thanks for writing to us.
Once you get typhoid fever
, typhoid lab test (widal) may remain positive for a long up to years in borderline titres of less than 160.But in your case there is significant rise in antibody titre (320) their are chances of relapse of typhoid fever as you have persistent lethargy
Relapse rate for typhoid is up to 10-20% and 3-4% patients can have chronic carrier state.
Relapses typically occur approximately 1 week after therapy is discontinued, but relapse after 70 days has been reported. In these cases, the blood culture
results are again positive, and high serum levels of H, O, and Vi antibodies
and rose spots may reappear.
Previous infection does not confer immunity. In any suspected relapse, infection with a different strain should be ruled out.
Hence get blood culture done for salmonella infection
Hope this could help you.