Typhoid Fever

key points

• Typhoid fever is a bacterial disease linked to fecal contamination, particularly prevalent in Asia and Africa.
• Transmission occurs through ingestion of contaminated water or food, or through direct contact with sick individuals.
• The disease can be treated with antibiotics, but prevention remains essential.

What is typhoid fever?

La typhoid fever is a acute bacterial infectious diseasepotentially serious, caused by Salmonella enterica Typhi serotype (and more rarely Paratyphi (for paratyphoid fevers). The reservoir for these bacteria is strictly human. The source of contamination lies in the feces of sick individuals or asymptomatic carriers who are still shedding the bacteria. Transmission, known as fecal-oral, can be direct human-to-human, but is most often indirect, via the ingestion of contaminated water or food (shellfish, seafood, raw vegetables, etc.).

Typhoid fever worldwide

Typhoid fever is endemic in developing countries with poor sanitation (Asia, Africa, South America). The risk is higher in populations without access to clean water, and even higher among children. In France, the disease is rare, and the majority of cases (83%) are imported after travel to an endemic area. According to the WHO, 9 million people are affected by typhoid fever worldwide each year, with approximately 110,000 deaths.

Symptoms of typhoid fever

The incubation period of the disease is most often seven to fourteen daysbut can vary from three days to a month. The natural course of the disease is classically described in three "septenaries" (= weeks) but the clinical presentation of typhoid fever can be extremely variable. The invasion phase This is manifested by a progressively increasing fever (without acceleration of pulse), frontal, fixed, insomnia-inducing headaches, a feeling of malaise with myalgia and sometimes a dry cough. It is followed by a state phase, with a high, plateau fever of around 40°C and a slow pulse, often associated with splenomegaly and signs of visceral distress:

• Digestive: abdominal pain (right iliac fossa), vomiting, bloating, "melon juice" diarrhea (especially in children) or more often constipation (especially in adults);
• Neurological: drowsiness, prostration, obnubilation (“tuphos”);
• Cutaneous-mucosal: maculopapular eruption (lenticular pink spots) of the trunk and limbs.

Complications may subsequently occur in about 10% of patients: they manifest as hemorrhages, digestive perforations, hepatic or splenic abscesses, myocarditis or pericarditis, encephalitis, disseminated intravascular coagulation, macrophage activation syndrome, or pleuro-pulmonary involvement.

Diagnosis of tiphoid fever

The diagnosis is confirmed by the detection of salmonella in blood cultures, urine culture, or stool culture. Serology has no place in the diagnosis of typhoid fever and should therefore not be performed.

Treatment of Typhoid Fever

Treatment is based on antibiotic therapy prescribed by a doctor, symptomatic treatment and rehydration.

Prevention

Collective prevention relies on access to safe drinking water and sanitation infrastructure. At the individual level, protection depends on adherence to hygiene and dietary guidelines (regular handwashing, consumption of safe drinking water and food) and vaccination. A polysaccharide injectable vaccine and an oral live attenuated vaccine (taken in capsule form) are available on the French market, both with a 3-year efficacy and ineffective against Salmonella paratyphi. Booster doses may be administered in the event of a return stay in an area of ​​exposure. Vaccination against typhoid fever is recommended for... voyageurs (Adults and children aged 2 and over) who will be staying for an extended period (more than one month) or in poor conditions in countries with poor hygiene and where the disease is present, particularly in India and Southeast Asia. Vaccination must be administered at least fifteen days before departure. Vaccination is not recommended for children under 2 years of age due to the risk of an insufficient antibody response. Typhoid vaccination is mandatory for military likely to be exposed in the course of their missions abroad.