Top 10 Most Contagious Illnesses

Being ill is seldom fun, getting pinned down by a particularly nasty cold usually results in a good few days of moping and generally feeling sorry for yourself whilst constantly blowing your nose. But it could be worse, I know medicine today is in many ways a blessing- however there are still frequent cases of devastating illnesses new and old that can act to infect a staggering amount of people over and unbelievably short period of time.

10. Smallpox

Far more under the control of humanity than in eras past, smallpox has been eradicated in its human form officially since 1979- despite this however; many countries continue to implicate required vaccination in way of precaution from the illness. Notorious in many parts of the world, the disease was known for its viral tendencies- spreading easily amongst humans and causing an uncountable number of epidemics throughout our history. Localizing in the blood vessels of the skin, mouth and throat- side effects are primarily maculopapular rashes and blistering of the skin- though the ailment was also known to frequently cause blindness and of course usually ended with fatality.

9. Leprosy

Also known as Hansen’s disease, Leprosy is caused by Mycobacterium Leprae, a germ that acts to affect the peripheral nerves, rendering them useless. Without use of such vital nerves, patients often neglect to feel pain and temperature in certain parts of the boy- usually leading to injury and the spread of opportunistic infection. Accounts of the disease date back several millennia, with a great stigma arising around it due to the myth that it causes the loss of limbs- a concept far more terrifying in days gone by. Leprosy is most contagious when allowed to develop in areas of poor hygiene and sanitation.

8. Typhoid Fever

Though not the most deadly ailment on this list, with a fatality rate of around 20 per cent- Typhoid Fever is nonetheless a vicious and sly manifestation. With symptoms that possess the ability to lie dormant for a staggering period of time after infection, the Fevers ability to spread unknowingly from person to person is uber-viral. Due to its method of transmission via ingestion of food and water contaminated with faeces of those infected, Typhoid Fever is also at its most effective in conditions of bad sanitation.

7. Bubonic Plague

As a Zoonotic illness, Bubonic Plague is spread from animals to humans- perhaps the reason for its undisputed notoriety in the middle-ages. Several epidemics of the infection have occurred throughout the world over the course of history, most notably in Europe- where it decimated an estimated half of the continents population during the 14^th Century. Spread by flea infested rats, the disease infects the lymphatic system- attacking the immune system directly and causing death as quick as four days after the emergence of initial symptoms.

6. Influenza

Though not thought of as a big deal today, Influenza or ‘flu’ has a long history of killing human beings. Highly contagious in most forms, the flu attacks the respiratory system causing fever, fatigue, coughing, congested sinuses, nausea, vomiting, diarrhoea and aching muscles. An estimated 36,000 people die a result of the flu in the US every year and it spreads primarily through contact, coughing and sneezing- often able to pass on up to one week before symptoms even develop.

5. Rabies

Though very uncommon amongst humans today, especially in the developed world, rabies was a constant threat for our kind just a couple of hundred years ago. Characterized by symptoms as diverse and erratic as foaming from the mouth, a new found fear of water, hostile delusions and violent hallucinations- the illness attacks the nervous system directly- aiming itself towards the brain in particular. Spread through the saliva of an infected animal (an animal suffering from aforementioned delusions etc) it was widely feared throughout the entire world until a vaccination was developed in 1885. Despite this cure, rabies still kills some 50,000 people every year.

4. Malaria

A mosquito borne disease, Malaria has the ability to infect human beings without any warning or restraint whatsoever. Characterized most typically by severe fever and headaches, the condition can often lead to coma’s and even death. Most common in tropical and subtropical climates, malaria parasites arise from the genus Plasmodium and can vary in seriousness depending on the case itself as well as the medical resources available.

3. Giardiasis

Also known as ‘beaver fever’ Giardiasis is an internal parasitic infection caused by the ingestion or exposure to infected volumes of water. As one of the most common waterborne diseases in America, it is expected that the infection is zoonotic- with the belief that beavers (amongst other animals) may be responsible for the spread of the infection into lakes, rivers and reservoirs- hence the pseudonym.

2. Ringworm

Dermatophytosis, or ringworm as its most commonly known- is a condition brought on by a fungal infection of the skin. A common misconception in relation to the illness is that its symptoms are caused by a breed of parasitic worm, when in fact they are completely the result of several species of fungi. Though far from deadly if taken care of properly, ringworms ability to spread from person to person is unrivalled- due to the fact it must only come into contact with the skin and not the internal organs/cells.

1. H.I.V

As the condition which inescapably leads to AIDS, HIV or the Human immunodeficiency virus to give it its full title is the most recent epidemic to strike at our species. Believed to have emerged in Africa in the late 19^th Century, the condition leads to the deterioration of the immune system- leaving sufferers extremely vulnerable and at the whim of opportunistic infections, ranging from the most deadly of tumours to the most common of colds. Elevated to the status of pandemic as of 2009, HIV/Aids effects an estimated 33 million people in the world today, with an annual death toll of around 1.8 million. The virus is transmitted through direct contact of a mucous membrane of the bloodstream with a bodily fluid already hosting it- most commonly through unprotected sex and the use of contaminated paraphernalia amongst drug addicts.