Typhoid fever (enteric fever) is a multisystemic bacterial disease caused by salmonella typhi. Common symptoms include fever, malaise, bradycardia, headache, abdominal pain, and constipation. As the clinical presentation of typhoid fever is variable, and since it is a potentially fatal condition, treatment is presumptively started in a majority of the cases.
Typhoid fever, also known as enteric fever, is a multisystemic disease which can have life-threatening outcomes. It is associated with a high incidence of asymptomatic carriers who continue to shed the bacteria in stool or urine for several years . The clinical presentation can be variable ranging from mild symptoms to atypical symptoms. The classical symptoms are fever, malaise, bradycardia, headache, abdominal pain, and constipation. Fever usually starts about 1-2 weeks after the ingestion of the bacteria and can be as high as 104° F and is described as "step-ladder" as it rises and falls over the course of a day. In recent times, however, the classic pattern of the fever is not encountered and the onset is usually insidious. Loss of appetite, constipation, abdominal discomfort or colicky pain, frontal headache, delirium and progressive malaise  develop over the course of the illness. A few patients develop rose or salmon - colored macular rash which resolves within 2-5 days . As the disease progresses, the patients may have increasing lassitude, loss of weight, bradycardia, dicrotic pulse, greenish-yellow diarrhea, tachypnea, abdominal distension, and hepatosplenomegaly. Myocarditis, toxemia and intestinal hemorrhage can develop and eventually lead to a fatal outcome if untreated.
Occasionally typhoid fever can present with atypical symptoms like headaches mimicking meningitis, or features of acute lobar pneumonia, joint pain, urinary complaints, icterus, pancreatitis , osteomyelitis, orchitis, and abscesses in various parts of the body . A few patients have even presented primarily with neurologic symptoms of Parkinson's disease and Guillain-Barré syndrome.
Typhoid fever does not have a specific clinical presentation , the latter making the diagnosis difficult. So physicians have to start treatment based on a presumptive diagnosis of typhoid fever. History and physical examination are essential in all patients with fever. While history may provide a clue to the probable source of infection and infected contacts, physical examination reveals the status of the patient and severity of toxemia. Complete blood count in patients with typhoid fever may show anemia with elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), low platelet and lymphocyte counts. Liver enzymes and serum bilirubin levels may be elevated. A serum alanine amino- transferase (ALT)–to–lactate dehydrogenase (LDH) ratio of less than 9:1 is indicative of typhoid hepatitis while a ratio >9.1 is indicative of viral hepatitis . Coagulation profile may show mildly elevated prothrombin time (PT) and activated partial thromboplastin time (aPTT), reduced levels of fibrinogen and elevated levels of fibrin degradation products identical to the levels in subclinical disseminated intravascular coagulation (DIC). Serum electrolyte abnormalities with hyponatremia and hypokalemia are also frequently encountered. Earlier the diagnosis of typhoid fever was based on the Widal test but it is no longer accepted due to its low sensitivity and specificity. Bone marrow culture is the most sensitive test    for diagnosing typhoid fever but as it is invasive and cumbersome, blood culture is more commonly used to confirm the diagnosis. Radiological investigations like computed tomography or magnetic resonance imaging are only recommended in patients with suspected complications like bowel perforation, osteomyelitis, and abscesses.