Welcome to HCM
Your wife is having fever for 5 days and Nausea
,please do not give any medicine yourself,as any fever we should know the cause of fever first and then treatment.
Please vist a good Physician who will examine and decide what is the cause of fever and may be some investigations like CBC,MP in PS,Urine routine,SGPT and a Xray of chest may be required and if Enteric fever
is suspected then a Blood Culture
is also required.
See these are possibilities Malaria
,enteric Fever,UTI, & RTI, once diagnosis is confirmed treatment can be modified and she can recover soon.
Please take care.
Good Luck to you