SCFHS Public Health Technician exam questions

The Public Health Technician exam in every GCC country

From each regulator's own exam pages; anything a regulator does not publish says so. Assessment mode also depends on your licence title, so confirm your route on your eligibility notice.

12 worked Public Health Technician practice questions

Original exam-style questions from the bank, spread across the blueprint domains. They are not real or recalled exam questions. Try each one, then open the answer for the rationale and reference. None of them appear in the free mock exam, so reading them will not spoil it.

1. Question 1 · Environmental Health

   Which condition in a hospital hot and cold water system most strongly promotes the growth of Legionella?

   1. AWater stored at 60 degrees Celsius or higher in a tank that is flushed through daily
   2. BCold water kept below 20 degrees Celsius and flushed daily
   3. CStagnant water held at about 25 to 45 degrees Celsius with biofilm
   4. DChlorinated water circulating continuously at high velocity
   Show answer and explanation

   Correct answer: C. Stagnant water held at about 25 to 45 degrees Celsius with biofilm

   Legionella multiplies in warm, stagnant water and biofilm, with the best growth between 25 and 45 degrees Celsius. Hot storage at 60 degrees or higher kills it, cold water below 20 degrees suppresses growth, and flowing disinfected water gives little chance to colonise.

   Reference: WHO, Legionella and the Prevention of Legionellosis (2007)

2. Question 2 · Environmental Health

   In a crowded labour camp there are repeated cases of pulmonary tuberculosis. Which housing factor most directly increases airborne transmission?

   1. AUneven flooring
   2. BOvercrowding with poor ventilation
   3. CLack of outdoor green space
   4. DUse of shared kitchens
   Show answer and explanation

   Correct answer: B. Overcrowding with poor ventilation

   Tuberculosis spreads by droplet nuclei, so close sharing of poorly ventilated air raises the chance of infection. The other factors may affect safety or enteric spread but do not drive airborne transmission.

   Reference: WHO, Guidelines on Tuberculosis Infection Prevention and Control (2019 update)

3. Question 3 · Epidemiology Concepts and Methods

   At a wedding banquet, 80 guests ate the buffet and 20 developed gastroenteritis within 24 hours. What is the attack rate?

   1. A20%
   2. B75%
   3. C25%
   4. D4%
   Show answer and explanation

   Correct answer: C. 25%

   Attack rate is the number ill divided by the number exposed, so 20 divided by 80 is 25%. Twenty percent would wrongly divide by 100, 75% is the proportion who stayed well, and 4% inverts the fraction.

   Reference: CDC, Principles of Epidemiology in Public Health Practice, 3rd ed. (2012)

4. Question 4 · Infection Control and Disease Reporting

   A large blood spill occurs on a hospital corridor floor. Which management is correct once gloves and apron are on?

   1. AWipe up the blood with dry paper towels and wash with detergent
   2. BSpray 70% alcohol over the spill and leave it to dry
   3. CCover with absorbent material, apply 0.5% hypochlorite, wait, remove the material, then clean the area
   4. DMop with hot water and place the mop in the general waste bin
   Show answer and explanation

   Correct answer: C. Cover with absorbent material, apply 0.5% hypochlorite, wait, remove the material, then clean the area

   Large spills are covered with absorbent material soaked in 0.5% hypochlorite (5,000 ppm) for the contact time, removed as infectious waste, and the area cleaned. Dry wiping spreads blood, alcohol is inactivated by organic matter and evaporates too fast, and a contaminated mop must not enter general waste.

   Reference: WHO, Practical Guidelines for Infection Control in Health Care Facilities (2004)

5. Question 5 · Infection Control and Disease Reporting

   A hospital wants to confirm that its steam autoclave is sterilising effectively. Which indicator gives the most reliable proof?

   1. AA chemical indicator tape on the outside of each wrapped pack that changes colour
   2. BA temperature and pressure gauge read at the end of each autoclave cycle
   3. CA visual check that the load is dry
   4. DA biological indicator using Geobacillus stearothermophilus spores
   Show answer and explanation

   Correct answer: D. A biological indicator using Geobacillus stearothermophilus spores

   Spore-based biological indicators show that the process killed the most resistant organisms, so they are the gold standard. Colour-change tape and gauges only show that a condition was reached, and a dry load says nothing about sterility.

   Reference: WHO, Decontamination and Reprocessing of Medical Devices for Health-care Facilities (2016)

6. Question 6 · Insecticides and Pest Control

   Workers who spray an organophosphate insecticide for months report headache, sweating and small pupils. Which monitoring would help protect them?

   1. AAnnual chest radiography
   2. BPeriodic blood cholinesterase testing
   3. CMonthly urine glucose testing
   4. DQuarterly serum sodium testing
   Show answer and explanation

   Correct answer: B. Periodic blood cholinesterase testing

   Organophosphates inhibit acetylcholinesterase, so a fall in cholinesterase activity shows excess exposure before severe toxicity. The other tests do not reflect organophosphate effect.

   Reference: WHO, The WHO Recommended Classification of Pesticides by Hazard (2019)

7. Question 7 · Epidemiology Concepts and Methods

   In a cohort study, 30 of 200 exposed workers and 10 of 200 unexposed workers develop the disease. What is the relative risk?

   1. A3.4
   2. B3.0
   3. C10 percentage points
   4. D0.33
   Show answer and explanation

   Correct answer: B. 3.0

   Risk in the exposed is 15% and in the unexposed 5%, so the relative risk is 15 divided by 5, which is 3.0. The figure 3.4 is the odds ratio, 10 percentage points is the risk difference, and 0.33 inverts the ratio.

   Reference: Gordis, Epidemiology, 6th ed. (2019)

8. Question 8 · Food and Water Safety

   Why does the disinfecting power of free chlorine in drinking water fall when the pH rises from 7 to 8.5?

   1. AMore of the chlorine is lost as a gas, because alkaline water holds it less stably
   2. BChlorine reacts with the alkali to form chloramines, which are much weaker disinfectants
   3. CLess of the chlorine is present as hypochlorous acid, the stronger disinfectant
   4. DThe hypochlorite ion is the stronger disinfectant and is used up more quickly
   Show answer and explanation

   Correct answer: C. Less of the chlorine is present as hypochlorous acid, the stronger disinfectant

   Hypochlorous acid is a far stronger disinfectant than the hypochlorite ion, and higher pH shifts the balance to hypochlorite. The other answers invent mechanisms that do not occur, so pH should be below about 8 for effective chlorination.

   Reference: WHO, Guidelines for Drinking-water Quality, 4th ed. incorporating the 1st addendum (2017)

9. Question 9 · Infection Control and Disease Reporting

   A patient with Clostridioides difficile diarrhoea is admitted. Which precaution set is correct?

   1. AA negative-pressure room with a fitted respirator for staff
   2. BA shared bay with alcohol gel after each contact
   3. CA single room with surgical masks, and alcohol gel after care
   4. DA single room with gloves and gown, and handwashing with soap and water after care
   Show answer and explanation

   Correct answer: D. A single room with gloves and gown, and handwashing with soap and water after care

   The spores spread by contact and are not killed by alcohol gel, so contact precautions with soap-and-water handwashing apply. Airborne precautions are not needed, and a shared bay or alcohol gel alone fails to stop spore spread.

   Reference: CDC and HICPAC, Guideline for Isolation Precautions (2007, updated 2019)

10. Question 10 · Infection Control and Disease Reporting

    A tape stuck on a wrapped instrument set turns black in the steam steriliser. What does this colour change prove?

    1. AThat the pack went through the process, not that it is sterile
    2. BThat the instruments inside have reached sterility
    3. CThat the correct time and temperature were achieved throughout the load
    4. DThat no spores survived in the heaviest part of the load
    Show answer and explanation

    Correct answer: A. That the pack went through the process, not that it is sterile

    A process indicator separates processed from unprocessed packs but cannot confirm sterility. Biological indicators with Geobacillus stearothermophilus spores are the proof, and integrating indicators add time and temperature information.

    Reference: CDC, Guideline for Disinfection and Sterilization in Healthcare Facilities (2008)

11. Question 11 · Outbreak Surveillance and Investigation

    In a foodborne outbreak, investigators compare the attack rate among those who ate each food with those who did not. What is the aim?

    1. ATo find the food that most people ate at the event
    2. BTo find the food with the largest difference in attack rates between eaters and non-eaters
    3. CTo measure how long the incubation period lasted
    4. DTo prove that the ill people ate one common food
    Show answer and explanation

    Correct answer: B. To find the food with the largest difference in attack rates between eaters and non-eaters

    The food-specific attack rate table points to the vehicle by showing which item has the largest gap between eaters and non-eaters. How many people ate a food, incubation time and a single common food for all cases do not identify the vehicle.

    Reference: CDC, Principles of Epidemiology in Public Health Practice, 3rd ed. (2012)

12. Question 12 · Medical Waste Disposal

    Which waste must not be treated by autoclaving and needs high-temperature incineration or a specialist process?

    1. ALaboratory cultures and stocks of infectious agents
    2. BUsed dressings and swabs soaked with blood or body fluids
    3. CCytotoxic waste from cancer drug preparation
    4. DSharps collected in a puncture-proof sealed container
    Show answer and explanation

    Correct answer: C. Cytotoxic waste from cancer drug preparation

    Cytotoxic waste is chemically hazardous, and steam does not destroy the drugs. Cultures, soaked dressings and sharps are infectious wastes that steam sterilisation can treat.

    Reference: WHO, Safe Management of Wastes from Health-Care Activities, 2nd ed. (2014)

Public Health Technician reference books and guidelines

Every question in this bank names the textbook or guideline its answer rests on. These are the sources our Public Health Technician questions cite most often - the reading list to revise from alongside the bank.

Where your regulator publishes a reading list, use the editions it names. Exam questions are not taken from any one book.