What is Typhoid Fever?
Typhoid fever is a serious disease caused by certain bacteria that infect the digestive tract through eating or drinking contaminated food and water. The disease is more common in low income countries featuring rural communities and poverty-ridden settings where proper hygiene is not maintained and food and water sources easily get contaminated by microbes. It is also called ‘Enteric fever’ and though it does not have a very high mortality rate, it can be fatal if proper and timely treatment is not administered.
What causes Typhoid Fever?
This disease is caused by a particular bacteria called Salmonella typhi, which can be found in the soil from the feces of infected persons, and can often get into food and water sources when adequate hygiene is not maintained. Once it infects an individual, the bacteria get to the intestine where it generally causes an ‘upset stomach’ and other abdominal discomforts. After a period of 1 to 3 weeks, it bores its way through the wall of the intestines and gets into the bloodstream, from which it can spread to other organs in the body. This causes the symptoms associated with the disease. There are also similar species of the bacteria, called Salmonella paratyphi and Salmonella enterica, which cause Paratyphoid fever, a condition very similar to typhoid fever, but happens to be less severe and has a lesser likelihood of fatality.
How is Typhoid Fever contracted and spread?
The disease is transmitted through the fecal-oral route by eating or drinking food and water that has been contaminated with the feces of an infected person. When adequate handwashing, proper cooking, purification of drinking water and other sanitary measures are not regularly practiced, the disease can be easily contracted and spread to others.
What are the signs and symptoms of Typhoid Fever?
The symptoms of typhoid fever usually begin about 6 to 30 days after infection by the bacteria. The major symptoms include a fever that gradually keeps rising over several days, accompanied by headaches, body weakness and fatigue, stomach aches, vomiting, lack of appetite and diarrhea or constipation. Sometimes, a rash consisting of rose-colored spots may develop on the neck and abdomen, though this only happens in a fraction of patients.
If left untreated, certain complications can occur, such as intestinal perforation and bleeding, where the bacteria reproduce exponentially and begin to destroy the intestinal lining to get into the bloodstream. Once in the bloodstream, the bacteria can spread to other organs in the body, causing a number of other complications such as pneumonia, meningitis, endocarditis, pancreatitis and sepsis. Psychological effects like confusion, delirium and hallucinations can also occur when the bacteria spreads through the bloodstream to the brain.
How can Typhoid Fever be diagnosed?
The initial diagnostic test used for typhoid fever was a rapid test known as ‘Widal’s test’, which detects antigens specific to the bacteria. However, this was mainly used in emergency cases where a quick diagnostic result is needed and is no longer recommended, but is still in use in a number of clinical labs in Africa. Currently, the gold standard for diagnosing typhoid or paratyphoid fever is a blood, bone marrow or stool culture, where the bacteria is grown on certain artificial media to confirm if it is actually Salmonella, and also determine what particular species it is. Also, polymerase chain reaction (PCR) techniques are being used for the specific diagnosis of the disease, with a good level of accuracy.
Efforts are currently underway to produce rapid diagnostic tests for typhoid fever so as to ensure quick diagnosis and timely commencement of treatment.
How can Typhoid Fever be treated?
The disease is mainly treated with antibiotics, which help to kill the bacteria. Some antibiotics commonly used to treat typhoid fever include Azithromycin, Fluoroquinolones and Ceftriaxone. Most persons begin to feel relief from the symptoms once treatment with antibiotics commences and within a week, total relief will be felt. There have been recent reports of increasing resistance of the bacteria to these drugs, making treatment with antibiotics more difficult, though certain combination therapies can be employed, whereby two or more antibiotics are taken at the same time to increase treatment effectiveness and reduce the chances of the bacteria developing resistance.
Persons sick with typhoid fever are advised to keep taking the drugs prescribed to them even after they feel relief from symptoms, so as to avoid emergence of drug resistance.
How best can Typhoid Fever be prevented?
It is important to ensure maximal hygienic practices and sanitary conditions to avoid getting infected. Habits such as drinking water from taps, wells and other unpurified sources should be avoided. Purified water such as bottled water should be used or if they are not easily affordable, one should always boil the water from non-purified sources for 2 to 3 minutes before drinking. Food should always be thoroughly cooked and raw edibles like fruits and vegetables should always be properly washed before consumption. Always wash your hands with enough soap and water, especially after using the restroom or you can make use of alcohol-based hand sanitizers with at least 70% alcohol.
A vaccine against typhoid fever is available, but is not necessary unless one is travelling to a region where typhoid is endemic or one happens to be a healthcare professional such as a clinical laboratory scientist and may come in contact with the bacteria during laboratory tests.
References
- Centers for Disease Control and Prevention (2019). Typhoid Fever and Paratyphoid Fever: Symptoms and Treatment. https://www.cdc.gov/typhoid-fever/symptoms.html.
- Pietrangelo A (2018). Typhoid: Symptoms, Causes and Vaccination. Health Line. https://bit.ly/3rkoZQv.
- Brusch J.L (2019). Typhoid Fever Workup: Laboratory Studies. Medscape. https://bit.ly/38vTL0f.