Salmonella Typhi
Salmonella typhi are pathogens that live in the intestines and bloodstream of human beings. These bacteria are responsible for an illness known as typhoid fever. Typhoid fever is the main problem in some developing countries in Asia and Africa but rare in developed countries. The Salmonella typhi bacteria were identified in 1885 by an American scientist, Dr. Daniel E. Salmon, who worked at the Department of Agriculture of the United States at the time (CDC, 2018). Infected persons usually begin to show symptoms after 1-21 days of exposure to the bacteria. These symptoms vary from mild to severe as the infection progresses. Rash and fever are the two most common symptoms of typhoid fever. The patient’s temperature is extreme, rising slowly up to 40.20C over several days. The rash typically consists of tiny red spots that are prevalent in the neck and stomach area. Other common symptoms include nausea, vomiting, constipation or diarrhea, and appetite loss.
The transmission of the S.typhi bacteria is through human interaction and the eating of food and drinking water that contains stool or urine, a sick person. Infected people continue to become symptomatic one to two weeks after exposure following the ingestion of contaminated food or water and experience mild symptoms (CDC, 2018). The infection then progresses and is characterized by high fever ranging from 39 to 40 degrees Celsius. The disease can get severe if left untreated. Patients at this stage of infection can experience acute delirium, showing increased agitation and intestinal perforation.
The Salmonella typhi bacteria possess a Type III Secretion System (T3SS) molecular mechanism that allows the bacteria to invade a host’s cell. This mechanism enables the bacteria to inject effector proteins into the cells of the host that change the functions of the cell and allow the bacteria to invade the host cells that cause infection (Marchello, Hong & Crump, 2019). Since the symptoms of Salmonella typhi infection are identical to symptoms of other well-known diseases of the digestive tract, a diagnosis of typhoid fever can only be verified by testing an infected person’s blood samples or feces. Such are examined for the Salmonella typhi bacteria, which cause the condition by the use of a microscope. Infection diagnosis in the laboratory typically requires a series of bacteria detection tests.
Durable, hygienic standards must be established to avoid and reduce the risk of infection. The disease’s risk is substantially reduced by regular washing of hands, clean drinking water, and proper sanitation. Those that are already contaminated need to be treated with antibiotics (CDC, 2018). Ciprofloxacin (for non- pregnant adults), and ceftriaxone are the most widely used antibiotics. For more severe cases where there is internal bleeding or bowel injury, patients may require surgery.
Typhoid fever can lead to death without any treatment. Additionally, in up to 10 percent of untreated patients, relapse of the infection can occur approximately one to three weeks after recovery from the initial disease and is mostly milder than the initial illness. Some patients may become long term carriers of the Salmonella typhi bacteria as a result of typhoid fever infection. (Marchello, Hong & Crump, 2019) .Long term carriers usually have the bacteria present in their urine or their blood even after treatment. A 28-day course of antibiotic therapy is required to ‘clean out’ the bacteria to prevent this.
References
Centers for Disease Control and Prevention. National Center for Emerging and Zoonotic Diseases. Typhoid Fever. Accessed 01/25/2018.
Marchello, C., Hong, C., & Crump, J. (2019). Global Typhoid Fever Incidence: A Systematic Review and Meta-analysis. Clinical Infectious Diseases, 68(Supplement_2), S105-S116. doi: 10.1093/cid/ciy1094