Knut Fylkesnes

Declining HIV prevalence and risk behaviours in Zambia: evidence from surveillance and population-based surveys.

ObjectiveTo examine trends in HIV prevalence and behaviours in Zambia during the 1990s. MethodsThe core Zambian system for epidemiological surveillance and research has two major components: (i) HIV sentinel surveillance at selected antenatal clinics (ANC) in all provinces; and (ii) population-based HIV surveys in selected sentinel populations (1996 and 1999). The former was refined in 1994 to improve the monitoring of prevalence trends, whereas the latter was designed to validate ANC-based data, to study change in prevalence and behaviour concomitantly and to assess demographic impacts. ResultsThe ANC-based data showed a dominant trend of significant declines in HIV prevalence in the 15–19 years age-group, and for urban sites also in age-group 20–24 years and overall when rates were adjusted for over-representation of women with low education. In the general population prevalence declined significantly in urban women aged 15–29 years whereas it showed a tendency to decline among rural women aged 15–24 years. Prominent decline in prevalence was associated with higher education, stable or rising prevalence with low education. There was evidence in urban populations of increased condom use, decline in multiple sexual partners and, among younger women, delayed age at first birth. ConclusionsThe results suggested a dominant declining trend in HIV prevalence that corresponds to declines in incidence since the early 1990s attributable to behavioural changes. Efforts to sustain the ongoing process of change in the well-educated segments of the population should not be undervalued, but the modest change in behaviour identified among the most deprived groups represents the major preventive challenge.

A randomized trial on acceptability of voluntary HIV counselling and testing

Objectives  To examine factors affecting readiness for and acceptability of voluntary HIV counselling and testing (VCT).

Studying dynamics of the HIV epidemic: population-based data compared with sentinel surveillance in Zambia.

Objectives:To establish population-based HIV survey data in selected populations, and to assess the validity of extrapolation from HIV sentinel surveillance amongst antenatal clinic attenders (ANC) to the general population. Methods:In a population survey, adults aged ≥ 15 years were selected by stratified random cluster sampling (n = 4195). The survey was carried out in catchment populations of clinics used for national HIV surveillance. The methodology allows detailed comparisons of HIV infection patterns to be made in two areas (urban and rural). Whereas the sentinel surveillance used serum-based HIV testing, the population survey used saliva (93.5% consented to provide a saliva sample). Results:Surveillance of ANC tended to underestimate the overall HIV prevalence of the general population, but differences were not statistically significant. In the urban area, the adjusted overall HIV prevalence rate of ANC (aged 15–39 years) was 24.4% [95% confidence interval (CI), 20.9–28.0] compared with 26.0% (95% CI, 23.4–28.6) in the general population. The respective rural estimates were 12.5% (95% CI, 9.3–15.6) versus 16.4% (95% CI, 12.1–20.6). Age-specific prevalence rates showed ANC to overestimate infection in teenagers (aged 15–19 years), whereas in the reverse direction of those aged ≥ 30 years. Teenagers analysed by single year of age revealed both ANC and women in the general population with about the same steep increase in prevalence by age, but the former at consistently higher rates. Extrapolations might be biased substantially due to the higher pregnancy rates amongst uninfected individuals. Conclusions:ANC-based data might draw a rather distorted picture of current dynamics of the HIV epidemic. Even though representing an obvious oversimplification, extrapolations of overall prevalence rates may correlate with that of the general population.

THE TROMSO STUDY : PREDICTORS OF SELF-EVALUATED HEALTH : HAS SOCIETY ADOPTED THE EXPANDED HEALTH CONCEPT ?

The determinants of self-evaluated general health status were examined in a comprehensive population study of 9408 men aged 20-61 and 9152 women aged 20-56. Reduced self-evaluated health was in both sexes closely related to symptoms and diseases connected to the musculo-skeletal system and psycho-social problems and less to age and some of the major chronic diseases. Physical activity at leisure time and workload were positively associated with self-evaluated health. Our findings indicate that an important dimension reflected by self-evaluation of health is the individuals perception of own physical performance and suffice in general. There is a striking gap between the conditions which reduce the populations subjective perceived health and our ability to offer these conditions effective treatment through the health care system. This suggests differences in health concept between the medical society and the population. The association between our applied measure and coronary risk profile, based on serum cholesterol, blood pressure and cigarette smoking, was found to be almost non-existent. This supports previous findings of self-evaluation of health as an independent predictor of survival.

The HIV epidemic in Zambia : socio-demographic prevalence patterns and indications of trends among childbearing women

Objective:To examine socio-demographic HIV prevalence patterns and trends among childbearing women in Zambia. Design:Repeated cross-sectional surveys. Methods:Personal interviews and unlinked anonymous testing of blood samples of women attending antenatal care in selected areas. Results:The 1994 data includes information from 27 areas and a total of 11 517 women. The HIV prevalence among urban residents appeared with moderate variation at a very high level (range 25–32%, comparing provinces). The geographical variation was more prominent in rural populations (range 8–16%) and was approximately half the prevalence level of the urban populations. With the exception of the 15–19 years age-group, HIV infection was found to rise sharply with increasing educational attainment (odds ratio, 3.1; confidence interval, 2.6–3.8) when contrasting extreme educational levels. Although the assessment of trends is somewhat restricted, the available information indicates stable prevalence levels in most populations over the last 2–4 years. Conclusions:The data showed extremely high HIV prevalence levels among childbearing women. Longer time-intervals between surveys are needed, however, in order to verify the stability in prevalence identified by this study. The tendency to changing differentials by social status is suggested as a possible sign of an ongoing process of significant behavioural change.

Marked HIV prevalence declines in higher educated young people: evidence from population-based surveys (1995-2003) in Zambia.

Objectives:Higher educational attainment has been associated with a greater risk of HIV infection in sub-Saharan Africa. We investigated change over time in HIV prevalence by educational attainment in the general population. Methods:The data stem from serial population-based HIV surveys conducted in selected urban and rural communities in 1995 (n = 2989), 1999 (n = 3506) and 2003 (n = 4442). Analyses were stratified by residence, sex and age-group. Logistic regression was used to estimate age-adjusted odds ratio of HIV between low (≤ 4 school years) and higher education (≥ 8 years) for the rural population and between low (≤ 7 school years) and higher education (≥ 11 years) for the urban population. Results:There was a universal shift towards reduced risk of HIV infection in groups with higher than lower education in both sexes among urban young people [odds ratio (OR), 0.20; 95% confidence interval (CI), 0.05–0.73] in men and (OR, 0.33; 95% CI, 0.15–0.72) in women. A similar pattern was observed in rural young men (OR, 0.17; 95% CI, 0.05–0.59) but was less prominent and not statistically significant in rural women. In age 25–49 years, higher educated urban men had reduced risk in 2003 (OR, 0.43; 95%CI, 0.26–0.72) but this was less prominent in women. Conclusions:The findings suggested a shift in the association between educational attainment and HIV infection between 1995 and 2003. The most convincing sign was the risk reduction among more educated younger groups where most infections can be assumed to be recent. The changes in older groups are probably largely influenced by differential mortality rates. The stable risk among groups with lower education might also indicate limitations in past preventive efforts.

HIV counselling and testing: overemphasizing high acceptance rates a threat to confidentiality and the right not to know

OBJECTIVE To examine factors affecting the readiness for HIV-related voluntary confidential counselling and testing (VCT). METHODS In a population-based HIV survey in selected urban and rural areas in Zambia, adults aged > or = 15 years were selected by stratified random cluster sampling. The participants were asked to provide a saliva sample for anonymous HIV testing (n=4812, consent rate 93.5%) and, as a part of an interview, were asked about previous HIV testing experience and if they wished to be counselled and tested for HIV. Those indicating interest (initially willing) were provided with an invitation letter to see a counsellor. In rural areas, VCT was provided by personnel brought in from outside the local community, whereas in urban areas it was provided by locally recruited staff. RESULTS The overall HIV test rate was 6.5%, but rates appeared to be considerably biased towards higher educational groups. The proportion initially willing was 37% while 3.6% actually came for counselling and were tested (9.3% of those initially willing), of which 47% returned for the result. Actual use was four to five times higher in rural compared with urban areas. Self-perceived risk and high-risk behaviour were positively associated with initial willingness but not with actual use. CONCLUSIONS The readiness for VCT in the general population was found to be very low. Provision factors such as concerns about confidentiality and length of time waiting for the test result contributed to the low utilization rate. Results of this study contrast sharply with reported VCT acceptance rates of 70-90% among women attending antenatal care in Zambian and in other African populations, suggesting an urgent need to evaluate testing policy and practice of antenatal VCT in particular.

HIV-1, HSV-2 and syphilis among pregnant women in a rural area of Tanzania: prevalence and risk factors.

BackgroundEvidence suggests that a substantial proportion of new HIV infections in African countries are associated with herpes simplex virus type 2 (HSV-2). Thus, the magnitude of HSV-2 infection in an area may suggest the expected course of the HIV epidemic. We determined prevalence of genital herpes, syphilis and associated factors among pregnant women from a remote rural Tanzanian community that has a low but increasing HIV prevalence.MethodsWe analysed 1296 sera and responses to a standard structured questionnaire collected from pregnant women aged between 15–49 years, attending six different antenatal clinics within rural Manyara and Singida regions in Tanzania. Linked anonymous testing (with informed consent) of the serum for specific antibodies against HSV-2 was done using a non-commercial peptide- 55 ELISA. Antibodies against syphilis were screened by using rapid plasma reagin (RPR) and reactive samples confirmed by Treponema pallidum haemagglutination assay (TPHA).ResultsPrevious analysis of the collected sera had shown the prevalence of HIV antibodies to be 2%. In the present study the prevalence of genital herpes and syphilis was 20.7% (95% CI: 18.53–23.00) and 1.6% (95% CI: 1.03–2.51), respectively. The presence of HSV-2 antibodies was associated with polygamy (OR 2.2, 95% CI: 1.62 – 3.01) and the use of contraceptives other than condoms (OR 1.7, 95% CI: 1.21 – 2.41). Syphilis was associated with reporting more than one lifetime sexual partner (OR 5.4, 95% CI: 1.88 – 15.76) and previous spontaneous abortion (OR 4.3, 95% CI: 1.52–12.02).ConclusionThe low prevalence of HIV infection offers a unique opportunity for strengthening HIV prevention in a cost-effective manner. The identification and control of other prevalent curable STIs other than syphilis and specific intervention of HSV-2 in specific populations like pregnant women would be one among approaches towards preventing incident HIV infections.

Human immunodeficiency virus (HIV) infection patterns and risk behaviours in different population groups and provinces in Viet Nam

OBJECTIVE To study patterns and determinants of HIV prevalence and risk-behaviour characteristics in different population groups in four border provinces of Viet Nam. METHODS We surveyed four population groups during April-June 2002. We used stratified random-cluster sampling and collected data concomitantly on HIV status and risk behaviours. The groups included were female sex workers (n = 2023), injecting drug users (n = 1391), unmarried males aged 15-24 years (n = 1885) and different categories of mobile groups (n = 1923). FINDINGS We found marked geographical contrasts in HIV prevalence, particularly among female sex workers (range 0-24%). The HIV prevalence among injecting drug users varied at high levels in all provinces (range 4-36%), whereas lower prevalences were found among both unmarried young men (range 0-1.3%) and mobile groups (range 0-2.5%). All groups reported sex with female sex workers. Less than 40% of the female sex workers had used condoms consistently. The strongest determinants of HIV infection among female sex workers were inconsistent condom use (adjusted odds ratio [OR], 5.3; 95% confidence interval [CI], 2.4-11.8), history of injecting drug use and mobility, and, among injecting drug users, sharing of injection equipment (adjusted OR, 7.3; 95% CI, 2.3-24.0) and sex with non-regular partners (adjusted OR 3.4; 95% CI 1.4-8.5). CONCLUSION The finding of marked geographical variation in HIV prevalence underscores the value of understanding local contexts in the prevention of HIV infection. Although lacking support from data from all provinces, there would appear to be a potential for sex work to drive a self-sustaining heterosexual epidemic. That the close links to serious injecting drug use epidemics can have an accelerating effect in increasing the spread of HIV merits further study.

Associations between sexual behaviour change in young people and decline in HIV prevalence in Zambia.

BackgroundEvidence suggests that HIV prevalence amongst young Zambians has declined recently, especially in higher-education groups. We studied trends in key sexual behaviour indicators among 15–24 year-olds from 1995 to 2003, including the associations between sexual behaviour change and education.MethodsThe data stem from a series of three population-based surveys conducted in 1995 (n = 1720), 1999 (n = 1946) and 2003 (n = 2637). Logistic regression and Extended Mantel Haenszel Chi Square for linear trends were used to compare the three surveys.ResultsMen and lower-education groups reported more than one sexual partner in the year immediately prior to the survey more frequently than did women and higher-education groups (p < 0.01), but these proportions declined regardless of sex and residence. Substantial delays in child-bearing were observed, particularly among higher-education and urban respondents. Condom use at least for casual sexual intercourse increased from 1995 to 2003; the level was highest among urban and higher-education groups. The number of women reporting frequent dry sex using traditional agents fell during the period. Participants from the rural area and those with less education reported more sexual experience than urban and higher-education participants in 2003. The reported number of sexual partners during the year immediately prior to the survey was a factor that reduced the association between HIV and survey times among sexually active young urban men and women.ConclusionHigh risk behaviours clearly decreased, especially in higher-educated and urban groups, and there is a probable association here with the decline in HIV prevalence in the study population. Fewer sexual partners and condom use were among the core factors involved for both sexes; and for women a further factor was delayed child-bearing.