Causes

Malaria can occur if a mosquito infected with the Plasmodium parasite bites you. There are four kinds of malarial parasites that can infect humans: Plasmodium vivax, P. Ovale, P. Malariae, and P. falciparum. P. falciparum causes a more severe form of the disease and those who contract this form of malaria have a higher risk of death. An infected mother can also pass the disease to her baby at birth. This is known as congenital malaria. Malaria is transmitted by blood, so it can also be transmitted through:

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Causes

Dengue is caused by one of four dengue viruses (dengue virus types 1-4 or DENV 1-4) that are transmitted by the bite of an infected Aedes aegypti mosquito that has previously bitten an infected person. In the Western Hemisphere, the Aedes aegypti mosquito is the most common transmitter of dengue infection; transmission by the Aedes albopictus mosquito bite has also been reported.

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Causes

Contamination of food can happen at any point of production: growing, harvesting, processing, storing, shipping or preparing. Cross-contamination — the transfer of harmful organisms from one surface to another — is often the cause. This is especially troublesome for raw, ready-to-eat foods, such as salads or other produce. Because these foods aren't cooked, harmful organisms aren't destroyed before eating and can cause food poisoning. Many bacterial, viral or parasitic agents cause food poisoning.

Symptoms

Food poisoning symptoms vary with the source of contamination. Most types of food poisoning cause one or more of the following signs and symptoms:

Causes

Typhoid is caused by the bacteria S. Typhi and spread through food, drinks, and drinking water that are contaminated with infected fecal matter. Washing fruit and vegetables can spread it if contaminated water is used.

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Causes

The Mycobacterium tuberculosis bacterium causes TB. It is spread through the air when a person with TB (whose lungs are affected) coughs, sneezes, spits, laughs, or talks. The chances of catching TB from someone you live or work with are much higher than from a stranger. Most people with active TB who have received appropriate treatment for at least 2 weeks are no longer contagious. MDR-TB (Multi-drug-resistant tuberculosis) is treatable and curable only with the use of very specific anti-TB drugs, which are often limited or not readily available. In 2012, around 450,000 people developed MDR-TB.

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Causes

The three most common types of viral hepatitis are all caused by viral infections.

Hepatitis A is caused by consuming food or water infected with the hepatitis A virus (HAV), often while traveling abroad. The virus can also be transmitted through anal-oral contact during sex or by injecting drugs.

Hepatitis B is caused by the hepatitis B virus (HBV) and is spread through contact with infected blood, semen, and some other body fluids. It can be a sexually transmitted disease (STD).

Hepatitis C mostly results from percutaneous infection, occurring when the HCV virus gets under the skin. It is usually spread through injected narcotics, needle-stick injuries, and a lack of infection control in healthcare settings.

Symptoms