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Biomedical subjects

J McAnerney

Publications and source records attributed to J McAnerney.

7 recordsLinked to original sources
PubMed2002

Viral hepatitis in South African healthcare workers at increased risk of occupational exposure to blood-borne viruses.

The prevalence of hepatitis A, B and C antibodies was measured in a group of healthcare workers (HCWs) at increased risk of occupational acquisition of blood-borne viruses (N=402) from a large, urban referral hospital in South Africa. The aims of this study were to determine the immunity of HCWs to these agents and to recommend policy for the protection of HCWs against occupational exposure to viral hepatitis in this country. Race, sex and age were shown to be important factors influencing the presence of hepatitis A (HAV) antibodies. Most black HCWs (96.2%) are protected from HAV infection. Females have significantly higher HAV antibodies compared with males and antibodies increase with increasing age. Hepatitis B antibodies (anti-HBs) were found in 30.6% of HCWs. Anti-HBs levels were significantly associated with a past history of HBV vaccination. However, only a small proportion of HCWs (21.2%) could remember ever being immunized against HBV. For those individuals that did receive HBV vaccination (N=83), the mean number of years since their last vaccine was 6.2 years (SD +/- 3.5). HCV antibodies were found in 1.8% of HCWs at increased risk of occupational exposure. It was not possible to define whether these infections were occupationally acquired but genotyping of the HCV (in two of seven cases) showed genotype 5, the predominant South African genotype. New recommendations for the prevention of viral hepatitis in HCWs in South Africa are made, including pre-employment screening for HAV based on self-selection criteria, universal anti-HBs screening with HBV booster vaccination. HCV recommendations are based on appropriate education of HCWs about this infection and its prevention and a standardized post-exposure testing protocol.

Adult↗
PubMed1999

Preimmunization epidemiology of hepatitis B virus infection in South African children.

The prevalence of hepatitis B surface antigen (HBsAg) was determined in a community-based, cross-sectional, age-stratified sample of children from 0 to 6 years of age (n = 2,299) from the Eastern Cape Province of South Africa. The purpose of the study was to investigate the epidemiology and the age of acquisition of hepatitis B virus (HBV) infection in children, thus providing a preimmunization baseline measure of this infection in the population targeted for HBV immunization in South Africa. Overall, 10.4% (95% CI, 9.2-11.7) of the children tested were HBsAg-positive. There was a high rate of positivity in the 0-6- and 7-12-month age groups at 8.1% (95% CI, 5.5-11.7) and 8.9% (95% CI, 6.1-12.7), respectively, suggesting a higher rate of early acquisition of this infection than previously reported in South Africa. The proportion of HBsAg-positive children increased significantly with increasing age (chi2trend = 5.9, df = 1, P = 0.02), reaching 15.7% in the 61-72-month age group. This is the highest rate of HBV infection reported in community-based children from South Africa, indicating a significant burden of this infection. The difference in HBsAg prevalence between urban and rural children was not statistically significant (chi2 = 0.32, df = 1, P = 0.57). There was also no difference in positivity between males (10.5%; 95% CI, 8.7-12.5) and females (9.8%; 95% CI, 8.1-11.7), (chi2 = 0.006, df = 1, P = 0.94). This study provides the most recent preimmunization, community-based baseline investigation of the epidemiology of HBV infection in children targeted for universal immunization in South Africa.

Age Distribution↗
PubMed1999

The epidemiology of respiratory syncytial virus (RSV) infections in South African children.

OBJECTIVES: To review the incidence, outcomes and risk factors associated with respiratory syncytial virus (RSV) infection in South African children. DESIGN: Review of published literature and laboratory records. METHODS: Review of the published literature. Articles listed on MEDLINE with 'South African' or 'children' and 'respiratory syncytial virus' or 'acute respiratory tract infections' as text words were retrieved. We analysed the data on respiratory virus activity from January 1990 to June 1996. Data were obtained from the National Institute for Virology database, which includes information on viral respiratory infections from the seven academic virology departments in South Africa. RESULTS: Acute respiratory tract infections cause approximately 8% of all deaths in the under-5 age group in South Africa. The published hospital-based incidence of RSV infection varies from 3% to 18%. Mortality rates in these studies were between 12% and 43%. Risk factors identified for severe RSV infection requiring hospitalisation were malnutrition, prematurity, age < 6 months, vitamin A deficiency, environmental pollution and congenital heart disease. There is a seasonal peak in RSV cases, with the majority occurring in winter. CONCLUSIONS: Acute respiratory tract infections and RSV infections are an important cause of mortality and morbidity in young children in South Africa. However, currently available information from laboratory records and published South African literature is not sufficient to assess the impact of this infection. Age-specific incidence data in the 0-5-year age group are essential for the rational planning and implementation of future vaccine strategies, public health interventions and treatment of RSV infections.

Age Distribution↗
PubMed1998

Genetic stability of oral polio vaccine prepared on primary monkey kidney cells or Vero cells--effects of passage in cell culture and the human gastrointestinal tract.

The genetic stability of the three Sabin oral poliovaccine (OPV) strains produced on either primary monkey kidney (VK) or Vero cell substrates was compared in vivo and in vitro by measuring the rate at which the bases most strongly associated with attenuation and reversion to neurovirulence (positions 480, 481, and 472 in the 5' non-coding region of Sabin 1, 2 and 3 respectively, and 2034 in VP3 of Sabin 3) reverted during passage of the vaccine strains in the gastrointestinal tract of primary vaccinees and in cell culture. For the in vivo study, the poliovirus excretion patterns of 21 infants receiving OPV produced on either VK or Vero cells were followed for 21 days. No significant differences in either the frequency of excretion or the rate of reversion were observed between the two vaccine groups. The rate of accumulation of revertants during passage in vitro was compared for the three Sabin strains passaged 10 times in either VK or Vero cells. For types 1 and 3, revertants accumulated faster upon passage through VK cells compared with passage through Vero cells. Type 2 appeared to be stable as no revertants were detected in either cell type. Results of this study suggest that the use of Vero as opposed to VK cells as substrate for the manufacture of OPV does not negatively influence the genetic stability of the three Sabin OPV strains in vivo or in vitro.

Animals↗
PubMed1994

Benefits and limitations of the Witwatersrand influenza and acute respiratory infections surveillance programme.

OBJECTIVE: To establish an ongoing active surveillance programme for acute respiratory infections in general, and influenza in particular. DESIGN: A network of 16 sentinel primary health care providers furnished morbidity information and clinical specimens for virus characterisation supplemented by school absenteeism and regional mortality data. SETTING: General practices, hospital outpatient departments and staff clinics in the Witwatersrand area. PARTICIPANTS: Subjects treated for acute respiratory infections by 7 general practitioners, 1 specialist pulmonologist, 4 paediatric outpatient departments, 1 mine hospital and university, factory and institutional staff clinics. Absenteeism data were obtained from 8 primary and 6 high schools in the region (representing 9,000 pupils). OUTCOME MEASURES: Morbidity information and strain characterisation of influenza isolates as well as other viral respiratory pathogens, school absenteeism, seasonal excess mortality. RESULTS: The most sensitive indicator of influenza activity was virus isolation, which gives an earlier warning signal of an impending epidemic than morbidity or absenteeism parameters. Both morbidity and school absenteeism provided quantitative indicators of the severity of the epidemic. Mortality from all causes showed characteristic winter increases in the 65-year-old and older population which were not seen in younger individuals. Circulating influenza viral strains matched the strains recommended for the vaccine in 1991 and 1992, but not in 1993. CONCLUSIONS: The course and extent of the annual winter influenza epidemic can be charted by means of an active surveillance programme, with sentinel primary health care providers furnishing morbidity data and clinical material from which virus isolations can be made. Antigenic characterisation of the isolates demonstrated that circulating strains may not match recommended strains in northern hemisphere-formulated vaccines and stresses the need for a southern hemisphere vaccine formulation for South Africa. Absenteeism information provides an indicator of the impact of influenza on the economy and excess mortality data emphasise the need for routine immunisation of the elderly.

Absenteeism↗
PubMed1991

Exposure to hepatitis B virus among South African health care workers--implications for pre-immunisation screening.

Vaccination of health care workers is highly effective in preventing occupationally acquired hepatitis B virus (HBV) infection, but cost is a major factor impeding routine immunisation programmes. Pre-vaccination serological screening may be cost-beneficial if the prevalence of immunity is sufficiently high to offset its cost against the consequent reduction in vaccination needs. This critical population prevalence can be calculated given the cost of vaccination and testing. Samples of health care worker populations were examined for immunity and, using local present-day costs, it was calculated that pre-vaccination screening would be cost-beneficial in black nursing and laboratory personnel, but not their white counterparts or any student health care workers.

Cost-Benefit Analysis↗