Prevention First

TYPHOID

Typhoid fever, also known as Enteric Fever or commonly just typhoid, is a common worldwide illness, transmitted by the ingestion of food or water contaminated with the feces of an infected person.

Typhoid fever is an acute illness associated with fever caused by bacteria. It can also be caused by Salmonella paratyphi, a related bacterium that usually causes a less severe illness. The bacteria are deposited in water or food by a human carrier and are then spread to other people in the area.

Causes

  • Typhoid fever is contracted by the ingestion of the bacteria in contaminated food or water.
  • Patients with acute illness can contaminate the surrounding water supply through stool, which contains a high concentration of the bacteria.
  • Contamination of the water supply can, in turn, spoil the food supply. About 3%-5% of patients become carriers of the bacteria after the acute illness.
  • Some patients suffer a very mild illness that goes unrecognized. These patients can become long-term carriers of the bacteria.
  • The bacteria multiply in the gallbladder, bile ducts, or liver and passes into the bowel. The bacteria can survive for weeks in water or dried sewage.
  • These chronic carriers may have no symptoms and can be the source of new outbreaks of typhoid fever.

Signs and Symptoms

  • Typhoid fever is characterized by a slowly progressive fever as high as 40 °C (104 °F).
  • Profuse sweating, gastroenteritis and nonbloody diarrhea. Less commonly a rash of flat, rose-colored spots may appear.
  • Classically, the course of untreated typhoid fever is divided into four individual stages, each lasting approximately one week.
  • In the first week, there is a slowly rising temperature with relative bradycardia, malaise, headache and cough. A bloody nose is seen in a quarter of cases and abdominal pain is also possible.
  • There is leucopenia, a decrease in the number of circulating white blood cells, with eosinopenia and relative lymphocytosis, blood cultures are positive for Salmonella typhi or paratyphi.
  • The classic Widal test is negative in the first week.
  • In the second week of the infection, the patient lies prostrated with high fever in plateau around 40 °C (104 °F) and bradycardia and palpitation.
  • Delirium is frequent, frequently calm, but sometimes agitated.
  • Rose spots appear on the lower chest and abdomen in around 1/3 patients.
  • The abdomen is distended and painful in the right lower quadrant.
  • Diarrhea can occur in this stage: six to eight stools in a day, green with a characteristic smell. However, constipation is also frequent.
  • The spleen and liver are enlarged and tender.
  • The Widal reaction is strongly positive.
  • Blood cultures are sometimes still positive at this stage. In the third week of typhoid fever a number of complications can occur.

The incubation period is usually one to two weeks and the duration of the illness is about four to six weeks. The patient experiences:

  • Poor appetite
  • Headaches
  • Generalized aches and pains
  • Fever
  • Lethargy
  • Diarrhea

Prevention and risk

  • Sanitation and hygiene are the critical measures that can be taken to prevent typhoid. Typhoid does not affect animals and therefore transmission is only from human to human.
  • Typhoid can only spread in environments where human feces or urine are able to come into contact with food or drinking water.
  • Careful food preparation and washing of hands are crucial to preventing typhoid.
  • A vaccine against typhoid fever was developed during World War II. There are two vaccines currently recommended by the World Health Organization for the prevention of typhoid.
  • Both are between 50% to 80% protective and are recommended for travelers to areas where typhoid is endemic.
  • Boosters are recommended every 5 years for the oral vaccine and every 2 years for the injectable form.
  • There exists an older killed whole-cell vaccine that is still used in countries where the newer preparations are not available, but this vaccine is no longer recommended for use, because it has a higher rate of side effects.
  • Flying insects feeding on feces may occasionally transfer the bacteria through poor hygiene habits and public sanitation conditions.
  • Public education campaigns encouraging people to wash their hands after defecating and before handling food are an important component in controlling spread of the disease.
  • According to statistics from the United States Center for Disease Control, the chlorination of drinking water has led to dramatic decreases in the transmission of typhoid fever in the U.S.