Factbox: Health risks ahead for flooded Pakistan

(Reuters) - The worst floods in decades in Pakistan have left millions without clean water, food and homes.

The U.N. has reported the first case of cholera and warned of other imminent waterborne diseases, including typhoid fever, shigellosis and hepatitis A and E, and vector-borne diseases like malaria and dengue. Aid agencies, like Save the Children, have already seen cases pneumonia, diarrhea and malaria.

Below are key facts of some of these diseases:

CHOLERA

Cholera is an acute disease that causes watery diarrhea and severe dehydration and can kill within hours if left untreated. Up to 80 percent of cases can be successfully treated with oral rehydration salts. Safe water and sanitation is critical in reducing the impact of cholera and other waterborne diseases. Vaccination for cholera can be considered, but a two-dose protocol will be very challenging logistically.

TYPHOID FEVER

A bacterial disease caused by Salmonella typhi, it is transmitted through ingesting of food or drink contaminated by the faeces or urine of infected people. Symptoms are high fever, malaise, headache, constipation or diarrhea, rose-colored spots on the chest, and enlarged spleen and liver. It can be treated with antibiotics but resistance to common antimicrobials is widespread. Healthy carriers must not handle food.

HEPATITIS A and E

Hepatitis A and E virus is shed in feces of infected people and they are acquired by ingesting faeces-contaminated food or water and is spread under unsanitary conditions. There is no treatment and therapy can only be supportive and aimed at maintaining comfort and ensuring proper nutrition.

MALARIA AND DENGUE

These mosquito-borne diseases proliferate in floods because of a sudden increase in vector breeding sites. Early treatment is critical for malaria, which endangers particularly children and pregnant women because of their weaker immune systems. The best available treatment is artemisinin-based combination therapy. Unlike malaria, there is no treatment for dengue, so early diagnosis and careful clinical management will be critical to save lives.

LEPTOSPIROSIS

The bacteria leptospira spp. is found in a variety of both wild and domestic animals, including rodents, insectivores, dogs, cattle, pigs and horses. Outbreaks happen due to crowding together of rodents and humans, and people become infected through direct contact with the urine of infected animals or by contact with a urine-contaminated environment, such as surface water, soil and plants. The bacteria gains entry through cuts and abrasions in the skin and through mucous membranes of the eyes, nose and mouth. Cases may peak during rainy season and even may reach epidemic proportions in case of flooding.

Source: World Health Organization

(Reporting by Tan Ee Lyn)