A 26-year-old woman from a strictly vegetarian family in Gujarat has new-onset focal seizures. CT shows a small cystic lesion with an eccentric dot in the left parietal cortex, typical of neurocysticercosis. How did she most likely acquire this infection?

Ingesting Taenia solium eggs in contaminated food

Larvae penetrating the skin from soil

Drinking water with infected copepods

Eating undercooked pork with cysticerci

A 22-year-old student in Kanpur has had a first generalised seizure. Contrast MRI shows a single 1.2 cm ring-enhancing cyst with a visible scolex in the right frontal lobe and mild surrounding oedema. The neurologist plans to start albendazole with steroids and an antiepileptic. Which examination must be done before albendazole is given?

Fundus examination of both eyes

Lumbar puncture for CSF analysis

Stool examination for Taenia eggs

Serum anti-cysticercus antibodies

A 14-year-old boy from rural Telangana has dry cough, wheeze and low fever for a week. Chest X-ray shows patchy, shifting infiltrates and the absolute eosinophil count is 3,800/µL. Two months later, he passes a large round worm in stool. Which phase of the worm's life cycle caused his chest symptoms?

Larval migration through the lungs

Adult worms entering the bronchi

Cysts formed in the lung tissue

Intestinal and tissue parasites

19 NEET-PG practice questions on Intestinal and tissue parasites, part of Microbiology. The first 19 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Easy
A 26-year-old woman from a strictly vegetarian family in Gujarat has new-onset focal seizures. CT shows a small cystic lesion with an eccentric dot in the left parietal cortex, typical of neurocysticercosis. How did she most likely acquire this infection?
1. ALarvae penetrating the skin from soil
2. BDrinking water with infected copepods
3. CEating undercooked pork with cysticerci
4. DIngesting Taenia solium eggs in contaminated food
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Answer: D · Ingesting Taenia solium eggs in contaminated food
Cysticercosis follows ingestion of Taenia solium eggs, from food or water contaminated with human faeces or by autoinfection in a tapeworm carrier, so it can occur in people who never eat pork. The eggs hatch in the intestine, and the oncospheres travel in the blood to the brain, muscle and eye to form cysticerci. Eating undercooked pork containing cysticerci causes intestinal taeniasis instead. Food handlers who carry the adult worm are an important source.
- A: Skin penetration by larvae is the route for hookworm and Strongyloides.
- B: Copepods transmit Dracunculus and Diphyllobothrium, not Taenia.
- C: Eating measly pork gives the adult tapeworm in the gut, not cysticercosis.
Question 2 · Easy
A 25-year-old man in Kolkata has loose stools with mucus for 2 weeks. A saline and iodine mount of the stool shows round cysts, each with four nuclei that have central karyosomes, and chromatoid bars with rounded ends. Which organism is most likely?
1. AGiardia lamblia
2. BEntamoeba histolytica
3. CEntamoeba coli
4. DEndolimax nana
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Answer: B · Entamoeba histolytica
The mature cyst of Entamoeba histolytica has up to four nuclei with small central karyosomes and fine peripheral chromatin, and chromatoid bars with rounded ends. Entamoeba coli cysts are larger, have up to eight nuclei with eccentric karyosomes and splinter-like chromatoid bodies. E. histolytica cannot be told from the non-pathogenic E. dispar by cyst morphology, so antigen or PCR tests are needed for certainty. Trophozoites with ingested red cells do indicate E. histolytica.
- A: Giardia cysts are oval with four nuclei and axonemes, not chromatoid bars.
- C: E. coli cysts have up to eight nuclei and splinter-shaped chromatoid bodies.
- D: Endolimax nana cysts have four nuclei with large blot-like karyosomes and no chromatoid bars.
Question 3 · Medium
A 22-year-old student in Kanpur has had a first generalised seizure. Contrast MRI shows a single 1.2 cm ring-enhancing cyst with a visible scolex in the right frontal lobe and mild surrounding oedema. The neurologist plans to start albendazole with steroids and an antiepileptic. Which examination must be done before albendazole is given?
1. AFundus examination of both eyes
2. BLumbar puncture for CSF analysis
3. CStool examination for Taenia eggs
4. DSerum anti-cysticercus antibodies
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Answer: A · Fundus examination of both eyes
Before cysticidal drugs are started, the fundus should be examined to rule out papilloedema from raised intracranial pressure and ocular cysticercosis. Killing an intraocular cyst can cause severe inflammation and loss of vision, so ocular cysts are removed surgically first, and raised pressure must be treated before giving albendazole. Steroids are given with the drug to reduce the inflammatory reaction to dying cysts. Antiepileptic drugs control the seizures.
- B: Lumbar puncture is unnecessary and risky if pressure is raised.
- C: Stool tests find a taeniasis carrier but do not change the safety of treatment.
- D: Serology supports the diagnosis but is not a safety check before treatment.
Question 4 · Medium
A 40-year-old man from Kottayam who often eats undercooked beef finds flat white segments crawling out of his anus and on his bedsheets. One segment pressed between slides and injected with India ink shows about 20 lateral uterine branches on each side. Which tapeworm is this?
1. ATaenia solium
2. BDiphyllobothrium latum
3. CTaenia saginata
4. DHymenolepis nana
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Answer: C · Taenia saginata
Actively motile gravid segments that crawl out of the anus, with about 15 to 30 lateral uterine branches on each side, identify Taenia saginata, the beef tapeworm. Taenia solium segments have fewer branches (about 7 to 13) and are usually passed passively in chains. The eggs of the two species look alike, so segments or molecular tests are needed to tell them apart. T. saginata does not cause cysticercosis in man.
- A: T. solium has fewer uterine branches and its segments are not usually actively motile.
- B: D. latum is acquired from fish and has a rosette-shaped central uterus.
- D: H. nana is a tiny tapeworm whose segments are not seen in this way.
Question 5 · Medium
A 14-year-old boy from rural Telangana has dry cough, wheeze and low fever for a week. Chest X-ray shows patchy, shifting infiltrates and the absolute eosinophil count is 3,800/µL. Two months later, he passes a large round worm in stool. Which phase of the worm's life cycle caused his chest symptoms?
1. AEggs deposited in the alveoli
2. BAdult worms entering the bronchi
3. CLarval migration through the lungs
4. DCysts formed in the lung tissue
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Answer: C · Larval migration through the lungs
Ascaris lumbricoides eggs hatch in the small intestine, and the larvae penetrate the gut wall, travel to the lungs, break into the alveoli and climb the airways to be swallowed and mature in the intestine. During the lung phase they cause Loeffler syndrome: transient, migratory infiltrates, cough, wheeze and blood eosinophilia. Eggs are not yet in the stool at this stage, so stool tests become positive only weeks later. Hookworm and Strongyloides larvae can cause a similar picture.
- A: Ascaris eggs are passed in stool and do not deposit in alveoli.
- B: Adult Ascaris lives in the intestine and does not cause this lung picture.
- D: Ascaris forms no cysts in the lung; hydatid disease does.
Question 6 · Medium
A 29-year-old shepherd from Ladakh has dull right upper quadrant pain. Ultrasound shows a 10 cm hepatic cyst in which the inner membrane has separated from the wall and floats in the fluid. What is the most likely diagnosis?
1. AHydatid cyst with detached laminated membrane
2. BSimple hepatic cyst with haemorrhage
3. CAmoebic liver abscess with debris
4. DCystadenoma with internal septations
Answer and explanation in LearnFree account
Question 7 · Hard
A 62-year-old man from coastal Kerala on high-dose prednisolone for 2 months for bullous pemphigoid develops abdominal pain, diarrhoea, cough with haemoptysis and then E. coli meningitis. A serpiginous rash is seen on his trunk. Stool and sputum show many larvae. Which drug should be started?
1. AAlbendazole for 3 days
2. BIvermectin
3. CPraziquantel
4. DDiethylcarbamazine
Answer and explanation in LearnFree account
Question 8 · Medium
In a residential school in Mysuru, several children have abdominal pain and mild diarrhoea. Stool shows small, round, thin-shelled eggs with an inner membrane bearing polar thickenings from which filaments arise. The children's teacher asks why the infection spreads so easily within the school. What is the reason?
1. AInfection needs a snail as an intermediate host
2. BThe eggs are directly infective without an intermediate host
3. CThe eggs need a period in soil before infecting
4. DInfective larvae penetrate the skin of bare feet
Answer and explanation in LearnFree account
Question 9 · Medium
A 6-year-old boy has had recurrent bouts of foul-smelling, greasy diarrhoea with bloating and poor weight gain. Duodenal aspirate shows pear-shaped flagellates with two nuclei and a ventral sucking disc. He has also had recurrent sinusitis and pneumonia. Which underlying defect should be looked for?
1. AIsolated T-cell deficiency
2. BSelective IgA deficiency
3. CTerminal complement deficiency
4. DChronic granulomatous disease
Answer and explanation in LearnFree account
Question 10 · Medium
A 4-year-old girl from a slum in Bhopal has chronic bloody diarrhoea, tenesmus, Hb 7.8 g/dL and a prolapsed rectum. Small worms with a thin whip-like front end are seen on the prolapsed mucosa. What will stool microscopy most likely show?
1. AOval thin-shelled eggs with segmented ova
2. BPlano-convex eggs with a larva inside
3. CBarrel-shaped eggs with bipolar plugs
4. DRound eggs with a mammillated coat
Answer and explanation in LearnFree account
Question 11 · Hard
During a stool microscopy session, a microbiology postgraduate reviews four statements: 1. Hookworm eggs are not bile-stained. 2. The eggs of Taenia solium and Taenia saginata can be told apart by light microscopy. 3. Trichuris eggs are not bile-stained. 4. Fertilised Ascaris eggs have a thick mammillated albuminous coat. Which statements are correct?
1. A2 and 3 only
2. B1, 3 and 4 only
3. C1, 2 and 4 only
4. D1 and 4 only
Answer and explanation in LearnFree account
Question 12 · Medium
A 30-year-old man in Lucknow has frequent small stools with blood and mucus for 10 days and mild abdominal pain, without high fever. Stool microscopy shows few pus cells, clumped red cells and Charcot-Leyden crystals. Which further finding in the fresh stool would confirm the likely cause?
1. ARhabditiform larvae with a short buccal cavity
2. BMotile trophozoites containing ingested red cells
3. CMany neutrophils with macrophages
4. DGram-negative curved rods in gull-wing forms
Answer and explanation in LearnFree account
Question 13 · Hard
A 10-year-old boy in Kozhikode has severe headache, fever, vomiting and neck stiffness 5 days after swimming in a stagnant pond; he is now drowsy. CSF shows 1,800 cells/µL (90% neutrophils), protein 260 mg/dL and glucose 18 mg/dL with blood glucose 110 mg/dL. Gram stain and bacterial antigen tests are negative. Which test should be done at once on the CSF?
1. AZiehl-Neelsen stain of the sediment
2. BIndia ink preparation
3. CWet mount of fresh, unrefrigerated CSF
4. DCulture on Sabouraud dextrose agar
Answer and explanation in LearnFree account
Question 14 · Easy
A 34-year-old tea garden worker in Assam who works barefoot has fatigue and pallor. Stool shows thin-shelled oval eggs with segmented ova inside. By which route did the infection most likely enter his body?
1. AIngestion of encysted larvae in meat
2. BBite of an infected blackfly
3. CFilariform larvae penetrating the skin
4. DIngestion of embryonated eggs in food
Answer and explanation in LearnFree account
Question 15 · Easy
A 5-year-old girl in an anganwadi in Pune scratches her perianal region at night and sleeps poorly. Her mother has seen tiny white thread-like worms near the anus. What is the best way to confirm the diagnosis?
1. AAbsolute eosinophil count
2. BAdhesive tape swab of the perianal skin
3. CStool for occult blood
4. DStool concentration by formol-ether
Answer and explanation in LearnFree account
Question 16 · Medium
A 38-year-old sheep farmer from Himachal Pradesh has a 9 cm cystic lesion in the right lobe of the liver with daughter cysts inside on CT. His family keeps several dogs that are fed raw offal. How did he acquire this infection?
1. ABeing bitten by an infected dog
2. BEating undercooked mutton containing cysts
3. CIngesting eggs passed in dog faeces
4. DDrinking milk from infected sheep
Answer and explanation in LearnFree account
Question 17 · Medium
A newborn in a medical college hospital in Ahmedabad has hydrocephalus, chorioretinitis and scattered calcifications throughout the brain parenchyma on CT. The mother had a flu-like illness with cervical lymphadenopathy in mid-pregnancy and keeps cats at home. Which organism is most likely?
1. ATreponema pallidum
2. BRubella virus
3. CToxoplasma gondii
4. DCytomegalovirus
Answer and explanation in LearnFree account
Question 18 · Medium
A truck driver from Namakkal, aged 29, recently found to be living with HIV, has passed large volumes of watery stool for 8 weeks and lost 9 kg. His last CD4 count was 45 cells/µL. On a Kinyoun-stained stool smear, the microbiologist sees round, pink, acid-fast oocysts about 4-6 µm across. Which parasite is this?
1. ACystoisospora belli
2. BCryptosporidium parvum
3. CMicrosporidia
4. DCyclospora cayetanensis
Answer and explanation in LearnFree account
Question 19 · Hard
A 45-year-old woman from Jammu has a 7 cm unilocular hepatic hydatid cyst with no daughter cysts and no communication with the bile ducts on MRCP. The surgeon plans PAIR. A resident lists four points: 1. Albendazole is given before and after the procedure. 2. Hypertonic saline can be used as the scolicidal agent. 3. Spillage of cyst fluid can cause anaphylaxis and new cysts. 4. PAIR is preferred if the cyst communicates with the biliary tree. Which statements are correct?
1. A2 and 3 only
2. B2 and 4 only
3. C1, 2 and 4 only
4. D1, 2 and 3 only
Answer and explanation in LearnFree account

Intestinal and tissue parasites

A 26-year-old woman from a strictly vegetarian family in Gujarat has new-onset focal seizures. CT shows a small cystic lesion with an eccentric dot in the left parietal cortex, typical of neurocysticercosis. How did she most likely acquire this infection?

A 25-year-old man in Kolkata has loose stools with mucus for 2 weeks. A saline and iodine mount of the stool shows round cysts, each with four nuclei that have central karyosomes, and chromatoid bars with rounded ends. Which organism is most likely?

A 40-year-old man from Kottayam who often eats undercooked beef finds flat white segments crawling out of his anus and on his bedsheets. One segment pressed between slides and injected with India ink shows about 20 lateral uterine branches on each side. Which tapeworm is this?

A 29-year-old shepherd from Ladakh has dull right upper quadrant pain. Ultrasound shows a 10 cm hepatic cyst in which the inner membrane has separated from the wall and floats in the fluid. What is the most likely diagnosis?

A 62-year-old man from coastal Kerala on high-dose prednisolone for 2 months for bullous pemphigoid develops abdominal pain, diarrhoea, cough with haemoptysis and then E. coli meningitis. A serpiginous rash is seen on his trunk. Stool and sputum show many larvae. Which drug should be started?

A 4-year-old girl from a slum in Bhopal has chronic bloody diarrhoea, tenesmus, Hb 7.8 g/dL and a prolapsed rectum. Small worms with a thin whip-like front end are seen on the prolapsed mucosa. What will stool microscopy most likely show?

A 30-year-old man in Lucknow has frequent small stools with blood and mucus for 10 days and mild abdominal pain, without high fever. Stool microscopy shows few pus cells, clumped red cells and Charcot-Leyden crystals. Which further finding in the fresh stool would confirm the likely cause?

A 34-year-old tea garden worker in Assam who works barefoot has fatigue and pallor. Stool shows thin-shelled oval eggs with segmented ova inside. By which route did the infection most likely enter his body?

A 5-year-old girl in an anganwadi in Pune scratches her perianal region at night and sleeps poorly. Her mother has seen tiny white thread-like worms near the anus. What is the best way to confirm the diagnosis?

A 38-year-old sheep farmer from Himachal Pradesh has a 9 cm cystic lesion in the right lobe of the liver with daughter cysts inside on CT. His family keeps several dogs that are fed raw offal. How did he acquire this infection?

A newborn in a medical college hospital in Ahmedabad has hydrocephalus, chorioretinitis and scattered calcifications throughout the brain parenchyma on CT. The mother had a flu-like illness with cervical lymphadenopathy in mid-pregnancy and keeps cats at home. Which organism is most likely?