Communicable diseases spread from one person to another or from an animal to a person. The spread often happens via airborne viruses or bacteria, but also through blood or other bodily fluid. The terms infectious and contagious are also used to describe communicable disease.
What is HIV/AIDS?
- HIV is the virus which attacks the T-cells in the immune system.
- AIDS is the syndrome which appears in advanced stages of HIV infection.
- HIV is a virus.
- AIDS is a medical condition.
HIV can be transmitted through:
- Sexual transmission. It can happen when there is contact with infected sexual secretions (rectal, genital or oral mucous membranes). This can happen while having unprotected sex, including vaginal, oral and anal sex or sharing sex toys with someone infected with HIV.
- Perinatal transmission. The mother can pass the infection on to her child during childbirth, pregnancy, and also through breastfeeding.
- Blood transmission. The risk of transmitting HIV through blood transfusion is nowadays extremely low in developed countries, thanks to meticulous screening and precautions. Among drug users, sharing and reusing syringes contaminated with HIV-infected blood is extremely hazardous.
Thanks to strict protection procedures the risk of accidental infection for healthcare workers is low.
Individuals who give and receive tattoos and piercings are also at risk and should be very careful.
Hepatitis means injury to the liver with inflammation of the liver cells.
Fast facts on hepatitis:
- The five main types of hepatitis are caused by viruses.
- Globally, around 250 million people are affected by hepatitis C and 300 million people are estimated to be hepatitis B carriers.
- Hepatitis A is caused by consuming contaminated food or water.
- Hepatitis B is a sexually transmitted disease.
- Hepatitis C is commonly spread via direct contact with the blood of a person who has the disease.
- A person can only become infected with hepatitis D if they are already infected with hepatitis B.
- Person can become infected with the hepatitis E virus (HEV) by drinking contaminated water.
- Hepatitis that cannot be attributed to one of the viral forms of the disease is called hepatitis X.
- Hepatitis G is another type of hepatitis caused by a specific virus (HGV).
- The initial symptoms of hepatitis are similar to those of flu.
Influenza, or flu, is a respiratory illness that is caused by a virus. Flu is highly contagious and is usually spread by the coughs and sneezes of a person who is infected.
Fast facts on flu:
- Flu shares many symptoms with the common cold.
- Although the majority of flu cases are not serious, some people may experience severe complications.
- Antibiotics cannot be used to treat flu.
- People who have flu should try to avoid contact with other people to prevent spreading the virus.
- Approximately 5-20% of the US population will develop flu.
- Around the world, experts estimate that between one quarter to one half of a million people die each year as a result of flu.
- Experts agree that the best way to prevent flu is to get vaccinated each year.
- The flu vaccine is not suitable for certain groups of people, such as those who have a severe allergy to chicken eggs.
Polio, or poliomyelitis, is a highly contagious viral infection that can lead to paralysis, breathing problems, or even death. The term poliomyelitis is from the Greek poliós meaning "grey", myelós referencing the spinal cord, and -itis meaning inflammation.
TB is an infectious disease that usually affects the lungs. It is the second greatest killer due to a single infectious agent worldwide, and in 2012, 1.3 million people died from the disease, with 8.6 million falling ill.
Fast facts on tuberculosis:
- In 2012, 1.3 million people were believed to have died because of tuberculosis with an estimated 8.6 million new cases of TB worldwide.
- The World Health Organization estimates that 9 million people a year get sick with TB, with 3 million of these "missed" by health systems.
- TB is among the top 3 causes of death for women aged 15 to 44.
- Tuberculosis is caused by bacteria (Mycobacterium tuberculosis) that most often affect the lungs, although it can also affect other organs such as the kidneys and heart.
- TB can either be active or latent (where no symptoms occur, and the condition cannot be passed on).
- TB symptoms (cough, fever, night sweats, weight loss etc.) may be mild for many months, and people ill with TB can infect up to 10-15 other people through close contact over the course of a year.
- TB is an airborne pathogen, meaning that the bacteria that cause TB can spread through the air from person to person.
- People with compromised immune systems are most at risk of developing active TB and dying from the disease; people with HIV are 26-31 times more likely to develop TB.
- Tobacco use has been found to increase the risk of developing active TB with more than 20% of TB cases worldwide attributable to smoking.
- TB bacteria can develop a resistance to antibiotics that fail to kill them completely.
- The most common diagnostic test for tuberculosis is a skin test.
- The majority of TB cases can be cured with antibiotic treatment, with isoniazid and rifampicin the two most powerful, first-line (or standard) anti-TB drugs. TB bacteria can develop a resistance to antibiotics that fail to kill them completely.
- It is vital that any courses of treatment given are fully completed to increase the chance of successful eradication of infection and to reduce the risk of antibiotic resistance developing.
Malaria is a life-threatening blood disease caused by parasites transmitted to humans through the bite of the Anopheles mosquito. Once an infected mosquito bites a human and transmits the parasites, those parasites multiply in the host's liver before infecting and destroying red blood cells.
Fast facts on malaria:
- Malaria was first identified in 1880 as a disease caused by parasitic infection
- The name of the disease comes from the Italian word mal'aria, meaning "bad air"
- Malaria is transmitted to humans through bites by infected mosquitoes
- The most common time for these mosquitoes to be active is between dusk and dawn
- Worldwide, there were an estimated 198 million cases of malaria in 2013 and 584,000 deaths
- Malaria occurs mostly in poor, tropical and subtropical areas of the world
- Malaria was eliminated from the US in the early 1950s, but the mosquitos that carry and transmit the malaria parasite still remain, creating a constant risk of reintroduction
- Reported malaria cases in the US reached a 40-year high of 1,925 in 2011
- A malaria vaccine for humans is close to being approved for use in Europe
- An estimated 3.4 billion people in 106 countries and territories are at risk of malaria - nearly half of the world's population
- Annual funding for malaria control in 2013 was three times the amount spent in 2005, yet it represented only 53% of global funding needs
- Malaria incidence rates are estimated to have fallen by 30% globally between 2000 and 2013 while estimated mortality rates fell by 47%
- The World Health Organization (WHO) has set out to reduce all malaria cases and deaths by 90% by 2030.
It may seem a daunting task to keep yourself and your loved ones free of infections. Beyond the obvious—steering clear of runny noses and hacking coughs—you may be wondering about some other practical ways of staying infection-free: