Essentials of Anatomy and Physiology

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Table 22–4 DISEASES CAUSED BY VIRUSES

Virus Discussion/Disease(s) Caused

Herpes simplex

Herpes varicella-

zoster

Epstein-Barr

virus(EBV)

Cytomegalovirus

(CMV)

Human herpes-

virus 6 (HHV-6)

Human herpes-

virus 8 (HHV-8)

Human papilloma

viruses(HPV)

Adenoviruses

Rhinoviruses

Influenza viruses

Respiratory

syncytial

virus(RSV)

Human meta-

pneumovirus

Hantaviruses

Measles virus

Type 1: fever blisters (cold sores) on the lip or in oral cavity; the virus is dormant in nerves of the

face between attacks. Spread in saliva; may cause eye infections (self-inoculation).

Type 2: genital herpes; painful lesions in the genital area; a sexually transmitted disease. Many

people have few or no symptoms but may still spread the virus to sexual partners. Several vac-

cines are being developed.

Either type may be oral or genital, and may cause systemic infection and herpes encephalitis in

newborns, whose immune systems cannot contain the virus.

Chickenpox: the disease of the first exposure; vesicular rash; pneumonia is a possible complica-

tion, especially in adults. The virus then becomes dormant in nerves. Shingles: painful, raised

lesions on the skin above the affected nerves following reactivation of the dormant virus.

Usually occurs in adults. The (HVZ) chickenpox vaccine is recommended for children. A shin-

gles vaccine has been approved for adults.

Mononucleosis: swollen lymph nodes, fatigue, fever, possible spleen or liver enlargement. Spread

by saliva. Has been statistically implicated as a contributing factor to the onset of multiple

sclerosis. EBV is linked to Burkitt’s lymphoma in Africa and to nasopharyngeal carcinoma in

China. No vaccine.

Most people have asymptomatic infection; the virus does no harm but remains in the body. Fetal

infection may result in mental retardation, blindness, or deafness. CMV is the most frequent

viral infection following organ transplants, and may cause a serious pneumonia. A cause of

blindness in people with AIDS. No vaccine.

Sixth disease (the 6th childhood illness that includes a rash, also called roseola or exanthema

subitum): high fever and a rash predominantly on the trunk. Most common in infants, and

most infections are mild. The virus remains dormant in T lymphocytes, may be reactivated

and spread by saliva. No vaccine.

Kaposi’s sarcoma: a malignancy of blood vessels often seen in people with AIDS; the virus is sexu-

ally transmitted. No vaccine.

More than 100 types, some of which cause genital warts. Several stimulate abnormal growth of

cells and cause cervical cancer in women. A vaccine for HPV-16 and HPV-18 (the causes of

approximately 70% of all cervical cancers) has had excellent results.

Many different types: some cause acute respiratory disease (ARD) similar to the common cold;

others cause pharyngoconjunctival fever and may occur in epidemics related to swimming

pools. The ARD vaccine is used only in the military.

Common cold: sore throat, runny nose, low fever; usually self-limiting. No vaccine, though sev-

eral are in the research stage (there are more than 100 types of rhinoviruses).

Influenza: muscle aches, fever, fatigue, spread in respiratory droplets. Three types: A, B, and

C. Type A is responsible for most epidemics. These are mutating viruses, and new vaccines

are needed as the virus changes. The most serious complication is secondary bacterial pneu-

monia.

Pneumonia: especially at risk are infants and young children, esp. those who must be hospital-

ized. Decades of work have yet to produce an effective vaccine.

Lower respiratory tract infection: bronchiolitis and pneumonia, especially in infants and probably

in elderly adults. Most infections occur during the winter. This is a newly discovered

pathogen, related to RSV, and much remains to be learned. No vaccine.

Hantavirus pulmonary syndrome: fever, cough, pulmonary edema, hypotension. Mortality rate is

40%–50%. Acquired by contact with rodent feces or urine, or inhalation of virus in rodent-

infested areas. No vaccine.

Measles (rubeola): fever, sore throat, Koplik’s spots (white) on lining of mouth, rash.

Complications are ear infections, pneumonia, and measles encephalitis, which may be fatal.

The vaccine is given to infants in combination with mumps and rubella (MMR).