Which form of herpes generally causes sores or fever blisters from the waist up?

Herpes type 1, also known as HSV-1, is primarily associated with oral herpes, which typically manifests as sores or fever blisters around the mouth and face. This form of the virus is commonly contracted during childhood through non-sexual contact or by kissing an infected individual. While HSV-1 can occasionally cause genital herpes, it is predominantly recognized for its role in causing lesions in the upper body, making it the correct choice for this question.

In contrast, herpes type 2 (HSV-2) is more commonly linked to genital herpes and typically causes sores in the genital area. HPV, or human papillomavirus, does not cause herpes sores; it is primarily associated with warts and is linked to certain cancers. Cytomegalovirus is a member of the herpes virus family but causes different symptoms and is not known for causing the typical fever blisters associated with HSV-1. Thus, HSV-1 is correctly identified as the virus responsible for sores from the waist up.