Understanding Typhoid fever
By Dr Chizoba Muoneke & Prof Olu Akinyanju
Typhoid fever is an infection. Infections in humans are caused by very small organisms which are too tiny to be seen by the naked eye, hence viewed with a microscope. Organisms may be: Bacteria e.g. typhoid fever, staphylococci which cause boils and abscesses; Viruses e.g. which cause the common cold/catarrh, influenza or HIV etc; or
- Protozoa which cause malaria.
What is Typhoid fever? Typhoid fever, also called enteric fever, is a serious infection caused by the Salmonella typhi bacteria and occasionally also by the Salmonella paratyphi bacteria. Typhoid (enteric) fever only rarely occurs in developed countries and it more commonly occurs in developing countries where the hygienic status of the environment is much reduced.
It is important to understand typhoid fever because, at present, it is very much over diagnosed and hence over treated in Nigeria. This is reflected by the fact that in our own clinic we cannot remember when we last diagnosed a patient with typhoid fever. Its rarity was corroborated by other medical practitioners we asked, including a consultant paediatrician at the Lagos University Teaching Hospital (LUTH) which is situated in Mushin where a large proportion of economically disadvantaged citizens live. The LUTH paediatrician informed us that in the past one year he could recall perhaps only one patient who really had typhoid fever. We shall later discuss the reasons for the over- diagnosis of typhoid in Nigeria.
How is Typhoid fever Transmitted?
Typhoid can be gotten by: A. Eating food, fruits or drinks that have been handled by an infected person. B. Contaminated sewage getting into the water used for drinking or washing food items.
What are the symptoms of Typhoid fever?
An infected person feels unwell and easily tired. He will probably have a headache, abdominal pain, fever (chills with high body temperature) skin rash, nausea and diarrhea. On examination the doctor finds that although the temperature rises higher, day by day (known as step ladder fever), the pulse rate is relatively slow and the white blood cell count is relatively low for a temperature so high.
How is Typhoid fever diagnosis confirmed?
Specimens of the blood, stool and urine are collected and sent to the medical laboratory for culture. The most rewarding specimen is the blood sent for culture and the diagnosis of typhoid is confirmed if the bacteria are found in the blood.
In previous decades a rise in the Widal test titre one week apart was taken as confirmation of the infection in a patient. Thus if the Widal test titre was say, 1: 80 in first week but rose to say 1:160 or higher in the second or third week of illness it will be regarded as a confirmation. However, after it was discovered that the Widal test was negative in about 30 percent of patients who genuinely had typhoid fever and that a large number of infections including malaria could cross react and give a falsely high Widal titre, the test was abandoned for diagnosis as can be seen from the relevant portions of the following modern medical textbooks on this subject.
The Oxford Handbook of Clinical Medicine, 8th Edition (2010; ISBN 978-0-19-923217-8) states on page 426, that “Widal test is unreliable”.
The Current Medical Diagnosis & Treatment Book, 52nd Edition (2013; ISBN 978-0-07-178182-4) has Typhoid Fever on pages 1445-1446 and in the section on Laboratory Findings did not mention talk less of recommend the Widal test.
Similarly, Davidson’s Principles & Practice of Medicine, 22nd Edition (2014; ISBN-13:978-0-7020-5047-3) has Typhoid Fever on pages 339-340 and fails to mention or recommend the Widal test for diagnosis.
Why is Typhoid fever over- diagnosed in Nigeria?
Its frequent over-diagnosis has become embarrassing to genuine medical practitioners. This misadventure largely stems from the mistaken belief that the diagnosis is reliably made by the Widal agglutination test alone.
As stated earlier, the Widal test can be falsely negative or falsely positive and hence has been abandoned for diagnosis. Sadly this is unknown to many, so much so, that some laboratories, confidently but wrongly conclude that a patient has typhoid fever based on their Widal test result!
Who is a Typhoid fever “Carrier”?
A lot of people can suffer from typhoid and recover completely but few numbers of people (about 3 – 5 percent) will continue to carry the bacteria even after recovery. These people are the “Carriers”.
They shed the organism in their stool which can be transmitted to a healthy person. The “carriers” are also called “Typhoid Reservoirs” because of their continual spreading of the infection.
How is Typhoid Fever Treated?
Confirmed typhoid fever is treated orally or intravenously with appropriate antibiotics and supportive medication meant to reduce some severe symptoms such as headache etc. Treatment usually lasts 2 to 3 weeks. On a few occasions, surgery may be required if the intestine is ruptured by severe disease.
How is Typhoid fever prevented?
- Drink and use only safe water for food preparation
- Maintain good environmental sanitation
- Culture the stool of all food handlers to identify typhoid carriers
- Wash your hands well after using the toilet and before handling foods.
- Avoid eating raw and uncooked foods.
- Heat left- over foods adequately before eating.
Can one be vaccinated Against Typhoid Fever? Yes. Typhoid fever vaccine is available in Nigeria. It’s given to adults and children aged above 2 years. It protects against typhoid fever in more than 50% of cases. It is also recommended to foreigners travelling to areas where the risk of typhoid is high.
Can Typhoid fever be contacted from animals? No. Typhoid does not affect animals. It is only spread from person to person.
Can Typhoid fever lead to death?
Yes. Typhoid infection that is not properly treated can lead to death. It is usually as a result of complications from the infection which includes perforation of the intestine, respiratory disease etc.