50 free Infectious Diseases trivia questions with answers — trivia quiz, new questions added Aug 2026.
Smallpox is the only human disease ever eradicated. Tuberculosis still kills more people than any other single pathogen. A cook called Mary spread typhoid without ever feeling ill, and a doctor who told colleagues to wash their hands was driven into an asylum. This infectious disease quiz covers the microbes, the outbreaks and the scientists who fought them: Jenner's cowpox, Pasteur's rabies shot, Koch's postulates, John Snow's pump handle, the 1918 flu, polio, HIV, Ebola, penicillin and the rise of antimicrobial resistance. It works for biology classrooms, nursing students and pub quizzes alike, with every answer sourced and explained.
30 of 50 questions with answers and explanations. Play the quiz
Q 01Which is the only human disease ever to have been eradicated?
Smallpox
The last natural case was a Somali cook, Ali Maow Maalin, in October 1977; the WHO certified eradication in 1980. Rinderpest, eradicated in 2011, is a cattle disease.
Q 02Edward Jenner's first vaccination in 1796 used material from which animal disease?
Cowpox
He scraped pus from milkmaid Sarah Nelmes, who had caught it from a cow called Blossom, and inoculated eight-year-old James Phipps. Blossom's hide hangs in a London medical school.
Q 03The word 'vaccine' derives from the Latin for which animal?
Cow
Jenner coined Variolae vaccinae, 'smallpox of the cow', for cowpox. In 1881 Pasteur proposed extending the term to all protective inoculations in Jenner's honour.
Q 04Which 9-year-old, mauled by a rabid dog, received Pasteur's rabies vaccine in July 1885?
Joseph Meister
The vaccine itself had been produced by Pasteur's colleague Émile Roux. Meister survived and later worked as a caretaker at the Pasteur Institute.
Q 05Robert Koch's 1876 discovery of the bacterium causing which disease is considered the birth of modern bacteriology?
Anthrax
He went on to identify the tuberculosis and cholera bacteria too, and won the 1905 Nobel Prize for his TB work.
Q 06How many criteria make up Koch's postulates for linking a microbe to a disease?
Four
Koch and Friedrich Loeffler formulated them in 1884. They have largely been superseded by the Bradford Hill criteria and molecular versions.
Q 07Before germs were understood, which rival idea blamed disease on 'bad air'?
Miasma
Galen's miasma theory dominated European medicine for centuries, even though the Roman writer Varro had speculated about invisible 'minute creatures' in 36 BC.
Q 08John Snow traced an 1854 cholera outbreak in London's Soho to what?
A public water pump
His map of deaths around the Broad Street pump was the first recorded piece of epidemiological tracking. He was also a pioneer of anaesthesia and gave Queen Victoria chloroform.
Q 09Cholera is an infection of the small intestine by which bacterium?
Vibrio cholerae
Some genetic strains, like the one in Haiti's 2010 epidemic, can kill within two hours of the first symptoms. The disease still causes up to 130,000 deaths a year.
Q 10Ignaz Semmelweis cut childbed fever deaths in 1847 by making doctors do what?
Wash hands in chlorinated lime
Doctors' wards at Vienna General Hospital had three times the mortality of the midwives' wards. Ridiculed, he died in an asylum of a gangrenous wound.
Q 11Which bacterium caused the Black Death?
Yersinia pestis
Spread mainly by flea bites, it killed up to half of Europe's population between 1346 and 1353. The continent did not recover its numbers until the 16th century.
Q 12Which form of plague infects the lungs and spreads between people through the air?
Pneumonic
Bubonic plague swells the lymph nodes and septicemic plague infects the blood, turning tissue black. Both are usually caught from fleas or infected animals.
Q 13The 1918 pandemic was misnamed 'Spanish flu' because of what?
Spain's press was not censored
Q 21Roughly how many deaths do mosquito-borne illnesses cause each year?
Over 1 million
Nearly 700 million people catch a mosquito-borne disease annually, making the insect the deadliest animal on Earth by a wide margin.
Q 22Jonas Salk announced a successful vaccine against which disease in April 1955?
Polio
He declined to patent it so it could be distributed widely; lawyers had concluded it was not patentable anyway. Albert Sabin's oral vaccine followed.
Q 23As of the mid-2020s, which two countries remain endemic for wild poliovirus?
Pakistan and Afghanistan
Cases fell from an estimated 350,000 in 1988 to just 30 confirmed in 2022. The iron lung that once filled polio wards is now essentially obsolete.
Wartime censors in combatant nations suppressed bad news, while neutral Spain reported freely. The earliest probable cases were in Haskell County, Kansas.
Q 14Roughly how many people, about a third of humanity, were infected in the 1918–1920 flu pandemic?
500 million
The culprit was an H1N1 influenza A virus. Death estimates range from 17 million to 100 million.
Q 15In flu strain names like H1N1, what do the H and N stand for?
Haemagglutinin and neuraminidase
They are the two antigenic proteins on the viral envelope of influenza A. There are four types of flu virus in all: A, B, C and D.
Q 16In 2024, which disease was the leading cause of death from a single infectious agent worldwide?
Tuberculosis
It infected an estimated 10.7 million people and killed 1.23 million. Historically called consumption, it has been found in Egyptian mummies from 3000 BC.
Q 17Which vaccine, named after two French scientists, protects against TB?
BCG
Bacillus Calmette-Guérin is a weakened strain of bovine TB. The disease itself is caused by Mycobacterium tuberculosis.
Q 18Malaria is caused by single-celled parasites of which genus?
Plasmodium
They are spread by female Anopheles mosquitoes and multiply in the liver, each infected cell eventually holding up to 40,000 parasites.
Q 19About what share of malaria cases and deaths occur in sub-Saharan Africa?
95%
In 2024 some 282 million cases caused roughly 610,000 deaths. Treatment guidelines require two drugs in combination, one derived from artemisinin.
Q 20Dengue fever is chiefly spread by mosquitoes of which genus?
Aedes
Aedes aegypti is the main culprit, with the Asian tiger mosquito A. albopictus also involved. More than 5 million infections were reported in 2023.
Q 24What was the negative-pressure ventilator used for polio patients commonly called?
The iron lung
Patients typically needed it for one to two weeks during acute infection, though some lived inside one for decades.
Q 25Alexander Fleming discovered penicillin in 1928 as a crude extract of which mould?
Penicillium rubens
He noticed it on returning from a Suffolk holiday to his untidy lab at St Mary's. Florey and Chain purified it in 1940 and shared his 1945 Nobel Prize.
Q 26Who shared the 1945 Nobel Prize in Medicine with Fleming for penicillin?
Florey and Chain
Howard Florey and Ernst Chain's Oxford team isolated the purified compound in 1940, turning a lab curiosity into a drug that could be mass-produced.
Q 27Prontosil, the first systemically active antibacterial drug, was developed in 1932–33 by a team led by whom?
Gerhard Domagk
It was the first sulfonamide, made at Bayer. Domagk famously used it to save his own daughter from a streptococcal infection.
Q 28The WHO estimates bacterial antimicrobial resistance directly caused how many deaths in 2019?
1.27 million
It contributed to more than 4 million further deaths in 2021. Multidrug-resistant microbes are nicknamed superbugs, and the WHO warns of 10 million deaths a year by 2050.
Q 29HIV belongs to which class of virus?
Retrovirus
Retroviruses copy their RNA into the host's DNA. With antiretroviral treatment started early, life expectancy is now close to normal.
Q 30Roughly how many deaths has AIDS caused worldwide since it was first identified?
42 million
About 40.9 million people were living with HIV in 2025, and 1.2 million acquired it that year. HIV jumped to humans from other primates early in the 20th century.