Paratyphoid fever is a bacterial infection caused by specific strains of Salmonella bacteria, primarily Salmonella enterica serotypes Paratyphi A, B, and C. This illness shares many similarities with typhoid fever but is caused by distinct bacterial serotypes.
Causes and Transmission
Paratyphoid fever is caused by Salmonella enterica serotypes Paratyphi A, Paratyphi B (also known as S. schottmuelleri), and Paratyphi C (also known as S. hirschfeldii). These bacteria primarily reside in the intestinal tract of humans. The infection spreads through the fecal-oral route, meaning the bacteria are ingested through food or water contaminated with feces or urine from an infected individual.
Consumption of contaminated raw fruits, vegetables, milk, or shellfish transmits the bacteria. Travel to areas where the disease is common, such as South Asia, Africa, and parts of Central and South America, increases risk. Poor sanitation and crowded populations also contribute to the spread. Some individuals can carry and spread the bacteria without showing symptoms.
Signs and Symptoms
Symptoms typically appear one to ten days after exposure. The illness often begins with a gradual onset of a high fever, which can increase daily to temperatures around 39-40°C by the third or fourth day. People commonly experience fatigue, headaches, and a loss of appetite.
Abdominal pain is a common gastrointestinal symptom, and changes in bowel habits, such as either constipation or diarrhea, can occur. Diarrhea and vomiting are more frequently observed in children. A faint, rose-colored rash may appear on the chest and abdomen, though this rash does not always develop. While similar to typhoid fever, paratyphoid symptoms can sometimes be milder.
Diagnosis and Treatment
Diagnosing paratyphoid fever requires laboratory testing because its symptoms overlap with other illnesses that cause fever. Blood cultures are a common diagnostic tool to isolate Salmonella bacteria. In some cases, stool or urine samples may also be analyzed for the bacteria.
Antibiotics are the primary method of treatment for paratyphoid fever and are generally effective. Common antibiotics include fluoroquinolones like ciprofloxacin, azithromycin, or third-generation cephalosporins. It is important to complete the entire course of antibiotics to fully eliminate the bacteria and prevent a relapse or the development of antibiotic resistance. Supportive care, such as maintaining proper hydration and nutrition, also aids recovery.
Prevention Strategies
Preventing paratyphoid fever involves safe food and water habits, especially when traveling to regions where the disease is common. Following the guideline “boil it, cook it, peel it, or forget it” reduces infection risk. This includes avoiding raw or undercooked foods, unpasteurized dairy products, and untreated water or ice.
Frequent and thorough handwashing with soap and water, particularly before eating or preparing food and after using the restroom, helps prevent the spread of bacteria. While a vaccine exists for typhoid fever, which may offer limited cross-protection against Salmonella Paratyphi B, there is currently no specific vaccine for paratyphoid fever. Therefore, adherence to food and water precautions remains the main preventative measure.