The completeness of AIDS case reporting, 1988: a multisite collaborative surveillance project

Estimating the future health burden of chronic hepatitis C and human immunodeficiency virus infections in the United States

The aim of this work was to estimate the future disease burden of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections in the United States until the year 2030. Two back-calculation models of the HIV and the HCV epidemic were developed. They were based on US epidemiological data regarding prevalence, age and gender of incident cases, AIDS, hepatocellular carcinoma (HCC) mortality and general population mortality from the Centers for Disease Control and WHO. Based on the HCV back-calculation model, HCV incidence peaked in 1984 at 350,000 new infections and then fell to about 77,000 in 1998. Based on the HIV back-calculation model, HIV incidence reached its maximum in 1989 at 142,000 new infections and then declined to 79,000 in 1998. Mortality related to HCV (death from liver failure or HCC) rose from about 3,700 in 1998 and is expected to peak at about 13,000 in 2030. Predicted HCV mortality would fall only if increased access to or more effective antiviral therapy occurs. For comparison, observed HIV-related mortality was 14,400 in 1998 and projected to be 4,200 for 2030. With the availability of effective highly active antiretroviral therapy for HIV infection, mortality from HIV appears to have declined substantially, whereas HCV-related deaths as a result of pre-1999 infections will likely continue to increase over the next 25 years.

Assessing the completeness of reporting of human immunodeficiency virus diagnoses in 2002-2003: capture-recapture methods

To determine the completeness of reporting of human immunodeficiency virus (HIV) diagnoses to state surveillance systems, the authors used capture-recapture methods. The numbers of cases diagnosed in the areas were estimated using HIV diagnoses reported to nine surveillance programs by different sources (e.g., laboratories, health-care providers). To account for dependencies between reporting sources, the authors used log-linear models to estimate the number of cases that had been diagnosed but were not identified by any reporting sources. Completeness of reporting (observed cases/expected cases) was determined for two time frames: cases diagnosed within a 1-year period (from October 1, 2002, to September 30, 2003, for most US states) reported up to 6 months after that diagnosis period and cases diagnosed within a 6-month period reported up to 12 months after that diagnosis period. A total of 11,266 HIV diagnoses were reported for the 1-year period with 21,589 report documents. Completeness of reporting of HIV diagnoses was 76% (95% confidence interval: 66, 83) when allowing 6 months of reporting delay (range: 72-95%) and improved to 81% (95% confidence interval: 72, 88) with 12 months' follow-up. When reporting systems retain all relevant documents, capture-recapture is a feasible approach for assessing completeness of reporting of HIV diagnoses. Completeness should be measured by allowing 12-months' reporting delay.

Describing the HIV/AIDS epidemic: using HIV case data in addition to AIDS case reporting

PURPOSE

We examined the demographic and risk characteristics of persons with HIV using traditional AIDS case reporting and the more recent system that includes HIV diagnoses without AIDS.

METHODS

Using data from 25 states with HIV reporting of HIV/AIDS cases diagnosed from 1994 through 2001, we calculated percentage distributions, annual diagnosis rates, and estimated annual percent change (EAPC) for persons with HIV (all HIV diagnoses with or without AIDS) and persons with AIDS.

RESULTS

The age at diagnosis of persons with all stages of HIV tended to be younger than that of the subset of persons with AIDS. Annual diagnosis rates decreased more among AIDS cases (men: EAPC, - 9.76; 95% CI, - 12.00, - 7.45; women: EAPC, - 3.40; 95% CI - 5.72, - 1.02) than for persons with HIV (men: EAPC, - 6.14; 95% CI, - 7.66, - 4.60; women: EAPC, - 2.99; 95% CI, - 4.15, - 1.82), except among women and black non-Hispanics, for whom the difference in the decreases in rates for both disease groups were small. Injection drug use was a more common mode of exposure for women with AIDS than for women with HIV.

CONCLUSIONS

The epidemiology of HIV differs for certain key population groups from that of AIDS.

Acquired immunodeficiency syndrome and the risk of stroke

BACKGROUND AND PURPOSE

Although acquired immunodeficiency syndrome (AIDS) is thought to increase the risk of stroke, few data exist to quantify this risk. This is the first population-based study to quantify the AIDS-associated risk of stroke.

METHODS

We identified all incident ischemic stroke (IS) and intracerebral hemorrhage (ICH) cases among young adults 15 to 44 years of age in central Maryland and Washington, DC, who were discharged from any of the 46 hospitals in the study area in 1988 and 1991. Using data from the medical records, 2 neurologists reviewed each case to confirm the diagnosis. Cases of AIDS among these patients with stroke were defined using Centers for Disease Control and Prevention criteria (1987). The number of cases of AIDS in the central Maryland and Washington population during 1988 and 1991 was determined from regional health departments working with the Centers for Disease Control and Prevention. Poisson regression was used to estimate the age-, race-, and sex-adjusted relative risk of stroke associated with AIDS.

RESULTS

There were 385 IS cases (6 with AIDS) and 171 ICH cases (6 with AIDS). The incidences of IS and ICH among persons with AIDS were both 0.2% per year. AIDS conferred an adjusted relative risk of 13.7 (95% confidence interval [CI], 6.1 to 30.8) for IS and 25.5 (95% CI, 11.2 to 58.0) for ICH. After exclusion of 5 cases of stroke in AIDS patients in whom other potential causes were identified, AIDS patients continued to have an increased risk of stroke with an adjusted relative risk of 9.1 (95% CI, 3.4 to 24.6) for IS and 12.7 (95% CI, 4.0 to 40.0) for ICH.

CONCLUSIONS

This population-based study found that AIDS is strongly associated with both IS and ICH.

Estimated Number of Children Left Motherless by AIDS in the United States, 1978???1998

When a mother dies of AIDS, basic needs of her children may be left unmet. To estimate the number and characteristics of maternal AIDS orphans in the United States, demographic techniques were applied to data from several sources. From the national HIV/AIDS surveillance system, reporting delays were adjusted for the number of deaths among women aged 15-44 diagnosed with AIDS through 1998 and reported as deceased by December 1999. No fertility was assumed in the year preceding death. To the adjusted number of deaths the annual age- and race-specific cumulative fertility and infant mortality rates from national vital statistics were applied. A perinatal infection rate of 25% was assumed among children born through 1994, and 10% among children born after 1994. Through 1998, 51,473 women died leaving 97,376 children motherless. Of the estimated 76,661-87,0018 uninfected children, 83% were younger than 21 years when orphaned. After increasing each year, the annual number of orphaned children younger than 21 years peaked in 1995. In 1998, between 4252-4489 uninfected youth were added to 47,863-54,025 existing orphans younger than age 21. Due to declines in AIDS deaths, the annual number of children orphaned by AIDS has declined. Nevertheless, each year thousands of youth are orphaned.

The completeness, validity, and timeliness of AIDS surveillance data

PURPOSE

To assess the completeness, validity, and timeliness of the AIDS surveillance system after the 1993 change in the surveillance case definition.

METHODS

To assess completeness of AIDS case reporting, three study sites conducted a comparison of their AIDS surveillance registries with an independent source of information. To evaluate validity, the same sites conducted record reviews on a sample of reported AIDS cases, we then compared agreement between the original report and the record review for sex, race, and mode of transmission. To evaluate timeliness, we calculated the median delay from time of diagnosis to case report, before and after the change in case definition, in each of the three study sites.

RESULTS

After expansion of the case definition, completeness of AIDS case reporting in hospitals (> or = 93%) and outpatient settings (> or = 90%) was high. Agreement between the information provided on the original case report and the medical record was > 98% for sex, > 83% for each race/ethnicity group; and > 67% for each risk group. The median reporting delay after the change was four months, but varied by site from three to six months.

CONCLUSIONS

The completeness, validity, and timeliness of the AIDS surveillance system remains high after the 1993 change in the surveillance case definition. These findings might be useful for programs implementing integrated HIV and AIDS surveillance systems.

Estimation of completeness of AIDS case reporting in Massachusetts

One of the most important aspects of any surveillance system is degree of completeness. We conducted a multiple source capture-recapture study using the 1994 Massachusetts Uniform Hospital Discharge Data Set (UHDDS) and Medicaid claims data to evaluate the completeness of the state's AIDS registry. We used encrypted social security numbers as the primary link to ensure confidentiality. For cases that did not link in the first round owing to missing social security numbers, we linked using gender and date of birth. Staff reviewed unmatched records from the Uniform Hospital Discharge Data Set and Medicaid datasets to determine subjects' AIDS case status. Using the Uniform Hospital Discharge Data Set, the AIDS registry was 92.6% complete (95% confidence interval (CI) = 91.6-93.5). The Medicaid claims dataset suggested the AIDS registry to be 94.5% complete (95% confidence interval = 93.7-95.3). The completeness of reporting to the state AIDS registry continues to be high, but there are differences by gender and mode of transmission of the virus. The continued assessment of completeness of reporting is important to ensure quality of the surveillance database over time.

The impact of the 1993 AIDS case definition on the completeness and timeliness of AIDS surveillance

OBJECTIVE

To assess the impact of the 1993 change in the AIDS case definition on the completeness and timeframe of AIDS case reporting in San Francisco.

DESIGN

Retrospective review of records: billing records, list of selected diagnostic codes, radiology logs, ophthalmology clinic records, and patient registries at a selection of hospitals, clinics, and physician offices.

SETTING

Hospitals, public/community health clinics, and physician offices.

MAIN OUTCOME MEASURES

The completeness of reporting and the median reporting delay was calculated for hospitals, clinics, and physician offices.

RESULTS

Reporting was 97% complete. Reporting from physician offices was less complete (75%) than from other facilities. The median reporting delay was 1 month and was shorter for persons who met the 1993 AIDS case definition (1 month) than for persons who met the 1987 case definition (3 months).

CONCLUSIONS

AIDS case reporting in San Francisco is highly complete but less so for persons diagnosed at physician offices. The 1993 AIDS case definition has resulted in more timely reporting. Health departments should consider efforts to improve reporting from private physician offices and should evaluate the use of laboratory-initiated CD4 reporting.

Sexual abuse of children: intersection with the HIV epidemic

OBJECTIVE

Sexual transmission of human immunodeficiency virus (HIV) is the predominant risk exposure among adolescents and adults reported with HIV infection and acquired immunodeficiency syndrome (AIDS). Although perinatal transmission accounts for the majority of HIV infection in children, there have been reports of HIV transmission through sexual abuse of children. We characterized children <13 years of age who may have acquired HIV infection through sexual abuse.

METHODS

All reports by state and local health departments to the national HIV/AIDS surveillance system of children with HIV infection not AIDS (n = 1507) and AIDS (n = 7629) through December 1996 were reviewed for history of sexual abuse. Information was ascertained from data recorded on the case report form as well as investigations of children with no risk for HIV infection reported or identified on initial investigation. For children with a possible history of sexual abuse, additional data were collected, including how sexual abuse was diagnosed; characteristics of the perpetrator(s) (ie, HIV status and HIV risks); and other possible risk factors for the child's HIV infection.

RESULTS

Of 9136 children reported with HIV or AIDS, 26 were sexually abused with confirmed (n = 17) or suspected (n = 9) exposure to HIV infection; mean age of these children at diagnosis of HIV infection was 8.8 years (range, 3 to 12 years). There were 14 females and 3 males who had confirmed sexual exposure to an adult male perpetrator at risk for or infected with HIV; of these, 14 had no other risk for HIV infection, and 3 had multiple risks for HIV infection (ie, through sexual abuse, perinatal exposure, and physical abuse through drug injection). The other 9 children (8 females, 1 male) had no other risk factors for HIV infection and were suspected to have been infected through sexual abuse, but the identity, HIV risk, or HIV status of all the perpetrator(s) was not known. All cases of sexual abuse had been reported to local children's protective agencies. Sexual abuse was established on the basis of physician diagnosis or physical examination (n = 20), child disclosure (n = 15), previous or concurrent noncongenital sexually transmitted disease (n = 9), and for confirmed cases, criminal prosecution of the HIV-infected or at-risk perpetrator (n = 8). For the 17 children with confirmed sexual exposure to HIV infection, 19 male perpetrators were identified who were either known to be HIV infected (n = 18) or had risk factors for HIV infection (n = 17), most of whom were a parent or relative.

CONCLUSIONS

These 26 cases highlight the tragic intersection of child sexual abuse and the HIV epidemic. Although the number of reported cases of sexual transmission of HIV infection among children is small, it is a minimum estimate based on population-based surveillance and is an important and likely underrecognized public health problem. Health care providers should consider sexual abuse as a possible means of HIV transmission, particularly among children whose mothers are HIV-antibody negative and also among older HIV-infected children. The intersection of child abuse with the HIV epidemic highlights the critical need for clinicians and public health professionals to be aware of the risk for HIV transmission among children who have been sexually abused, and of guidelines for HIV testing among sexually abused children, and to evaluate and report such cases.

Health benefits and risks of reporting HIV-infected individuals by name

With more treatment options emerging for human immunodeficiency virus (HIV) infection, the policy of reporting HIV-infected individuals by name merits reevaluation. This paper reviews the benefits and risks of name reporting of persons infected with HIV. Public health departments have linked name reporting with medical referrals, risk reduction counseling, and partner notification programs. Yet some studies indicate that people are less likely to be tested for HIV infection when name reporting is implemented. Whether name reporting actually improves individual or public health, therefore justifying the increased risk of loss of confidentiality and possibly reduced testing rates, remains unknown. The lack of health outcome data on name reporting allows beliefs rather than facts to dominate debate about this policy. Before this practice is more widely adopted, a determination should be made as to whether the potential benefits of name reporting outweigh the risks.

Estimating the number of AIDS-defining opportunistic illness diagnoses from data collected under the 1993 AIDS surveillance definition

Expansion of the surveillance definition for AIDS in the United States in 1993 caused a substantial distortion in the trend in AIDS incidence, mainly because CD4-positive (CD4+) T-lymphocyte criteria were added to the definition. To evaluate trends in the rate at which HIV-infected persons develop the opportunistic illnesses listed in the AIDS surveillance definition (AIDS-OIs), we developed a procedure for estimating the incidence of these diseases. This estimate is based primarily on the probability distributions of the time from a CD4+ count in given ranges to the diagnosis of the first AIDS-OI. Our estimates of AIDS-OI incidence change by <4% during most calendar quarters during 1991 through 1995 if we also include the estimated effects of unreported AIDS-OIs among persons with AIDS reported based on the CD4+ criteria. Our procedure eliminates the transient effect of adding the CD4+ criteria to the AIDS surveillance definition and permits us to evaluate trends in the incidence of AIDS-OIs.

Tuberculosis among AIDS patients in the United States, 1993

To evaluate the demographic characteristics, risk factors, and reported mortality of adults and adolescents with AIDS and tuberculosis (TB), we analyzed surveillance reports of persons with AIDS from state, territorial, and local health departments. Of 72,306 persons with AIDS diagnosed in 1993, 3,589 (5%) were reported with TB; of these, 2,782 (78%) with pulmonary TB, 552 (15%) with extrapulmonary TB, and 255 (7%) with both pulmonary and extrapulmonary TB were reported. In multivariate analysis, black [odds ratio (OR) 3.3, 95% confidence interval (CI) 2.9-3.7] and Hispanic (OR 2.5, 95% CI 2.2-2.9) persons had a higher risk of TB than white persons; injecting drug users (IDUs: OR 2.3, 95% CI 2.0-2.5) and persons exposed to HIV by heterosexual contact (OR 1.4, 95% CI 1.2-1.7) had a higher risk than men who have sex with men, and persons who were foreign born (OR 2.1, 95% CI 1.8-2.4) had a higher risk than those born in the United States. The highest proportions of AIDS patients with TB were in New York (11%), Illinois (7%), Florida (6%), Georgia (6%), and Texas (5%). The 1-year mortality rate among AIDS patients with pulmonary TB only (26%) and among those with extrapulmonary TB only (28%) was lower than among those with other AID-defining illnesses (38%) (p<0.001 and p<0.001, respectively). The high rate of TB among persons with AIDS, particularly in specific areas of the country and HIV exposure groups, emphasizes the need for continued support of strong TB control measures among persons infected with HIV.

Evidence for recent growth of the HIV epidemic among African-American men and younger male cohorts in Los Angeles County

To estimate the recent course of the human immunodeficiency virus type 1 (HIV) epidemic among men within birth cohorts, ethnic groups, and HIV-risk groups in Los Angeles County, backcalculation methods were combined with log-linear models and census data to reconstruct HIV incidence in subgroups from AIDS surveillance data. Results were compared with directly measured HIV seroprevalence in public sexually transmitted disease (STD) clinics in Los Angeles. Models of HIV incidence indicate that the initial epidemic pattern among men who have sex with men, including a decline in incidence since the mid-1980s, does not apply to all post-1960 birth cohorts. Later peaks were observed in younger birth cohorts and among injection drug users, especially among African-American men, with no evidence of a peak before the 1990s among men born after 1960. Our results indicate that HIV continued to spread near peak rates into the 1990s among younger birth cohorts, especially among young African-American men who have sex with men. Because of the lengthy incubation period from HIV infection to AIDS incidence, our results imply that the AIDS epidemic has not yet peaked in these cohorts and may continue to grow through the present decade in several subgroups. The large variation in HIV incidence and prevalence across birth cohorts and other subgroups needs to be addressed in future community intervention plans.

Completeness of tuberculosis case reporting, San Juan and Caguas Regions, Puerto Rico, 1992

Completeness of tuberculosis case reporting in Puerto Rico was assessed. Cases diagnosed among hospitalized, tuberculosis, and human immunodeficiency virus clinic patients during 1992 were retrospectively reviewed. Hospital discharge diagnoses, pharmacy listings of patients receiving anti-tuberculous medications, laboratory and acquired immunodeficiency syndrome registry data were used for case finding in selected hospitals and clinics. Identified cases were matched to the health department TB case registry to determine previous reporting through routine surveillance. Records of unreported cases were reviewed to verify tuberculosis diagnoses. Of 159 patients with tuberculosis, 31 (19.5%) were unreported. A case was defined according to the Centers for Disease Control and Prevention definition. Unreported cases were less likely than previously reported cases to have specimens that were culture positive for M. tuberculosis, 14 of 31 (45.2%) compared with 111 of 128 (86.7%). Excluding the laboratory, tuberculosis diagnoses in acquired immunodeficiency syndrome registry patients had the highest predictive value of finding tuberculosis (94.1%), followed by tuberculosis clinic records (71.7%), and pharmacy listings (45.6%). Tuberculosis discharge diagnoses, however, yielded the largest number of unreported cases (14). Health care providers should be educated regarding the importance of promptly reporting all suspected TB cases regardless of results of laboratory testing.

Completeness of AIDS reporting and quality of AIDS death certification in Tuscany (Italy): a linkage study between surveillance system of cases and death certificates

In Italy, the AIDS cases defined according to the CDC criteria are reported to the National AIDS Registry (RAIDS, compulsory surveillance system). The aim of the present study is to evaluate the completeness of AIDS cases reported and the quality of AIDS death certification in an Italian Region (Tuscany, about 3,500,000 inhabitants). The 737 AIDS cases reported to RAIDS as residents in Tuscany (1987-91) were cross-linked (key link: name and date of birth) with the data of the Mortality Registration system of the Region (RMR). For the residents in Tuscany decreased with a 279.1 death diagnosis (the code for AIDS deaths stated by the Italian Census Bureau) and not reported to RAIDS as AIDS cases, the clinical records were reviewed to check whether the diagnosis fitted the 1987-CDC diagnostic criteria. This study shows that there is a high completeness (97-98%) of the AIDS cases resident in Tuscany, reported to the RAIDS. The quality of RAIDS data is not as good with regard to life status assessment (23% of under-reporting of death). In Tuscany, the death certification for AIDS (code 279.1 of ICD IX) has a sensitivity of 88% and a specificity around 100% in comparison to RAIDS. About 50% of 'false negatives' in death certification are due to causes of death presumably unrelated to HIV infection. The evaluation of the quality of AIDS surveillance and mortality data is important in the assessment of the impact for AIDS epidemic in a target population.

Using administratively collected hospital discharge data for AIDS surveillance

The objectives of this study were twofold: to improve methods of identifying possible and acquired immunodeficiency syndrome (AIDS)-related hospital discharges in administrative databases and to measure AIDS-reporting completeness in Massachusetts both overall and by subgroup. We used fiscal year 1988 discharge data from the Massachusetts Rate Setting Commission (RSC) and data from the Massachusetts AIDS Reporting System (ARS). We identified 3362 discharges of adult patients (> 12 years old) from the RSC file that had diagnosis codes which are human immunodeficiency virus (HIV)-specific (042.x, 043.x, 044.x, or 795.8) or pertain to AIDS-defining "manifestations." Medical records of 650 patients apparently not reported to the ARS were reviewed. THe best set of codes overall consisted of either (a) the 042.x code or (b) the 043.x, 044.x, or 795.8 code plus selected manifestation codes (sensitivity, 93%; specificity, 86%; predictive value positive, 71%). Of the 927 AIDS cases identified from the 3362 discharges, only 36 had not been reported. AIDS cases among women (odds ratio (OR) = 2.9; 95% confidence interval (CI): 1.33 to 6.33), intravenous drug users (OR = 4.2; 95% CI: 2.20 to 8.02), and persons residing outside the Boston metropolitan area (OR = 2.3; 95% CI: 1.18 to 4.57) were more likely to be unreported than those among comparison groups.

Prophylaxis against Pneumocystis carinii pneumonia among children with perinatally acquired human immunodeficiency virus infection in the United States. Pneumocystis carinii Pneumonia Prophylaxis Evaluation Working Group

BACKGROUND

Pneumocystis carinii pneumonia (PCP) remains a common and often fatal opportunistic infection among children infected with the human immunodeficiency virus (HIV). HIV-infected infants between three and six months of age are particularly vulnerable. Current guidelines recommend prophylaxis in children from birth to 11 months old who have CD4+ counts below 1500 cells per cubic millimeter.

METHODS

We used national surveillance data to estimate the annual incidence of PCP among children less than one year old. We reviewed the medical records of 300 children given a diagnosis of PCP between January 1991 and June 1993 to determine why treatment according to the 1991 guidelines for prophylaxis against PCP either was not given or failed to prevent the disease.

RESULTS

In our study the incidence of PCP in the first year of life among infants born to HIV-infected mothers changed little between 1989 and 1992. Among 7080 children born to HIV-infected mothers in 1992, PCP developed in 2.4 percent. Of 300 children with PCP diagnosed from January 1991 through June 1993, 199 (66 percent) had never received prophylaxis, and for 118 of those children (59 percent) exposure to HIV was first identified 30 days or less before the diagnosis of PCP. Among 129 children less than one year old, the CD4+ count declined by an estimated 967 cells per cubic millimeter (95 percent confidence interval, 724 to 1210 cells per cubic millimeter) during the three months before the diagnosis of PCP. Among infants in whom CD4+ counts were determined within one month of the diagnosis of PCP, 18 percent (20 of 113) had at least 1500 cells per cubic millimeter, a level higher than the currently recommended threshold for prophylaxis.

CONCLUSIONS

In the United States the incidence of PCP among HIV-infected infants has not declined. If this infection is to be prevented, infants exposed to HIV must be identified earlier, and prophylaxis must be offered to more children than the guidelines currently recommend.

Municipal drinking water and cryptosporidiosis among persons with AIDS in Los Angeles County

To assess unfiltered drinking water as a source of cryptosporidium infection in patients with the acquired immunodeficiency syndrome (AIDS) the prevalence of cryptosporidiosis among persons with AIDS in Los Angeles County was assessed by water service area. One water distributor, serving approximately 60% of the county's residents (area B), has consistently employed filtration. The other company, which serves the remainder of the county (area A), did not institute filtration until mid-December 1986. This difference provided a 'natural experiment' in which to assess the effect of municipal water filtration on the level of cryptosporidiosis among persons with AIDS. The prevalence of cryptosporidiosis among AIDS patients was compared for the two water service areas for the time period (1983-6) preceding the implementation of filtration in area A. From 1983 to 1986 the age-standardized prevalence of cryptosporidiosis among AIDS patients was 32% lower in area A (4.2%), which received unfiltered water, than in area B (6.2%). Following addition of filtration in area A, the prevalence of cryptosporidiosis among AIDS patients decreased by 20%; however, a decline, of 47%, was also observed in area B. The similar baseline levels of cryptosporidiosis and the corresponding post-filtration decline in both areas suggest that filtration had no effect on levels of cryptosporidiosis among persons with AIDS. Thus it does not appear that municipal drinking water is an important risk factor for cryptosporidiosis in AIDS patients residing in Los Angeles County.

HIV infection in hospitalized patients and Medicaid enrollees: the accuracy of medical record coding

To evaluate the accuracy of computerized medical-record coding for human immunodeficiency virus (HIV), medical charts were reviewed in six sites. In 7601 hospital and 867 Medicaid records with a listed diagnosis of HIV, the predictive value for HIV was 91% or higher. HIV was identified in 34% of 1155 Medicaid records listing immune disorder or illness in the acquired immunodeficiency syndrome (AIDS) surveillance definition (without an HIV code). In hospital and Medicaid records, AIDS was identified both in records listing AIDS and records listing HIV without AIDS. HIV codes on hospital and Medicaid records were highly predictive for HIV; undercoding of HIV occurred in Medicaid records.