Typhoid fever is a systemic bacterial infection caused by Salmonella Typhi , typically transmitted via contaminated food or water. It is characterized by a slow-rising, non-localizing fever without rigors in the early phase.
1. Initial Presentation
- May begin as sore throat unresponsive to standard sore throat treatment.
- S. Typhi proliferates initially in the lymphoid tissue of the oropharynx and ileum.
2. Fever Pattern
- Slow rising temperature due to gradual bacteremia increase.
- Fever escalates over days (e.g., mild on day 2, higher on day 3+).
- Absence of rigors due to slow onset bacteremia.
3. Non-localizing Fever
- Early fever is non-localizing , as bacteria circulate in the blood without organ-specific symptoms.
- Localizing signs develop only if infection persists beyond 1–2 weeks.
4. Ileal Involvement
- The ileum acts as a bacterial reservoir, not initially inflamed .
- Ileal symptoms (pain, diarrhea, constipation) appear only in late stages (2nd–3rd week).
- Early ileal symptoms suggest other infections (e.g., Campylobacter , Yersinia , E. coli ).
- Perforation or obstruction is a late complication, not diarrhea.
5. Diagnostic Tests – Early
- Blood culture is the gold standard in the first week.
- Bone marrow culture is highly sensitive but invasive.
6. Diagnostic Tests – Serology
- Widal test becomes positive only after the first week; single tests have low specificity.
- Rising antibody titers over 2–3 days are more diagnostic than a single positive test.
- In endemic areas, positive Widal alone is often misleading; treat clinically, not serologically.
7. Diagnostic Tests – Late
- Urine, feces, or bile cultures may be positive in the late second or third week due to bacterial shedding.
8. Disease Duration
- Typhoid is an acute infection , unlike tuberculosis.
- Weight loss is minimal or absent.
9. Hematological Effects
- Endotoxins may suppress bone marrow and myocardium, causing leukopenia rather than leukocytosis.
10. Skin Manifestations
- Classic rash: Rose-pink macules , mainly on the abdomen, rare and often missed in darker skin.
11. Complications
- After 2–3 weeks, complications may develop including:
- Pneumonia
- Brain infections (encephalitis, abscess)
- Bone and joint infections
- Kidney infections (pyelonephritis)
- Cholecystitis, hepatitis
- Abscess formation
12. Neurological Signs
- Altered sensorium (“typhoid state”) can occur without meningitis/encephalitis.
- Focal neurological deficits suggest direct brain involvement.
