Typhoid Fever - Causes, Pathogenesis, Signs and Symptoms, Diagnosis, Treatment and Prevention

Summary

Typhoid fever, also known as enteric fever, is a potentially fatal multi-systemic illness caused primarily by Salmonella typhi and sometimes by Salmonella paratyphi. It spreads through contaminated food, water, or poor hygiene, particularly in developing regions. If untreated, the disease can lead to severe complications such as delirium, intestinal obstruction, and death. Symptoms include fever, gastrointestinal issues, and in severe cases, neurological and cardiovascular complications. Diagnosis is confirmed through cultures, and treatment involves antibiotics. Preventive measures include vaccination and maintaining good hygiene, especially for travelers to endemic regions.

Takeaways

• 🔬 Typhoid fever, also known as enteric fever, is a systemic illness primarily caused by Salmonella typhi and, to a lesser extent, by Salmonella paratyphi.
• 💊 With proper treatment, typhoid fever has a high cure rate, but untreated cases can lead to severe complications like delirium, intestinal obstruction, and death.
• 🌍 The disease is most prevalent in developing countries with poor sanitary conditions and is endemic in parts of Asia, Africa, Latin America, and the Caribbean.
• 🚫 Transmission occurs mainly through the ingestion of contaminated food and water, with food handlers often being asymptomatic carriers.
• 👤 Factors such as reduced gastric acidity and certain genetic polymorphisms can increase an individual's susceptibility to typhoid fever.
• 🧬 Pathogenic Salmonella species infect the host by adhering to the epithelium in the distal ileum and then spreading through the lymphatic system to the liver and spleen.
• 🤒 The classic symptoms of typhoid fever include a stepwise fever pattern, abdominal pain, and rose spots, with symptoms typically appearing 7-14 days post-infection.
• 🏥 Complications of typhoid fever can affect multiple organ systems, including the neuropsychiatric, respiratory, cardiovascular, hepatobiliary, intestinal, genitourinary, and hematologic systems.
• 🩺 Diagnosis is primarily clinical, based on symptoms and travel history, with laboratory confirmation through culture of the organism.
• 💊 Treatment involves antibiotics, with fluoroquinolones not recommended due to resistance; third-generation cephalosporins and carbapenems are used for severe cases.
• 🛡 Prevention strategies include maintaining good personal hygiene and vaccination, with two types of vaccines available: inactivated and live attenuated.

Q & A

What is typhoid fever?

Typhoid fever, also known as enteric fever, is a potentially fatal multisystemic illness caused primarily by Salmonella typhi and, to a lesser extent, by Salmonella paratyphi.

What are the consequences of untreated typhoid fever?

Untreated typhoid fever may progress to delirium, intestinal obstruction, intestinal hemorrhage, bowel perforation, and death within one month of the onset of the disease.

How is typhoid fever commonly transmitted?

Typhoid fever is most commonly transmitted orally via ingestion of contaminated food and beverages, often handled by asymptomatic carriers who shed the bacteria through feces or urine.

Which regions have a high prevalence of typhoid fever?

Typhoid fever is endemic in Asia, Africa, Latin America, and the Caribbean, with travelers to these regions being at high risk.

What factors can increase the risk of developing typhoid fever?

Factors that can increase the risk of typhoid fever include reduced gastric acidity due to antacids, proton pump inhibitors, H2 receptor blockers, gastrectomy, and conditions like achlorhydria, as well as genetic polymorphisms that dampen macrophage activity.

How does Salmonella typhi enter the host system?

Salmonella typhi enters the host system primarily through the distal ileum, where it adheres to the epithelium over clusters of lymphoid tissue known as Payer's patches, and is then phagocytosed by macrophages.

What are the typical signs and symptoms of typhoid fever?

Typical signs and symptoms of typhoid fever include a stepwise fever pattern, abdominal pain, constipation, dry cough, headache, delirium, and rose spots. The symptoms usually appear after seven to fourteen days of ingestion of the bacteria.

What complications can arise from typhoid fever?

Complications of typhoid fever can affect multiple organ systems and include toxic confusional state, myocarditis, intestinal hemorrhage and perforation, nephritis, and hematologic disorders like disseminated intravascular coagulation.

How is typhoid fever diagnosed?

Typhoid fever is primarily diagnosed clinically based on history and symptoms. Culture of the organism from blood, intestinal secretions, and feces can confirm the diagnosis and test antibiotic sensitivity.

What are the treatment options for typhoid fever?

Proper treatment of typhoid fever includes antibiotics; fluoroquinolones are not recommended due to resistance. Third-generation cephalosporins are often used for severe or complicated disease, and different antibiotics may be used for travelers to specific regions like Pakistan.

How can typhoid fever be prevented?

Maintaining good personal hygiene and vaccination are recommended for prevention. There are two types of vaccines available: inactivated, given as an intramuscular injection, and live attenuated, given orally as a capsule.