This
special surveillance report describes the data collected from the 24 areas
in the United States that were funded
to conduct the Enhanced Perinatal Surveillance (EPS) project. These project
sites include 18 state health departments and 6 city health
departments that expect to serve annually at least 60 HIV-infected women who
will give birth (number determined by the 1994 Survey of Childbearing Women
[SCBW]). This project constitutes a population-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 sites).
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, sites conducted a match with the HIV/AIDS Reporting
System (HARS) and the birth registry for the birth
years 1999–2001 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 who were not reported
or their HIV-exposed children who tested negative or
were not tested but presumed to be negative.
Methods used by the sites to collect these data required
additional 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 site-specific methods for collecting these data, however, differed to
comply with local HIV reporting laws and regulations. Using the EPS abstraction
forms, the sites collected information on the mother: prenatal care, HIV testing
history,
receipt of antiretroviral therapy during pregnancy, substance use, and clinical
information. The sites 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
sites conducted the project as population-based or facility-based. Population-based
sites 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
sites 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.
For
7 sites piloting these enhanced surveillance methods for births during 1993–1997,
completeness of ascertainment of HIV-infected mothers and HIV-exposed
infants was 90% (1). For data reported here,
the estimated completeness of ascertainment of
mother-infant pairs, based on the 1994 SCBW
estimates for each participating site, is 63%. Use of
the 1994 SCBW to estimate completeness assumes that the number of HIV-infected
women who gave birth during 1999–2001
is the same as the number who gave birth during 1994. This assumption may not
be valid. After 1994, the SCBW was conducted by 10
sites, all of which used state-specific funds to estimate
the prevalence of births to HIV-infected women. At 1 site, the prevalence
estimate increased 3%; however, at the other 9 sites, prevalence estimates
declined substantially (range, 5% to 60%).
When the updated prevalence estimates for the 10
sites are included, completeness of EPS reporting
improves to 81%.
Most
project areas collected data on HIV-exposed infants (and their mothers) born
during
1999,
2000, and 2001 (see Figure 1 for participating sites
and birth years for data collection). All infants born in
the state, 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
September 8, 2003. All data tables are stratified by
year of infant’s birth. Data on the infants include
each infant who was 1 of a multiple birth; the mother
is counted only once per pregnancy. 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. 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 1999, 2000, and 2001, 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 1 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 specific 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, and 13 show
data by infant’s birth year
and the mother’s race/ethnicity. The cumulative
totals reflect all racial/ethnic categories for the
3 birth cohort years. Because of small numbers for
Asians/Pacific Islanders and American Indians/
Alaska Natives, Tables 9, 10,11,12,
and 13 do
not show data for these groups.
Tables 15 and 16 show
data by the number of infants, including all single and multiple births. Because
these tables include all children born to HIV-infected
women, the number of infants exceeds the
number of women who gave birth during the 3-year
period. Thus, the totals in these tables differ from
those in Tables 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
and 14.
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
(32%) 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. CDC. CDC report regarding
selected public health topics affecting women’s health. MMWR
2001;50(No. RR-6):17–28.
2. CDC. HIV/AIDS Surveillance Report
2002;14:14–15. Accessed July 26, 2004.
3. CDC. Guidelines for national human immunodeficiency
virus case surveillance, including monitoring
for human immunodeficiency virus infection and
acquired immunodeficiency syndrome. MMWR
1999;48(No. RR-13):1–31.
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