Viruses are interesting infectious organisms because they have no capacity to reproduce on their own. They infect the cells of living organisms from plants to people, hijacking the host’s cellular machinery to reproduce itself. Hundreds of viruses infect humans. Some infections are so mild they usually go unrecognized.
If you are experiencing serious medical symptoms, seek emergency treatment immediately.
Other viruses can rapidly cause death. You will contract many viruses throughout your lifetime--and chances are you have already contracted one or more types of common human viruses.
The U.S. Centers for Disease Control and Prevention (CDC) states more than 200 viruses can cause the common cold--and rhinoviruses lead the pack 145. In a review article on rhinoviruses published in the “Archives of Internal Medicine,” Dr. Stephen Greenburg noted this group of viruses causes more than 50 percent of all colds.
Types of Human Viruses
Rotavirus infections are the leading cause of severe diarrheal illness in children. The CDC reports that roughly 55,000 children are hospitalized with rotavirus each year in the U.S. More than 500,000 children die annually of the illness worldwide. Rotavirus symptoms include abdominal pain, vomiting and watery diarrhea, which persist for three to eight days.
Adults are susceptible to rotavirus gastroenteritis, but the illness is typically much milder than it is in young children. The U.S. Advisory Committee on Immunization Practices recommends routine immunization against rotavirus for all children beginning at age 2 months.
- Rotavirus infections are the leading cause of severe diarrheal illness in children.
Herpes Simplex Viruses
Herpes simplex viruses are common worldwide.
Two versions of the virus, herpes simplex virus 1 and 2, cause a wide spectrum of human infections. Genital herpes, cold sores, herpes eye infections, herpes encephalitis (brain infection) and congenital herpes are common HSV infections. A distinguishing characteristic of HSV infection is the cycle of dormancy and reactivation.
Once infected with HSV, the virus remains in the body. During inactive periods, HSV remains dormant in nerve cells. The viruses, however, are capable of reactivating and causing another round of symptoms if triggered.
- Herpes simplex viruses are common worldwide.
- A distinguishing characteristic of HSV infection is the cycle of dormancy and reactivation.
List of Diseases Caused by Viruses
There are more than 100 types of human papillomaviruses. They cause benign epithelial skin growths better known as warts. Plantar warts commonly occur on the soles of the feet. **Common warts occur on the hands or feet.
Plane warts are most common in children and usually occur on the neck, face or hands. Of greatest public health concern are sexually transmitted genital warts caused by 30 different types of HPV.
** The CDC reports 20 million Americans are currently infected with genital warts; 6 million new infections occur annually.
A group of high-risk genital HPVs can lead to cervical cancer. Vaccines that protect against infection with some—but not all—of the high-risk HPVs are currently available.
- There are more than 100 types of human papillomaviruses.
- Plane warts are most common in children and usually occur on the neck, face or hands.
Humans commonly contract influenza viruses type A and B, which cause seasonal flu.
Influenza type A typically causes a more severe form of the illness than does type B.
Only influenza type A causes pandemic influenza outbreaks.
The unpredictability, capacity for pervasiveness, and potential for lethality of influenza viruses was demonstrated during the global influenza pandemic of 1918, known as the Spanish flu. In a 2006 article published in the CDC journal “Emerging Infectious Diseases,” Drs. Taubenberger and Morens point out that one-third of the worldwide population was infected during the 1918 flu pandemic, which caused an estimated 50 million to 100 million deaths.
- Humans commonly contract influenza viruses type A and B, which cause seasonal flu.
- The unpredictability, capacity for pervasiveness, and potential for lethality of influenza viruses was demonstrated during the global influenza pandemic of 1918, known as the Spanish flu.
Types of Human Viruses
List of Diseases Caused by Viruses
Common Viruses in Children
Hand Sanitizers and Viruses
What Is the Difference Between Influenza A & B?
How Long Is Stomach Flu Contagious?
Causes of a High Fever and Runny Nose
About Type B Strain Flu
The Symptoms of Spanish Influenza
Causes of Kids' Breathing Problems
- U.S. Centers for Disease Control and Prevention: Common Cold and Runny Nose
- Archives of Internal Medicine: Respiratory Consequences of Rhinovirus Infection
- “Principles and Practice of Infectious Diseases, Sixth Edition”; Gerald L. Mandell, M.D., et al, Editors; 2004
- U.S. Centers for Disease Control and Prevention: About Rotavirus
- U.S. Centers for Disease Control and Prevention: Genital Herpes Fact Sheet
- American Academy of Dermatology. Herpes simplex
- Centers for Disease Control and Prevention. Genital Herpes - CDC Fact Sheet (Detailed)
- Jorgensen GH, Arnlaugsson S, Theodors A, Ludviksson BR. Immunoglobulin A deficiency and oral health status: a case-control study. J Clin Periodontol. 2010 Jan;37(1):1-8. doi:10.1111/j.1600-051X.2009.01494.x. Epub 2009 Nov 24.
- Righini-Grunder F, Hurni M, Warschkow R, Rischewski J. Frequency of Oral Mucositis and Local Virus Reactivation in Herpes Simplex Virus Seropositive Children with Myelosuppressive Therapy. Klin Padiatr. 2015 Nov;227(6-7):335-8. doi:10.1055/s-0035-1564086. Epub 2015 Oct 26.
Dr. Tina M. St. John owns and operates a health communications and consulting firm. She is also an accomplished medical writer and editor, and was formerly a senior medical officer with the U.S. Centers for Disease Control and Prevention. St. John holds an M.D. from Emory University School of Medicine.