Here’s what you need to know about diseases brought about by floods:
- Cholera: This is an acute diarrheal infection caused by ingestion of food or water contaminated with the bacteriumVibrio cholerae. “Up to 80 percent of cases can be successfully treated with oral rehydration salts,” the World Health Organization (WHO) says.
About 75 percent of people infected with V. cholerae do not develop any symptoms although the bacteria are present in their feces for seven to 14 days after infection and are shed back into the environment, potentially infecting other people.
Among those who develop symptoms, 80 percent have mild or moderate symptoms, while around 20 percent develop acute watery diarrhea with severe dehydration. This can lead to death if untreated.
- Typhoid Fever: Caused by the gran-negative bacilli Salmonella typhi, it is characterized by prolonged fever, abdominal pain, and a rash.
“Salmonella typhi is passed in the stool and urine of infected people,” notes The Merck Manual of Medical Information. “Inadequate hand washing after defecation or urination may spread the bacteria to food or drink; inadequate treatment of sewage may lead to contamination of water supplies.”
Flies may spread the bacteria directly from stool to food. “About 3 percent of the infected people who do not receive treatment continue to pass on bacteria in their stool for more than a year,” the Merck manual warns.
- Leptospirosis: This is a bacterial disease that affects both humans and animals. Humans become infected through direct contact with the urine of infected animals or with a urine-contaminated environment. “The bacteria enter the body through cuts or abrasions on the skin, or through the mucous membranes of the mouth, nose and eyes,” says WHO, adding that person-to-person transmission is rare.
In the early stages of the disease, symptoms include high fever, severe headache, muscle pain, chills, redness of the eyes, abdominal pain, jaundice, hemorrhages in the skin and mucous membranes, vomiting, diarrhea and rash.
- Hepatitis A: The virus causing this is found mostly in the stool and blood of an infected person. The virus is present about 15 to 45 days before symptoms occur and during the first week of illness, according to the US National Institutes of Health.
You can catch hepatitis A if you eat or drink food or water that has been contaminated by hepatitis A virus. Fruits, vegetables, shellfish, ice, and water are common sources of the disease.
Symptoms most often show up two to six weeks after being exposed to the hepatitis A virus. They are usually mild, but may last for up to several months, especially in adults. Symptoms include dark urine, fatigue, itching, loss of appetite, low-grade fever, nausea and vomiting, pale or clay-colored stools and yellow skin (jaundice).
- Malaria: Like the dreaded dengue fever, malaria is caused by a bite of a mosquito, which has about 2,000 species. It is caused by four types of plasmodium, a single-cell parasite transmitted by the bite of the female Anopheles.
“Malaria is a great imitator and the only safe rule, if you live in or have visited an area where malaria is known to exist, is to consider every fever as a potential case of the disease,” the WHO publication advises. “High levels of awareness and rapid appropriate treatment are the keys to preventing the disease from developing to the dangerous state of severe or complicated malaria.”
If treatment is not started quickly, the patient gets more ill. The symptoms are caused by the destruction of the red cells, causing anemia, the release of toxins into the bloodstream as the parasite bursts out of the red cells, and the blocking of small blood vessels throughout the body. The patient becomes weaker. Danger signs include persistent vomiting, becoming confused, increasing difficulty in breathing, or having an epileptic fit.
The patient may become unconscious, a condition known as “cerebral malaria.” Any of these symptoms is a sign of serious problem and the patient needs urgent admission to a hospital or health center with the facilities for good inpatient care.
- Dengue Fever: Also known as “break-bone” fever, dengue is the Swahili term for “a sudden overtaking by a spirit.” Caused by four distinct virus serotypes (varieties recognized as distinct by the immune system), it is a distant cousin of yellow fever.
A more lethal complication, called dengue hemorrhagic fever (DHF), was first recognized during the 1950s and is today a leading cause of childhood deaths in many countries, including the Philippines.
Approximately 5 percent of all DHF cases are fatal. Without proper treatment, DHF fatality rates reach 15 percent more. Dengue viruses are transmitted to humans through the bite of an infected Aedes mosquito.
However, not all Aedes mosquitoes are carriers of the dengue virus, but only those that have bitten people infected with the virus. Once infected, a mosquito remains infective for life, transmitting the virus to susceptible individuals during probing and blood feeding.
- Yellow Fever: Yellow fever is an acute viral hemorrhagic disease transmitted by infected mosquitoes. The “yellow” in the name refers to the jaundice that affects some patients.
Once contracted, the virus incubates in the body for three to six days, followed by infection that can occur in one or two phases. The first, “acute,” phase usually causes fever, muscle pain with prominent backache, headache, shivers, loss of appetite and nausea or vomiting. Most patients improve and their symptoms disappear after three to four days.
However, 15 percent of patients enter a second, more toxic phase within 24 hours of the initial remission. High fever returns and several body systems are affected. “The patient rapidly develops jaundice and complains of abdominal pain with vomiting,” the WHO informs. “Bleeding can occur from the mouth, nose, eyes or stomach. Once this happens, blood appears in the vomit and faces. Kidney function deteriorates.”
Half of the patients who enter the toxic phase die within 10 to 14 days, the rest recover without significant organ damage. “Up to 50 percent of severely affected persons without treatment will die from yellow fever,” the WHO says.