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Distribution of the latency period for perinatally acquired AIDS
1Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115.
Insights
Over 86% of pediatric AIDS cases stem from mother-to-child transmission. This study estimates the median age for diagnosis in children with perinatally acquired human immunodeficiency virus (HIV) infection is 4.1 years.
Area of Science:
- Pediatric Infectious Diseases
- Epidemiology
- Public Health
Background:
- Maternal-to-child transmission is the primary route for pediatric acquired immunodeficiency syndrome (AIDS) in the United States.
- An estimated 6,000 children are born to human immunodeficiency virus (HIV)-infected women annually in the U.S.
- Less than 25% of maternally exposed infants in industrialized nations acquire HIV.
Purpose of the Study:
- To determine the latency period for perinatally acquired human immunodeficiency virus (HIV) infection in children.
- To estimate the unconditional latency distribution for pediatric AIDS diagnosis.
Main Methods:
- Utilized 7 years of surveillance data for children with perinatally acquired AIDS in New York City.
- Combined newborn screening data with surveillance data to remove conditional biases.
- Analyzed data to estimate the time from birth to clinical AIDS diagnosis.
Main Results:
- Estimated a median diagnosis age of 4.1 years for children with perinatally acquired AIDS.
- This median age is longer than previously estimated.
- Newborn screening is crucial for accurate maternal exposure data.
Conclusions:
- The latency period for pediatric AIDS diagnosis is longer than previously thought.
- Accurate estimation requires combining surveillance and newborn screening data.
- Understanding transmission dynamics is key for prevention strategies.
Abstract:
In the United States, over 86 per cent of paediatric cases of acquired immunodeficiency syndrome (AIDS) were infected through maternal or perinatal transmission and current estimates suggest that approximately 6000 children are born to infected women each year. In industrialized countries, less than 25 per cent of infants maternally exposed to the human immunodeficiency virus (HIV) are infected. The exact time of infection is unknown. However an endpoint, birth, exists from which the latency period or the time to diagnosis with clinical AIDS can be measured. In New York City, 7 years of reliable surveillance data were available for children with perinatally acquired AIDS. Using these data, the only estimable aspect of the latency is a conditional distribution, which conditions on diagnosis occurring before age 7. Because newborns carry maternal antibodies, a positive antibody test at birth is only an indication of maternal infection. Screening all newborns for HIV antibodies, while maintaining the anonymity of the mother and child, provides data on the number of children maternally exposed. The above conditioning can be removed by combining the surveillance and newborn screening data to obtain the unconditional latency distribution. We estimate a median diagnosis age of 4.1 years, somewhat longer than previously believed.