cytomegalovirus infection

Cytomegalovirus Infection

 

Definition

Cytomegalovirus (CMV) is a virus related to the group of herpes viruses. Infection with CMV can cause no symptoms, or can be the source of serious illness in people with weak immune systems. CMV infection is also an important cause of birth defects.

Description

CMV is an extremely common organism worldwide. It is believed that about 85% of the adults in the United States have been infected by CMV at some point in their lives. CMV is found in almost all of the body's organs. It is also found in body fluids, including semen, saliva, urine, feces, breast milk, blood, and secretions of the cervix (the narrow, lower section of the uterus).

CMV is also able to cross the placenta (the organ that provides oxygen and nutrients to the unborn baby in the uterus). Because CMV can cross the placental barrier, initial infection in a pregnant woman can lead to infection of the developing baby.

Causes and symptoms

CMV is passed between people through contact with body fluids. CMV also can be passed through sexual contact. Babies can be born infected with CMV, either becoming infected in the uterus (congenital infection) or during birth (from infected cervical secretions).

Like other herpes viruses, CMV remains inactive (dormant) within the body for life after the initial infection. Some of the more serious types of CMV infections occur in people who have been harboring the dormant virus, only to have it reactivate when their immune system is stressed. Immune systems may be weakened because of cancer chemotherapy, medications given after organ transplantation, or diseases that significantly lower immune resistance like acquired immunodeficiency syndrome (AIDS).

In a healthy person, initial CMV infection often occurs without symptoms and is rarely noticed. Occasionally, a first-time infection with CMV may cause a mild illness called mononucleosis. Symptoms include swollen glands, liver, and spleen; fever; increased white blood cells; headache; fatigue; and sore throat. About 8% of all mononucleosis cases are due to CMV infection. A similar infection, though slightly more serious, may occur two to four weeks after receiving a blood transfusion containing CMV.

In people with weakened immune systems, CMV infection can cause more serious and potentially life-threatening illnesses. These illnesses include pneumonia, and inflammations of the liver (hepatitis), brain (encephalitis), esophagus (esophagitis), large intestine (colitis), and retina of the eye (retinitis).

Babies who contract CMV from their mothers during birth rarely develop any illness from these infections. Infants born prematurely who become CMV infected during birth have a greater chance of complications, including pneumonia, hepatitis, decreased blood platelets.

However, an unborn baby is at great risk for serious problems when the mother becomes infected with CMV for the first time while pregnant. About 10% of these babies will be born with obvious problems, including prematurity, lung problems, an enlarged liver and spleen, jaundice, anemia, low birth weight, small head size, and inflammation of the retina. About 90% of these babies may appear perfectly normal at birth. Unfortunately, about 20% will later develop severe hearing impairments and mental retardation. A 2003 report found that pregnant women 25 years and older who are immune to CMV are much less likely to pass the virus to their babies than younger women who have never been exposed to CMV.

Diagnosis

Body fluids or tissues can be tested to reveal CMV infection. However, this information is not always particularly helpful because CMV stays dormant in the cells for life. Tests to look for special immune cells (antibodies) directed specifically against CMV are useful in proving that a person has been infected with CMV. However, these tests do not give any information regarding when the CMV infection first occurred.

Treatment

Ganciclovir and foscarnet are both antiviral medications that have been used to treat patients with weak immune systems who develop a serious illness from CMV (including retinitis). As of 1998, research was still being done to try to find useful drugs to treat newborn babies suffering from congenital infection with CMV. Antiviral drugs are not used to treat CMV infection in otherwise healthy patients because the drugs have significant side effects that outweigh their benefits. In 2003, researchers in Europe announced a new compound that appeared to be highly effective against CMV infections. The new drug acted earlier in the viral replication of the infection and showed promise, however, clinical trials were continuing.

Key terms

Cervix — The narrowed, lowest part of the uterus through which a baby must pass in order to enter the birth canal.

Congenital — A condition that exists before birth and at birth.

Placenta — The organ that provides oxygen and nutrition from the mother to the unborn baby during pregnancy. The placenta is attached to the wall of the uterus and leads to the unborn baby via the umbilical cord.

Prognosis

Prognosis in healthy people with CMV infection is excellent. About 0.1% of all newborn babies will have serious damage from CMV infection occurring while they were developing in the uterus. About 50% of all transplant patients will develop severe illnesses due to reactivation of dormant CMV infection. These illnesses have a high rate of serious complications and death.

Prevention

Prevention of CMV infection in the normal, healthy person involves good handwashing. Blood products can be screened or treated to insure that they do not contain CMV. In 2003, a new high-dose prophylactic (preventive) treatment was being tested to reduce CMV risk in stem cell transplant recipients.

Resources

Periodicals

Fowler, Karen B., Sergio Stagno, and Robert F. Pass. "Maternal Immunity and Prevention of Congenital Cytomegalovirus Infection." JAMA, The Journal of the American Medical Association February 26, 2003: 1008.

"High-Dose Acyclovir May Reduce Cytomegalovirus Infection Risk." Virus Weekly July 15, 2003: 16.

"Novel Compound Highly Effective Against Cytomegalovirus Infection." AIDS Weekly November 25, 2003: 17.

Organizations

Baylor College of Medicine. 1 Baylor Plaza, Houston, TX 77030. (713) 798-4951. http://public.bcm.tmc.edu.

Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311. http://www.cdc.gov.

March of Dimes Birth Defects Foundation. 1275 Mamaroneck Ave., White Plains, NY 10605. (914) 428-7100. resourcecenter@modimes.org. http://www.modimes.org.

cytomegalovirus infection

Abbreviation: CMV infection

A persistent, latent infection of white blood cells caused by cytomegalovirus (CMV). Approx. 60% of people over 35 have been infected with CMV, usually during childhood or early adulthood; the incidence appears to be higher in those of low socioeconomic status. Primary infection is usually mild in people with normal immune function, but CMV can be reactivated and cause overt disease in pregnant women, AIDS patients, or those receiving immunosuppressive therapy following organ transplantation. CMV has been isolated from saliva, urine, semen, breast milk, feces, blood, and vaginal secretions of those infected; it is usually transmitted through contact with infected secretions that retain the virus for months to years.

During pregnancy, the woman can transmit the virus transplacentally to the fetus with devastating results. Approx. 10% of infected infants develop CMV inclusion disease, marked by anemia, thrombocytopenia, purpura, hepatosplenomegaly, microcephaly, and abnormal mental or motor development; more than 50% of these infants die. Most fetal infections occur when the mother is infected with CMV for the first time during this pregnancy, but they may also occur following reinfection or reactivation of the virus. Patients with AIDS or organ transplants may develop disseminated infection that causes retinitis, esophagitis, colitis, meningoencephalitis, pneumonitis, and inflammation of the renal tubules.

Etiology

CMV is transmitted from person to person by sexual activity, during pregnancy or delivery, during organ transplantation, or by contaminated secretions; rarely, (5%) blood transfusions contain latent CMV. Health care workers caring for infected newborns or immunosuppressed patients are at no greater risk for acquiring CMV infection than are those who care for other groups of patients (approx. 3%). Pregnant women and all health care workers should strictly adhere to standard infection control precautions.

Symptoms

Primary infection in the healthy is usually asymptomatic, but some people develop mononucleosis-type symptoms (fever, sore throat, swollen glands). Symptoms in immunosuppressed patients are related to the organ system infected by CMV and include blurred vision progressing to blindness; severe diarrhea; and cough, dyspnea, and hypoxemia. Antibodies seen in the blood identify infection but do not protect against reactivation of the virus.

Treatment

Antiviral agents such as ganciclovir and foscarnet are used to treat retinitis, colitis, and pneumonitis in immunosuppressed patients; chronic antiviral therapy has been used to suppress CMV, but this protocol has not been effective in preventing recurrence of CMV or development of meningoencephalitis. Ganciclovir has limited effect in congenital CMV. No vaccine is available.

Patient care

Health care providers can help prevent CMV infections by advising pregnant women and the immunocompromised to avoid exposure to contact with people who have confirmed and or suspected cases of CMV. The virus spreads from one person to another as a result of exposure to blood (as in transfusions) and other body fluids including feces, urine, and saliva. Contact with the diapers or drool of an infected child may result in infection of a person who has previously been unexposed to the infection. CMV is the most common congenital infection, affecting about 35,000 newborns each year. CMV infection that is newly acquired during the first trimester of pregnancy can be esp. hazardous to the developing fetus. As a result, young women who have no antibodies to CMV should avoid providing child care to infected youngsters. In the U.S., nurses who have failed to advise infected patients of the risk that CMV may pose to others have been judged to be negligent by the courts. Parents of children with severe congenital CMV require support and counseling. Although CMV infection in most nonpregnant adults is not harmful, it can cause serious illnesses or death in people with HIV/AIDS, organ transplants, and those who take immunosuppressive or cancer chemotherapeutic drugs. Infected immunosuppressed patients with CMV should be advised about the uses of prescribed drug therapies, the importance of completing the full course of therapy, and adverse effects to report for help in managing them. Family caregivers for infected people should be taught to observe standard precautions when handling body secretions. Since asymptomatic people may have and secrete the virus, standard precautions should be maintained by health care professionals at all times when such secretions are present or being handled.

See also: infection

cytomegalovirus infection

An infection caused by a virus of the herpes group which causes enlargement of the cells which it invades. In infants the infection causes liver enlargement, jaundice and blood disorders, and is sometimes fatal. Cytomegalovirus infection is a common feature of AIDS.

Cytomegalovirus Infection

DRG Category:	866
Mean LOS:	3.4 days
Description:	MEDICAL: Viral Illness, Without Major CC

Cytomegalovirus (CMV) is a member of the herpes simplex virus group. The virus, transmitted by human contact, results in an infection so mild that it is usually overlooked because no symptoms are present. Approximately 80% of the general population experience a CMV infection by the time they reach middle age. Imunosuppressed patients, however, and particularly patients who have received transplanted organs, are highly susceptible to CMV, with estimates as high as 90% of such patients contracting a CMV infection. Generally, the CMV infection occurs 4 to 6 weeks after the implementation of increased doses of immunosuppressive drugs to treat rejection. CMV infection is also present in at least 80% of patients with AIDS, causing serious problems such as encephalitis, retinitis, pneumonia, and esophagitis in 30% of them.

The virus generally inhabits the salivary glands in a latent infection that is reactivated by pregnancy, blood transfusions, or immunosuppressive medications. Benign in people with normal immune systems, the virus can be devastating to an unborn fetus or a person with immunosuppression. The virus is spread throughout the body by the white blood cells (lymphocytes and mononuclear cells) to organs such as the liver, lungs, gastrointestinal (GI) tract, and central nervous system (CNS), leading to cellular inflammation and possibly organ dysfunction.

Causes

CMV is transmitted by contact with the fluids that contain the virus, such as saliva, urine, breast milk, cervical mucus, and semen. It can be transmitted during pregnancy from a primary or reactivated CMV infection. It can be transmitted during delivery from contact with cervical secretions or after delivery in the breast milk. The virus may be present for years after the primary infection.

Genetic considerations

Heritable immune responses could be protective or increase susceptibility.

Gender, ethnic/racial, and life span considerations

Fetuses and infants are at particular risk because intrauterine CMV infection is the most common congenital infection; it occurs in 0.5% to 3% of all live births. Infection of the fetus by CMV may not be recognized until birth or several years after birth because pregnant women with CMV infections may not have clinical symptoms. Infants who have been infected with CMV during gestation may have intrauterine growth retardation, microcephaly (small head size), or hydrocephaly (increased cerebrospinal fluid in the brain).

In adults, CMV may be serious and can cause blindness or a mononucleosis-type infection. CMV mononucleosis is the most common form of CMV infection, and it occurs at about 25 to 30 years of age. In adults with no immunosuppression difficulties, the risk of infection increases with age. Of adults over the age of 40, approximately 50% have antibodies to CMV, but most do not have a history of infection. Both genders and people of all races and ethnicities are susceptible to CMV. Mexican American and black/African American people and people born outside of the United States have higher prevalence of CMV than other groups. Men who have sex with men are considered a high-risk group and have a prevalence of CMV of at least 90%. Other high-risk groups are people who spend time at day-care centers, have sex with multiple sex partners, and receive blood transfusions.

Global health considerations

The global prevalence of CMV varies widely. Infants and children in developed countries tend to acquire CMV early in their lives in developing countries but not in developed countries, where half of young adults are seronegative.

Assessment

History

Ask about immunosuppressive conditions such as recent traumatic injury that may have required multiple blood transfusions, organ transplantation, or HIV infection. The patient may describe a recent viral infection with symptoms such as sore throat, tiredness, joint and muscle aches, and headache. Some patients will remember an episode that lasted approximately 3 weeks with high fevers as the only symptom. In an immunosuppressed patient, there may be specific organ involvement, such as the lungs (dry cough, difficulty breathing), the GI tract (watery diarrhea, bloody diarrhea, nausea, vomiting, and cramping), and the CNS (blurred vision, headache, neck rigidity, tremors, lethargy, and even seizures and coma).

Physical examination

Common signs and symptoms include fever, sore throat, tiredness and fatigue, and headache. Infants may show signs of delayed development and may show signs of jaundice, petechial rash, respiratory distress, and hearing loss.

With adults, assess all body systems, but the most severe signs and symptoms occur with CNS or liver involvement. Evaluate patients for signs of fever, pallor, changes in the lymph node tissue, and pharyngitis. Auscultate the patient’s lungs to assess for crackles. Note decreased breath sounds, cough, shortness of breath, and symptoms of pneumonia.

Patients may also have mental status changes such as irritability, lethargy, and even seizures and coma. Patients may evidence hyperactive bowel sounds, tenderness to palpation of the stomach, and possible distention. Assess for neck rigidity, pupil changes, motor weakness, positive Babinski reflex, and tremors. Perform an eye examination to identify changes in the eye grounds, initially with small, white, cotton-wool spots with irregular borders on the retina that enlarge to fluffy white exudates and visible hemorrhages, causing vision loss progressing to blindness.

Psychosocial

Assess the patient’s or his or her parents’ ability to cope. The unborn child’s mother and father will need counseling and support to deal with the possible effects of CMV on their unborn infant.

Diagnostic highlights

General Comments: A viral culture is the most sensitive diagnostic laboratory procedure. Cultures, however, take 3 to 7 days and cannot differentiate acute from chronic infection.

Test	Normal Result	Abnormality With Condition	Explanation
Antigen testing and polymerase chain reaction	Negative for CVM antigens or CMV genetic material	Positive	Detects the presence of antigens against the virus or genetic material from the virus
Culture of the urine, sputum, or mouth swab	Virus not isolated	Virus isolated	Presence of virus confirms the diagnosis
IgM antibodies	Antibodies not present	CMV antibodies present	Indicates a recent infection

Other Tests: Virus isolation of samples from cervix, semen, breast milk, white blood cells, and biopsy specimens; shell vial assay; because cultures of CMV may grow slowly and require up to 6 weeks of incubation, this assay is an adaptation of tissue culture technique that provides results more rapidly. It is described as the centrifugation enhancement monoclonal-antibody culture technique, or the shell-vial assay. Complement-fixation tests, indirect immunofluorescent antibody (IFA) tests.

Primary nursing diagnosis

Diagnosis

Risk for infection (spread or reactivation) related to immune suppression

Outcomes

Risk control; Treatment behavior: Illness or injury; Risk detection

Interventions

Infection protection; Medication prescribing

Planning and implementation

Collaborative

infants.

Infants with congenital abnormalities require careful monitoring of growth and developmental patterns throughout infancy. Parents may need referrals for information on special education, physical therapy, and social services.

adults.

Treatment focuses on preventing complications and relieving symptoms; treatment varies depending on the type and degree of infection. Patients with a generalized infection receive antipyretics for fever and analgesics for aching and sore throat. Such patients need rest, good nutrition, and adequate fluid intake for chronic fatigue. Other, more severe infections are usually treated with antiviral medications. The amount and duration of medication depend on the severity of the infection. Organ system complications are managed based on the symptoms.

Pharmacologic highlights

Medication or Drug Class	Dosage	Description	Rationale
Ganciclovir	5 mg/kg q 12 hr of IV for 14–21 days, then 5 mg/kg q day for 7 days, then 1,000 mg PO tid	Antiviral	Inhibits DNA production in CMV
Foscarnet	60 mg/kg q 8 hr or 90 mg/kg q 12 hr for 2–3 wk, then 90–120 mg/kg per day of IV	Antiviral	Inhibits replication of virus

Other Drugs: Immunoglobulins may also be used as passive immunization for the prevention of CMV disease. Valganciclovir is used for the prevention of CMV infection in transplant patients.

Independent

Important priorities are to maintain an adequate level of functioning, prevent complications, support the recuperative process, and provide information about the disease process, prognosis, and treatment. Patients, and caregivers in the case of infants, need to be educated about decreasing the risk of spreading CMV infection. Secretions, particularly in infants, are apt to contain the virus.

Families of infants with CMV infection will need emotional support. Answer questions about CMV infection, symptoms, complications, and treatment.

Teach adult patients about the CMV infection, the need for adequate rest, exercise, good nutrition, and fluid intake.

Evidence-Based Practice and Health Policy

Yamamoto, A.Y., Mussi-Pinhata, M.M., Boppana, S.B., Novak, Z., Wagatsuma, V.M., Oliveira, P., …Britt, W.J. (2010). Human cytomegalovirus reinfection is associated with intrauterine transmission in a highly cytomegalovirus-immune maternal population. American Journal of Obstetrics and Gynecology, 202(3), 297e1–e8.

• Investigators compared 40 mothers of infants with a congenital CMV infection to a matched sample of 109 mothers of uninfected infants and found an overall seroprevalence of 96% among the mothers.
• However, infection with two or more strains of CMV was more prevalent among mothers of infants with a CMV infection (35%) compared to mothers of infants without a CMV infection (15.6%) (p = 0.009).
• Antibody reactivity was present at birth in 17.5% of mothers of infants with a CMV infection compared to 4.6% of mothers of infants without a CMV infection (p = 0.02).

Documentation guidelines

• Physical changes, such as enlarged lymph nodes, GI symptoms, pulmonary symptoms, funduscopic abnormalities
• Response to medications and treatments
• Complications, resistance, recurrence of symptoms

Discharge and home healthcare guidelines

prevention.

Teach the patient’s caregiver to handle diapers carefully, washing hands to prevent the spread of CMV. In the hospital, universal precautions are needed for women of childbearing potential. Frequent funduscopic examinations are imperative in HIV-positive and AIDS patients. Female healthcare workers who are attempting pregnancy may wish to have CMV titers drawn to identify their risk for the disease. Pregnant women working in day-care centers or hospital nurseries need to avoid caring for infected infants and to use universal precautions.

medications.

Teach the patient information about the prescribed dosage, route, action, and follow-up laboratory work needed for all medications. Teach the patient the appropriate use of antipyretics for fever and analgesics for pain and discomfort.

complications.

Inform the patient that signs of a relapse or complications may occur after an initial improvement. The patient should be instructed to report visual changes; changes in GI function, such as weight loss, nausea, vomiting, and anorexia; continued fever; and pulmonary symptoms (cough, shortness of breath, chest tightness). If these complications occur, teach the patient to seek medical attention.

Patient discussion about cytomegalovirus infection

Q. What is it CMV during pregnancy? can i infect with that?

A. CMV is a virus. What you refer to is infection with CMV, either the initial infection, or re-activation of latent (dormant) virus that resides in the mother's body during pregnancy.

The dangers are that CMV will infect the fetus, which may cause malformations, particularly growth restriction and hearing impairment.

You may read more here:
www.nlm.nih.gov/medlineplus/cytomegalovirusinfections.html

Q. What is it CMV during pregnancy ? can i infect with that?

A. CMV or cytomegalovirus (http://en.wikipedia.org/wiki/Cytomegalovirus) is a virus that can cause disease (i.e. infectious mononucleosis, http://en.wikipedia.org/wiki/Infectious_mononucleosis) in everyone, not only pregnant women. The problem is that when a pregnant woman is infected in CMV for the first time of her life during pregnancy, CMV can cause malformations and problems with the baby, including hearing impairment and others (see also TORCHES: http://en.wikipedia.org/wiki/TORCH_infections).