Typhoid

Cause  I  Identification  I  Transmission  I  Prevention

Typhoid fever is contracted when people eat food or drink water that has been infected with Salmonella typhi. It is recognized by the sudden onset of sustained fever, severe headache, nausea and severe loss of appetite. It is sometimes accompanied by hoarse cough and constipation or diarrhoea. Case-fatality rates of 10% can be reduced to less than 1% with appropriate antibiotic therapy. Paratyphoid fever shows similar symptoms, but tends to be milder and the case-fatality rate is much lower. The annual occurrence of typhoid fever is estimated at 17 million cases, with approximately 600,000 deaths. Some strains of Salmonella typhi are resistant to antibiotics.

Typhoid fever is caused by Salmonella typhi, the typhoid bacillus. At present, there are 107 different strains of the bacteria. Typhoid fever is characterized by the sudden onset of sustained fever, severe headache, nausea, severe loss of appetite, constipation or sometimes diarrhoea. Severe forms have been described with mental dullness and meningitis. Case-fatality rates of 10% can be reduced to less than 1% with appropriate antibiotic therapy.
Paratyphoid fever can be caused by any of three variations or bioserotypes of S. enteritidis Paratyphi A, B and C. It is similar in its symptoms to typhoid fever, but tends to be milder, with a much lower case fatality rate.

Typhoid fever is transmitted by food and water contaminated by the faeces and urine of patients and carriers. Polluted water is the most common source of typhoid. In addition, shellfish taken from sewage contaminated beds, vegetables fertilized by nightsoil and eaten raw, contaminated milk and milk products have been shown as a source of infection.

People can transmit the disease as long as the bacteria remain in their system; most people are infectious prior to and during the first week of convalescence. About 10% of untreated patients will discharge bacteria for up to three months; 2 to 5% of untreated patients will become permanent carriers.

· Protect and chlorinate public water supplies. Provide safe water supplies and avoid possible back flow connections between sewers and water supplies.
· Dispose of human faeces in a sanitary manner and maintain fly-proof latrines.
· Use scrupulous cleanliness in food preparation and handling.
· Educate the public regarding the importance of handwashing: this is important for food handlers and attendants involved in the care of patients and/or children. Thorough and frequent handwashing is essential, especially after a bowel movement.