There is no such thing as cancer a few years after EBV infection; EBV generally causes nasopharyngeal carcinoma in some people, but there is no evidence of such a temporal pattern of EBV infection or nasopharyngeal carcinoma. EBV is a herpesvirus, mainly transmitted through human saliva, and infection occurs at an early age, usually peaking at 3 to 5 years of age. More than 80% of children aged 3 to 5 years in developing countries are seropositive for EBV, so there is a large population of EBV infections. Many don’t and don’t have cancer, suggesting that infection with EBV doesn’t necessarily lead to cancer, so the timing is uncertain. Nasopharyngeal Cancer The risk of nasopharyngeal cancer was significantly higher in subjects who smoked 20 to 40 packs per year and more than 40 packs per year compared to non-smokers (OR 1.52 and 1.76, respectively). Smoking was the only factor contributing to morbidity in EBV seropositive patients in both the extended control population and the independent low-risk morbidity population. However, for a relatively good prognosis, prompt hospitalization and treatment are recommended.