Typhoid Fever (Paratyphoid Fever)

Typhoid or paratyphoid fever is a febrile illness most commonly caused by the bacteria salmonella typhi, but can also be caused by salmonella typhi B, salmonella paratyphi A & C. It is contracted by the ingestion of contaminated food and water.

It is very prevalent in developing countries but in western countries most cases are seen in returning travelers.

The illness can range in severity from mild fever, headache, abdominal pain, to confusion, delirium, and perforation of the intestines, septic shock and death.

Where does it occur?

The bacteria are prevalent worldwide, but the disease is most prevalent in the Indian subcontinent, South East Asia, Africa, the Caribbean and Central & South America.

How is it transmitted?

The bacteria are transmitted to humans through fecally contaminated food and water. Raw seafood especially shellfish, raw vegetables and fruits, milk and milk products are notorious sources for the bacteria.

Flies can transfer bacteria to foods that are laid out in the open, thus spreading the illness.

Is it contagious from person to person?

It is contagious from person to person through soiled hands, as the bacteria are shed in stool and urine from the first week of illness to nearly 3 months after. A small proportion of individuals (3-5%) can shed the bacteria forever called a ‘silent carrier’ state. Food handlers who are silent carriers are a common source of transmission.

What is the risk for travelers?

Travelers are at risk in countries with low standard of hygiene, food handling and sewage disposal.

How soon after exposure will one develop symptoms?

Symptoms usually develop one week after ingestion of contaminated food or water, but can occur as late as 3 weeks after exposure.

What are the signs and symptoms?

Symptoms develop gradually with fever, headache, and loss of appetite, fatigue, body aches, muscle pains and dizziness. A small proportion may have diarrhea or more commonly constipation. Clues to typhoid fever are a relatively slow heart rate for the degree of fever and constipation as opposed to diarrhea.

A red rash can be seen in 25-40% of fair skinned individuals along with abdominal pain. Some can develop confusion or delirium with fever; called ‘typhoid state.’

If untreated, disease can progress and 1-2% of people may develop perforation of the bowels with associated complications and death.

Are there any lab tests to diagnose the illness?

Salmonella bacteria can be cultured from the blood in the first week of the illness. Stool and urine cultures become positive after the first week. A bone marrow aspiration for cultures is the best test, but it is painful. Blood antibody tests are also available.

Is there any treatment?

Antibiotics like Ceftriaxone & Azithromycin are used to treat salmonella. There is increasing resistance to the quinolone family of antibiotics (ciprofloxacin/levofloxacin etc.). In severe case involving shock, steroids are indicated along with good supportive care in the intensive care setting.

What preventive measures can be taken?

Typhoid vaccine is recommended for travelers to countries with low standards of hygiene, food handling and sewage disposal. The vaccine needs to be taken 2 weeks prior to the trip.

Even if you received the vaccine, strict food safety and water safety precautions need to be followed. These include:

Only use bottled, boiled or filtered and purified water

Only eat food that is well cooked and brought to you hot

Avoid raw vegetables, pre-cut fruits, raw seafood and dairy products

Only eat fruit that you peel yourself

Wash your hands frequently with soap and safe water

Please go to our safe water and safe food sections for more details.

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