تحليل التيفوئيد التجلطي , السابمونيلا , مصل

The diagnosis of typhoid fever on clinical grounds is difficult, as the presenting symptoms are diverse and similar to those observed with other febrile illnesses. The definitive diagnosis of typhoid fever requires the isolation of Salmonella enterica serotype Typhi from the patient. Blood culture is the preferred diagnostic method and is positive in about 50-75% of cases during the first week of illness before antibiotic treatment. Bone marrow culture, although invasive, offers higher sensitivity (~80%) and is less affected by prior antibiotic use. Stool culture has less sensitivity in early illness. In settings where patients have already used antibiotics or where culture facilities are limited, serological tests such as the Widal test continue to be used despite their limitations in sensitivity and specificity. The Widal test measures antibody titers but is prone to false positives and negatives due to cross-reactivity and previous exposure, reducing its reliability. No single test is sufficient alone, and diagnosis often depends on a combination of clinical evaluation, culture, and supportive serological tests, especially in low-resource settings.

High anti H and anti O antibody titres are suggestive of a positive diagnosis of typhoid fever. However, in certain parts of the world where there is high prevalence of typhoid fever, high H or O antibody titres are found in a proportion of healthy individuals. Therefore, the demonstration of rising H and/or O antibody titres is more reliable in the diagnosis of infection, confirming active infection.

2 ml Serum Room Temperature Stability: 2 Days at 2-8 °C 1 Month at -20 °C

S. typhi O: Negative< 1:40 Titre S. typhi H: Negative< 1:40 Titre S. paratyphi AO: Negative< 1:40 Titre S. paratyphi BO: Negative< 1:40 Titre S. paratyphi CO: Negative< 1:40 Titre S. paratyphi AH: Negative< 1:40 Titre S. paratyphi BH: Negative< 1:40 Titre S. paratyphi CH: Negative< 1:40 Titre