Hi thanks for asking question. There is not direct association between headache and typhoid fever. Headache may be associated as constitutional symptom of typhoid. Do your culture study and confirm that typhoid is eliminated. Check your blood pressure. If sinusitis is present then also headache can occur. Headache can be because of viral infection. So first rule out about total elimination of typhoid and then if one the above cause not present then further causes can be excluded after doing physical examination and according to that further work up. I hope my suggestion will help you