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Biomedical subjects

N Crofts

Publications and source records attributed to N Crofts.

At least 37 records · Page 2Linked to original sources
PubMed1999

The impact of diagnosis of hepatitis C virus on quality of life.

The aim of this study was to examine the effects of diagnosis of hepatitis C virus (HCV) infection on quality of life in a cohort admitted to Fairfield Infectious Diseases Hospital with acute hepatitis from 1971 to 1975. Sera stored from the original admission were tested for antibody to HCV. Systematic approaches were used to locate anti-HCV-positive individuals and outcomes assessed by the Short Form 36 (SF-36) scale and a study-specific questionnaire as well as clinical review. Study subjects' SF-36 scores were compared with Australian population norms. Anti-HCV and HCV-RNA positive individuals (n = 15) aware of their serostatus rated significantly worse on 7 of 8 SF-36 scales compared with population norms. However, HCV-seropositive and RNA-positive individuals unaware of their HCV serostatus (n = 19) scored significantly worse in only 3 scales. Those aware of their serostatus did not differ sociodemographically, clinically, virologically, or serologically from those who were unaware, nor was there a link between quality of life (QOL) scores and objective measures of ill health. All subjects had injected drugs in the past. In conclusion, HCV-RNA and anti-HCV-positive individuals in our study have significantly poorer subjective health status 26 years after original infection compared with population norms. QOL measures were significantly worse for HCV-seropositive individuals aware of their serostatus compared with those unaware. We feel that the reduced QOL in the diagnosed group may be partially an effect of labeling and that the impact of the diagnostic process per se on QOL in individuals with HCV requires further evaluation.

Adult↗
PubMed1999

Hepatitis infection among adolescents resident in Melbourne Juvenile Justice Centre: risk factors and challenges.

OBJECTIVE: To describe patterns of infection with, and risks for, hepatitis A, B and C viruses (HAV, HBV, and HCV) in male adolescents detained in the Melbourne Juvenile Justice Centre (MJJC). METHODS: A cross-sectional serosurvey for HAV, HBV, and HCV among 90 male adolescents aged 15-18 years who were resident in MJJC for more than 1 week in 1996. RESULTS: Nine percent had been exposed to HAV, 8% were positive or equivocal for exposure to HBV, and 21% were antibody positive for HCV. All those with hepatitis markers except one positive for HAV had been injection heroin users for more than 1 year. Of those who were not HBcAb positive, only 28% were immune to HBV. For most respondents, sexual and drug-using risks began in the early teens and were associated with leaving school prematurely. CONCLUSIONS: Respondents were vulnerable to exposure to blood-borne viruses from an early age, posing a challenge for health education programs. An opportunity exists for harm minimization and prevention of spread of blood-borne viruses within the first year of injection drug use in this population.

Adolescent↗
PubMed1999

A computer model of the spread of hepatitis C virus among injecting drug users.

A number of behavioural and clinical parameters influence the transmission of an infectious agent through direct contact between two individuals. The behavioural parameters encountered in such situations are also likely to exhibit an enormous amount of variability. With the spread of hepatitis C among injecting drug users, the parameters associated with injecting behaviour play an important role in the modelling of the transmission process. Computer simulation modelling is an ideal approach to deal with a large number of parameters as well as high levels of variability without excessive simplification. The simulation model presented in this paper is tested on data from a cohort of injecting drug users and the results obtained are very encouraging from a public health perspective. The model clearly indicates that the rate at which HCV spreads through a population of injecting drug users is extremely sensitive to the interaction rate and to the probability of infection through a single contact with an infective. At the same time it shows that rate of spread is not very sensitive to initial prevalence, which is very encouraging from a public health perspective.

Computer Simulation↗
PubMed1999

Assessment of long-term outcomes of hepatitis C virus infection in a cohort of patients with acute hepatitis in 1971-1975: results of a pilot study.

BACKGROUND: To examine the long-term effects of hepatitis C virus (HCV) infection in a cohort of patients admitted to Fairfield Hospital with hepatitis from 1971 to 1975. The availability of stored sera from this time enabled testing to identify those who were anti-HCV positive on admission. METHODS: Sixteen per cent (n = 230) of the cohort tested positive for HCV antibody (anti-HCV). The 'unexposed' group was selected from those who were anti-HCV negative. Systematic approaches were used to locate the cohort and health outcomes assessed by a study specific questionnaire and clinical review with repeat serology and liver function tests. RESULTS: Complete follow up has been achieved on a subset of 35 HCV-seropositive and 70 seronegative individuals. The seropositive group was significantly more likely to have given a history of injecting drug use, the presumed route of infection. The seropositive group was also more likely to have elevated serum alanine aminotransferase levels, but only two (6%) were known to have progressed to cirrhosis. DISCUSSION: The anti-HCV-positive individuals followed up to date are at increased risk of liver-related pathology, but few had progressed to cirrhotic liver disease. This differs from findings of transfusion-related studies and suggests, within the limitations of the study, that the natural history of community acquired HCV may be more benign.

Acute Disease↗
PubMed1999

Risk factors for hepatitis C transmission in the Victorian population: a telephone survey.

OBJECTIVE: To measure knowledge and prevalences of risk factors for hepatitis C infection in the Victorian community. METHOD: Telephone survey of 757 Victorian householders aged 15+ years, March 1996. RESULTS: An estimated 2.2% of Victorians have injected illicit drugs; 4.8% have tattoos and 49.6% have skin piercings; 11.4% received a blood transfusion before screening for HCV was introduced; 10.9% have had a test for HCV antibody. A majority of respondents perceived sexual contact and receipt of a transfusion to be risks for HCV transmission. CONCLUSIONS: Risk factors associated with the spread of HCV are widespread in the Victorian community; however, the most important risk factor--injecting drug use--has low prevalence. Considerable uncertainty exists about risk factors for hepatitis C. IMPLICATIONS: A very small percentage of Victorians are injecting drug users and therefore at highest risk of hepatitis C infection, therefore transmission control programs can be efficiently focused on this group. The Victorian community needs to be better educated about risk factors for hepatitis C, in particular that transfusions and blood donations are safe.

Adolescent↗
PubMed1999

Tuberculosis infection and homelessness in Melbourne, Australia, 1995-1996.

OBJECTIVE: To describe tuberculosis infection among persons experiencing homelessness in inner Melbourne, Australia. DESIGN: Homeless people were surveyed during late 1995 and early 1996. In stage one of the study 284 homeless people from crisis and long-term accommodation sites were recruited by means of stratified, systematic, random sampling. In stage two a convenience sample of 100 homeless people from squats and the streets were recruited. Participants completed a questionnaire and Mantoux testing was performed. RESULTS: A past history of tuberculosis was reported by 3%. Thirty-seven per cent had a Mantoux > or =10 mm; 21% > or =15 mm; and 11% > or =20 mm. A Mantoux > or =15 mm was independently associated with being aged > or =40 years, coming from the accommodated sample, overseas birth, and a past history of tuberculosis. Using logistic regression modelling, a Mantoux > or =15 mm was predicted by being aged > or =40 years, overseas birth, and past history of tuberculosis. CONCLUSION: Mantoux test results suggest that this group of homeless people had a high prevalence of infection with the tubercle bacillus. Many aspects of the physical and social circumstances of homeless people predispose to reactivation and have the potential to enhance rapid spread should latent infection become active disease.

Adolescent↗
PubMed1998

The prevalence of hepatitis C in patients admitted with acute hepatitis to Fairfield Infectious Diseases Hospital, 1971-1975.

OBJECTIVE: To identify and determine trends in the prevalence of hepatitis C virus (HCV) antibody in stored sera from 1971 to 1975 and to determine associations with HCV seropositivity, including markers for other hepatitis infections and possible routes of transmission. DESIGN: A retrospective cross-sectional study. PATIENTS AND SETTING: 1511 adults admitted to Fairfield Infectious Diseases Hospital, Victoria, with a clinical and biochemical diagnosis of hepatitis between 1 January 1971 and 31 December 1975. MAIN OUTCOME MEASURES: Prevalence over study period of hepatitis A virus antibody (anti-HAV) IgM, hepatitis B core antibody (anti-HBc), hepatitis B surface antigen (HBsAg) and hepatitis C virus antibody (anti-HCV) in stored sera; sociodemographic data and risk factors for blood-borne viruses documented in original medical records. RESULTS: Anti-HCV was detected in 17% of adults admitted with hepatitis from 1971 through 1975. Prevalence increased significantly over this period. Most cases were in young men who had a history of injecting drug use. HCV seropositivity was also significantly associated with markers for hepatitis B infection. CONCLUSIONS: Given the 20-30-year period between infection with hepatitis and the development of liver disease, our findings predict significant liver-related morbidity in Australia in the next decade. The increase in prevalence over the five years studied suggests rapid spread of HCV through susceptible populations, principally injecting drug users.

Acute Disease↗
PubMed1998

Juvenile offenders and hepatitis B: risk, vaccine uptake and vaccination status.

OBJECTIVE: To determine the hepatitis B vaccination status of juvenile offenders in a custodial setting, their perceived risk of hepatitis B infection, and factors influencing vaccine uptake. DESIGN: 130 males aged 14-17 years resident at the Melbourne Juvenile Justice Centre for at least one week between mid-January and mid-December 1996 were invited to participate; 90 (69%) completed a doctor-administered questionnaire, and blood for serological testing was obtained from 83 of these participants. MAIN OUTCOME MEASURES: Whether hepatitis B vaccine had been offered; whether hepatitis B vaccine had been given; the presence of antibodies to hepatitis B and C; risk factors and self-perceived risk of hepatitis B. RESULTS: About a quarter of participants (22/83) had protective levels of antibody to hepatitis B surface antigen (anti-HBs). Forty (44%) participants reported having been offered hepatitis B vaccine; they were more likely to be vaccinated and have protective levels of anti-HBs. Perceived risk for bloodborne virus infection was low, although two-thirds of participants were at high risk of hepatitis B infection. On serological testing, 6.4% (5/78) were positive for antibody to hepatitis B core antigen (anti-HBc), and a further 2.6% (2) had equivocal antibody levels. Of the 71 who were negative for anti-HBc, 51 (71.8%) were negative for anti-HBs. CONCLUSIONS: The targeted hepatitis B vaccination program has not adequately protected this group at high lifetime risk of hepatitis B. Failure to deliver vaccine may reflect lack of contact with healthcare services, oversight in offering vaccine and reluctance of youth to participate in preventive healthcare measures, often through not seeing themselves to be at risk. Universal approaches to vaccination may be more successful in vaccinating this group.

Adolescent↗
PubMed1998

Conceptual development of an information systems framework for improving continuity in epidemiological research.

Lack of continuity is a problem for survey-based epidemiological research. Poor access to experience and inadequate retention of information means new projects seldom build on successful predecessors to the maximum possible extent. We have designed a data management framework which addresses this problem using a well-known information systems approach. Our ideas provide a means of storing data in a manner which reflects the original research concepts. This makes collected data accessible and understandable without reference to the questionnaire, and allows new questionnaires to be designed quickly and easily. Our framework provides a means for recording developmental, conceptual and other supporting information and documentation which is traditionally poorly conserved. We illustrate the components of the framework using a major Australian epidemiological project as a case study. Once the necessary software is developed, our framework will improve organisational memory within individual research units and has the potential to become a valuable support tool for survey-based research.

Australia↗
PubMed1998

AIDS impact.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Health care costs of a continuing epidemic of hepatitis C virus infection among injecting drug users.

OBJECTIVES: To estimate the direct health care costs of a continuing epidemic of hepatitis C virus (HCV) infection among injecting drug users (IDUs) in Australia from the formal health care system's perspective. DESIGN: A Markov cohort model is used to map the disease paths of successive hypothetical cohorts of 1,000 patients as they develop the sequelae of HCV over an extended period of time. PATIENTS AND SETTING: IDUs becoming infected with HCV. OUTCOME MEASURES: Estimates of the number of persons in each of a limited number of disease states are used in conjunction with direct medical costs associated with ambulatory visits and inpatient hospital admissions over the course of the disease to estimate the long-term impact on the health care system of HCV infection among successive cohorts of IDUs. RESULTS: For every 1,000 IDUs newly infected with hepatitis C in a given year, there is an implied $14.32 million in health care spending over the years as sequelae become manifest, with cumulative total costs of some $0.5 billion (1994 dollars) after 60 years as the costs of successive cohorts of HCV-infected IDUs are added to the prevalence pool. If the estimated 10,000 new HCV infections in IDUs in Australia per year continue for the next 60 years, total direct health care costs will be around $4 billion over that period. CONCLUSIONS: Efforts to prevent HIV transmission among IDUs have been shown to be clearly cost-effective. These data imply that there is an even more pressing need to halt or slow the current epidemic of HCV infection among IDUs on fiscal grounds alone.

Ambulatory Care↗
PubMed1998

Health indicators and risks among people experiencing homelessness in Melbourne, 1995-1996.

During the study's first stage, 284 homeless people from crisis and long-term accommodation sites were surveyed using stratified, systematic sampling. The second stage involved a survey of a convenience sample of 100 homeless people from squats and the streets. Participants completed a questionnaire, Mantoux testing was performed and blood taken for gamma-interferon assay, liver and renal function tests. The group's health status was poor, with 72% experiencing medical conditions in the preceding two years and 77% symptoms in the month prior to interview. Bronchitis, asthma and gastroenteritis were the most commonly reported conditions; productive and persistent coughing, shortness of breath and wheezing the commonest symptoms. Twenty-one per cent had Mantoux reactions 15 mm or greater, 28% a raised GGT and 19% a raised ALT. Seventy-seven per cent smoked, 74% were current drinkers, 28% had injected drugs at some time in their lives and 14% were regularly injecting drugs. Forty-four per cent had experienced mental illness, 49% of whom reported depression and 15% schizophrenia. Homeless people in Melbourne have poor health status and engage in behaviours that place their health at risk. The high number of respiratory and gastro-intestinal complaints, the high level of cigarette smoking and injecting drug use (IDU) and the proportion likely to be infected with Mycobacterium tuberculosis (MTb) are all issues with important health consequences. Participants recruited from the street had significantly poorer health and engaged in more risk behaviours than those from accommodation sites; those from the accommodated sample were more likely to be infected with Mtb.

Adolescent↗
PubMed1998

Vietnamese-speaking injecting drug users in Melbourne: the need for harm reduction programs.

While research on aspects of injecting drug use (IDU), including injecting and sexual risks for HIV transmission, has been progressing in 'mainstream' Australian populations, there has been little among non-English speaking background (NESB) communities in Australia, particularly the South-East Asian communities, of which the Vietnamese is the largest. This exploratory study employed and trained peer workers to recruit and interview IDUs of Vietnamese origin in Melbourne on a wide range of subjects related to risks associated with their drug using, as an initial assessment of risk-taking behaviours for blood-borne viruses among Vietnamese-speaking IDUs. A finger-prick blood sample was taken where possible to measure antibody status to HIV, HBV and HCV. The profile which emerged was not dissimilar to that of their English-speaking counterparts prior to the benefit of currently available harm-reduction programs. A relatively isolated group whose social world often related only to other Vietnamese-speaking drug users, they were engaging in unsafe sex and unsafe injecting and were unfamiliar with procedures for cleaning injecting equipment and where they could seek out information and services, including needle exchanges. This study has identified an urgent need not only to promote currently available information and services to this group, but also to provide culturally relevant education and other harm-reduction measures needed to prevent transmission of HIV, other BBVs and STDs. The study has highlighted the lack of responsiveness of mainstream health services to the needs of Vietnamese-speaking IDUs.

Adolescent↗
PubMed1998

A methodology for sampling and accessing homeless individuals in Melbourne, 1995-96.

A methodology for sampling homeless populations in inner Melbourne was developed to study their health status and prevalence of tuberculosis. This paper describes the design, development and implementation of the project. The results of health status and tuberculosis analysis are published elsewhere. Involvement and interaction with local service providers and agencies to homeless people was central to the project throughout. A definitional construct of homelessness was developed, drawn from local and overseas literature and contemporary local experience. The study's aim was to obtain a representative sample of homeless individuals in various levels of accommodation and a convenience sample of those who were unaccommodated (streets and parks). A comprehensive sampling frame of accommodation options was constructed from available databases, and systematic sampling applied to produce a sample of 396 beds, from which 284 participants were enrolled. Convenience sampling of unaccommodated homeless individuals produced 100 participants. All agreed to undergo a comprehensive questionnaire, blood and Mantoux testing, the latter being completed successfully in 94%. Commonsense, cultural sensitivity and a non-threatening approach were critical to the success of the project and the security of the field workers. The methods described attempt to address recognised difficulties of sampling from homeless populations and should be reproducible both in the future and elsewhere. Potential for selection bias remains the main threat to validity, which the described methodology combined with adequate resources should help to address.

Health Surveys↗
PubMed1998

Serostatus for vaccine-preventable diseases in residents at Melbourne Juvenile Justice Centre.

There are concerns in Australia about inadequate rates of childhood immunisation, an important preventive measure to reduce infectious diseases. The population passing through the Melbourne Juvenile Justice Centre (MJJC) comes from a background at high risk for inadequate immunisation and outbreaks can occur in residential institutions. MJJC residents were invited to participate in a study by completing a medical officer-administered risk behaviour questionnaire and/or giving a blood sample. Ninety residents completed the questionnaire; 83 gave blood samples. Sera were tested for measles, mumps, rubella and hepatitis A, B and C markers using standard commercial assays. Diphtheria and tetanus were tested with an ELISA in a public health laboratory familiar in the technique. Sixty four per cent (53/83) of participants were non-immune to at least one component of MMR and 44.6% (37/83) non-immune to either tetanus or diphtheria. Despite 61.1% of participants reporting injecting drug use, only 28.2% had protective levels of anti-HBs, 6.1% were positive for anti-HBc (2.4% equivocal), 22.9% were anti-HCV positive and 9.6% had markers of exposure to hepatitis A virus. These results show suboptimal levels of immunity in this institutional setting with the potential for disease outbreaks. Many residents miss adolescent school-based programs for immunisation because of truancy and early school leaving. Despite considerable risk of blood-borne viruses, many MJJC residents are inadequately vaccinated against hepatitis B.

Adolescent↗