 20 times daily with scant volume, mucus, and pus/blood. Stool microscopy shows red blood cells (++), white blood cells (++), and mucus (++). Diagnosed with acute bacillary dysentery. Which measure should be prioritized to prevent its transmission?

A 26-year-old male presents with abdominal pain, diarrhea, and vomiting for 1 day, after consuming seafood the previous day. The abdominal pain is not accompanied by tenesmus, with over 10 watery bowel movements per day. No history of chronic diarrhea, drug allergies, or exposure to epidemic areas. Physical exam: T36.7°C, P105/min, weak and thready pulse, BP 75/50 mmHg, alert, sunken orbits, no rash or petechiae, non-icteric sclera, mild lower abdominal tenderness without rebound or guarding, active bowel sounds. 24-hour urine output is 400ml. Based on symptoms, plasma specific gravity, and urine output, which 24-hour fluid replacement regimen is correct?

A 45-year-old male with a 17-year history of chronic hepatitis B reports decreased stamina, occasional abdominal distension, and weight loss over the past year. One week ago, he developed diarrhea and abdominal pain after consuming contaminated food, which improved with medication. However, over the past 3 days, he developed fever, significant abdominal pain and distension, yellow urine, and markedly decreased urine output. On admission: alert but agitated and talkative, chronic liver disease facies, mild icterus of the sclera, prominent liver palms, spider angiomas, no abnormalities in heart and lungs; abdominal distension, tenderness in the lower abdomen, mild rebound tenderness, positive ascites sign. Emergency labs: WBC 9.8×10⁹/L (neutrophils 89%), K⁺ 3.4 mmol/L, Na⁺ 137 mmol/L, Cl^- 98 mmol/L, blood ammonia 96 μmol/L. The key determinant of successful treatment for this patient is:

A 28-year-old male farmer presented on October 30 with high fever, headache, low back pain, vomiting, and diarrhea, with continuous fever for 4 days and one episode of epistaxis. After taking paracetamol, the fever subsided but dizziness, oliguria, and painful urination developed. Lab results: WBC count 18×10⁹/L (neutrophils 60%, abnormal monocytes 12%, lymphocytes 23%), platelets 50×10⁹/L, and membranous material in urine. Despite treatment, urine output remains ~100ml/24h. Which treatment should be initiated?

A 28-year-old male farmer presented with fever for 5 days accompanied by petechiae, transferred from a rural clinic to Zhongshan Hospital of Shanghai Medical University in November 1993. Physical examination: temperature 38°C, BP 70/50 mmHg, marked facial and periorbital congestion, conjunctival edema and congestion, cord-like petechiae in the axilla, and significant renal region tenderness. The suspected diagnosis is epidemic hemorrhagic fever. Regarding the epidemiological concepts of this disease, which of the following is incorrect?

What is the mode of transmission for Hepatitis E?

A 25-year-old female presented with fever, abdominal pain, and diarrhea one week ago, passing over 20 stools daily consisting of bloody pus, small in volume, accompanied by tenesmus. She was treated for acute bacillary dysentery with oral antibiotics for 5 days, with symptom improvement. After consuming spoiled fruit yesterday, she experienced recurrent abdominal pain, diarrhea (10+ stools/day), and tenesmus. Currently, the most effective antibiotic for bacillary dysentery is:

An 18-year-old male presented with diarrhea yesterday, passing loose stools 5-6 times. Today, the stools became mucopurulent, occurring every 2 hours with small volume, accompanied by tenesmus. Physical examination revealed a soft abdomen, tenderness in the left lower quadrant, and hyperactive bowel sounds. Laboratory tests showed WBC 14.6×10⁹/L (86% neutrophils), stool microscopy revealed RBCs 20/HPF, WBCs covering the entire field, and 0-1 macrophages/HPF. Multiple classmates had similar diarrhea in the past week. The clinical diagnosis is bacterial dysentery. In China, the most common causative pathogen of this disease is:

A 17-year-old male patient ate street barbecue 2 days ago. Today he developed chills, fever, abdominal pain, diarrhea (5-6 times/day with mucus), and tenesmus. Exam: temperature 39°C, soft abdomen, left lower quadrant tenderness without rebound, active bowel sounds. The clinical types of bacillary dysentery include all EXCEPT:

A 26-year-old male presents with sudden onset of fever, chills, headache, and myalgia for 3 days after harvesting rice. Physical exam: temperature 38.6°C, conjunctival congestion, heart rate 90/min, clear lungs. Initially treated as "upper respiratory infection," but symptoms persisted. Laboratory tests: WBC 21.6×10⁹/L (neutrophils 90%), microscopic agglutination test titer 1:400. Diagnosed with leptospirosis. After intramuscular penicillin 800,000U and streptomycin 0.5g, the patient develops chills, high fever, headache, dyspnea, and BP 86/60 mmHg within 30 minutes. The diagnosis and management are:

A 36-year-old male farmer presents with persistent high fever for 1 week, progressing to chills, high fever, body aches, lumbar muscle pain, conjunctival congestion, proteinuria (+++), inguinal lymph nodes the size of broad beans. From day 5 of illness, he develops continuous cough with hemoptysis, shortness of breath, gurgling phlegm in throat, heart rate 110/min, and cyanosis of lips. The primary treatment to control pulmonary hemorrhage is:

A 32-year-old female presents with 4 days of generalized myalgia and fever after harvesting rice, accompanied by cough, abdominal pain, and one episode of hemoptysis (50-60ml). Examination: temperature 39.2°C, pallor, conjunctival congestion, heart rate 140/min with gallop rhythm, bilateral lung crackles, and gastrocnemius tenderness. Leptospirosis is suspected. What is the route of entry for Leptospira into the human body?

A 40-year-old male fisherman, residing in a schistosomiasis endemic area with a habit of drinking untreated water, presents with persistent high fever (40°C, remittent type) for 3 weeks, abdominal distension, and mucoid stools 2-3 times daily. Physical exam reveals liver 2 cm below the costal margin and spleen 1 cm below the costal margin. Lab results: WBC count 3.0×10⁹/L (neutrophils 55%, lymphocytes 45%), eosinophil count zero, with accompanying cough. The most likely site of pathology is:

A 34-year-old male patient presented on July 5 with frequent diarrhea and vomiting for 1 day. Stools were watery with no significant abdominal pain. Physical examination: BP 70/40 mmHg, clear consciousness, obvious signs of dehydration. What is the primary treatment for cholera?

A 40-year-old male farmer presents with 3 days of irregular fever accompanied by headache, low back pain, and blurred vision to a rural clinic. Physical exam shows facial and upper chest congestion, conjunctival edema, petechiae, and scattered pinpoint hemorrhages in the axilla and back. BP is 90/60 mmHg. As similar cases were reported in his village, he was transferred to a city hospital with suspected epidemic hemorrhagic fever (febrile phase). On the first night, he suddenly developed dyspnea and orthopnea. Examination reveals heart rate 140 bpm, gallop rhythm, and bilateral rales/crackles, suggesting acute left-sided heart failure (HF). The most likely mechanism is:

A 32-year-old female presents with 4 days of myalgia and fever after overexertion during rice harvesting, accompanied by cough, abdominal pain, and one episode of hemoptysis (50-60ml). Physical exam: temperature 39.2°C, pallor, conjunctival congestion, heart rate 140/min with gallop rhythm, bilateral lung rales/crackles, and gastrocnemius tenderness. Presumptive diagnosis of leptospirosis is confirmed by lab tests. The primary treatment is:

A 34-year-old male farmer presents with frequent diarrhea and vomiting for 1 day (approximately 20 episodes, watery stools), accompanied by calf muscle cramps but no significant abdominal pain. Physical examination shows clear consciousness, signs of severe dehydration, BP 60/40 mmHg, plasma specific gravity 1.035, hematocrit 60%, WBC 18×10⁹/L, and stool microscopy reveals 0-2 WBC/HPF. Stool suspension and smear tests preliminarily diagnose paracholera. What is the correct management for the patient's family members and close contacts?

Complete loss of consciousness, unarousable; hyperactive tendon reflexes and increased muscle tone; flapping tremor (asterixis) absent; markedly abnormal electroencephalogram (EEG)

A 28-year-old male farmer presents with high fever, headache, low back pain, vomiting, and diarrhea since October 30, with continuous fever for 4 days and one episode of epistaxis. After taking paracetamol, fever subsided but dizziness, oliguria, and painful urination developed. Lab results: WBC 18×10⁹/L (neutrophils 60%, abnormal monocytes 12%, lymphocytes 23%), platelets 50×10⁹/L, and membranous material in urine. Which clinical type does this patient belong to?

A 40-year-old male farmer presents with 3 days of irregular fever, headache, low back pain, and blurred vision. Physical exam shows facial and upper chest congestion, conjunctival edema, petechiae, and scattered pin-sized hemorrhages in axillae and back. BP is 90/60 mmHg. Suspected epidemic hemorrhagic fever (febrile phase) due to similar cases in the village. Persistent oliguria for 3 days. Laboratory tests: BUN 60 mmol/L, Cr 602 μmol/L, serum K+ 6.9 mmol/L. The most appropriate management is:

Which of the following abdominal signs is seen in this patient with intestinal infection? A 35-year-old male presents to the emergency department with 8-9 episodes of watery diarrhea and 4-5 episodes of vomiting since returning from a trip to Ningbo yesterday. On examination: dry lips and skin, BP 90/56 mmHg, soft abdomen, no hepatosplenomegaly, active bowel sounds. Stool microscopy shows rapidly motile bacteria with darting movements.

Which is the first-line treatment for the following intestinal infection? A 36-year-old male presents with 1 day of diarrhea (10+ watery stools), vomiting 2-3 times. Stool Gram stain shows parallel-arranged Gram-negative curved bacilli resembling fish schools, suggesting suspected paracholera. After rapid IV infusion of 500 mL dextran and 2000 mL isotonic saline plus 3000 mL glucose solution, the patient develops palpitations, dyspnea, and inability to lie flat. Exam shows cyanotic lips, orthopnea, heart rate 140 bpm, and basal lung rales.

Mild personality and behavioral changes with coherent responses; presence of flapping tremor (asterixis); normal electroencephalogram (EEG)

Active replication of hepatitis B virus

Which abdominal sign is present in this patient with intestinal infectious disease? Male, 18 years old. Abdominal pain and diarrhea for 2 days, with 7-8 bowel movements daily, scant stool containing mucus, accompanied by tenesmus. Laboratory tests: Stool microscopy shows WBC 20-30/HPF, RBC 5-10/HPF, macrophages 0-2/HPF.

For the following infectious disease patient, what is the definitive etiological diagnostic method? A 32-year-old female with persistent fever for 10 days, accompanied by headache and poor appetite, passing stools 3-4 times daily. Treated with chloramphenicol and SMZCO at a local clinic without fever resolution. Widal test shows 'O' 1:160, 'H' 1:320. Clinical diagnosis: typhoid fever.

Mental confusion, able to respond when awake, presence of hallucinations; positive flapping tremor (asterixis); increased muscle tone, positive pyramidal signs; abnormal electroencephalogram (EEG)

Recovery from hepatitis B infection, immunity developed

T≥40°C with refractory shock, anuria for >2 days, or other organ dysfunction

The typical clinical symptoms of malaria (fever, chills, sweating) are caused by:

A 30-year-old male presents with intermittent chills, high fever, and sweating for over 2 weeks, visiting in October. Asymptomatic during intervals. Physical exam: temperature 40.5°C, mild anemic appearance, herpes labialis, heart rate 120 bpm (regular rhythm), liver 1 cm below costal margin, spleen 2 cm below costal margin (soft and tender). Laboratory tests: Hb 89 g/L. The most likely diagnosis is:

A 28-year-old male presents with a 1-month history of sudden severe chills every night between 8-9 PM, followed by high fever (peak temperature 41°C), profuse sweating after 2-3 hours, and fever resolution. Symptoms recur daily, and he continues working. Anti-inflammatory drugs were ineffective. The most likely positive finding on physical examination is:

A 27-year-old female presents with chills, high fever, and profuse sweating for one week on September 20. The fever pattern was irregular. Malaria parasites were found on blood smear, and she was treated with chloroquine plus primaquine. Fever subsided after 2 days but recurred abruptly on day 4 with low back pain and dark brown urine. What signs should be specifically checked during physical examination at this stage?

A 33-year-old male presents with intermittent chills, fever, and sweating for 10 days. Laboratory tests: Hb 90 g/L (anemia), WBC 4.0×10⁹/L, and peripheral blood smear reveals Plasmodium falciparum. Which of the following physical findings is LEAST likely to be present?

A 20-year-old male with a history of favism presents with chills, fever, and sweating. Plasmodium vivax is identified on blood smear. Which drug should NOT be used in his treatment?

A 45-year-old male with a 10-year history of chronic schistosomiasis presents with hepatomegaly (liver palpable 1 cm below costal margin, 4 finger-breadths below xiphoid), splenomegaly reaching the umbilicus, positive serum Schistosoma japonicum antibody, and elevated ALT (100 U/L) without jaundice. The most effective treatment for the pathogen is:

A 42-year-old woman presents with intermittent chills, high fever, and sweating for 2 weeks. Physical examination: mild anemic appearance, liver palpable below the costal margin, spleen 2 cm below the costal margin with moderate consistency and no tenderness. Malaria is suspected. What is the preferred initial diagnostic test?

A 41-year-old male from Shanghai went on a business trip to Guangxi for 1 week in August. Two weeks after returning, he suddenly developed chills, severe rigors, followed by a temperature rise to 41°C within 30 minutes, accompanied by headache. The fever lasted 4-5 hours, followed by profuse sweating upon defervescence. After 3 such recurrent episodes, he sought medical attention, and malaria parasites were found on blood smear. Which stage of Plasmodium development in humans is associated with the patient's symptoms?

A 45-year-old male migrant worker from Hunan presents with recurrent diarrhea for 2 years, occasionally with mucopurulent bloody stool. Physical exam: No abnormalities in heart/lungs. Liver palpable 3 cm below xiphoid, medium consistency; spleen palpable 3.5 cm below costal margin, firm. Laboratory tests: CBC shows WBC 7.6×10⁹/L (neutrophils 62%, eosinophils 10%). Stool analysis reveals mucopurulent bloody stool with RBC (++)/HPF and WBC (+)/HPF. The most likely diagnosis is: