50 Fun Facts About Common Cold

Roughly how many virus strains are implicated in causing the common cold?

That variety, plus rapid mutation, is why no vaccine exists.

Which group of viruses causes the largest share of colds, up to 40 percent?

They have more than 100 known serotypes; the cause of 20 to 30 percent of colds remains unidentified.

How many colds does the average adult get per year?

Children average six to eight, and infections cluster in winter.

How soon after exposure can cold symptoms begin?

They usually peak two to four days after onset and clear within seven to ten days.

What is the average duration of a cough caused by a cold?

In children the cough lasts more than 25 days in about one case in ten.

What mainly produces the symptoms of a cold?

The main cold virus barely damages the nasal lining; it binds ICAM-1 receptors and triggers inflammatory mediators.

For how long can the commonest cold viruses survive on surfaces?

Hands then carry the virus to eyes or nose, which is why hand washing is the main prevention.

What does the colour of nasal mucus, from clear to green, tell you?

All colds are viral, so antibiotics never help.

Which symptom is less likely in influenza than in a common cold?

Flu symptoms are usually more severe; in adults a cough plus fever points more towards flu.

Why is there no vaccine for the common cold?

Prevention comes down to hand washing, not touching your face and avoiding sick people.

Which supplement may shorten a cold by up to a third if started within 24 hours?

Some nasal zinc products have caused loss of smell, and reviews still disagree on whether to recommend it.

What effect has regular vitamin C supplementation been shown to have on colds?

Linus Pauling argued in 1970 that humans should take at least 2,300 mg a day, far above official recommendations.

What proportion of the benefit from cold remedies is attributed to the placebo effect?

Rest, fluids and gargling warm salt water are considered reasonable conservative measures.

In 2009, Canada restricted over-the-counter cough and cold medicines for children up to what age?

Evidence of effectiveness in children is lacking and there is potential for harm.

What is the effect of antibiotics on the common cold?

More than a third of Americans who see a doctor for a cold still leave with a prescription, fuelling resistance.

Which oral decongestant does Wikipedia say appears effective in adults?

Antihistamines help only for a day or two and cause drowsiness; ipratropium spray eases a runny nose but not stuffiness.

Under what conditions is moderate exercise considered safe with a cold?

Fever, widespread muscle aches or fatigue are the signs to rest instead.

What is the estimated basic reproduction number of common cold viruses?

Each infected person typically passes it to two or three others.

In what proportion of colds does an ear infection develop as a complication?

Sinusitis follows in about 8 percent; serious complications are mostly confined to the very old, very young or immunosuppressed.

Should a breastfeeding mother with a cold keep breastfeeding?

By the time she has symptoms the baby has already been exposed anyway.

A cold outbreak at a British Antarctic base after 17 weeks of isolation was blamed on what?

Transmission from animals is considered highly unlikely.

Is there evidence that recirculated cabin air spreads colds on commercial flights?

Daycare centres and schools are the classic amplifiers, with children bringing infections home.

Which ancient text, the oldest surviving medical work, describes cold symptoms and treatments?

The English name 'cold' only came into use in the 16th century, from the resemblance to the effects of cold weather.

When did the name 'cold' come into use for the illness?

Its cause was not identified until the 1950s.

Near which English city was the Medical Research Council's Common Cold Unit based from 1946?

It occupied the Harvard Hospital at Harnham Down, a wartime gift from the American Red Cross and Harvard University.

How did the Common Cold Unit present a stay at its facility in adverts recruiting volunteers?

Volunteers stayed about ten days, kept apart from each other, and could walk in the countryside but not visit residential areas.

How many scientific papers did the Common Cold Unit produce between 1946 and 1989?

Its only treatment success in all that time was zinc gluconate lozenges, completed two years before it closed.

Which family of viruses was first identified in nasal washes from a boy at the Common Cold Unit in 1960?

Strain B814 was reported in the BMJ in 1965; June Almeida imaged it and a group of eight virologists named the family in 1968.

In which year was the rhinovirus discovered at the Common Cold Unit?

In the 1970s the unit also showed interferon given during incubation offered some protection, but no practical treatment followed.

What did German bacteriologist Walther Kruse do in 1914 to show a filterable agent caused colds?

Four of the twelve staff who received the bacteria-free filtrate went on to develop colds.

At what temperature do the commonest cold viruses prefer to replicate?

That is cooler than core body temperature, which is why they favour the nose and upper airway rather than the lungs.

From which language does the 'rhino' in rhinovirus come, and what does it mean?

The virus is a single-stranded RNA enterovirus in the family Picornaviridae.

What is the medical term for a sneeze?

Singultus is a hiccup and eructation a burp; borborygmus is a rumbling stomach.

Is it really impossible to sneeze with your eyes open?

You cannot, however, sneeze during REM sleep, because motor neurons are switched off.

What is the photic sneeze reflex?

Its tongue-in-cheek medical acronym is ACHOO, for autosomal dominant compulsive helio-ophthalmic outbursts of sneezing.

What does the German response to a sneeze, 'Gesundheit', literally mean?

One theory traces 'bless you' to the 14th-century plague, when a sneeze was feared as a sign of impending death.

By what nickname is chicken soup known for its reputed powers against colds?

A 2000 University of Nebraska study found it might dampen the inflammatory response in the lab.

Which arthritis rub inspired Lunsford Richardson to formulate Vicks VapoRub?

Richardson worked in Selma, North Carolina; the rub must never be heated or added to hot water.

For what purpose was Kleenex first marketed in 1924?

The crepe paper had been a wartime gas-mask filter and then the Kotex pad before becoming a tissue.

Roughly how many doctor visits a year does the common cold cause in the United States?

The conservative cost estimate is $7.7 billion a year, plus $2.9 billion on over-the-counter drugs.

How many US school days are estimated to be missed each year because of colds?

Parents in turn missed about 126 million workdays to stay home with sick children.

Which antiviral showed promise against cold viruses but hit safety issues in oral form?

An aerosol form was under study; as of 2009 no antiviral had been both effective and licensed for colds.

How many colds a year may a child typically catch, compared with two to three for adults?

Rates rise again in the elderly as immunity declines; the cold is the most common human disease on the planet.

Roughly how many US workdays do employees miss each year because they have a cold?

Add 126 million days parents take off to care for sick children and cold-related work loss tops $20 billion a year, 40% of all US work time lost.

What share of Americans who see a doctor for a cold receive an antibiotic prescription?

Antibiotics do nothing against cold viruses, and the needless prescriptions feed antibiotic resistance.

Which two lifestyle factors are linked to a higher risk of infection after rhinovirus exposure?

Both are thought to weaken immune function; herd immunity from past exposure helps limit spread among adults.

How many recognised types of rhinovirus exist across its three species, A, B and C?

At about 30 nanometres they are among the smallest viruses, roughly a tenth the size of smallpox, and remain a major trigger of asthma attacks.

Roughly how big is a rhinovirus particle?

Influenza viruses run 80 to 120 nanometres and smallpox about 300; rhinovirus belongs to the Enterovirus genus of the Picornaviridae.

Which cough-medicine ingredient has been banned in several countries because of misuse?

Cough medicines are not recommended for children at all, and Canada restricted them for under-sevens in 2009.

What is the only reliable protection against cold-virus aerosols, according to Wikipedia?

Regular hand washing helps too, especially among children, but zinc does not reduce the chance of catching a cold.