Enteric Fever – Typhoid Fever (Salmonella typhi)

Enteric fever, also known as typhoid fever is an infection that causes diarrhoea and a rash. It is most commonly due to a type of bacterium called Salmonella typhi. It can also be caused by Salmonella paratyphi, a related bacterium that usually causes a less severe illness.

Enteric Fever – Typhoid & Paratyphoid Fever

Causative Organisms: Salmonella typhi (thyphoid): 80%. Salmonella paratyphi A: 18 %. Salmonella paratyphi B&C: 2% of cases. The infection is transmitted through food and water contaminated with human waste.

Incidence: world-wide distribution, more common in tropics and where poor hygiene/sanitation prevails.

Pathogenesis: Typhoid germs are approved in the faeces and, to some extent, the urine of infected people. The germs are spread by eating or drinking water or foods impure by faeces from the infected individual.

Ingested S. typhi not kill by gastric acid – enter the ileum – invade lymphatic and multiply in the reticuloendothelial system. Subsequent bacteraemia and gut re-invasion cause clinical illness.

Incubation period: 1-3 weeks, average 10-14 days.

Onset: Almost insidious

Important Features:

• Gradual onset
• Marked anorexia-malaise
• Headache
• Continuous fever
• Pink macular truncal rash (rose spots)
• Pea-soup stools
• Splenomegaly (palpable spleen)

Chronic Carrier State: Only about 3% of cases go on to become life-long carrier of the germ and this tends to happen more often in adults than in children. Those persons excrete Salmonella for a minimum period of one year (in the bile and stool), they are asymptomatic but serve as the natural reservoir of S. typhi

Diagnosis (isolation of Salmonella): Salmonella can be cultured from faeces or, in cases with high fever, from the blood.

Treatment: The antibiotics of choice are now Ciprofluxacin. Treatment should always continued for two weeks after temperature subsides to normal

Prevention: Be careful with food and water. Avoid food and drinks, which may be contaminated. Boiling will kill the bacteria and cooking or frying food also destroys the bacteria.

Because the germ is passed in the faeces of impure people, only people with active diarrhea who are unable to control their bowel behavior should be isolated. Most infected people may return to work or school when they feel healthier, provided that they carefully wash hands after toilet visits. Children in daycare, health care, workers, and persons in other responsive setting must obtain the approval of the local or state health department before returning to their custom activities. Food handlers may not return to work until three successive negative stool cultures are confirmed.

Vaccination is usually recommended to travellers staying more than 4 weeks in third countries, or for short-term stays under primitive conditions. There are two types of vaccine available:

• Vaccine for injection: one injection protects up to 3 years. The vaccine can be used in children down to 2 years.
• Vaccine in capsules: The three capsules are swallowed 48 hours apart. The vaccine protects for at least one year, but longer if you have been exposed to S. typhi. The vaccine can be used in children down to 5 years.

Enteric Fever in Dahab

Thyphoid fever is endemic in Dahab, main predisposing factors:

• contaminated water
• infected raw vegetables
• flies
• inadequate disposal of sewage

I have notice more sporadic cases suffering from enteric fever in the las 3 weeks, since 25/4/2012

Because of poor facility, I depend upon Widal test to diagnose Thyphoid fever (fast, simple, cheap)

All cases have been treated with no complications.

There has been no obvious focus of infection. People suffering were from various areas within Dahab with no apparent connection.

Most of the cases were guests and residents, a rare few were Egyptians and nil amongst the Bedouin community.

REFERENCES
Dr. Salah Ibrahim. Atlas & Short Textbook of Medicine
A.P Ball / J.A. Gray. Colour Guide Infectious Diseases

By Dr. Heikal A. Tawab and Lorraine Horesh