This surveillance supplemental report describes the data collected from the 24 areas in the United States and dependent areas that were funded to conduct the Enhanced Perinatal Surveillance (EPS) project. During the time period covered by this report, these project sites included 17 state health departments, Puerto Rico, and 6 city health departments. This project constitutes a population-based and facility-based surveillance system for HIV-infected mothers and their perinatally exposed children. Data were collected by using both the HIV/AIDS case report form and a supplemental EPS data abstraction form. After the removal of personally identifying information, the data collected for EPS were submitted to CDC (see Figure 1 for list of participating areas).

Mother-infant pairs were identified through several means: pediatric HIV/AIDS surveillance, reports of HIV-infected pregnant women to surveillance, birth registry matching, and hospital discharge summaries. If the laws and regulations allowed, areas conducted a match with the HIV/AIDS Reporting System (HARS) and the birth registry for the birth years 2000–2003 to obtain a list of all possible mother-infant pairs. A small proportion of women who had not been tested or who did not disclose their HIV status during pregnancy were identified through their child’s HIV-infection status. This report does not include HIV-infected women and HIV-exposed children who were tested negative. The report also does not include HIV-exposed children who were not tested but presumed to be negative.

Methods used by the areas to collect these data required linkage of mother-infant pairs and review of the records of both mother and infant. These records include prenatal care records, maternal HIV clinic records, labor and delivery records, pediatric birth records, pediatric HIV medical records, other pediatric medical records, birth certificates, death certificates, and health department records. The area-specific methods for collecting these data, however, differed to comply with local HIV reporting laws and regulations. Using the EPS abstraction forms, the areas collected information on the mother: prenatal care, HIV testing history, receipt of antiretroviral therapy during pregnancy, substance use, and clinical information. The areas also collected birth history and pediatric history for the infant and then conducted follow-up of each infant every 6 months until the infant’s HIV status was determined.

EPS areas conducted the project as population-based or facility-based. Population-based areas were defined as those that included all HIV-exposed infants born to HIV-infected mothers within the geographic area defined by the project (e.g., state or city). Medical records for all HIV-exposed infants and HIV-infected mothers were abstracted from all facilities within the defined geographic area. Facility-based areas conducted the project in selected facilities within the geographic area defined by the project. The selected facilities were those serving large numbers of HIV-infected women (e.g., delivery hospitals or high-risk prenatal clinics) and HIV-exposed children (e.g., specialty pediatric clinics, pediatric HIV clinics). The medical records for HIV-exposed infants and HIV-infected mothers were abstracted from the facilities selected in these geographic areas.

Most project areas collected data on HIV-exposed infants (and their mothers) born during 2000 through 2003 (see Figure 1 for participating area and birth years for data collection). All infants born in the state, dependent area, city, or facility specified as the project site have been included. These include each infant of a multiple birth (e.g., twins, triplets).

TABULATION AND PRESENTATION OF DATA

Data in this report are provisional. This report includes EPS reports received by CDC through June 2007. All data tables are stratified by year of infant’s birth. Data on the infants include singleton births; the mother may deliver multiple infants in one pregnancy, but only one infant is represented in the data. The mother, however, may be represented more than once if she gave birth more than once during the project period.

Table 1 shows the numbers and percentages of HIV-infected women who gave birth to a live infant and who were reported to EPS. The race/ethnicity categories in this table are the categories used before the implementation of Office of Management and Budget (OMB) Statistical Policy Directive 15 [1]. These revised standards, which were to be implemented by January 1, 2003, superseded the 1977 standards and reflect a change in federal policy on the collection of data on race and ethnicity. Because data for this report were compiled from births to HIV-infected women during 2000 through 2003, the race/ethnicity data are presented as they are in HIV/AIDS surveillance data collected before January 1, 2003. For EPS reports received after January 1, 2003, race and ethnicity data were collected in accordance with OMB Statistical Policy Directive 15.

For the purposes of this report, women with HIV infection or AIDS are counted only once in a hierarchy of exposure categories. If a woman is reported as having more than one mode of exposure, she is classified in the exposure category listed first in the hierarchy. Women whose exposure category is classified as heterosexual contact are those who reported heterosexual contact with a person with, or at increased risk for, HIV infection (e.g., an injection drug user) [2].

Tables 9, 10, 11, 12, 13, 17, 18, and 19 show data by infant’s birth year and the mother’s race/ethnicity. The cumulative totals reflect all racial/ethnic categories for the four birth cohort years. Because of small numbers for American Indians/Alaska Natives, Tables 9, 10, 11, 12, 13, 17, 18, and 19 do not show data for this group.

Tables 15, 16, 17, and 19 represent the number of singleton births and not the total number of infants born to HIV-infected women.

The high proportions of cases with missing information are due to data collection methods. Charts and medical records are often missing key information and are sometimes not available. Patients are also lost to follow-up which makes it difficult to ascertain missing or unknown information. EPS data are collected prospectively and therefore completeness of data may improve over time.

The EPS protocol includes follow-up of all HIV-exposed infants until HIV status can be determined. The revised HIV surveillance case definition for adults and children was published in December 1999 and became effective January 1, 2000. For surveillance purposes, a child younger than 18 months and born to an HIV-infected woman can be classified as not infected only if virologic or antibody testing was performed during specified periods. If the tests were not performed or were not performed during the specified time periods, the child’s status is classified as indeterminate [3]. In this report, the status of approximately one third (31%) of the total number of infants is indeterminate. It is presumed that many of these infants are not infected with HIV, but their status is indeterminate because the criteria for classification as not infected have not been met. Therefore, caution must be used in interpreting the perinatal HIV transmission rates. Follow-up of these indeterminate cases is ongoing.

REFERENCES

1. Office of Management and Budget. Revisions to the standards for the classification of federal data on race and ethnicity. Federal Register 1997;62:58781–58790. Accessed November 18, 2008.
2. CDC. Cases of HIV Infection and AIDS in the United States, 2004. Accessed August 6, 2008.
3. CDC. Guidelines for national human immunodeficiency virus case surveillance, including monitoring for human immunodeficiency virus infection and acquired immunodeficiency syndrome. MMWR 1999;48(RR-13):1–28. Accessed December 16, 2008.