Thanks for posting your query.
Yes! it is possible that your husband suffered from typhoid and he has a relapse of typhoid fever
. You might have missed typhoid in previous episode if you were advised Widal test
S.Typhi or S.Paratyphi bacteria harbors gallbladder
, sometimes antibiotics fails to eradicate it completely and it may cause relapsing fever.
Sometimes, it live in gallbladder for many years without causing symptoms but continues to infect other, such patients are called carriers.
You should continue your treatment according to doctor's advise and repeat your tests to be sure.
Hope it helps.