Hi Widal Test is a presumptive serological test for typhoid fever. The report is compared with child s history of previous typhoid fever, typhoid vaccination, general level of antibody in the community (local titre) and present clinical condition of the child. False positive value of Widal test is possible in some cases. Another test after 4 weeks could be necessary to verify it. Typhoid fever is often a clinical diagnosis. Your child must had some clinical features of typhoid. That is why doctor had asked you to go for the test. More definite investigations like Blood culture, stool culture can be done in doubtful cases. However, titre report of S. Typhi O Ag= 1:320 and H Ag 1:160 is strongly suggest active typhoid infection. In clinical picture of typhoid, there is step-ladder pattern of fever. That means, intensity of fever gradually increases to high in episodic pattern and maintain a high level (plateau). But, remember that it is seen in classical cases when medicines are not used. Moreover, all typhoid fever don t show the classical pattern. Your son had taken Zimax (azithromycin) that is also effective on the causing organism (Salmonella typhi). So, fever pattern may have changed for that. Muscle pain in calf muscle area may be due to variety of reasons. Most common is dehydration and salt imbalance in the body. Others are muscle injury, trauma, straining during exercise etc. Give him plenty of water, analgesic medicine (Ibuprofen , Paracetamol) and cold compress over muscle to relieve it. As doctor had examined your child and diagnosed it as a case of typhoid fever, hopefully he was right. Consult your pediatrician if you have more doubts and get your son re-examined.