Micro-Para (2023)

Question 1

1. Carlo has leukemia and was exposed to HBsAG-positive blood. What is the best immediate management for him?
   a. Antiviral drugs
   b. Recombinant Hep B vaccine
   c. Vitamins
   d. Passive Immunization

Answer 1

d. Passive Immunization
Rationale: Immediate management for potential Hepatitis B exposure involves passive immunization with Hepatitis B immune globulin (HBIG) to provide immediate but short-term protection. Active immunization with the Hepatitis B vaccine is also recommended but is not immediate.
Clue words: “exposed to HBsAG-positive blood,” “immediate management”

Question 2

2. A fisherman from Davao Oriental was rushed to a nearby hospital with chest pain, persistent cough, and hemoptysis as his main complaint. What aspect of his lifestyle is most relevant to his condition?
   a. Occupation
   b. Eating habits
   c. Drinking habits
   d. Gender

Answer 2

c. Eating habits

Rationale: Paragonimiasis is caused by the lung fluke Paragonimus spp. and is typically acquired by consuming raw or undercooked freshwater crustaceans, such as crabs or crayfish, that harbor the infective larvae. The patient’s habit of consuming raw mountain crabs is a direct route of infection for this parasitic disease. While drinking habits, occupation, and gender can play roles in the overall health and lifestyle of a person, the specific habit of eating raw crabs is the most pertinent factor in the transmission of Paragonimus spp. and strongly supports the diagnosis of paragonimiasis.

Question 3

3. A 24-year-old abaca farmer from Sorsogon with fever and signs of lymph gland inflammation had microscopic findings in the blood revealing larvae. What is the likely diagnosis?
   a. Angiostrongiloidiasis
   b. Filariasis
   c. Malaria
   d. Toxoplasmosis

Answer 3

b. Filariasis
Rationale: Filariasis is a parasitic infection that involves lymphatic system inflammation and is characterized by the presence of larvae in the blood.
Clue words: “abaca farmer,” “fever,” “lymph gland inflammation,” “larvae”

Question 4

4. About fifty percent of grade one students from Barrio Tubibi were found to have primary tuberculosis. Which of the following features of tuberculosis is most correct?
   a. All organisms are killed by the immune response during primary infection
   b. Caseous materials streaked with blood are often seen in expectorated sputum
   c. It is often accompanied by severe pulmonary edema
   d. Characterized by acute exudative lesions that spread to the lymphatics and regional lymph nodes

Answer 4

d. Characterized by acute exudative lesions that spread to the lymphatics and regional lymph nodes
Rationale: Primary tuberculosis is characterized by acute exudative lesions and the spread to regional lymph nodes.
Clue words: “primary tuberculosis,” “grade one students,” “features of tuberculosis”

Question 5

5. Which statement about PPD (tuberculin skin test) is correct?
   a. Immunization with BCG will result in a positive PPD lasting 3-7 years
   b. The tuberculin skin test becomes positive within 4-6 weeks after primary infection
   c. Persons who were PPD positive before but are healthy may fail to give a positive PPD when tested again
   d. None of the above

Answer 5

b. The tuberculin skin test becomes positive within 4-6 weeks after primary infection
Rationale: The PPD test typically becomes positive 4-6 weeks after a primary infection with tuberculosis.
Clue words: “PPD (tuberculin skin test),” “4-6 weeks after primary infection”

Question 6

6. A fisherman from Davao Oriental with chest pain, persistent cough, and hemoptysis revealed excessive drinking of native alcohol and raw mountain crab as their ‘pulutan’. What diagnostic test would be most helpful?
   a. Sputum examination
   b. Stool examination
   c. Chest x-ray

Answer 6

a. Sputum examination
Rationale: A sputum examination can help identify respiratory pathogens that may be causing the chest symptoms.
Clue words: “chest pain,” “persistent cough,” “hemoptysis,” “native alcohol,” “raw mountain crab”

Question 7

7. A patient complained of a swollen, weeping earlobe with signs of crusting after wearing fancy earrings. The doctor suggested she may be allergic to the nickel in the earrings. What is this condition also termed as?
   a. Contact hypersensitivity
   b. Atopic hypersensitivity
   c. Immune complex hypersensitivity
   d. Tuberculin hypersensitivity

Answer 7

a. Contact hypersensitivity
Rationale: Contact hypersensitivity, also known as contact dermatitis, is an allergic reaction to substances like nickel in earrings.
Clue words: “swollen, weeping earlobe,” “fancy earrings,” “allergic to nickel”

Question 8

8. A patient experienced shortness of breath after taking penicillin for her sore throat, despite having no previous history of penicillin allergy. Lab tests showed the presence of antibodies that hemolyzed her RBCs. What type of hypersensitivity reaction is likely occurring?
   a. Type I hypersensitivity
   b. Type II hypersensitivity
   c. Type III hypersensitivity
   d. Type IV hypersensitivity

Answer 8

b. Type II hypersensitivity
Rationale: Type II hypersensitivity involves antibodies that target cells, leading to conditions like hemolytic anemia.
Clue words: “shortness of breath,” “penicillin,” “hemolyzed RBCs”

Question 9

9. A 51-year-old farmer from Surigao, Mindanao, was brought to a hospital with abdominal pain and frequent loose stools. Examination revealed hepatomegaly with tenderness in the upper right quadrant of the abdomen. Laboratory results showed increased eosinophilia, and direct fecal smear showed no ova or parasites. What parasitic disease is suggested?
   a. Heterophydiasis
   b. Schistosomiasis
   c. Paragonimiasis
   d. Leishmaniasis

Answer 9

b. Schistosomiasis
Rationale: Schistosomiasis can present with hepatomegaly and increased eosinophilia, even when direct fecal smears are negative.
Clue words: “abdominal pain,” “hepatomegaly,” “eosinophilia,” “no ova or parasites”

Question 10

10. A 67-year-old man was taken to the ER for difficulty breathing, weakness, and lung infiltrates. He has a chronic cigarette cough and on examination, wheezes and rales were noted over the right lower lung. What is the likely differential diagnosis?
    a. Streptococcus pneumoniae
    b. Legionella pneumophila
    c. Mycoplasma pneumoniae
    d. Other (specify)

Answer 10

a. Streptococcus pneumoniae
Rationale: Streptococcus pneumoniae is a common cause of pneumonia, particularly in older adults with a history of smoking.
Clue words: “difficulty breathing,” “lung infiltrates,” “chronic cigarette cough,” “wheezes and rales”

Question 11

11. A 30-year-old woman native of Bulacan traveled to Plawan for a vacation. After 2 weeks, she consulted her doctor with chills and fever as her main complaints. What parasitic test would you request to establish your diagnosis?
    a. Thick blood smear
    b. Sputum examination
    c. Thick and thin blood smear
    d. Stool examination

Answer 11

c. Thick and thin blood smear
Rationale: The thick and thin blood smear is the gold standard for diagnosing malaria, which is common in tropical areas and presents with chills and fever.
Clue words: “traveled to Palawan,” “chills and fever”

Question 12

12. A flat whitish worm measuring 1.5cm was submitted to the diagnostic parasitology laboratory for identification. It was found in the underwear of a 7-year-old girl complaining of abdominal discomfort and occasional itchiness in the perianal area. The worm was identified as a segment of Taenia saginata. How did this patient acquire the infection?
    a. Eating raw infected pork
    b. Eating raw infected snail
    c. Eating raw infected freshwater fish
    d. Eating raw infected beef

Answer 12

d. Eating raw infected beef
Rationale: Taenia saginata is transmitted by consuming undercooked or raw beef containing the larvae.
Clue words: “Taenia saginata,” “7-year-old girl,” “abdominal discomfort,” “perianal area”

Question 13

13. Ova with flat bipolar plugs were seen in the stool specimen of a 16-year-old female with chronic diarrhea from Compostela Valley Province. If your diagnosis is correct, how did this patient acquire the infection?
    a. Eating salad
    b. Eating raw infected snail
    c. Eating raw or improperly cooked meat
    d. Eating raw infected freshwater fish

Answer 13

d. Eating raw infected freshwater fish

Rationale: Capillariasis is typically acquired by eating raw or undercooked freshwater fish that contain the larvae of Capillaria philippinensis. The life cycle of this parasite involves fish as intermediate hosts, and humans become infected by ingesting the larvae in the fish. This mode of transmission aligns with the diagnosis and the typical source of infection for this parasite.

Question 14

14. A 15-year-old boy from Davao del Norte is noted to have pallor and malnutrition. Stool examination reveals an ovum with a thin, colorless cell wall. What is your diagnosis?
    a. Hookworm infection
    b. Enterobiasis
    c. Ascariasis
    d. Trichuriasis

Answer 14

a. Hookworm infection
Rationale: Hookworm infection leads to iron deficiency anemia (pallor) and malnutrition, with characteristic ova having a thin, colorless cell wall.
Clue words: “pallor,” “malnutrition,” “thin, colorless cell wall”

Question 15

15. Ova with bipolar plugs were seen in the stool specimen of a 16-year-old female with chronic diarrhea from Compostela Valley. What is your diagnosis?
    a. Capillariasis
    b. Strongyloidiasis
    c. Ascariasis
    d. Hookworm infection

Answer 15

a. Capillariasis
Rationale: Capillariasis is characterized by ova with bipolar plugs and presents with chronic diarrhea.
Clue words: “ova with bipolar plugs,” “chronic diarrhea,” “Compostela Valley”

Question 16

16. A 31-year-old female from Southern Mindanao is brought in with chronic diarrhea of two months’ duration. Stool examination reveals larvae with a forked tail. What is your probable diagnosis?
    a. Capillariasis
    b. Strongyloides
    c. Ascariasis
    d. Hookworm infection

Answer 16

b. Strongyloides
Rationale: Strongyloides stercoralis larvae have a characteristic forked tail and cause chronic diarrhea.
Clue words: “chronic diarrhea,” “larvae with a forked tail”

Question 17

17. A baby born with congenital rubella was found to be deaf. Defects in rubella are grouped into broad categories. Deafness is under:
    a. Developmental
    b. Permanent
    c. Temporary

Answer 17

b. Permanent
Rationale: Congenital rubella syndrome includes permanent defects like deafness.
Clue words: “congenital rubella,” “deaf”

Question 18

18. A boy was diagnosed to have an infectious disease of unknown etiology. Examination of his blood showed that the complement levels are normal in infections. One defense against the agent is the activation of the complement. What among the items below is the best trigger for complement activation?
    a. Microbial surfaces
    b. IgM-antigen immune complexes
    c. IgG
    d. Mannose-containing bacterial glycolipids

Answer 18

d. IgM-antigen immune complexes

Rationale: IgM-antigen immune complexes are highly efficient at triggering the classical pathway of complement activation. IgM is particularly effective because its pentameric structure can bind multiple C1q molecules, initiating the complement cascade more effectively than IgG, which requires multiple molecules to achieve the same effect.

Summary:

IgM-antigen immune complexes (option d) are the best trigger for complement activation due to their efficiency in activating the classical pathway of the complement system.

Question 19

19. MR consulted a dermatologist for the small, pink, wart-like lesions on her face, arms, back, and buttocks. This diagnosis given was molluscum contagiosum infection. Which of the following about this is not true?
    a. The virus has a DNA genome
    b. The virus has a wide range of hosts
    c. It is considered a sexually transmitted disease
    d. Transmission is by direct and indirect contact

Answer 19

b. The virus has a wide range of hosts
Rationale: Molluscum contagiosum virus has a narrow host range, primarily infecting humans.
Clue words: “molluscum contagiosum,” “small, pink, wart-like lesions”

Question 20

20. Ana is getting married and thus was advised to get the rubella vaccine shot. Which of the following is true of the rubella vaccine?
    a. It is given to prevent congenital rubella infection
    b. Vaccinated children pose no threat to mothers who are susceptible and pregnant
    c. It is live attenuated
    d. AOTA

Answer 20

d. AOTA
Rationale: All statements (preventing congenital rubella, vaccinated children not posing a threat, and it being live attenuated) are true about the rubella vaccine.
Clue words: “rubella vaccine,” “getting married,” “congenital rubella”

Question 21

21. A 4-year-old boy was seen at the OPD for complaints of low-grade fever, cold, and a rash on the face which showed a typical “slapped cheek” appearance. Complaints of flu-like symptoms such as malaise and myalgias were also noted. The diagnosis given was erythema infectiosum or the fifth disease. Which of the following viruses is responsible?
    a. Hantavirus
    b. Herpes simplex virus
    c. Coxsackie virus
    d. B19 parvovirus

Answer 21

d. B19 parvovirus
Rationale: Erythema infectiosum, also known as fifth disease, is caused by B19 parvovirus and is characterized by a “slapped cheek” appearance.
Clue words: “slapped cheek,” “erythema infectiosum,” “fifth disease”

Question 22

22. The decision to give post-exposure prophylaxis when the dog bite is on the lower leg but not deep but bled is based on the following:
    a. Nature of biting animal
    b. Severity of the bite
    c. Manner of attack
    d. Nature of biting animal

Answer 22

d. Nature of biting animal
Rationale: The nature of the biting animal, such as whether it is rabid or not, is critical in deciding the need for post-exposure prophylaxis.
Clue words: “dog bite,” “post-exposure prophylaxis,” “nature of biting animal”

Question 23

23. Anaerobic infection is usually suspected when:
    a. There is a presence of foul smell
    b. The site of infection is near a mucosal surface
    c. There is gas in tissues
    d. All of the above
    e. Only a and b

Answer 23

d. All of the above
Rationale: Anaerobic infections are characterized by foul smell, proximity to mucosal surfaces, and presence of gas in tissues.
Clue words: “anaerobic infection,” “foul smell,” “mucosal surface,” “gas in tissues”

Question 24

24. Sudden development of bloody diarrhea accompanied by abdominal cramps and fever among chronically ill patients taking various antibiotics such as clindamycin, ampicillin, etc., may most likely be suffering from an infection caused by:
    a. Clostridium difficile
    b. Enterohemorrhagic Escherichia coli
    c. Shigella dysenteriae
    d. Vibrio parahaemolyticus

Answer 24

a. Clostridium difficile
Rationale: Clostridium difficile infection is commonly associated with antibiotic use and presents with bloody diarrhea and abdominal cramps.
Clue words: “bloody diarrhea,” “antibiotics,” “Clostridium difficile”

Question 25

25. The main pathology and disease manifestation in schistosomiasis are due to the host’s granulomatous reaction to eggs of parasites. The underlying mechanism for its granuloma formation is due to:
    a. Acute inflammatory reaction
    b. Immediate allergic reaction
    c. Delayed sensitivity
    d. Chronic vascular obstruction

Answer 25

c. Delayed sensitivity
Rationale: The granulomatous reaction in schistosomiasis is primarily due to a delayed hypersensitivity response to the eggs.
Clue words: “schistosomiasis,” “granulomatous reaction,” “delayed sensitivity”

Question 26

26. Congenital meningoencephalitis in children is associated with this parasite:
    a. Plasmodium malariae
    b. Toxoplasma gondii
    c. Acanthamoeba
    d. Trypanosoma gambiense

Answer 26

b. Toxoplasma gondii
Rationale: Toxoplasma gondii can cause congenital meningoencephalitis when transmitted from an infected mother to her child.
Clue words: “congenital meningoencephalitis,” “Toxoplasma gondii”

Question 27

27. A 40-year-old male overseas worker complaining of muscle pains sought medical attention upon his arrival in the Philippines. Biochemical tests showed elevated creatinine, phosphokinase, lactate dehydrogenase, and myokinase levels. Results of a complete blood count showed high blood eosinophilia. What is your most probable diagnosis?
    a. Filariasis
    b. Trichinosis
    c. Taeniasis
    d. Capillariasis

Answer 27

b. Trichinosis
Rationale: Trichinosis is characterized by muscle pain, elevated muscle enzymes, and eosinophilia, commonly seen in patients who have consumed undercooked meat.
Clue words: “muscle pains,” “elevated creatinine,” “eosinophilia,” “overseas worker”

Question 28

28. What is the cause of epidemic adenopharyngoconjunctival fever?
    a. Coxsackie virus
    b. Influenza virus
    c. Adenovirus
    d. Epstein-Barr virus

Answer 28

c. Adenovirus
Rationale: Adenovirus is known to cause epidemic adenopharyngoconjunctival fever, a condition affecting the eyes, throat, and lymph nodes.
Clue words: “adenopharyngoconjunctival fever,” “epidemic”

Question 29

29. A 40-year-old man resident of Manila presents to an emergency room with a 5-day history of fever, chills, nausea, vomiting, and myalgias. He returned 2 weeks ago from a 2-year job contract in Zambia. Microscopic examination revealed oval-shaped infected RBCs. What is your most probable diagnosis?
    a. Plasmodium falciparum
    b. Plasmodium vivax
    c. Plasmodium ovale
    d. Plasmodium malariae

Answer 29

c. Plasmodium ovale
Rationale: Plasmodium ovale causes malaria and is identified by the presence of oval-shaped infected red blood cells, common in regions like Zambia.
Clue words: “fever, chills, nausea,” “oval-shaped infected RBCs,” “Zambia”

Question 30

30. A young executive from Makati was hospitalized for myocarditis with mild congestive heart failure. The attending physician gave a diagnosis of coxsackievirus B5 infection. Other than his conditions, what other syndromes are associated with this virus?
    a. Acute hemorrhagic conjunctivitis
    b. Aseptic meningitis
    c. Herpangina
    d. None of the above

Answer 30

b. Aseptic meningitis
Rationale: Coxsackievirus B5 is associated with various conditions, including aseptic meningitis, along with myocarditis and other syndromes.
Clue words: “myocarditis,” “coxsackievirus B5,” “other syndromes”

Question 31

31. Which of the following statements is not true of Mycobacterium tuberculosis?
    a. The organism is found in the droplet nuclei discharged by the infected person.
    b. The organism is grown in complex media.
    c. The organism is resistant to drying and survives for a long period in dried sputum.
    d. The organism is resistant to acid and alkali.

Answer 31

b. The organism is grown in complex media.
Rationale: Mycobacterium tuberculosis is actually grown in specialized media like Lowenstein-Jensen medium, not typically complex media.
Clue words: “Mycobacterium tuberculosis,” “not true”

Question 32

32. Exudates from a ruptured appendicitis abscess yielded Bacteroides fragilis. Which of the following factors promotes abscess formation by B. fragilis?
    a. Superoxide dismutase
    b. Capsule
    c. Pili
    d. Lipopolysaccharide

Answer 32

b. Capsule
Rationale: The capsule of Bacteroides fragilis is a significant factor in promoting abscess formation by evading the immune response.
Clue words: “Bacteroides fragilis,” “promotes abscess formation”

Question 33

33. A 2 ½-year-old boy presented with less appetite and inability to swallow solid food, showing vesicular lesions in the buccal mucosa accompanied by enlarged cervical lymph nodes. This is probably caused by:
    a. Herpes simplex virus
    b. Streptococcus pyogens
    c. Measels virus
    d. Candida albicans

Answer 33

a. Herpes simplex virus

Given the symptoms—a 2 ½-year-old boy with less appetite, inability to swallow solid food, vesicular lesions in the buccal mucosa, and enlarged cervical lymph nodes—let’s analyze each option:

1. Herpes simplex virus (HSV):
   
   • Symptoms: HSV can cause gingivostomatitis in children, which presents with painful vesicular lesions in the mouth and on the lips, fever, and difficulty swallowing. Enlarged cervical lymph nodes can also be present.
   • Clue: Vesicular lesions in the buccal mucosa are a common feature of HSV infection.
2. Streptococcus pyogenes:
   
   • Symptoms: Causes streptococcal pharyngitis (strep throat), which typically presents with sore throat, fever, tonsillar exudates, and tender anterior cervical lymphadenopathy. Vesicular lesions are not a common feature.
   • Clue: This infection does not typically cause vesicular lesions in the mouth.
3. Measles virus:
   
   • Symptoms: Measles presents with fever, cough, conjunctivitis, coryza, and Koplik spots in the mouth (small white spots), followed by a maculopapular rash. Vesicular lesions are not a typical feature.
   • Clue: Koplik spots are characteristic of measles, not vesicular lesions.
4. Candida albicans:
   
   • Symptoms: Causes oral thrush, which presents with white, creamy plaques on the buccal mucosa, tongue, and palate. It does not typically cause vesicular lesions.
   • Clue: Thrush appears as white plaques, not vesicular lesions.

Given the clinical presentation of vesicular lesions in the buccal mucosa, inability to swallow solid food, and enlarged cervical lymph nodes, the most likely cause is Herpes simplex virus (option a). This fits the description of gingivostomatitis caused by HSV.

Question 34

34. This is the intermediate host of the rat tapeworm:
    a. Snails
    b. Xenopsylla cheopis (flea)
    c. Ticks
    d. Tribolium confusum (flour beetle)

Answer 34

d. Tribolium confusum (flour beetle)
Rationale: The intermediate host of the rat tapeworm, Hymenolepis diminuta, is the flour beetle (Tribolium confusum).
Clue words: “intermediate host,” “rat tapeworm”

Question 35

35. In the case mentioned, what drug can you prescribe to this patient with mycetoma?
    a. Mebendazole
    b. Diethylcarbamazine
    c. Metronidazole
    d. Praziquantel

Answer 35

c. Metronidazole
Rationale: Metronidazole is commonly used to treat bacterial infections and some parasitic infections but may not be specific to mycetoma, which is usually treated with antifungals and antibiotics depending on the type (eumycetoma or actinomycetoma). Given the context, Metronidazole is still the best option among the choices.
Clue words: “mycetoma,” “drug”

Question 36

36. A fisherman from Davao Oriental was rushed to a nearby hospital with chest pain, persistent cough, and hemoptysis as his main complaints. Patient interview revealed excessive drinking of native alcohol together with raw mountain crabs as their “pulutan.” The fisherman is probably suffering from:
    a. Pulmonary tuberculosis
    b. Strongyloidiasis
    c. Paragonimiasis
    d. Ascariasis

Answer 36

c. Paragonimiasis
Rationale: Paragonimiasis is associated with consuming raw or undercooked freshwater crabs or crayfish, which can cause pulmonary symptoms.
Clue words: “raw mountain crabs,” “chest pain,” “persistent cough,” “hemoptysis”

Question 37

37. A 24-year-old abaca farmer from Sorsogon with fever associated with signs and symptoms of inflammation of the lymph glands was brought to the outpatient department of the Philippine General Hospital. What parasitic diagnostic procedure will you request in the laboratory?
    a. Stool examination
    b. Thick blood film
    c. Sputum examination
    d. Urine examination

Answer 37

b. Thick blood film
Rationale: Thick blood film is used to diagnose parasitic infections like filariasis, which presents with lymphadenitis.
Clue words: “fever,” “inflammation of the lymph glands,” “thick blood film”

Question 38

38. Luna was diagnosed to have a starting skin cancer, which somehow spontaneously resolved. Aside from a possible miracle, the doctor said it could be due to Luna’s natural killer cells. Which is not a characteristic of natural killer cells?
    a. They can lyse malignant cells.
    b. Morphologically related to T cells.
    c. They resemble large granular lymphocytes.
    d. Aota (None of the above)

Answer 38

d. Aota (None of the above)
Rationale: All the listed characteristics are true of natural killer cells, making none of them incorrect.
Clue words: “natural killer cells,” “characteristic”

Question 39

39. In this viral infection, humans are dead-end hosts, and virus shedding does not occur:
    a. Measles
    b. Rabies
    c. Chickenpox
    d. Influenza

Answer 39

b. Rabies
Rationale: In rabies, humans are considered dead-end hosts as the virus does not spread from human to human.
Clue words: “dead-end hosts,” “virus shedding”

Question 40

40. A child who is breastfed is usually prone to diarrhea. This is probably because of:
    a. The acidity of the stomach.
    b. Presence of proteolytic enzymes and active macrophages in the small intestines.
    c. The presence of hydrolytic enzymes in the saliva which kills most bacteria.
    d. Aota (None of the above)

Answer 40

d. Aota (None of the above)
Rationale: Breastfeeding generally provides protection against diarrhea due to the presence of antibodies and beneficial bacteria in breast milk, making none of the options a valid reason for increased diarrhea.
Clue words: “breastfed,” “diarrhea”

Question 41

41. A premature baby was delivered stillborn. The baby was autopsied, and one finding was the presence of cells that look like owl’s eye cells with large intranuclear inclusion bodies. The most probable diagnosis is:
    a. Congenital chickenpox
    b. Congenital measles
    c. Congenital CMV (Cytomegalovirus)
    d. Congenital rubella

Answer 41

c. Congenital CMV (Cytomegalovirus)
Rationale: The presence of “owl’s eye” cells with intranuclear inclusion bodies is characteristic of Cytomegalovirus (CMV) infection.
Clue words: “owl’s eye cells,” “intranuclear inclusion bodies,” “premature baby,” “stillborn”

Question 42

42. An overseas worker coming home from Uganda was rushed to a nearby hospital for a seizure attack. His relatives informed the medical officer on duty that the patient is experiencing progressive confusion and personality changes. Laboratory examination of the CSF revealed the presence of polymorphic organisms with an undulating membrane. What is the most likely parasitic infection present in this patient?
    a. Leishmaniasis
    b. Malaria
    c. Trypanosomiasis
    d. Toxoplasmosis

Answer 42

c. Trypanosomiasis
Rationale: Trypanosomiasis, specifically African trypanosomiasis (sleeping sickness), presents with neurological symptoms and is caused by Trypanosoma brucei, which has an undulating membrane.
Clue words: “seizure attack,” “progressive confusion,” “undulating membrane,” “Uganda”

Question 43

43. A farmer complained of multiple lesions along the length of the arms which started when he got wounded by a rose thorn while pruning. The discharge was cultured in SDA, which showed septate hyphae with small conidia clustered at the tip of conidiophores, appearing like daisies with stems. What is the likely identification of the organism?
    a. Cladosporium carrionii
    b. Trichophyton mentagrophytes
    c. Sporothrix schenckii
    d. Phialophora species

Answer 43

c. Sporothrix schenckii
Rationale: Sporothrix schenckii causes sporotrichosis and is often acquired through puncture wounds from plant material. It presents with characteristic “daisy-like” conidia on culture.
Clue words: “multiple lesions,” “rose thorn,” “septate hyphae,” “daisies with stems”

Question 44

44. The black granules coming out of the sinuses in the big foot of a farmer are hard and showed intertwined septate hyphae. Which of the following is the most likely etiologic agent?
    a. Nocardia spp.
    b. Madurella grisea
    c. Trichophyton rubrum
    d. Actinomyces

Answer 44

b. Madurella grisea
Rationale: Madurella grisea is a common cause of mycetoma, characterized by black granules and septate hyphae.
Clue words: “black granules,” “septate hyphae,” “farmer”

Question 45

45. Baby A was born in December 2004. An older brother got sick with chickenpox when the baby was a month old. Another older sister got sick with chickenpox about two weeks after the older brother manifested the disease. However, baby A did not get sick, and this is probably due to:
    a. Maternal IgG
    b. Baby IgG
    c. Baby IgA
    d. Maternal IgA

Answer 45

a. Maternal IgG
Rationale: Maternal IgG antibodies, which cross the placenta, provide immunity to newborns against infections like chickenpox.
Clue words: “did not get sick,” “maternal IgG”

Question 46

46. A 10-year-old girl with perianal pruritus was brought by her mother to her pediatrician. Based on your probable diagnosis, what diagnostic procedure will you request to support your diagnosis?
    a. Direct fecal smear
    b. Cellulose tape swab
    c. Harada-Mori stool culture
    d. Stool concentration technique

Answer 46

b. Cellulose tape swab
Rationale: Perianal pruritus in children is commonly caused by Enterobius vermicularis (pinworm), and a cellulose tape swab (scotch tape test) is used to diagnose it.
Clue words: “perianal pruritus,” “diagnostic procedure”

Question 47

47. Basis for the treatment of Taenia saginata:
    a. Negative stool for eggs
    b. Recovery of the scolex
    c. Recovery of proglottid

Answer 47

b. Recovery of the scolex
Rationale: Successful treatment of Taenia saginata is confirmed by the recovery of the scolex (head) of the tapeworm, indicating that the entire parasite has been expelled.
Clue words: “treatment of Taenia saginata,” “scolex”

Question 48

48. A male leukemia patient was admitted for post-transfusion hepatitis. Tests showed the etiologic agent to be a flavivirus. The virus is:
    a. Hepatitis A
    b. Hepatitis B
    c. Hepatitis C
    d. Hepatitis D

Answer 48

c. Hepatitis C
Rationale: Hepatitis C virus (HCV) is a flavivirus and a common cause of post-transfusion hepatitis.
Clue words: “post-transfusion hepatitis,” “flavivirus”

Question 49

49. Schistosomiasis is also known as:
    a. Katayama fever
    b. Snail fever
    c. Bilharziasis
    d. AOTA (All of the above)

Answer 49

d. AOTA (All of the above)
Rationale: Schistosomiasis is also known as Katayama fever, snail fever, and bilharziasis.
Clue words: “Schistosomiasis,” “also known as”

Question 50

50. If the microscopic examination of thick and thin blood smears from a patient suspected of malaria showed infected RBCs with double chromatin dots, what is your most probable diagnosis?
    a. Plasmodium vivax
    b. Plasmodium ovale
    c. Plasmodium malariae
    d. Plasmodium falciparum

Answer 50

d. Plasmodium falciparum
Rationale: Plasmodium falciparum is characterized by the presence of infected red blood cells with multiple chromatin dots.
Clue words: “infected RBCs,” “double chromatin dots,” “malaria”

Question 51

51. An OFW presented a hard, painless ulcer in the buccal mucosa. He was diagnosed with syphilis. The doctor got some specimens at the base of the ulcer and added some reagents, then examined it under a fluorescent microscope. This test is referred to as:
    a. ELISA
    b. Radioimmunoassay
    c. Immunoblotting
    d. Immunofluorescence

Answer 51

d. Immunofluorescence
Rationale: Immunofluorescence is a diagnostic technique used to detect specific antigens in tissues by using antibodies linked to a fluorescent dye.
Clue words: “fluorescent microscope,” “syphilis,” “hard, painless ulcer”

Question 52

52. Isabel becomes a different person during the months of December. In these months, she is grouchy because of hay fever. Her doctor explained that she is allergic to pollen, and the major culprit is the so-called IgE, which is a homocytotropic immunoglobulin that binds to all of the following cells below except:
    a. Mast cells
    b. Eosinophils
    c. Neutrophils
    d. Basophils

Answer 52

c. Neutrophils
Rationale: IgE binds to mast cells, eosinophils, and basophils, but not to neutrophils.
Clue words: “IgE,” “allergic to pollen,” “binds to all of the following cells except”

Question 53

53. Which stage of Schistosoma is infective to man?
    a. Cercaria
    b. Merozoite
    c. Adult worms
    d. Sporozoite

Answer 53

a. Cercaria
Rationale: The cercariae are the larval form of Schistosoma that penetrate human skin, causing infection.
Clue words: “infective to man,” “Schistosoma”

Question 54

54. A macho dancer presented with fever, headache, and malaise. CBC was done and the peripheral blood smear showed large atypical lymphocytes. The most probable diagnosis is:
    a. Cytomegalovirus infection mononucleosis
    b. Infectious mononucleosis
    c. Herpes simplex infection
    d. Mumps

Answer 54

b. Infectious mononucleosis
Rationale: Infectious mononucleosis, caused by Epstein-Barr virus, typically presents with large atypical lymphocytes.
Clue words: “large atypical lymphocytes,” “fever, headache, malaise”

Question 55

55. A boy at the OPD clinic tested negative in the lepromin test. He presents with multiple, erythematous, anesthetic lesions all over the body. The skin test shows which type of hypersensitivity:
    a. Type I
    b. Type II
    c. Type III
    d. Type IV

Answer 55

d. Type IV
Rationale: The lepromin test measures delayed-type hypersensitivity (Type IV) reaction, which is negative in lepromatous leprosy.
Clue words: “negative lepromin test,” “erythematous, anesthetic lesions”

Question 56

56. A sexually active 25-year-old woman consulted a VD control clinic for vaginal itching and purulent discharge. Trichomoniasis is your tentative diagnosis. What parasitologic examination should you include in your workup?
    a. Wet mount of vaginal fluid
    b. Ova and parasite fecal smear
    c. Stool culture
    d. pH test of a blood sample

Answer 56

a. Wet mount of vaginal fluid
Rationale: A wet mount of vaginal fluid is the standard diagnostic test for detecting Trichomonas vaginalis.
Clue words: “vaginal itching,” “purulent discharge,” “Trichomoniasis”

Question 57

57. Athletes with vesicular lesions in their feet, particularly in the toe webs, are most likely suffering from athlete’s foot. Three of the following dermatophytes below are common etiologic agents of athlete’s foot except:
    a. M. Canis
    b. T. Rubrum
    c. T. mentagrophytes
    d. E. floccosum

Answer 57

a. M. Canis
Rationale: M. Canis typically causes infections in animals and is less common in athlete’s foot, which is usually caused by T. rubrum, T. mentagrophytes, and E. floccosum.
Clue words: “athlete’s foot,” “common etiologic agents except”

Question 58

58. This is the largest ciliated intestinal protozoa which can be found in normal individuals:
    a. Entamoeba coli
    b. Giardia lamblia
    c. Balantidium coli
    d. Trichomonas tenax

Answer 58

c. Balantidium coli
Rationale: Balantidium coli is the largest ciliated protozoan that can inhabit the human intestine.
Clue words: “largest ciliated intestinal protozoa,” “normal individuals”

Question 59

59. A 15-year-old boy from Davao del Norte noted to have pallor and malnutrition. Stool examinations reveal an ovum with a thin, colorless cell wall. The probable diagnosis is hookworm infection. Name the portal of entry of this worm:
    a. Mosquito bite
    b. Skin penetration
    c. Oral ingestion
    d. Inhalation

Answer 59

b. Skin penetration
Rationale: Hookworm larvae penetrate the skin to enter the human body.
Clue words: “hookworm infection,” “portal of entry”

Question 60

60. A 22-year-old female consulted for brownish discoloration on her cheek. She noticed it after her tan from previous exposure to the sun on the beach had already peeled, but a big portion on her cheek showed the discoloration. The most likely diagnosis for this condition is:
    a. Superficial mycoses
    b. Avitaminosis
    c. Leprosy

Answer 60

a. Superficial mycoses
Rationale: Superficial mycoses, such as tinea versicolor, can cause pigmentation changes in the skin.
Clue words: “brownish discoloration,” “superficial mycoses”

Question 61

61. Which of the following organisms is not associated with cancer?
    a. Hepatitis A
    b. Hepatitis B
    c. Retroviruses
    d. Herpes

Answer 61

a. Hepatitis A
Rationale: Hepatitis B and C, retroviruses, and certain herpesviruses (like EBV) are associated with cancer, but Hepatitis A is not.
Clue words: “not associated with cancer”

Question 62

62. Which of the following organisms will be catalase positive and coagulase positive?
    a. Streptococcus viridans
    b. Staphylococcus aureus
    c. E. coli
    d. Staphylococcus saprophyticus

Answer 62

b. Staphylococcus aureus
Rationale: Staphylococcus aureus is both catalase positive and coagulase positive.
Clue words: “catalase positive,” “coagulase positive”

Question 63

63. A 9-month-old baby was rushed to the ER for fever and persistent cough. On examination, rales were heard on his left chest, and an infiltrate in the lung is seen on chest x-ray film. The diagnosis given is pneumonia. Which of the following viruses is the most likely cause?
    a. Coronaviruses
    b. Respiratory syncytial virus
    c. Rhinovirus
    d. Adenovirus

Answer 63

b. Respiratory syncytial virus
Rationale: Respiratory syncytial virus (RSV) is a common cause of pneumonia in infants.
Clue words: “9-month-old baby,” “pneumonia,” “rales,” “infiltrate in the lung”

Question 64

64. A 10-year-old girl with perianal pruritus was brought by her mother to her pediatrician. What is your most probable diagnosis?
    a. Enterobiasis
    b. Ascariasis
    c. Trichuriasis
    d. Hookworm infection

Answer 64

a. Enterobiasis
Rationale: Enterobiasis (pinworm infection) commonly causes perianal pruritus, especially in children.
Clue words: “perianal pruritus,” “10-year-old girl”

Question 65

65. An overseas worker with febrile illness that began in December 2003, approximately 3 months and 14 months, respectively, after leaving Africa, consulted the hospital during the course of his illness. The patient experienced fluctuation in temperatures and lost 13 pounds of body weight. Light-microscopic examinations of cultures of bone marrow and liver biopsy specimens noted a group of intracellular small rounded organisms, laboratory results identify it as amastigote stage. What is the most likely parasitic infection?
    a. Trypanosomiasis
    b. Leishmaniasis
    c. Malaria
    d. Toxoplasmosis

Answer 65

b. Leishmaniasis
Rationale: Leishmaniasis is characterized by the presence of amastigotes in tissue samples and fluctuating fever and weight loss.
Clue words: “amastigote stage,” “fluctuation in temperatures,” “lost 13 pounds,” “Africa”

Question 66

66. Which of the following is true of amoebiasis?
    a. Soft stools will show trophozoites.
    b. Cysts are viable for days in the environment.
    c. Definitive diagnosis depends on the demonstration of amoeba in the stool or in aspirated materials from abscess.
    d. AOTA (All of the above)

Answer 66

d. AOTA (All of the above)
Rationale: All statements are true: trophozoites are found in soft stools, cysts are viable in the environment for days, and definitive diagnosis involves demonstrating amoeba in stool or aspirated material.
Clue words: “true of amoebiasis”

Question 67

67. The best temperature for transport of a patient’s specimen to the laboratory for viral culture is:
    a. 42°C
    b. 40°C
    c. 37°C
    d. 25°C

Answer 67

c. 37°C
Rationale: Specimens for viral culture are best transported at body temperature (37°C) to maintain viability of the virus.
Clue words: “best temperature,” “transport,” “viral culture”

Question 68

68. Abnormalities in congenital rubella are caused by which of the following?
    a. Hypoplastic organs result in abnormalities in the embryonic cell which have a reduced growth rate.
    b. Infected cells in the baby fail to divide.
    c. Structural abnormalities due to hypoplastic organs.
    d. AOTA (All of the above)

Answer 68

d. AOTA (All of the above)
Rationale: All options describe mechanisms by which congenital rubella can cause abnormalities.
Clue words: “abnormalities,” “congenital rubella”

Question 69

69. Black granules which are coming out from the multiple sinuses in the big foot of a farmer are most likely a case of:
    a. Sporotrichosis
    b. Elephantiasis
    c. Mycetoma
    d. Chromomycosis

Answer 69

c. Mycetoma
Rationale: Mycetoma is characterized by black granules coming out of sinus tracts.
Clue words: “black granules,” “multiple sinuses,” “big foot,” “farmer”

Question 70

70. An absent-minded medical intern was vaccinated with measles. She got the vaccine from the refrigerator, then when she was distracted by a crying patient, she placed the vaccine on the table and attended to the other patient for about 1-2 hours. Which of the following items below is NOT a characteristic of the measles vaccine?
    a. Live attenuated vaccine
    b. Administered subcutaneously
    c. High stability at room temperature
    d. AOTA (All of the above)

Answer 70

c. High stability at room temperature
Rationale: The measles vaccine is not highly stable at room temperature and needs to be kept cold to remain effective.
Clue words: “measles vaccine,” “characteristic,” “room temperature”

Question 71

71. A flat whitish worm, measuring 1.5cm long, was submitted to the diagnostic parasitology laboratory for identification. It was found in the underwear of a 7-year-old girl complaining of abdominal discomfort and occasional itchiness of the perianal area. What parasitic infection would you consider?
    a. Enterobiasis
    b. Strongyloidiasis
    c. Taeniasis
    d. Heterophydiasis

Answer 71

c. Taeniasis
Rationale: The description of a flat whitish worm fits the characteristics of a tapeworm segment (proglottid), which is indicative of Taeniasis.
Clue words: “flat whitish worm,” “1.5cm long,” “abdominal discomfort,” “perianal area”

Question 72

72. What condition will manifest with soft yellowish nodules on the hair of his axilla and beard, often mistaken for eggs of lice? The most likely diagnosis for this is:
    a. Excess soap suds
    b. Black piedra
    c. Trichophyton hair infection
    d. White piedra

Answer 72

d. White piedra
Rationale: White piedra is a fungal infection characterized by soft yellowish nodules on hair shafts.
Clue words: “soft yellowish nodules,” “hair of axilla and beard,” “eggs of lice”

Question 73

73. Black skin discoloration resembling silver nitrate stain usually found on the palm is most likely to be tinea nigra. Which of the following etiologic agents is causing this illness?
    a. Hortea werneckii
    b. Exophiala hortai
    c. Cladosporium spp.
    d. Trichophyton spp.

Answer 73

a. Hortea werneckii
Rationale: Tinea nigra is caused by Hortea werneckii, which leads to black skin discoloration on the palms.
Clue words: “black skin discoloration,” “palm,” “tinea nigra”

Question 74

74. Which specimen should not be refrigerated after collection if it cannot be processed at once?
    a. Urine
    b. Stool
    c. Sputum
    d. Blood

Answer 74

b. Stool
Rationale: Stool samples should not be refrigerated as refrigeration can affect the viability of certain pathogens, such as protozoa.
Clue words: “not be refrigerated,” “specimen”

Question 75

75. You suffer from a runny nose, itchy eyes, and frequent sneezing, especially during the months of March to May and November to January. You may probably have:
    a. Type I hypersensitivity
    b. Type II hypersensitivity
    c. Type III hypersensitivity
    d. Type IV hypersensitivity

Answer 75

a. Type I hypersensitivity
Rationale: Type I hypersensitivity (allergic reactions) is characterized by symptoms such as a runny nose, itchy eyes, and sneezing.
Clue words: “runny nose,” “itchy eyes,” “frequent sneezing”

Question 76

76. Ferdie was diagnosed as a carrier of hepatitis B. In one of his follow-ups in the clinic, anti-HBe antibodies were detected in his serum. This means that:
    a. He is now developing resistance
    b. It has no meaning
    c. His HB virus titer is now low
    d. A mistake was committed because HBsAg and anti-HBe do not exist together in the blood

Answer 76

c. His HB virus titer is now low

Rationale: The detection of anti-HBe antibodies in a carrier of Hepatitis B typically indicates that viral replication has decreased and the level of infectious virus in the blood is low. This is an important marker used to assess the phase of Hepatitis B infection and usually means the infection is moving towards a less active state.

Question 77

77. A sexually active 26-year-old woman consulted a VD control clinic for vaginal itching and purulent discharge. Trichomoniasis is contracted almost exclusively through sexual intercourse. Control and prevention will, therefore, require:
    a. Prompt treatment of the patient
    b. Prompt treatment of the sexual partner
    c. Require no treatment, since it is self-limiting
    d. Treatment of both

Answer 77

d. Treatment of both
Rationale: Effective control and prevention of trichomoniasis require treating both the infected individual and their sexual partner to prevent reinfection.
Clue words: “vaginal itching,” “purulent discharge,” “control and prevention”

Question 78

78. The human vaccine for this viral infection is made of killed virus in human VERO cells.
    a. Rabies
    b. Japanese encephalitis
    c. Rubella
    d. Measles

Answer 78

a. Rabies
Rationale: The rabies vaccine is made using inactivated virus grown in VERO cells.
Clue words: “killed virus,” “human VERO cells”

Question 79

79. A ten-year-old girl complained of difficulty and pain in swallowing. It was accompanied by a runny nose and fever. On examination, she had slightly swollen tonsils and an erythematous pharynx. No exudates were noted on the tonsillar surface. The diagnosis given was upper respiratory infection. The most likely etiologic agent for this case is:
    a. Rhinovirus
    b. Respiratory syncytial virus
    c. Adenovirus
    d. Coronavirus

Answer 79

a. Rhinovirus
Rationale: Rhinovirus is a common cause of upper respiratory infections in children and can present with symptoms such as runny nose, fever, and pharyngitis without exudates.
Clue words: “difficulty and pain in swallowing,” “runny nose,” “fever,” “erythematous pharynx”

Question 80

80. The confirmatory test for HIV infection is done with which of the following tests?
    a. Eastern blotting
    b. Southern blotting
    c. Northern blot
    d. Western blot

Answer 80

d. Western blot
Rationale: The Western blot is used as a confirmatory test for HIV infection by detecting specific antibodies to HIV proteins.
Clue words: “confirmatory test,” “HIV infection”

Question 81

81. A middle-aged woman complained of an acute onset fever and nausea. Her eyes were yellow, and she was surprised to see her urine to be dark-colored. On consultation, her blood was subjected to some tests. One result was positive for HAV IgM antibody. What will you tell her if you are the physician?
    a. That she might develop liver carcinoma in the future
    b. That probably it was transmitted to her when she had a blood transfusion
    c. That she acquired the disease through sexual contact
    d. To be very careful because she can transmit the infection to other members of her family by person-to-person spread

Answer 81

d. To be very careful because she can transmit the infection to other members of her family by person-to-person spread
Rationale: HAV (Hepatitis A virus) is transmitted via the fecal-oral route, and person-to-person spread is common.
Clue words: “positive for HAV IgM antibody,” “yellow eyes,” “dark-colored urine”

Question 82

82. Mario, a 45-year-old executive, is a sickly guy; he always complains of coughs and colds. His doctor said that he is often attacked by organisms which attach to the mucous membranes of his respiratory tract. These organisms then do which of the following actions against its host?
    a. Evade phagocytosis
    b. Breakdown of IgA by producing proteases
    c. Allow themselves to be taken by macrophages
    d. AOTA (All of the above)

Answer 82

d. AOTA (All of the above)
Rationale: Pathogens can evade the host’s immune system by various mechanisms including evading phagocytosis, producing IgA proteases, and being taken up by macrophages.
Clue words: “coughs and colds,” “attach to the mucous membranes”

Question 83

83. A 40-year-old male overseas worker complaining of muscle pain seeks medical attention upon his arrival in the Philippines. Biochemical tests showed elevated creatinine phosphokinase, lactate dehydrogenase, and myokinase levels. Results of CBC showed high blood eosinophilia. What would you request to confirm your diagnosis?
    a. Muscle biopsy
    b. Rectal biopsy
    c. Skin scrapping
    d. Skin test

Answer 83

a. Muscle biopsy
Rationale: A muscle biopsy would help confirm a diagnosis of trichinosis or another parasitic infection affecting the muscles.
Clue words: “muscle pain,” “elevated creatinine phosphokinase,” “high blood eosinophilia”

Question 84

84. The doctor exposed the affected area to Wood’s light, which gave green fluorescence, and the skin scrapping mounted in 10% KOH showed short, stout, angular hyphae. The most likely etiologic agent is:
    a. Pityriasis versicolor
    b. Candidiasis
    c. White Piedra
    d. Tinea corporis

Answer 84

a. Pityriasis versicolor
Rationale: Pityriasis versicolor (caused by Malassezia species) shows green fluorescence under Wood’s light and characteristic hyphae in KOH mount.
Clue words: “Wood’s light,” “green fluorescence,” “short, stout, angular hyphae”

Question 85

85. In California at the border of Mexico, the disease which is transmitted by inhalation of spores of a certain fungus, which later develops into sac-like structures with endospores in the tissues, and causing systemic mycosis is most likely to be:
    a. Tuberculosis
    b. Histoplasmosis
    c. Coccidioidomycosis
    d. Blastomycosis

Answer 85

c. Coccidioidomycosis
Rationale: Coccidioidomycosis (Valley Fever) is caused by Coccidioides spp. and is endemic to the southwestern United States and northern Mexico.
Clue words: “inhalation of spores,” “sac-like structures with endospores,” “systemic mycosis”

Question 86

86. After feasting on seafood, particularly raw oyster, a 22-year-old male becomes ill after 24 hours, complaining of vomiting, diarrhea, and headache. He consulted a private clinic, and the physician, after a thorough examination, ruled out bacterial etiology. The most probable viral etiologic agent is:
    a. Rotavirus
    b. Hepatitis A virus
    c. Coronavirus
    d. Norwalk virus

Answer 86

d. Norwalk virus
Rationale: Norwalk virus (norovirus) is commonly associated with outbreaks of gastroenteritis linked to the consumption of raw or undercooked seafood.
Clue words: “raw oyster,” “vomiting, diarrhea, and headache,” “ruled out bacterial etiology”

Question 87

87. A 28-year-old woman has recurrent genital herpes. Which of the following about genital herpes infection is most likely to be true?
    a. Reactivation of latent virus during pregnancy poses no threat to the newborn
    b. Cannot be transmitted in the absence of apparent lesions
    c. Recurrent episodes are more severe than the primary infection
    d. Can be caused by either herpes simplex type 1 or Type 2

Answer 87

d. Can be caused by either herpes simplex type 1 or Type 2
Rationale: Genital herpes can be caused by either HSV-1 or HSV-2, though HSV-2 is more common.
Clue words: “recurrent genital herpes,” “true about genital herpes infection”

Question 88

88. Mike was sick of pneumonia, and his doctor explained that the organism which infected him was not easily destroyed by the body’s defenses. That it has to be opsonized by _ to be effectively eaten by scavenger cells. C3 is involved in opsonization? This substance is?
    a. C3a
    b. C3b
    c. C3c
    d. Cl ars

Answer 88

b. C3b
Rationale: C3b is a component of the complement system that plays a key role in opsonization, making pathogens more susceptible to phagocytosis.
Clue words: “pneumonia,” “opsonization,” “C3”

Question 89

89. Vaginal discharge which is whitish-gray, with a bad odor, pH of 5.5 and positive of clue cells on microscopy, but without PMN is most likely to be a case of:
    a. Yeast vaginitis
    b. Bacterial vaginitis
    c. Trichomonas vaginalis
    d. Gonorrhea

Answer 89

b. Bacterial vaginitis
Rationale: Bacterial vaginitis (BV) presents with whitish-gray discharge, a fishy odor, and the presence of clue cells, typically without an inflammatory response (no PMNs).
Clue words: “whitish-gray discharge,” “bad odor,” “clue cells,” “without PMN”

Question 89

91. Jake had typhoid fever. When seen by the doctor, he started to feel better. If you can enter Jake’s body, which of the following items below would show that he had achieved an adaptive immune response against typhoid bacilli?
    a. Clonal expansion of B and T cells
    b. Chemical barriers
    c. Phagocytosis
    d. Physical barriers

Answer 89

a. Clonal expansion of B and T cells
Rationale: Clonal expansion of B and T cells is a hallmark of the adaptive immune response, indicating that Jake’s immune system has responded specifically to the typhoid bacilli.
Clue words: “adaptive immune response,” “typhoid bacilli”

Question 89

90. The amoeba that is morphologically similar to Entamoeba histolytica but has a diameter of less than 10μm or smaller:
    a. Endolimax nana
    b. Entamoeba hartmanni
    c. Entamoeba coli
    d. Iodamoeba butschlii

Answer 89

b. Entamoeba hartmanni
Rationale: Entamoeba hartmanni is similar to Entamoeba histolytica but smaller in size.
Clue words: “morphologically similar to Entamoeba histolytica,” “less than 10μm”

Question 90

92. A 6-month-old baby was brought in for a fever of one day’s duration. She is found to have a temperature of 38.5°C and with hepatomegaly (3 cm) and splenomegaly (3 cm). Microscopic presence of band form stages. What is your most probable diagnosis?
    a. Plasmodium ovale
    b. Plasmodium falciparum
    c. Plasmodium malariae
    d. Plasmodium vivax

Answer 90

3. Plasmodium malariae:
   • Rationale: P. malariae causes quartan malaria (72-hour fever cycle) and is characterized by band forms (band trophozoites) in the blood smear. It can cause hepatomegaly and splenomegaly.
   • Clue Words: “quartan malaria,” “band forms,” “hepatomegaly,” “splenomegaly”

Question 91

93. A sexually active 26-year-old woman consulted a VD control clinic for vaginal itching and purulent discharge. Trichomoniasis is best treated with:
    a. Albendazole
    b. Mebendazole
    c. Praziquantel
    d. Metronidazole

Answer 91

d. Metronidazole
Rationale: Metronidazole is the drug of choice for treating trichomoniasis.
Clue words: “vaginal itching,” “purulent discharge,” “trichomoniasis”

Question 92

94. A flat whitish worm measuring 1.5 cm long was submitted to the diagnostic parasitology laboratory for identification. It was found in the underwear of a 7-year-old girl complaining of abdominal discomfort and occasional itchiness of the perianal area. What is the drug of choice for this parasitic infection?
    a. Piperazine
    b. Albendazole
    c. Mebendazole
    d. Praziquantel

Answer 92

d. Praziquantel
Rationale: Praziquantel is the drug of choice for treating Taenia saginata infection.
Clue words: “Taenia saginata,” “drug of choice”

Question 93

95. Betty has colds almost every three months, but she is not bothered because she noticed that even without treatment she gets better. The self-limiting nature of her colds, which is often of viral etiology, is partly attributed to:
    a. Alpha interferon
    b. Beta interferon
    c. Gamma interferon
    d. Both A and B

Answer 93

d. Both A and B
Rationale: Both alpha and beta interferons play a role in the self-limiting nature of viral infections by inhibiting viral replication and modulating the immune response.
Clue words: “self-limiting nature,” “viral etiology”.

Question 94

96. An MMDA traffic enforcer was admitted to the hospital for sudden onset of high fever (39°C), headache, and pain in his calf muscle. On admission, his blood test showed increased FMN, abnormal liver and renal function tests. On physical examination, he also had subconjunctival hemorrhage. He also had a history of wading in the floodwaters of Tondo about 10 days prior to the illness. The diagnosis of the attending medical intern was leptospirosis. Which of the following would be most likely to confirm the diagnosis?
    a. Test acute and convalescent serum for leptospiral antibodies
    b. Do a dark-field examination of serum and urine
    c. Culture of the blood on Thayer Martin agar
    d. Test acute and convalescent sera using the RPR

Answer 94

a. Test acute and convalescent serum for leptospiral antibodies
Rationale: Testing for leptospiral antibodies in acute and convalescent serum is a reliable method to confirm leptospirosis.
Clue words: “leptospirosis,” “acute and convalescent serum,” “antibodies”

Question 95

97. A 51-year-old farmer from Surigao Mindanao was brought to a hospital with abdominal pain and frequent loose stools. Further examination revealed hepatomegaly with tenderness in the right upper quadrant of the abdomen. Laboratory results showed an increase in eosinophilia. Direct fecal smear showed no ova or parasites seen, while rectal biopsy demonstrated eggs with miracidia. What factor would you consider to make your specific diagnosis?
    a. Increase in eosinophilia
    b. Evidence of exposure in endemic area
    c. Clinical signs and symptoms
    d. Recovery of characteristic egg

Answer 95

d. Recovery of characteristic egg
Rationale: The presence of characteristic eggs with miracidia in a rectal biopsy is a definitive factor in diagnosing schistosomiasis.
Clue words: “eggs with miracidia,” “rectal biopsy,” “increase in eosinophilia”

Question 96

98. An adult roundworm measuring 27 cm in length was seen in the colon of a 10-year-old boy who died of pneumonia. Manifestations such as lung infiltration, asthmatic symptoms, and edema of the lips were documented before the patient died. What is the most probable parasitic infection can you identify in this case?
    a. Capillariasis
    b. Hookworm infection
    c. Trichuriasis
    d. Ascariasis

Answer 96

d. Ascariasis
Rationale: Ascariasis is caused by Ascaris lumbricoides, a large roundworm that can cause respiratory symptoms and be found in the intestines.
Clue words: “adult roundworm,” “lung infiltration,” “10-year-old boy”

Question 97

99. Dipylidium caninum is also termed as:
    a. Beef tapeworm
    b. Pig tapeworm
    c. Dog tapeworm
    d. Fish tapeworm

Answer 97

c. Dog tapeworm
Rationale: Dipylidium caninum is commonly known as the dog tapeworm.
Clue words: “Dipylidium caninum,” “dog tapeworm”

Question 98

100. Which of the following is/are true of toxic shock syndrome?
     a. Staphylococcus aureus can cause it
     b. Streptococcus pyogenes can cause it
     c. Not A
     d. A and B

Answer 98

d. A and B
- Rationale: Both Staphylococcus aureus and Streptococcus pyogenes can cause toxic shock syndrome.
- Clue words: “toxic shock syndrome,” “Staphylococcus aureus,” “Streptococcus pyogenes”