Through its national HIV/AIDS surveillance system, CDC can monitor many aspects of the HIV/AIDS epidemic, including HIV/AIDS and AIDS diagnoses, deaths among persons with AIDS, people living with HIV/AIDS or AIDS, and beginning in 2008, the number of new HIV infections. All of these components work together to provide the most complete profile of the epidemic that is possible.
Definitions
CDC publishes reported and estimated data for HIV and AIDS.
Reported cases are those that CDC receives from state and local
health departments. As of 2008, all 50 states, the District of Columbia,
and five US dependent areas report HIV cases to CDC.
Reported cases reflect the number of cases reported in a given
year, regardless of when they were diagnosed. They are useful for
monitoring the reporting and validity of a surveillance system and are
the basis of the estimated cases.
Estimated cases are the reported cases after CDC has applied
appropriate adjustments to them. Only states that have been conducting
name-based HIV surveillance for at least four years (to date, 33 states
and 5 areas) are included in the estimated data in order to allow for
data adjustments and stabilization of the data. Estimated cases are
considered a more accurate reflection of the epidemic than reported
data because they are adjusted for reporting delays.
Estimated cases reflect the number of cases diagnosed in a given time
period and are useful for planning, resource allocation, and program
evaluation.
CDC monitors data on HIV, HIV/AIDS, and AIDS. Within
those categories, it monitors diagnoses, deaths, prevalence, and
incidence.
HIV/AIDS diagnoses are the number of individuals diagnosed with
HIV, at any stage of disease, in a given time period.
- The current CDC surveillance report contains reported HIV/AIDS
cases from 45 states with confidential name-based HIV infection
reporting as of 2006. As of 2008, all 50 states, the District of
Columbia, and five US dependent areas are now reporting HIV/
AIDS cases to CDC. These data will be included in future reports.
- Estimated HIV/AIDS diagnoses currently include the 33
states with long-term name based HIV reporting (mature HIV
surveillance systems) and 5 US dependent areas. The number
of states represented in the estimated diagnoses will increase in
the coming years as the surveillance systems mature from the
states that only recently implemented a name-based surveillance system. In 2012, all 50 states, the District of Columbia, and the 5
US territories will be represented in CDC’s estimated data.
Uses of these data: HIV/AIDS diagnoses data have historically
served as a marker for new HIV infections (incidence). However, a
person can be infected with HIV for a long time before receiving a
diagnosis. Therefore, and particularly with the establishment of the
new HIV incidence system, HIV/AIDS diagnoses are now best used
to monitor the epidemic in younger people, who will not have been
infected for very long, as well as to help correlate and monitor testing
and treatment patterns. HIV/AIDS diagnoses data are also useful
to monitor the HIV epidemic in local areas that do not have HIV
incidence surveillance at this time. HIV diagnoses data are the
basis for the incidence calculations. AIDS diagnoses and deaths of individuals with AIDS are the
number of individuals diagnosed with AIDS and the number of
individuals with AIDS who have died in a given time period.
- Reported AIDS cases and deaths among persons with AIDS are
from 50 states, the District of Columbia, and US dependent areas.
- Estimated AIDS diagnoses and deaths among persons with AIDS
are from 50 states, the District of Columbia, and US dependent
areas. Because all areas implemented AIDS reporting in the
early 1980s, their AIDS data can be adjusted to arrive at the
estimations.
Uses of these data: AIDS diagnoses and AIDS death data provide
trends since the beginning of the epidemic and are useful to track the
time from an HIV diagnoses to an AIDS diagnoses and/or death.
Discrepancies between populations in time from HIV diagnoses to
AIDS diagnosis or time to AIDS death will point out inequities in
access to testing and care; this knowledge can help direct resource allocation.
HIV/AIDS prevalence and AIDS prevalence are the number of
people living with HIV/AIDS or AIDS in a given population. CDC
reports prevalence as the number of people living with HIV/AIDS or
AIDS and also prevalence rates, usually calculated per 100,000 people.
Uses of these data: Prevalence is useful for planning and resource
allocation. Prevalence rates are useful for comparing HIV/AIDS
between populations and for monitoring trends over time.
HIV incidence is the number of new HIV infections in a specific
population during a specific time period.
Uses of these data: Incidence estimates are useful for planning and
allocation of funds, as well as evaluating the impact of prevention
programs.
Fact Sheet Continued: HIV/AIDS Surveillance Table
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