In initial stages of typhoid, salmonella can be detected in:

Blood culture: Blood culture is a very useful procedure for diagnosis of enteric fever. It is positive in approximately 90% of cases in the first week of fever, 75% of cases in the second week, 60% in the third week, and 25% thereafter till the subsidence of pyrexia. Blood cultures, however, rapidly become negative on treatment with antibiotics. Parija SC. Textbook of Microbiology & Immunology. Elsevier Health Sciences; 2014. Page: 277