Question 1

All stages of rashes are seen simultaneously in?

Accepted Answer

Answer reason: This leads to the hallmark finding of lesions in different stages at the same time (macules, papules, vesicles, pustules, and crusts) on a single exam. Measles typically has a more synchronous morbilliform rash that progresses in a predictable cephalocaudal pattern rather than mixed stages. Typhoid and malaria do not characteristically cause a generalized vesicular rash with simultaneous lesion stages.

Question 2

What is the causative agent of COVID-19 disease?

Accepted Answer

Answer reason: Viruses are obligate intracellular agents that replicate inside host cells and commonly cause respiratory outbreaks spread by droplets/aerosols. This matches the known etiology of COVID-19 and explains why antibacterial therapies do not treat the underlying infection. Fungal and protozoal pathogens have different transmission patterns and disease syndromes and are not responsible for the COVID-19 pandemic.

Question 3

Hydrophobia is seen in .......?

Accepted Answer

Answer reason: Rabies is most commonly transmitted to humans through the saliva of an infected animal via bites, with dogs being a major reservoir in many regions. Therefore a dog bite is the exposure classically associated with hydrophobia. Envenomations such as scorpion, snake, and spider bites cause toxic systemic or local effects rather than this characteristic fear of water due to swallowing spasms.

Question 4

Mycology is the study of?

Accepted Answer

Answer reason: The “myco-” prefix derives from the Greek word for fungus, distinguishing it from osteology (bones) and entomology (insects). Clinically, mycology underpins understanding of fungal transmission, morphology, and antifungal therapy selection. The other options refer to fields outside fungal biology and therefore do not match the term.

Question 5

The AIDS is caused by..?

Accepted Answer

Answer reason: This immune depletion leads to opportunistic infections and certain malignancies that define AIDS. Protozoa, bacteria, and fungi can cause opportunistic diseases in AIDS, but they are not the underlying cause of the syndrome. Therefore, the causative agent is a virus.

Question 6

Which of the following is a fungal disease?

Accepted Answer

Answer reason: This condition typically presents as oral thrush, vulvovaginal yeast infection, or intertrigo, especially after antibiotics, with diabetes, or in immunosuppression. Leptospirosis is a bacterial zoonosis caused by Leptospira, not a fungus. Ascariasis is a helminthic (nematode) infestation caused by Ascaris lumbricoides, so it is also not fungal.

Question 7

Gonorrhoea is a Disease transmitted through?

Accepted Answer

Answer reason: This includes vaginal, anal, and oral sex, with infection occurring at the cervix/urethra, rectum, or pharynx. Transmission through food does not occur, and blood-borne spread (e.g., transfusion) is not a typical or clinically relevant route because the organism is not sustained in blood products and requires mucosal exposure. Although perinatal transmission can occur during birth, among the listed options sexual transmission is the correct route.

Question 8

Rice water stool is the typical sign of?

Accepted Answer

Answer reason: This results in profuse, watery diarrhea that appears pale with flecks of mucus, resembling “rice-water,” and can rapidly cause severe dehydration and hypovolemic shock. Dysentery typically causes small-volume stools with blood and mucus plus tenesmus due to colonic inflammation, not the voluminous watery output described here. Hepatitis A and B primarily present with systemic symptoms and jaundice rather than characteristic watery diarrhea.

Question 9

A skin infection that can be a sequel of a staphylococcal infection is?

Accepted Answer

Answer reason: Because it can directly follow or result from staphylococcal infection of the skin, it fits the idea of a sequel to staphylococcal infection. Herpes simplex is viral, scabies is a mite infestation, and intertrigo is primarily an inflammatory rash in skin folds that may become secondarily infected but is not specifically a staphylococcal sequel diagnosis. The option that most directly reflects a staphylococcal-associated skin infection is therefore the bacterial condition listed.

Question 10

Immune status in diphtheria can be tested by?

Accepted Answer

Answer reason: The classic way to assess susceptibility/immunity is an intradermal test using a small amount of diphtheria toxin and observing for a local reaction, which indicates lack of neutralizing antitoxin. A negative reaction implies adequate antitoxin levels and therefore immunity. By contrast, the Frei test is associated with lymphogranuloma venereum, and lepromin testing is used for cell-mediated immunity in leprosy rather than diphtheria antitoxin status.

Question 11

Major Route of transmission of hepatitis A is?

Accepted Answer

Answer reason: It commonly spreads through contaminated food or water and through close household or daycare contact where fecal contamination can occur. In contrast, parenteral transmission is characteristic of blood-borne hepatitis viruses (especially HBV and HCV) rather than HAV. Vertical (placental) transmission is not a major route for HAV, and sexual spread is typically related to fecal-oral exposure during certain sexual practices rather than a dominant mechanism like with HBV.

Question 12

The vital layer of slow sand filter is?

Accepted Answer

Answer reason: This biologically active layer is the schmutzdecke, formed on the top of the sand bed and responsible for most of the filter’s effective “vital” action. Supernatant water mainly provides hydraulic head and contact time but is not the primary treatment layer. The under-drainage system and control valves are mechanical components for collection and flow regulation, not microbial removal.

Question 13

Venereal Disease Research Laboratory test is used to diagnose?

Accepted Answer

Answer reason: This makes it useful for identifying syphilis and for monitoring treatment response via changes in titer. HIV/AIDS diagnosis relies on antigen/antibody immunoassays and confirmatory testing rather than VDRL. Tuberculosis and pneumonia are diagnosed with microbiologic studies and imaging, not this serologic test.

Question 14

Which of the following is the route of transmission of polio virus?

Accepted Answer

Answer reason: Transmission classically occurs via ingestion of contaminated food or water or via poor hand hygiene after fecal contamination. This aligns with high spread risk in areas with inadequate sanitation and close household contact. Droplet spread is not the main route for ongoing community transmission compared with fecal shedding. Bloodborne transmission is not a recognized primary pathway for poliovirus.

Question 15

The protozoa causing sexually transmitted diseases are?

Accepted Answer

Answer reason: Trichomonas vaginalis is a protozoan parasite and is a classic cause of the STI trichomoniasis, producing vaginitis/cervicitis and urethritis. Herpes simplex is a virus, while gonococcus (Neisseria gonorrhoeae) and Chlamydia trachomatis are bacteria, so they do not fit the protozoa category. Therefore the only protozoan option listed is the correct choice.

Question 16

Which group of organisms helps prevent the accumulation of organic waste in nature?

Accepted Answer

Answer reason: Many bacteria secrete enzymes that digest complex organic compounds and recycle nutrients (e.g., carbon, nitrogen, phosphorus) back into soil and water. Rabbits are consumers and do not drive large-scale decomposition of waste. Mosses and ferns are producers, primarily contributing biomass rather than degrading accumulated organic material.

Question 17

Diseases which are transmitted by water and food are called as?

Accepted Answer

Answer reason: Water and food act as inanimate transport media (a “vehicle”) that can deliver microorganisms to many people through ingestion. This matches the definition of vehicle-borne transmission used in epidemiology and microbiology. Vector-borne requires a living carrier like a mosquito or tick, and fomite-borne refers to contaminated objects/surfaces rather than food/water as the primary medium. Therefore the best answer is the option describing transmission via a common vehicle.

Question 18

Bacteria that thrive in high temperature (40°C - 70°c) are called?

Accepted Answer

Answer reason: Organisms that grow best at elevated temperatures around 40–70°C are classified as thermophiles. Mesophiles typically prefer moderate temperatures (roughly 20–45°C), while psychrophiles prefer cold environments (about 0–20°C). Hyperthermophiles generally have optimal growth at even higher temperatures (often ≥80°C), exceeding the range given in the stem.

Question 19

The causative organism of chickenpox is?

Accepted Answer

Answer reason: This agent produces the classic pruritic, vesicular rash in successive crops and then establishes latency in dorsal root ganglia, explaining later reactivation as shingles. Paramyxoviruses are associated with illnesses like measles and mumps rather than varicella. Bordetella pertussis is a bacterium that causes whooping cough, not a vesicular exanthem.

Question 20

MOST COMMON CAUSE OF TONSILITIS IS?

Accepted Answer

Answer reason: This organism commonly infects the oropharynx and produces the typical exudative pharyngotonsillitis picture tested in exams. Pneumococci are more strongly linked to otitis media, sinusitis, and pneumonia rather than primary tonsillar infection. E. coli is primarily an enteric/urinary pathogen, and staphylococci are less common as the primary cause of uncomplicated tonsillitis.

Question 21

The diseases that comes under National vector borne disease control program are: EXCEPT?

Accepted Answer

Answer reason: Malaria, filariasis, and Japanese encephalitis are all mosquito-borne diseases and are included under this program’s scope. Swine flu (influenza A/H1N1) is a respiratory viral infection primarily spread person-to-person via droplets and is not vector-borne. Therefore it is the exception among the listed options.

Question 22

Culex (Vector), Wuchereria Bancrofti (Cause) are associated to which disease?

Accepted Answer

Answer reason: The question is testing recognition of the pathogen–vector–disease association, which is a core parasitology concept. Malaria is caused by Plasmodium and classically transmitted by Anopheles, not Wuchereria. Dengue and chikungunya are viral illnesses primarily spread by Aedes mosquitoes, so they do not match the stated causative agent.

Question 23

Father of microbiology is?

Accepted Answer

Answer reason: Antonie van Leeuwenhoek built powerful simple microscopes and was the first to document “animalcules” (bacteria and protozoa), establishing the observational foundation of the field. Robert Koch is more specifically linked to bacteriology and causation of disease through Koch’s postulates, not the origin of microbiology as a whole. Joseph Lister is associated with antiseptic surgery, and Paul Ehrlich with chemotherapy and immunologic staining concepts, making them later contributors rather than the field’s originator.

Question 24

Hepatitis is caused by...?

Accepted Answer

Answer reason: These viruses are transmitted via fecal-oral or blood/body-fluid routes and directly infect hepatocytes, producing the characteristic clinical syndrome and laboratory pattern (elevated aminotransferases, jaundice in some cases). While bacteria, fungi, and protozoa can rarely involve the liver, they do not represent the typical etiology described by the term “hepatitis” in standard exam usage. Therefore, the best single answer is the viral cause.

Question 25

OPV protects from:

Accepted Answer

Answer reason: It is administered orally and is designed specifically to protect against infection and transmission of poliovirus. Measles prevention is covered by measles-containing vaccines (e.g., MMR), hepatitis by hepatitis vaccines (e.g., HepB), and TB by BCG, so those options do not match OPV’s target pathogen. Therefore the only option aligned with OPV’s indication is the one referring to poliomyelitis prevention.

Question 26

Which disease can be controlled by Vaccination?

Accepted Answer

Answer reason: Measles is a highly contagious viral infection that is effectively preventable and controllable through routine immunization (e.g., MMR), with herd immunity playing a major role in outbreak control. In contrast, diabetes and heart attack are noninfectious conditions driven by metabolic/vascular risk factors and are not prevented by vaccines. While some cancers are vaccine-preventable indirectly (e.g., HPV-related cervical cancer, HBV-related hepatocellular carcinoma), “cancer” as a broad category is not controlled by a single vaccine in the way measles is.

Question 27

Rabies virus will use which kind of molecular motor to cause involvement of Central nervous system from the site of inoculation into the host?

Accepted Answer

Answer reason: Retrograde transport on microtubules is powered by dynein, which moves cargo toward the neuronal cell body (minus end). This directly explains how virus particles travel from the bite site to dorsal root ganglia/spinal cord and then brain. Kinesin is the main motor for anterograde axonal transport (away from the cell body), making it a common distractor but incorrect here.

Question 28

What is the duration of treatment for Multi-Drug Resistant Tuberculosis?

Accepted Answer

Answer reason: Traditional MDR-TB regimens typically last about 18–24 months (often counted as ~20–24 months overall) to achieve durable culture conversion and prevent amplification of resistance. The 6–8 and 12 month options align more with drug-susceptible TB or select shortened MDR regimens under strict criteria and specific drug combinations, not the general expectation tested in classic exam questions. Extending to 24–27 months is not the usual standard duration and is more reflective of complicated cases rather than the typical taught baseline for MDR-TB.

Question 29

Which among the following is a Gram positive organism?

Accepted Answer

Answer reason: Clostridium species are classically Gram-positive, anaerobic, spore-forming bacilli, and this organism fits that profile. In contrast, Klebsiella, Pseudomonas, and Acinetobacter are well-known Gram-negative rods/coccobacilli with an outer membrane. Therefore the only Gram-positive choice listed is the Clostridium species.

Question 30

Father of bacteriology is ?

Accepted Answer

Answer reason: This is best represented by the development of Koch’s postulates, pure culture techniques, and systematic identification of bacterial pathogens such as Mycobacterium tuberculosis and Vibrio cholerae. Louis Pasteur is more strongly associated with the broader field of microbiology and immunization concepts (e.g., fermentation, pasteurization, vaccines) rather than the formalization of bacteriologic causation criteria. Leeuwenhoek pioneered early microscopy and first observations of “animalcules,” but did not establish disease causation frameworks central to bacteriology.

Question 31

Measles is caused by a?

Accepted Answer

Answer reason: Its clinical course (prodrome with cough, coryza, conjunctivitis, Koplik spots, followed by a maculopapular rash) reflects viral replication and immune response rather than bacterial, fungal, or protozoal mechanisms. Because it is viral, antibiotics do not treat the underlying cause, and prevention relies primarily on vaccination (MMR) and infection control measures. Common complications like pneumonia and encephalitis are consistent with systemic viral spread and immune-mediated injury. The other options represent different pathogen classes that do not cause classic measles.

Question 32

When interviewing the parents of a 2-year-old child, a history of which of the following illnesses would lead the nurse to suspect pneumococcal meningitis?

Accepted Answer

Answer reason: Otitis media is a frequent pneumococcal infection and can precede invasive disease, with potential spread leading to bacteremia and meningitis. A recent or recurrent ear infection therefore raises suspicion for pneumococcal meningitis in a febrile, symptomatic toddler. In contrast, an uncomplicated bladder infection is typically caused by enteric gram-negative organisms and does not specifically point toward pneumococcal CNS invasion.

Question 33

The most virulent blood borne pathogen is: (Choose the BtST answer.)?

Accepted Answer

Answer reason: Hepatitis B virus has the highest infectivity of the listed blood-borne viruses and can be transmitted with a much smaller inoculum than HIV or HCV. It is also environmentally resilient and can remain infectious on surfaces for prolonged periods, increasing exposure risk. A common distractor is HIV, which is clinically serious but has a substantially lower per-needlestick transmission rate than HBV.

Question 34

Normal flora mainly live in:

Accepted Answer

Answer reason: The skin and gastrointestinal tract (especially the intestine) are the major reservoirs, where commensals contribute to colonization resistance and immune modulation. In contrast, blood, brain, and heart are normally sterile sites, and the presence of microorganisms there typically indicates infection or contamination. Therefore the best choice is the skin and intestine.

Question 35

Which organism causes pneumonia?

Accepted Answer

Answer reason: This organism commonly colonizes the nasopharynx, can be aspirated into the lower airways, and produces lobar consolidation with fever and productive cough. Its polysaccharide capsule is a key virulence factor that helps it evade phagocytosis, explaining its prominence as a pneumonia cause. A common distractor is E. coli, which can cause pneumonia mainly in hospital-acquired/aspiration settings but is not the typical primary organism tested for pneumonia. Plasmodium causes malaria, and Salmonella primarily causes gastroenteritis/enteric fever rather than primary pneumonia.

Question 36

Which one is a fungal infection?

Accepted Answer

Answer reason: g., Trichophyton, Microsporum, Epidermophyton) infect keratinized tissues and cause the classic “ring” rash known as tinea (ringworm). Cholera is a bacterial infection caused by Vibrio cholerae leading to profuse watery diarrhea. Typhoid is caused by Salmonella enterica serovar Typhi (bacterial). Measles is a viral infection caused by the measles virus, not a fungus.

Question 37

Which vaccine prevents tuberculosis?

Accepted Answer

Answer reason: It primarily protects children against severe forms such as miliary TB and TB meningitis, and is included in many national immunization programs where TB burden is high. IPV is for poliovirus, DPT covers diphtheria-pertussis-tetanus, and MMR protects against measles-mumps-rubella, so they do not provide TB-specific protection. Therefore, the only option aligned with TB prevention is the BCG vaccine.

Question 38

The vector for malaria is?

Accepted Answer

Answer reason: This is the established biologic vector in the Plasmodium life cycle and is central to malaria epidemiology and prevention strategies (e.g., insecticide-treated nets targeting Anopheles). Culex mosquitoes are more classically associated with infections like lymphatic filariasis and some arboviruses, not malaria. Rat fleas are vectors for plague and murine typhus, while houseflies act mainly as mechanical carriers of enteric pathogens rather than true biologic vectors for malaria.

Question 39

Which bacteria is acid-fast?

Accepted Answer

Answer reason: Organisms in this genus characteristically have this structure, so they stain positive on Ziehl–Neelsen or Kinyoun staining. The other listed bacteria are typical gram-negative organisms without mycolic acids and therefore do not demonstrate acid-fast staining. This property is clinically important for recognizing pathogens such as those causing tuberculosis and some chronic pulmonary or soft-tissue infections.

Question 40

The shape of Vibrio bacteria is?

Accepted Answer

Answer reason: Vibrio species are distinguished by their curved, comma-like appearance on microscopy. This morphology helps differentiate them from straight bacilli and true spiral organisms. Therefore the best match among the options is the curved “comma-shaped” form.

Question 41

Which virus causes chickenpox?

Accepted Answer

Answer reason: The stem asks for the etiologic viral agent, which is a direct microbiology fact rather than a management decision. Rabies virus causes fatal encephalitis after animal bites, rotavirus primarily causes pediatric gastroenteritis, and hepatitis A virus causes acute viral hepatitis with fecal–oral transmission. Therefore the only option that matches chickenpox etiology is the herpesvirus responsible for varicella.

Question 42

The causative organism for typhoid is?

Accepted Answer

Answer reason: The organism classically responsible is the human-adapted serovar that produces prolonged fever, abdominal symptoms, and potential complications like intestinal hemorrhage or perforation. Vibrio cholerae primarily causes profuse watery diarrhea via toxin-mediated secretion rather than bacteremia. Shigella typically causes dysentery with colonic inflammation, and Clostridium species are more associated with toxin-mediated soft tissue or antibiotic-associated colitis syndromes.

Question 43

Incubation period of rabies is usually?

Accepted Answer

Answer reason: The virus replicates locally and then travels via peripheral nerves to the central nervous system, so the time to symptom onset depends on inoculum size and distance of the bite from the brain. This typical timing makes the 1–3 month window the best general answer for “usually.” Very short periods like days are uncommon, while many months to years can occur but are not the usual presentation.

Question 44

Sterilization kills:

Accepted Answer

Answer reason: This distinguishes it from disinfection, which reduces or removes many pathogens but may not reliably eliminate spores. Because spores are the most resistant forms, any process that truly sterilizes must be capable of killing them along with bacteria, viruses, and fungi. Options claiming it kills only one class of organisms reflect disinfection or incomplete antimicrobial action rather than sterilization.

Question 45

True about measles is all except?

Accepted Answer

Answer reason: Measles prevention is primarily through active immunization with live attenuated vaccine, and passive immunization with immunoglobulin can be used for post-exposure prophylaxis in high-risk contacts. Otitis media is a common complication in measles, and measles-induced transient immunosuppression can worsen or reactivate infections including tuberculosis. Therefore, the statement about the timing of Koplik spots is the incorrect one.

Question 46

What term is used to describe all disease-causing micro-organisms?

Accepted Answer

Answer reason: This umbrella term includes bacteria, viruses, fungi, protozoa, and certain parasites that produce infection and illness. In contrast, “prokaryote” and “eukaryotes” describe cellular organization and include many non–disease-causing organisms. “Decompose” is a process rather than a classification for disease-causing organisms.

Question 47

DOTS is a treatment strategy for?

Accepted Answer

Answer reason: The core principle is that supervised ingestion of anti-tubercular drugs reduces treatment default, relapse, and the emergence of drug resistance. TB therapy requires prolonged combination regimens, so adherence support and monitoring are central to successful cure. In contrast, conditions like malaria or typhoid typically use shorter courses and are not classically managed under the DOTS framework as a named strategy.

Question 48

The most effective method of sterilization of water during epidemics is?

Accepted Answer

Answer reason: This method provides residual disinfectant activity in the distribution system, continuing to suppress pathogens after treatment and during storage/transport. It is effective against most bacteria and many viruses responsible for waterborne outbreaks, and it can be implemented centrally and consistently across communities. By contrast, boiling is highly effective at the household level but is less practical for mass treatment and offers no residual protection once the water cools or is recontaminated.

Question 49

The carrier of plague is?

Accepted Answer

Answer reason:  Plague is caused by Yersinia pestis and is classically transmitted to humans via the bite of infected fleas, especially Xenopsylla cheopis, which commonly infest rodents. This makes the rat flea the key vector responsible for maintaining and spreading plague in endemic settings. Houseflies are more associated with mechanical transmission of enteric pathogens, not Y. pestis. Sandflies transmit leishmaniasis, and tsetse flies transmit African trypanosomiasis, making them incorrect here.

Question 50

Which test is used for screening syphilis?

Accepted Answer

Answer reason: This option fits that role because it is a classic nontreponemal screening test used for population screening and for monitoring treatment response via titers. ELISA is not the standard first-line name used for syphilis screening in many exam contexts and is more commonly associated with HIV screening, while confirmatory syphilis testing is typically treponemal (e.g., FTA-ABS/TPPA). Widal targets typhoid fever antibodies and Mantoux evaluates tuberculosis exposure, so they do not apply.

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