Confirming a Shigella infection involves a combination of clinical evaluation and laboratory testing.
Clinical Evaluation
- Symptoms: Doctors typically consider the patient's symptoms, which often include diarrhea (often bloody), abdominal cramps, fever, and sometimes vomiting.
- Exposure History: They also inquire about the patient's recent exposure to potential sources of Shigella, such as contaminated food or water, or close contact with someone infected with Shigella.
Laboratory Testing
- Stool Culture: The most reliable way to confirm Shigella is through a stool culture. This involves collecting a stool sample and growing the bacteria in a laboratory.
- Molecular Tests: Molecular tests like PCR (Polymerase Chain Reaction) can detect the presence of Shigella DNA in stool samples, offering faster results compared to cultures.
- Serological Tests: In some cases, serological tests that detect antibodies against Shigella in the blood may be used, but these are less common than stool cultures or molecular tests.
Confirmation
- Positive Culture: A positive stool culture confirms the presence of Shigella.
- Positive Molecular Test: A positive PCR test also confirms Shigella infection.
- Clinical Correlation: The results of laboratory tests are always interpreted in conjunction with the patient's clinical presentation and history.
Treatment
Once Shigella is confirmed, treatment usually involves antibiotics and fluid replacement to manage dehydration.