Overview of the nine types of herpes viruses found in humans

1. Herpes simplex virus type 1 (HSV-1)

Febrile blisters and cold sores on the face, mouth, and lips are the most common symptoms of HSV-1 outbreaks. Also known as human herpes virus 1 (HHV-1).

Surprisingly, most infections with this virus occur by the age of two through breaks in the skin barrier around the mouth or elsewhere on the body. While HSV-1 is thought to be the cold sore virus and HSV-2 (see below) is considered the genital herpes virus, the distinctions between them often fail. It is well documented in the medical literature, although it has not yet been widely reported, that the virus released by a cold sore can be easily transferred through oral-genital contact to establish a genital herpes infection in another person.

In addition to causing cold sores and possibly spreading to the genital region, HSV-1 has also been linked to the development of serious neurological diseases such as Alzheimer’s disease, Bell’s palsy, and trigeminal neuralgia. Recent research also shows that HSV-1 and HIV (human immunodeficiency virus) coinfection can enhance the activity of both viruses in patients who have AIDS and non-genital herpes lesions.

HSV-1 infects at least 50% of people worldwide.

2. Herpes simplex virus type 2 (HSV-2)

Also called human herpes virus 2 (HHV-2). This type is the common cause of genital herpes, which is classified as a sexually transmitted disease. HSV-2 reached epidemic status in the 1980s and 1990s, primarily due to its higher incidence among adolescents. In the world of virus classification, HSV-2 and HSV-1 are almost indistinguishable except for their different clinical symptoms. However, even these differences are inconsistent, as both types of herpes simplex can cause outbreaks of oral and genital herpes.

3. Herpes zoster virus (HZV)

Also called varicella zoster virus (VZV) and human herpes virus-3 (HHV-3). Chickenpox is the result of a first HZV infection. When this virus reappears later in a person’s life, it causes shingles. As the average age of our population increases, more and more people suffer recurrent episodes of postherpetic neuralgia (pain in the nerves) as a result of shingles. This herpes virus is considered the most infectious of the known herpes viruses. More than 90% of the population is infected.

HZV has been linked to the autoimmune disease called lupus. Additionally, HZV outbreaks, now an epidemic among people with AIDS, are often the first indicator of HIV infection.

4. Epstein-Barr virus (EBV)

Also called human herpes virus 4 (HHV-4). EBV, the leading cause of infectious mononucleosis (“kissing disease”), may also be the main culprit in causing chronic fatigue syndrome and other immune system disorders. EBV has also been linked to lupus, lymphomas, and other cancers. This virus is now considered quite harmful and mutagenic (causes genetic mutations) in the body.

About 75% of the population will test positive for EBV.

5. Cytomegalovirus (CMV)

Also called human herpes virus-5 (HHV-5). CMV can cause mononucleosis and hepatitis, and it can also be transmitted sexually. Recent research suggests that CMV plays a role, along with other types of viruses, in activating cancer genes.

The appearance of CMV is strongly correlated with vascular diseases such as coronary artery disease and atherosclerosis. Although generally asymptomatic, CMV can become a key factor in the development and progression of heart and blood vessel disease, one of the leading causes of death in all developed nations.

CMV infects approximately 60% of adults, but it is even more common among gay men and is associated with AIDS.

6. Human herpes virus-6

7. Human herpes virus-7

8. Human herpes virus 8

9. Human herpes virus-9

(HHV-6, HHV-7, HHV-8 and HHV-9, respectively)

All HHVs are associated with immune system disorders, especially AIDS. HHV-8 is also called Kaposi’s sarcoma-associated human herpes virus (KSHV), which causes a type of skin cancer that occurs most often in people with AIDS.

The recent discovery of new HHVs in people with AIDS suggests that there are more herpes viruses to discover. In fact, new types of these herpes viruses are likely to develop each year. HHV-6 and HHV-7, both found in approximately 90% of the population, are two closely related viruses that are relatively new discoveries and are considered “universal” herpes viruses.

HHV-6 infection during childhood causes “roseola infantum”, also known as “sixth disease.” HHV-6 has recently been linked to the development of multiple sclerosis.