Projection of AIDS incidence in women in New York State

Evaluating two adjustment methods to extrapolate HIV prevalence from pregnant women to the general female population in sub-Saharan Africa

OBJECTIVE

To evaluate two methods for estimating HIV prevalence among the general female population of reproductive age by adjusting data observed among antenatal clinic (ANC) attendees.

METHODS

We adjusted the HIV prevalence among ANC attendees in Fort Portal (Uganda; 1994-1995), Mwanza municipality (Tanzania; 1990-1991), rural Mwanza (Tanzania; 1991-1993), Mposhi district (Zambia; 1994), Chelston (Lusaka, Zambia; 1994, 1996 and 1998) and Ndola (Zambia; 1998), using firstly a method that accounts for differences in age-specific fertility by HIV serostatus and secondly a method that accounts for differences in HIV prevalence by fertility risk category and parity.

RESULTS

The non-adjusted HIV prevalence among ANC attendees underestimates the prevalence among the general female population by 8.0% in Chelston in 1998 and by between 20.7% and 31.9% in all other cases. The adjusted prevalence obtained using the first method underestimates the prevalence among the general female population by about 0.5% in Fort Portal and Mposhi; it overestimates that observed in Chelston in 1994 and 1996 by about 3.5%, and that observed in Ndola, urban Mwanza and rural Mwanza, by 6.5%, 10.6% and 12.8%, respectively. The second method (applied for only four sites) provides an overestimate of 7.0% in Chelston in 1994 and an underestimate of 3.8% and 2.1% in Ndola and rural Mwanza, respectively. Both adjustment methods overestimate the 1998 prevalence in Chelston, producing less accurate estimates than the non-adjusted data.

CONCLUSIONS

The HIV prevalence among women in the general population could be estimated fairly accurately by these methods in settings with mature epidemics.

Adjusting ante-natal clinic data for improved estimates of HIV prevalence among women in sub-Saharan Africa

OBJECTIVES

To find a simple and robust method for adjusting ante-natal clinic data on HIV prevalence to represent prevalence in the general female population in the same age range, allowing for fertility differences by HIV status.

BACKGROUND

HIV prevalence comparisons for pregnant women and women in the general community show that prevalence in the latter is significantly higher than in the former. An adjustment procedure is needed that is specific for the demographic and epidemiological circumstances of a particular population, making maximum use of data that can easily be collected in ante-natal clinics or are widely available from secondary sources.

METHODS

Birth interval length data are used to allow for subfertility among HIV-positive women. To allow for infertility, relative HIV prevalence ratios for fertile and infertile women obtained in community surveys in populations with similar levels of contraception use are applied to demographic survey data that describe the structure of the population not at risk of child-bearing.

RESULTS

For populations with low contraception use, the procedure yields estimates of general female HIV prevalence of 35-65% higher than the observed ante-natal prevalence, depending on population structure. Results were verified using general population prevalence data collected in Kisesa (Tanzania) and Masaka (Uganda). For high contraception use populations, adjusted values range from 15% higher to 5% lower, but only limited verification has been possible so far.

CONCLUSIONS

The procedure is suitable for estimating general female HIV prevalence in low contraception use populations, but the high contraception variant needs further testing before it can be applied widely.

A comparison of male and female intravenous drug users' risk behaviors for HIV infection

Despite the central role played by female intravenous drug users (IVDUs) in the worsening AIDS statistics of states in the northeastern United States, the relative paucity of research into the HIV risk behaviors--particularly risky needle practices--of female drug injections has left significant gaps in researchers' understanding of how and to what extent such women may differ in their risks from their better-studied male counterparts. This study, derived from a sample of 769 out-of-treatment IVDUs residing in an area (Paterson, New Jersey) characterized by high levels of AIDS and HIV infection among drug users, attempts to address this lacuna in the research literature by comparing the drug usage, AIDS knowledge, and needle and sexual behaviors of male and female IVDUs that place them at risk for HIV infection. In this sample, gender was found to be unrelated to HIV serostatus, injection frequency and injected drug of choice, and to most dimensions of knowledge about AIDS and the means of HIV transmission. Overall, it appears that the average Paterson female IVDU may be at greater risk for HIV infection as a result of involvement with a drug-using sex partner than because of especially risky needle practices, for females in this sample were significantly more likely than males to report injecting with a sex partner in the previous 6 months, and female IVDUs with one sex partner were more than twice as likely as males with one partner to report that this individual was an IVDU. Condom use was relatively rare, particularly among those with one partner. Moreover, female IVDUs were significantly more likely than males to be daily users of crack cocaine, and significantly more likely to report poorer health. However, current needle and sexual practices were found to be unrelated to HIV seropositivity among both males and females. In logistic regression analysis, only length of IV drug involvement was found to be independently associated with HIV seropositivity for both sexes. Implications of the data for future prevention efforts aimed at female IVDUs are discussed.

HIV infection among women entering the New York State correctional system

Human immunodeficiency virus infection is the leading medical problem among prison inmates in several states. In 1988 a blinded seroprevalence study was conducted on 480 New York female prison entrants to determine the prevalence of and risk factors for HIV infection in this population. Ninety (18.8 percent) women were HIV-seropositive. Seroprevalence was highest among women ages 30-39 (25.0 percent) and varied by ethnicity (Hispanics, 29.4 percent; Blacks, 14.4 percent; Whites, 7.1 percent) and residence (New York City, 23.8 percent; Upstate, 5.1 percent). Nearly half (44.9 percent) of the 136 acknowledged intravenous drug users and one-third (33.8 percent) of the 71 women with a positive syphilis serology were HIV-seropositive. There was no difference in fertility histories between seropositive and seronegative women, and two of 21 pregnant women were seropositive. This study led to increased clinical and prevention services for this high-risk population.