Determinants of false positive recall in an Australian mammographic screening program.

We conducted a case-control study (n=30128) to assess the importance of clinical (e.g., family history, age, hormone replacement therapy (HRT) use and duration) and service-related characteristics (e.g., time since introduction of Kodak MINR2000 film, year of screen) for false positive (FP) recall at BreastScreen Victoria, Australia. There was an age-adjusted upward trend in FP recall rates with year of screen at first (odds ratio (OR) 1.11, 95% confidence interval (95% CI) 1.08-1.13) and subsequent rounds (OR 1.04, 95% CI 1.01-1.06). In the multivariate analysis, the upward trend only remained for first round and age and family history also remained statistically significant at first round. At subsequent rounds the time since introduction of MINR2000, age, strong family history of breast cancer, use of HRT, recall at previous screen and previous screen at more than 27 months were all important predictors of FP recall. The rise in FP rates with year of screen at first round screening is of concern and may require further training of radiologists to improve confidence when viewing films when there a no films for comparison.

Use of hormone replacement therapy (HRT) and survival following breast cancer diagnosis.

Although hormone replacement therapy (HRT) use has been associated with breast cancers that have better prognostic features, it is not clear whether this leads to improved survival. We studied a cohort of 4022 postmenopausal women diagnosed with breast cancer between 1993 and 2000, who attended a mammographic screening program, among whom 312 deaths subsequently occurred. Proportional hazards models were used to examine survival from breast cancer and all-causes among HRT users and non-users. The multivariate hazard ratio for HRT use was 0.64 (95% CI: 0.41-1.00) for breast cancer deaths and 0.69 (95% CI: 0.49-0.96) for all-cause mortality. This was attenuated by grade (HR 0.71; 95% CI: 0.45-1.10). HRT use at diagnosis was associated with modestly improved survival from breast cancer that appeared in part to be explained by the influence of HRT on tumour grade, although we cannot exclude the possibility of confounding by factors associated with the choice to use HRT.

A comparison of estradiol levels between women with a hysterectomy and ovarian conservation and women with an intact uterus.

OBJECTIVES: To compare the distribution of estradiol levels between women with a hysterectomy and ovarian conservation and women with an intact uterus. METHODS: A large cross-sectional study of women aged between 40 and 69 years, residing in Melbourne, Australia. Estradiol levels were available for 152 women with a hysterectomy and ovarian conservation and 1423 women with an intact uterus. All of the women were 'never-users' of hormone replacement therapy. RESULTS: For women under 55 years of age, we observed that those with a hysterectomy and ovarian conservation had slightly higher estradiol levels compared with those with an intact uterus after adjustment for age, body mass index, smoking status and alcohol intake (ratio of geometric means of estradiol levels = 1.24; 95% confidence interval = 1.00-1.53). For women who were 55 years or greater, the distribution of estradiol levels varied little by hysterectomy status. CONCLUSIONS: Our data do not suggest that women with hysterectomy and ovarian conservation have markedly different estradiol levels compared to women with an intact uterus.

Cytomegalovirus, Epstein-Barr virus and risk of breast cancer before age 40 years: a case-control study.

We investigated whether there is an association between cytomegalovirus (CMV) and Epstein-Barr virus (EBV) IgG levels and risk of breast cancer before age 40 years. CMV and EBV IgG levels were measured in stored plasma from 208 women with breast cancer and 169 controls who participated in the Australian Breast Cancer Family Study (ABCFS), a population-based case-control study. CMV and EBV IgG values were measured in units of optical density (OD). Cases and controls did not differ in seropositivity for CMV (59 and 57% respectively; P=0.8) or EBV (97 and 96% respectively; P=0.7). In seropositive women, mean IgG values were higher in cases than controls for CMV (1.20 vs 0.98 OD, P=0.005) but not for EBV (2.65 vs 2.57 OD, P=0.5). The adjusted odds ratios per OD unit were 1.46 (95% CI 1.06-2.03) for CMV IgG and 1.11 (0.93-1.33) for EBV IgG. The higher mean CMV IgG levels found in women with breast cancer could be the result of a more recent infection with CMV, and may mean that late exposure to CMV is a risk factor for breast cancer.

Novel germline mutations in the PTEN tumour suppressor gene found in women with multiple cancers.

Germline mutations in PTEN can predispose people to Cowden syndrome (CS) and Bannayan-Ruvalcaba-Riley (BRR) syndrome, rare, autosomal dominantly inherited neoplastic disorders. To determine whether germline mutations in PTEN contribute to genetic predisposition to multiple primary tumours within the general population, we conducted a nested case-control study, among 32 826 members of the prospective Nurses' Health Study cohort; cases were women with more than one primary tumour at different anatomical sites. We screened all nine exons of PTEN and flanking intronic splice sites for all 103 eligible cases using SSCP and sequencing. We observed two novel germline heterozygous missense mutations in exon 5 in five of the cases; three were V119L and two were V158L. Neither mutation was observed in 115 controls free of diagnosed cancer (p = 0.02). Both mutants showed partial tumour suppressor activity when compared to wild type PTEN when transfected into a PTEN null breast cancer cell line. The phenotype was cell line specific suggesting that genetic background affects growth suppression activity of the mutants. These data provide evidence that germline mutations in PTEN may be a more frequent predisposing factor for cancers in women than previously suggested.

Prospective study of talc use and ovarian cancer.

BACKGROUND: Perineal talc use has been associated with an increased risk of ovarian cancer in a number of case-control studies; however, this association remains controversial because of limited supporting biologic evidence and the potential for recall bias or selection bias in case-control studies. In this study, we conducted a prospective analysis of perineal talc use and the risk of ovarian cancer. METHODS: The Nurses' Health Study is a prospective study of 121 700 female registered nurses in the United States who were aged 30-55 years at enrollment in 1976. Talc use was ascertained in 1982 by use of a self-administered questionnaire: after exclusions, 78 630 women formed the cohort for analysis. Three hundred seven epithelial ovarian cancers subsequently diagnosed in this cohort through June 1, 1996, were confirmed by medical record review and met inclusion criteria. Proportional hazards models by use of pooled logistic regression were used to derive relative risks (RRs) and 95% confidence intervals (CIs). RESULTS: In 1982, 40.4% (n = 31 789) of the cohort reported ever using talc, and 14.5% (n = 11 411) reported ever using talc daily. We observed no overall association with ever talc use and epithelial ovarian cancer (multivariate RR = 1.09; 95% CI = 0.86-1.37) and no increase in risk of ovarian cancer with increasing frequency of use. There was a modest elevation in risk for ever talc use and invasive serous ovarian cancer (multivariate RR = 1.40; 95% CI = 1.02-1.91). The risk of epithelial ovarian cancer for talc users was not greater among women who had never had a tubal ligation (multivariate RR = 0.97; 95% CI = 0.71-1.32). CONCLUSION: Our results provide little support for any substantial association between perineal talc use and ovarian cancer risk overall; however, perineal talc use may modestly increase the risk of invasive serous ovarian cancer.

Association of age and reproductive factors with benign breast tissue composition.

Reproductive breast cancer risk factors are hypothesized to act by increasing exposure of the breast to endogenous estrogens, but few studies have quantitatively examined the association of these risk factors with breast tissue composition. This study is part of a case-control study of breast histological characteristics and breast cancer risk, nested within the Nurses' Health Study, a prospective study of 121,700 registered nurses. We studied 300 women who had not been diagnosed with breast cancer, but for whom we obtained slides from a prior benign breast biopsy. We used a computer-assisted image analysis technique to assess the proportion of epithelial and fibrous stromal tissue on benign breast biopsy slides, excluding obvious mass lesions. Mean epithelial proportion was 5.3% (0.1-23%), and mean stromal proportion was 58.7% (3-93%). Women with proliferative breast disease without atypia had higher epithelial and stromal proportions than women with nonproliferative breast disease (P < 0.001). Postmenopausal women had a lower epithelial proportion (P = 0.01), and increasing age at biopsy was associated with decreasing stromal proportion among postmenopausal parous women (P = 0.004). Among premenopausal women, increasing years since last birth was associated with lower epithelial proportion (P < 0.001). Other reproductive risk factors were not independently associated with epithelial or stromal proportion. Epithelial and stromal breast tissue were associated with different factors with the exception of proliferative breast disease, which was associated with an increase in both epithelial and stromal proportion. The quantitative measurement of epithelial and stromal proportion may be useful for measuring changes in breast composition.

N-acetyl transferase 2 genotypes, meat intake and breast cancer risk.

Heterocyclic amines (HAs) are carcinogens produced by high-temperature cooking of meat and animal protein; metabolism of HA is influenced by polymorphisms in the N-acetyltransferase-2 (NAT-2) gene. Data from a variety of sources suggest that HA may play a role in human carcinogenesis. We examined the associations between meat intake and cooking method, acetylator genotype and breast cancer risk in a sub-cohort of 32,826 women in the Nurses' Health Study who gave a blood sample in 1989-1990. Women who were diagnosed with breast cancer (n = 466) after blood draw and prior to June 1, 1994, were matched to 466 controls. Overall, rapid acetylators were not at increased risk of breast cancer compared with slow acetylators (multivariate OR = 1.1, 95% CI 0.8-1.5), and there were no associations between meat intake or cooking method of meat and breast cancer risk. Rapid acetylators with the highest red meat intake (one or more servings per day) were not at increased risk of breast cancer compared with slow acetylators with the lowest red meat intake (OR = 1.1, 95% CI 0.7-1.8). Frequent intake of charred meat among rapid acetylators (one or more times per week) was not associated with increased risk (OR = 1.2, 95% CI 0.6-2.3) compared with slow acetylators who ate charred meat less than once per month. We observed no significant associations for rapid acetylators who frequently consumed beef, pork or lamb cooked with high-temperature cooking methods, such as barbecuing (OR = 0.9, 95% CI 0.4-1.9) or roasting (OR = 0.9, 95% CI 0.5-1.6). Our data suggest that HAs may not be a major cause of breast cancer, although we cannot exclude misclassification of HA intake as the reason for the lack of association. We observed no evidence of differential susceptibility to these exposures by NAT2 genotype.

Genes and environment in the etiology of colorectal cancer.

Environmental factors, including diet, are important in the etiology of colorectal cancer. Genetic pathways of hereditary and sporadic bowel cancer are being elucidated. Highly penetrant mutations in certain genes, such as mismatch repair genes, play a major role in development of hereditary colorectal cancer, while interactions between low penetrance polymorphisms in carcinogen-metabolizing enzymes and environmental factors may identify susceptible subgroups and shed light on the etiology of sporadic colorectal cancers. In this review we summarize the current state of knowledge regarding the role of gene-environment interactions in development of colorectal cancer and discuss areas of particular promise, as well the limitations of these studies.

Glutathione S-transferase GSTM1 and GSTT1 polymorphisms and colorectal cancer risk: a prospective study.

Glutathione S-transferase (GST) M1 and T1 genes encode GST enzymes, and are polymorphic in humans. These enzymes catalyze conjugation with glutathione, which is an important step in the detoxification of certain carcinogens. Several case-control studies have found associations of the homozygous null deletions in GSTM1 and GSTT1 with increasing the risk of colorectal and lung cancer. We prospectively examined the associations of the GSTM1 and GSTT1 polymorphisms with colorectal cancer risk in a nested case-control study (212 cases of colorectal cancer and 221 controls) within the Physicians' Health Study. Among controls, the prevalence of the GSTM1 homozygous null genotype was 53% and for GSTT1 homozygous null genotype, 23%. We found no increase in the risk of colorectal cancer for either GSTM1 null [odds ratio (OR) = 1.0; 95% confidence interval (CI), 0.7-1.5] or GSTT1 null (OR = 0.8; 95% CI, 0.5-1.2) genotypes. No differences were seen by site of colon cancer (proximal versus distal) or by age (< or = 60 years versus > 60 years). Current cigarette smokers with GSTM1 null genotype were not at an increased risk of colon cancer (OR = 1.2; 95% CI, 0.3-4.2) compared with current smokers without the null genotype; for the GSTT1 null genotype this OR was 1.1 = 95% CI (0.3-4.7). This lack of association persisted when we examined pack-years of smoking and age at starting smoking. Our results do not support an association of GSTM1 or GSTT1 polymorphisms with colorectal cancer or an interaction with cigarette smoking.

A prospective study of NAT2 acetylation genotype, cigarette smoking, and risk of breast cancer.

Polymorphisms in the N-acetyltransferase 2 (NAT2) gene are determinants of the rate of metabolic activation of carcinogenic compounds such as aryl aromatic amines. Homozygosity for any combination of three variant alleles in Caucasians defines 'slow' acetylators; presence of one or two wild-type alleles characterizes 'rapid' acetylators. Although most previous studies have not observed an overall elevation in risk of breast cancer among slow acetylators, a recent study observed that cigarette smoking was associated with a large increase in risk of breast cancer among slow acetylators. We assessed the relation between NAT2 acetylation status and breast cancer risk, and its interaction with smoking, in a prospective study of mainly Caucasian US women. Four hundred and sixty-six incident cases who were diagnosed with breast cancer after giving a blood specimen in 1989-90 were matched to 466 controls in a nested case-control study. NAT2 genotype was determined using PCR-RFLP assays. The multivariate relative risk (RR) comparing slow with rapid acetylators was 0.9 (95% CI 0.7-1.2). Among slow acetylators, current smoking immediately prior to diagnosis was not associated with a significant elevation in risk compared with never smoking rapid acetylators (RR = 1.4, 95% CI 0.7-2.6). No significant association was seen between pack-years of smoking and risk of breast cancer among either slow or fast acetylators. A non-significant elevation in risk was observed among women who smoked for > or = 5 years prior to first pregnancy and were rapid acetylators, compared with never smoking rapid acetylators (RR = 1.5, 95% CI 0.9-2.6). In analyses limited to 706 post-menopausal women, the elevated risks for current smokers immediately prior to diagnosis who were slow acetylators compared with never smokers who were fast acetylators were slightly stronger but still not statistically significant. In summary, we observed little evidence of an association between NAT2 genotype and breast cancer. In this prospective study, cigarette smoking was not appreciably associated with breast cancer among either slow or fast NAT2 acetylators.

Risk factors for sexually transmitted diseases among women attending family planning clinics in Dar-es-Salaam, Tanzania.

BACKGROUND: Identification of risk factors for sexually transmitted diseases (STDs) assists in development of treatment algorithms, which are potentially important components of STD control when microbiologic facilities are limited. METHODS: A cross-sectional study was performed to assess STD and HIV risk factors of 2285 women attending three family planning clinics in Dar-es-Salaam, Tanzania during 1991-92. Women were interviewed and examined for signs of STDs. Specimens were taken for laboratory diagnosis of HIV, other sexually transmitted organisms, and Candida albicans. RESULTS: The prevalence of gonorrhoea was found to be 4.2%, prevalence of trichomoniasis was 14.3%, and positive syphilis serology was found in 2.5% of women. Unmarried women were at increased risk of trichomoniasis (age-adjusted OR = 1.48 95% CI [1.12, 1.95]), gonorrhoea (age-adjusted OR = 1.81 95% CI [1.14, 2.86]) and syphilis (age-adjusted OR 1.5 [0.84, 2.68]). An increasing number of sexual partners in the past five years was associated with an increased risk of all STDs. Current use of the oral contraceptive pill was positively associated with gonorrhoea, multivariate OR = 1.75 95% CI [1.05, 2.93]. The prevalence of candidiasis was 11.5% and was not associated with any of the demographic or behavioural risk factors examined. Clinical diagnostic algorithms for STDs in this study population had relatively low sensitivity and low positive predictive value. CONCLUSION: Being unmarried and having a higher number of sexual partners were consistently associated with each STD, while the associations for other risk factors varied between STDs, emphasising the complexity of STD distribution. Further development of diagnostic algorithms and other methods for screening women for STDs are needed to reduce the impact of STDs and HIV in developing countries.

Lombok Hepatitis B Model Immunization Project: toward universal infant hepatitis B immunization in Indonesia.

The Lombok Hepatitis B (HB) Model Immunization Project was the first mass infant HB immunization project in Indonesia. Key aspects were the procurement of low-cost HB vaccine, integration into routine infant immunization services, and delivery of the first dose in the home within 1 week of birth. The project achieved > 90% coverage with 3 doses of vaccine. The prevalence of HB surface antigen was 1.4% in infants who received 3 doses (with the first dose within 7 days of birth) and 3.0% in those who received the first dose > 7 days after birth, compared with a baseline prevalence of 6.2% (P < .001 in each case). Most vaccine failures occurred in children born to HBe antigen-positive mothers. Antibody prevalence and titers did not correlate with protection. HB vaccine can be successfully integrated into the Expanded Programme on Immunization (EPI), strengthening the EPI and significantly reducing chronic HB infection.

A national surveillance system for newly acquired HIV infection in Australia. National HIV Surveillance Committee.

OBJECTIVES: The purpose of this study was to describe the establishment of a national surveillance system for newly acquired human immunodeficiency virus (HIV) infection and present the first 3 years' results. METHODS: All new cases of diagnosed HIV infection were reported to the national HIV surveillance center through state and territory health authorities. Information sought on each case included evidence of whether the infection had been newly acquired, defined by the diagnosis of HIV seroconversion illness or by the report of a negative or indeterminate HIV antibody test result occurring within the 12 months prior to diagnosis of infection. RESULTS: Of 3602 reported cases of HIV infection in adults and adolescents newly diagnosed in Australia between 1991 and 1993, 11.4% were identified as newly acquired. The majority (85%) of cases of newly diagnosed HIV infection occurred among men who reported homosexual contact, and 15% of these cases were identified as newly acquired. Average age at diagnosis was 31 years for cases of newly acquired infection and 34 years for other cases. CONCLUSIONS: Surveillance for newly acquired HIV infection has been established at a national level in Australia and provides valuable information for planning primary HIV prevention programs.

Surveillance for sexually transmissible diseases in Victoria, 1983 to 1992.

Surveillance systems have been developed in Victoria to determine trends in sexually transmissible diseases (STDs). Notifications to the Health Department (including laboratory notification since May 1990) have been supplemented by data about strains of Neisseria gonorrhoeae and cultures for Chlamydia trachomatis processed by the Microbiological Diagnostic Unit, enhanced laboratory surveillance of syphilis, and data on genital herpes and genital warts from the Melbourne Sexual Health Centre. During the period under review the incidence of gonorrhoea declined, rapidly at first, and then more slowly. For women, this trend has continued, while gonorrhoea acquired abroad by men has become relatively more important. Since 1988, gonorrhoea in homosexual men has increased, and rectal isolates have increased concurrently, raising concerns about HIV risk behaviour. Cases of syphilis are likely to be ascertained through STD, antenatal and refugee screening, rather than because of symptoms or contact tracing. Chlamydia is a the most common notifiable STD, despite underreporting and underdiagnosis. In 1991, 832 cases were notified, increasing to 1377 in 1992. In 1992, of the 73 cases (65 per cent of notifications) where the doctor identified a risk, 15 per cent was attributed to homosexual contact, and 27.4 per cent to heterosexual exposure. Limitations in the data include inadequate standard case definitions for many STDs, changes in the statutory requirement for notifications in 1990, underreporting, changes in diagnostic and screening patterns, and lack of detailed demographic data. Education of general practitioners is needed to improve diagnosis and notification of chlamydia.

Assessment of self-report in HIV surveillance: a pilot study.

The basis of HIV exposure category classification was investigated among selected cases of newly diagnosed HIV infection. Questionnaires seeking specific information on patient-reported exposure to HIV were forwarded to doctors who had requested the HIV antibody test for patients who met the study sample criteria. The cases of interest were those newly diagnosed between 1 January and 31 October 1991 and notified to state and territory health authorities as having been attributed to exposures to HIV other than male homosexual contact or receipt of blood, blood products or tissue. A total of 158 questionnaires was forwarded and 59 per cent were returned. Among the returned questionnaires included in the study sample, exposure to HIV on the original notification to the health authority was given as injecting drug use (8 per cent, 3 of 37), heterosexual contact (46 per cent, 17 of 37), or unavailable (46 per cent, 17 of 37). A clear basis for HIV exposure category classification was provided on the questionnaires for 70 per cent (7 of 10) of cases among women, whereas among men whose infection was attributed to heterosexual contact, a basis for exposure category classification was specified for only 43 per cent (10 of 23) of cases. Although the study was limited by the low response rate, use of the questionnaire provided a relatively simple means for assessing self-reported HIV exposure history.

The pattern of diagnosed HIV infection in Australia, 1984-1992.

OBJECTIVE: To describe the pattern of newly diagnosed HIV infection in Australia, between 1984 and 1992. METHODS: State and Territory health authorities reported cases of newly diagnosed HIV infection to the national HIV surveillance centre. Information sought on each case included the State or Territory of diagnosis, the case identifying number, the sex, date of birth and postcode of residence of the person with newly diagnosed HIV infection, the source of exposure to HIV and the date of specimen collection for the diagnosis of infection. RESULTS: By the end of December 1992, a total of 16,765 cases of newly diagnosed HIV infection had been reported in Australia. The annual number of cases declined between 1985 and 1992. Most diagnoses were among males, and exposure to HIV was attributed to male homosexual contact for more than 80% of cases for which information on exposure to HIV was available. Cases of HIV infection attributed to heterosexual contact represented an increasing proportion of the annual number of diagnoses over the period 1985-1992, among both men and women. CONCLUSION: National surveillance for newly diagnosed HIV infection has complemented national surveillance for diagnoses of AIDS as a key mechanism for monitoring the course of the HIV epidemic in Australia. The pattern of newly diagnosed HIV infection was similar to the pattern of AIDS diagnoses, with the overwhelming majority of diagnoses of infection being in adult males whose exposure to HIV was attributed to homosexual contact. Limitations of HIV surveillance include the lack of information on HIV testing patterns, incomplete information on HIV exposure histories and duplication of reported diagnoses.

Genital chlamydial infection: diagnostic practices of general practitioners in Melbourne, Australia.

BACKGROUND AND OBJECTIVES: There is marked underdiagnosis of genital chlamydial infection in Victoria, Australia, and little is known about the diagnostic or treatment practices of general practitioners (GPs) for this condition. Such information is required to develop more effective epidemiologic surveillance and control of this disease in Australia. GOAL OF THIS STUDY: To measure indicators of knowledge and practices of GPs in Melbourne in relation to their diagnosis and management of genital chlamydial infection. STUDY DESIGN: A self-administered questionnaire delivered by mail to a random sample of 327 Melbourne GPs. RESULTS: The response rate was 83%. Female doctors were significantly more likely to test symptomatic patients and to screen asymptomatic patients than were male doctors. Having a large proportion of patients in the high-risk age groups was not a reliable predictor of diagnostic practices. Only 49% of respondents knew how to correctly take specimens for diagnosis of chlamydial infection, and only 41% knew the disease is notifiable. CONCLUSION: Underdiagnosis of chlamydia is due partially to general practitioners having a low level of suspicion of the disease in their patients and to inappropriate specimen collection technique. The present system of chlamydia surveillance is inadequately measuring disease trends, and the information from this survey should be useful in the development of medical training programs.

HIV and AIDS in Asia and the Pacific: an epidemiological overview.

PIP: The authors define for the purpose of this overview Asia and the Pacific to be the 46 countries and other administrative areas belonging to the Southeast Asia and Western Pacific regions of the World Health Organization. Defined as such, 55% of the world's population lives in the Asia-Pacific region. China, India, and Indonesia, three of the four most populous countries in the world, are part of the region. The region is highly diverse with highly diverse systems in place to monitor the course of the HIV epidemic. This diversity makes it difficult to develop an accurate picture of the epidemiology of HIV and AIDS in Asia and the Pacific. Despite underreporting and data of varying quality, one may reasonably conclude on the basis of available evidence that countries overall in Asia and the Pacific are in a relatively early stage of the HIV/AIDS epidemic. Reported modes of transmission vary widely and include heterosexual sexual contact, homosexual sexual contact, IV drug use, the receipt of blood products, and mother-to-child transmission. A cumulative total of 851,628 AIDS cases had been reported to the World Health Organization (WHO) by December 31, 1993. Reports from the Asia-Pacific region represent 1% of that total. The WHO estimates that there have been more than 3 million AIDS cases and 14 million infections in adults worldwide since the beginning of the epidemic, while other estimates are substantially higher. The Asia-Pacific region accounts for 3% of the estimated AIDS cases, but 15% of the total estimated HIV infections, indicating the relatively recent arrival of the epidemic to that part of the world. The authors discuss HIV case reporting, surveys of HIV prevalence, risk factors for HIV infection, geographic patterns of HIV transmission, molecular and clinical epidemiology, and the future of the HIV epidemic in Asia and the Pacific.^ieng

Genital Chlamydia trachomatis infection in Australia.

OBJECTIVE: To review available data on genital chlamydial infections in Australia, to determine trends and to make recommendations for improving future data collection. DATA SOURCES: Data are presented from representative laboratories around Australia for the 11-year period 1980-1990. Studies of the prevalence of chlamydial infection in Australia and overseas for the same period were selected for review where relevant epidemiological information (such as patient population, reason for test, demographic data) was available. RESULTS: Overall rates of chlamydial infection from the surveyed laboratories ranged from 3.2%-14.6% for the period 1980-1982 and 2.7%-5.5% for 1990. Rates of diagnosis of Chlamydia appeared to decline in some centres while remaining relatively stable at others. Between 2800 and 4000 cases per year have been reported to the CDI (Communicable Diseases Intelligence) scheme since 1985. Substantial increases in the number of tests performed were seen in nearly all laboratories, reflecting a shift towards screening asymptomatic lower-risk women, however detailed data on the populations tested were unavailable. Studies of prevalence of genital chlamydial infection in Australia revealed highest infection rates among sexually transmitted disease clinic clients (2.5%-14%) and a prevalence of more than 5% in women attending family planning clinics. Studies from overseas showed wide variations in prevalence of infection, from 6% to 28% depending on the populations studied. CONCLUSION: Improved data collection is imperative for assessing the impact of intervention programs for chlamydial infection, which has potentially serious but largely preventable sequelae in women. Although diagnosis of genital chlamydial infection appears to be declining or at least stable in Australia, possibly due to intervention programs, it remains a relatively common sexually transmitted infection. Comparison of rates and interpretation of the figures is made difficult by changes in screening practices, lack of standard case definitions, denominator information and probable under-reporting. Recommendations proposed for improving data collection for Chlamydia include establishing sentinel sites, standardising the collection of data, and ensuring standard case definitions between sites.