Human Immunodeficiency Virus Infection
Human Immunodeficiency Virus Infection: Excerpt from The 5-Minute Pediatric Consult
Richard M. Rutstein, MD
Human Immunodeficiency Virus Infection - BASICS
Human Immunodeficiency Virus Infection - description
- HIV-1 and HIV-2 are the etiologic agents of HIV infection and AIDS.
- HIV infection is lifelong.
- For most infected individuals, a long clinically asymptomatic period (5–15 years in adults, frequently shorter in children) is followed by the development of generalized nonspecific signs and symptoms (weight loss, adenopathy, hepatosplenomegaly) and mild clinical immunodeficiency.
- Eventually, after progressive immunologic deterioration, patients are susceptible to a wide variety of opportunistic infections and cancers, which represent the clinical syndrome known as AIDS.
Human Immunodeficiency Virus Infection - general prevention
- HIV infection is almost completely preventable.
- It is now possible to significantly decrease the risk to newborns of HIV-infected women:
- With prenatal 3-drug regimens, delivery via elective cesarean section for selected cases, and 6 weeks of postnatal zidovudine, perinatal transmission rates are now 2–3% in HIV specialty care sites.
- All pregnant women should be offered HIV testing at the 1st prenatal visit. In areas of high incidence, repeat testing should be done at 36 weeks’ gestation.
Human Immunodeficiency Virus Infection - epidemiology
HIV infection is transmitted via:
- Sexual contact:
- Male to female transmission more efficient than female to male
- Anal receptive sex more likely to transmit than vaginal sex
- Exposure to infected blood:
- Almost always involves parenteral exposure to infected blood (via transfusions or sharing needles)
- In occupational exposure, risk of transmission from percutaneous exposure to a needle contaminated with HIV-infected blood is 1/300.
- Breast milk:
- Overall risk of breast-feeding is ~15%.
- In countries where breast-feeding is the norm, up to 30% of perinatally acquired HIV infections occur through breast-feeding.
- Perinatally, either in utero or during labor and delivery:
- Of perinatally infected infants, 5–10% are believed infected in utero; the rest acquire the infection around the time of birth.
- Risk of an HIV-infected mother (not on treatment) giving birth to an infected infant is ~20%, with increased rate of transmission for women with low CD4 counts or higher viral titers, and for those who were previously diagnosed with AIDS.
- Vaginal delivery, especially with rupture of membranes >8 hours, appears to increase the risk of infant infection.
- Presence of untreated STDs, chorioamnionitis, and prematurity all increase the risk of mother-to-child transmission of HIV.
- HIV is not believed to be transmitted by:
- Bites
- Sharing utensils, bathrooms, bathtubs
- Exposure to urine, feces, vomitus (except where these fluids may be grossly contaminated with blood, and even then transmission is rare, if it happens at all)
- Casual contact in the home, school, or day care center
Human Immunodeficiency Virus Infection - DIAGNOSIS
Human Immunodeficiency Virus Infection - signs & symptoms
Indications for HIV testing:
- Perinatal risk factors (e.g., prematurity, premature rupture of membranes, HIV testing in the mother)
- IV drug use
- Noninjectable drug use
- STDs, especially syphilis
- Bisexuality
- Transfusions before 1986
- Frequent infections
- Sinopulmonary infections
- Recurrent pneumonia/invasive bacterial disease
- Severe acute pneumonia (Pneumocystis)
- Recurrent or resistant thrush, especially after 12 months of age
- Congenital syphilis
- Presence of STDs in an adolescent
- Acquired microcephaly
- Progressive encephalopathy, loss of developmental milestones
- History of idiopathic thrombocytopenic purpura/thrombocytopenia
- Failure to thrive
- Recurrent/chronic diarrhea
- Recurrent/chronic enlargement of parotid gland
Human Immunodeficiency Virus Infection - physical exam
- May be entirely normal in the 1st few months of life
- 90% will have some physical findings by age 2 years
- Most common findings are:
- Adenopathy, generalized
- Hepatosplenomegaly
- Failure to thrive
- Recurrent/Resistant thrush, especially after 1 year of age
- Recurrent or chronic parotitis
Human Immunodeficiency Virus Infection - tests
Human Immunodeficiency Virus Infection - lab
- Enzyme-linked immunosorbent assay (ELISA) antibody screen:
- For children >18 months of age, repeatedly reactive ELISA antibody screen, followed by confirmation with Western blot analysis, is diagnostic of HIV infection.
- Any positive test should always be repeated before a definitive diagnosis is discussed with family.
- In 1st year of life, positive HIV ELISA and Western blot antibody tests simply confirm maternal infection, because the antibody test is IgG based and maternal anti-HIV antibodies readily cross placenta. Maternal antibodies may remain detectable until 15 months of age.
- HIV blood culture and/or polymerase chain reaction (PCR) DNA testing:
- Most reliable way of diagnosing HIV infection in infancy
- PCR test has slightly more false positives and false negatives; the blood culture is more expensive, takes longer to run, and is technically more difficult.
- Both tests have sensitivities and specificities >95% when performed after 4 weeks of age.
- Elevated IgG levels: 1st observed immune abnormality noted in HIV-infected infants, generally reaching twice the normal values by 9 months of age
- CD4 counts:
- Obtained at diagnosis and every 1–3 months
- Results need to be evaluated on the basis of age-adjusted normal values. Absolute CD4 counts are elevated in childhood, with normal median values >3,000/mm3 in the 1st year of life, which then gradually decline with age, reaching values comparable with adult levels (800–1,000/mm3) by age 7.
- Quantitative viral RNA PCR assays:
- Termed “viral loads,” results are reported in a range from undetectable, usually <50 copies/mL, to upper values of >10 million
- Long-term prognosis is closely related to viral loads.
- Viral loads that remain >100,000 are associated with poor short-term (2- to 5-year) outcomes.
- Also used as a marker of efficacy of treatment; goal is to suppress viral replication to the undetectable range for as long as possible. ~40–50% of pediatric patients presently followed at tertiary sites have an undetectable viral load.
- Test is done at time of diagnosis (twice) to establish baseline, 1 month after initiating or changing therapies, and every 1–3 months thereafter.
- Neurologic evaluation, with psychometric testing, and an initial CT scan/MRI screening for cerebral atrophy should be repeated at yearly intervals.
- Postimmunization antibody levels to assess B cell function
- Other frequent lab abnormalities include thrombocytopenia, anemia, and elevated liver enzymes.
Human Immunodeficiency Virus Infection - differencial diagnosis
- Neoplastic disease:
- Lymphoma
- Leukemia
- Histiocytosis X
- Infectious:
- Congenital/Perinatal cytomegalovirus
- Toxoplasmosis
- Congenital syphilis
- Acquired Epstein-Barr virus
- Congenital immunodeficiency syndromes:
- Wiskott-Aldrich syndrome
- Chronic granulomatous disease
The result of failing to screen for HIV infection is the inability to offer antiretroviral therapy for pregnant women, therefore possibly preventing infant infection, and also the inability to prescribe Pneumocystis carinii pneumonia prophylaxis to infected newborns.
Human Immunodeficiency Virus Infection - TREATMENT
Human Immunodeficiency Virus Infection - general measures
- Immunizations:
- All infected children receive standard childhood immunizations, including the recently approved pneumococcal conjugate vaccine.
- Infected children should receive yearly influenza A/B immunizations and the pneumococcal vaccine at age 2 years.
- Symptomatic children should not receive the varicella vaccine, and those with severely low CD4 counts should not receive measles-mumps-rubella.
- Immune enhancement:
- Passive: Recent studies suggest that monthly gamma globulin infusions somewhat decrease febrile episodes and pneumococcal bacteremia. The children who benefit the most are those not on antibiotic prophylaxis for P. carinii pneumonia or otitis media.
- Prophylaxis: One of the major advances in the care of HIV-infected children and adults has been the ability to offer prophylaxis against the most common opportunistic infections.
Human Immunodeficiency Virus Infection - medication
- Antiretroviral therapy:
- Specific combination antiretroviral therapy prolongs life, delays progression of illness, promotes improved growth, and improves neurologic outcome.
- Standard of care now involves the administration of combination therapy (usually 3 or more drugs). Drug regimens are complex, with as many as 9 doses of medication a day:
- There are now more than 22 approved antiretroviral agents, of 4 different drug classes.
- Given the complexities of therapy, and the rapid changes in available therapies, antiretroviral therapy should always be prescribed in consultation with a specialist in pediatric/ adolescent HIV infection.
- Adherence to prescribed schedules is critical: When patients miss even 10–20% of doses, the durability of response is short.
Human Immunodeficiency Virus Infection - FOLLOW UP
- Psychosocial support for the family is critical.
- Because of the complex, rapidly changing therapies available to treat pediatric HIV infection, all infected patients should be comanaged with an HIV specialty care site.
- Patients should be seen every 1–3 months to monitor immune status (CD4 counts) and virologic suppression (quantitative plasma viral RNA).
Human Immunodeficiency Virus Infection - prognosis
Since the use of combinations of 3 or more drugs have become standard, morbidity and mortality have both greatly decreased:
- Median survival is now clearly into adulthood.
- Incidence of new opportunistic infections (AIDS signal illnesses) has decreased greatly, as have hospital admissions.
Human Immunodeficiency Virus Infection - complications
- P. carinii pneumonia:
- Most common early fatal illness in HIV-infected children (peak age 3–9 months) mortality is 30–50%. A high index of suspicion is necessary for prompt diagnosis (by lavage) and initiation of therapy.
- 40% of new cases of HIV-related pediatric P. carinii pneumonia involve infants not previously recognized as HIV infected.
- Lymphocytic interstitial pneumonitis:
- Frequently asymptomatic; can lead to slow onset of chronic respiratory symptoms
- Causes a distinctive diffuse reticulonodular pattern on chest radiographs
- Usually diagnosed between 2 and 4 years of age; related to dysfunctional immune response to Epstein-Barr virus infection
- Definitive diagnosis is made by lung biopsy.
- For symptomatic patients, prednisone is effective.
- Recurrent invasive bacterial infections:
- Risk of bacteremia is ~10%/year in HIV-infected children.
- Pneumococcal bacteremia is the most common invasive bacterial disease.
- Bacterial pneumonia, sinusitis, and otitis media are common among infected children.
- Progressive encephalopathy:
- Diagnosed between 9 and 18 months of age, the hallmark is progressive loss of developmental milestones or neurologic dysfunction.
- Cerebral atrophy, with or without basal ganglion calcifications, on neuroimaging
- Disseminated Mycobacterium avium intracellulare:
- Older children, usually >5 years of age, with severe immunodeficiency (CD4 ≤100)
- Symptoms include prolonged fevers, abdominal pain, anorexia, and diarrhea.
- Candida esophagitis: Older children with severe immunodeficiency usually present with dysphagia or chest pain and oral thrush. Diagnosis suggested by findings on barium swallow, but definitive diagnosis made by biopsy
- Disseminated cytomegalovirus disease:
- Retinitis less common in HIV-infected children than in adults
- Cytomegalovirus may also cause pulmonary disease, colitis, and hepatitis.
- HIV-related cancers: Non-Hodgkin lymphoma most common cancer, with primary site usually located in the CNS
- Other organ dysfunction associated with HIV-infection in children:
- Cardiomyopathy
- Hepatitis
- Renal disease
- Thrombocytopenia/Idiopathic thrombocytopenic purpura
Human Immunodeficiency Virus Infection - bibliography
Perinatal HIV Guidelines Working Group. PHS Task Force recommendations for use of antiretroviral drugs in pregnant HIV-1 infected women for maternal health and interventions to reduce perinatal transmission in the United States. Revised October 2006. Available at: http://www.hivatis.org. Accessed December 2006.Working Group on Antiretroviral Therapy and Medical Management of HIV-1 Infected Children. Guidelines for the use of antiretroviral agents in pediatric HIV infection. Available at: http://www.hivatis.org. Accessed December 2006.
Human Immunodeficiency Virus Infection - CODES
Human Immunodeficiency Virus Infection - icd9
042 Human immunodeficiency virus infection
795.71 Nonspecific evidence of human immunodeficiency virus
Human Immunodeficiency Virus Infection - FAQ
- Q: When the HIV-exposed infant has seroreverted to antibody-negative status, how sure are we that he or she is uninfected?
- A: With today’s technology, if the child has also been PCR and/or HIV blood culture negative at least twice, and is clinically well, the chance that the child still harbors HIV is very low and appears to be <1/5,000. The child should continue to be followed by a health care provider aware of his or her past HIV antibody status. If clinical conditions warrant, retesting would be an option at a later date.
>>
Book Source Details
- Book Title: The 5-Minute Pediatric Consult
- Author(s): M. William Schwartz MD; et al.
- Year of Publication: 2008
- Copyright Details: The 5-Minute Pediatric Consult, Copyright © 2008 Lippincott Williams & Wilkins.
More About HIV/AIDS
More Medical Textbooks Online about HIV/AIDS
Review other book chapters online related to HIV/AIDS:
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
|
|
More About This Book:
Title: The 5-Minute Pediatric Consult
Authors: M. William Schwartz MD; et al.
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7577-9
|
|
» Next page: Human Papilloma Virus (The 5-Minute Pediatric Consult)
Rate This Website
What do you think about the features of this website?
Take our user survey and have your say:
Website User Survey
Medical Tools & Articles:
Next articles:
Tools & Services:
Medical Articles:
Forums & Message Boards
- Ask or answer a question at the Boards:
