WHAT IS A COLD AND FLU (INFLUENZA) ?

WHAT IS A COLD?

The common cold is a viral infection that causes inflammation of the nose, throat, sinuses and larynx. It is often called an upper respiratory tract infection (URTI) to distinguish it from more serious infections of the lower respiratory tract. Colds aren’t dangerous to most people, but they can be very unpleasant, lasting between 7 to 10 days.

Over 200 viruses can cause the common cold, but rhinoviruses are the most common. Rhinoviruses can also trigger asthma attacks and have been linked to sinus and ear infections.

Other viruses that can cause colds include respiratory syncytial virus, human parainfluenza viruses, adenovirus, human coronaviruses, and human metapneumovirus.

Colds are more prevalent in winter because we are generally confined indoors together with other infected people, who pass on the virus.

Kids are walking reservoirs of viruses, and adults who are in contact with kids, such as teachers, are more prone to URTIs. People who smoke, have diabetes, impaired immunity or asthma are more likely to develop complications such as pneumonia from a cold.

WHAT IS FLU (INFLUENZA)?

What most of us think of as ‘the flu’ is the influenza virus, which can be seasonal, pandemic or zoonotic (also called variant). The most common type is seasonal influenza, so called because it comes around in the coldest season twice a year (once in the Northern hemisphere’s winter, and once in the Southern hemisphere’s winter) in temperate zones of the world, and circulates year-round in the tropics and subtropics.

Influenza may not always be thought of by most people as a serious illness – the symptoms of headaches, runny nose, cough and muscle pain mean that people may confuse it with a heavy cold.

Yet seasonal influenza kills up to 650,000 people every year. That is why influenza vaccinations are so important, especially to protect young children, older people, pregnant women, or people who have vulnerable immune systems.

Pandemic influenza
A pandemic occurs when an influenza virus which was not previously circulating among humans and to which most people don't have immunity emerges and transmits among humans. These viruses may emerge, circulate and cause large outbreaks outside of the normal influenza season.

Zoonotic or variant influenza
Humans can also be infected with influenza viruses that are routinely circulating in animals, such as avian and swine influenza viruses. All of these animal viruses are distinct from human influenza viruses and do not easily transmit between humans. Some may occasionally infect humans, however, and may cause disease ranging from mild conjunctivitis to severe pneumonia and even death. Usually these human infections of zoonotic influenza are acquired through direct contact with infected animals or contaminated environments, and do not spread very far among humans. However, if such a virus acquired the capacity to spread easily among people it could start an epidemic or a pandemic.

DID YOU KNOW:
Seasonal influenza kills up to 650,000 people every year.

DIFFERENCES BETWEEN THE COMMON COLD AND FLU

Because these two illnesses have similar symptoms, it can be difficult (or even impossible) to tell the difference between them based on symptoms alone. In general, flu symptoms are worse than the common cold and can also lead to very serious complications (such as pneumonia), some of which can be life-threatening and result in death.

Opposite you will find the most common signs and symptoms of cold and flu:

DID YOU KNOW:
Well over 200 virus strains are implicated in causing the common cold, with rhinoviruses being the most common.

Signs and Symptoms	Influenza	Cold
Symptom onset	Abrupt	Gradual
Fever	Usual; lasts 3-4 days	Rare
Aches	Usual; often severe	Slight
Chills	Fairly common	Uncommon
Fatigue, weakness	Usual	Sometimes
Sneezing	Sometimes	Common
Stuffy nose	Sometimes	Common
Sore throat	Sometimes	Common
Chest discomfort, cough	Common; can be severe	Mild to moderate; hacking cough
Headache	Common	Rare