Typhoid and paratyphoid fever

Typhoid and paratyphoid fever

Sometimes known as enteric fever, typhoid is caused by the bacterium Salmonella Typhi and paratyphoid by the bacterium Salmonella paratyphi. The incubation period is usually between 8 and 14 days. Symptoms include fever, malaise, slow pulse, spleen enlargement, rose spots on the trunk and constipation or sever diarrhoea. The fatality rate for typhoid is between 2% and 10%. Paratyphoid is generally much less severe and symptoms may be similar to food poisoning caused by salmonella.

The organism is excreted in the faeces and urine of patients and carriers. Enteric fever may be water borne, due to contamination by sewage, or food borne, for example, milk or cooked meat contaminated by polluted water or by carriers who are food handlers. Laboratory confirmation is by bacteriological examination of blood, faeces and urine.

Control measures

  • Using approved suppliers.
  • Ensuring the safety of all water supplies. Water used for food preparation or drinking should be chlorinated.
  • Ensuring the satisfactory disposal of sewage.
  • Ensuring the heat treatment of milk products, including ice cream.
  • Preventing the sale of raw shellfish from sewage-polluted waters.
  • Identify carriers and ensuring that they are not employed within the food industry. Medical questionnaires should be used as an aid to recruitment.
  • Maintaining high standards of personal hygiene amongst food handlers, especially with regard thorough hand washing after visiting the toilet.
  • Ensuring high standards of hygiene in food production and distribution.
  • Washing/blanching of fruit and vegetables.