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Biomedical subjects

P J Christopher

Publications and source records attributed to P J Christopher.

At least 19 recordsLinked to original sources

The acquired immunodeficiency syndrome: a tuberculosis threat?

In the United States there has been an increase in mycobacterial infections that is attributable to the acquired immunodeficiency syndrome (AIDS). Since 1983, when the first case of AIDS was reported in Australia, there have been 523 patients (to June 30, 1987) notified with group-IV AIDS and, of these, 361 (69%) cases have been in New South Wales. Of these 361 notifications, 59 (16%) patients have had concurrent mycobacterial infection. Seven of these patients had Mycobacterium tuberculosis infection and five of these infections occurred in 1986. This means that, in 1986, patients with group-IV AIDS had a rate of infection with Myco. tuberculosis of 3000 per 100,000 population, compared with 5.2 cases per 100,000 population for New South Wales. We sought to determine whether or not there was any unexplained increase in notifications which might be attributable to AIDS. This paper reports cases that were notified to the AIDS and tuberculosis registers, finds that atypical mycobacterial infections are underreported by at least 19.5%, and examines trends in notifications for mycobacterial disease since the onset of the AIDS epidemic. It also raises the importance of appropriate measures to protect health workers from tuberculosis.

Acquired Immunodeficiency Syndrome

Legionella pneumophila and water temperatures in Australian hospitals.

Thirty-four samples of warm waters from 12 psychiatric centres in Victoria and New South Wales were examined for legionellae by guinea-pig inoculation. Legionella pneumophila was isolated from 20 of the samples collected from ten of the establishments investigated. The detected prevalence proportion of L. pneumophila in waters of temperatures 36 to 43 degrees C was 0.9 (18/20), whereas the prevalence in waters of temperatures 45 to 54.2 degrees C was 0.14 (2/14). The two 'positive' waters within the latter range showed evidence of low numbers of L. pneumophila. No significant antibody titres to relevant serogroups were detected in the 112 exposed residents tested from seven psychiatric hospitals in New South Wales. The findings show that the temperature range with the greatest prevalence of L. pneumophila in warm waters is 36 to 43 degrees C. The presence of legionellae in these warm water-distribution systems contrasts with their absence from the water-distribution systems of Victorian hospitals in an earlier survey and underlines the value and simplicity of the usual Australian practice of maintaining hospital hot water temperatures at about 70 degrees C in the control of L. pneumophila.

Animals

Hepatitis B infection among STD clinic patients in Sydney.

Evidence of current or past infection with hepatitis B has been studied in 809 patients attending clinics for sexually transmitted diseases in Sydney by assaying serological markers. Prevalence rates were 13.9% among male heterosexuals; 13.5% among female heterosexuals; 30.7% among female prostitutes; 64.3% among male homosexuals and 47.1% among male bisexuals. The prevalence was 80% for male homosexuals aged 36 years or more. Vaccination should be considered for persons at high risk of sexual transmission of hepatitis B, and it is the immunization of this group that is likely to have a major impact on this disease.

Adolescent

Measles in the 1980s.

We detail aspects of measles immunization programmes in several countries. Live measles vaccine has been available in Australia for 16 years, yet, in 1981, there were outbreaks of measles in the State of New South Wales (population 5 200 000) which led to 2200 admissions to hospital and five deaths. In response to complaints of "vaccine failure", a survey determined that 22.5% of children with measles seen by general practitioners and 10.3% of those admitted to hospitals had been previously immunized. There was no evidence of waning immunity, and noparticular batch of vaccine was implicated. The vaccine failures are attributed in part to failure of seroconversion in some recipients when immunized at 12 months of age as a result of interference by transplacentally acquired antibodies. As more of the susceptible population is vaccinated, there will be fewer cases of measles, but among these cases will be an increasing proportion of cases occurring in previously vaccinated individuals. The equation to calculate this expected proportion of "vaccine failures" is given. We support the measures to increase immunization compliance.

Australia

Immunity to poliomyelitis in Sydney's children.

No indigenous cases of poliomyelitis have occurred in New South Wales since 1970, and it was presumed that herd immunity was high. However, our survey of Sydney's children by the neutralization test showed that only 42% of children had antibody levels (titre 8 or higher) to all three serotypes, 30% had antibodies to two, 16% to one, and 12% had no demonstrable antibodies at all. The immune status could not be determined with confidence from the immunization history, as 48% of the children who were reported as having received four or more doses of Sabin vaccine were not fully immune. When children who had inadequate levels of antibodies were given a single dose of Sabin vaccine, 77% of them achieved adequate antibody levels to all three viruses. The Health Commission of New South Wales subsequently undertook a mass Sabin immunization campaign of primary-school children, and reviewed the recommended immunization schedule.

Antibodies, Viral

Norwalk virus gastroenteritis in volunteers consuming depurated oysters.

Following the widespread outbreaks of oyster-associated gastroenteritis which occurred throughout Australia in 1978, several programmes were introduced to minimise the occurrence of further outbreaks. One programme included the depuration (purification) of oysters and the use of human volunteers to test-consume samples from batches of depurated oysters before their sale to the public. Oysters from the Georges River and Brisbane Waters were test-consumed from December, 1978, to August, 1979. None of the volunteers was ill after consuming Brisbane Waters oysters but 52 reported ill after eating Georges River oysters. The predominant symptoms were nausea, vomiting and diarrhoea with an average incubation period of 42 hours. Recovery was usually complete in 36-48 hours. Of the 52 illnesses reported 31 (60%) occurred in two particular weeks ending July 1st and 22nd when rates of 18.3% and 7.8% were reported. The average illness rate for the remainder of the period under study was only 1%. Norwalk virus was found in 8 of 25 (32%) stools, and antibody increases demonstrated in seven of ten paired sera, giving an overall diagnostic rate for Norwalk infection of 37.0% for these two peak periods. Heavy rain preceded these two weeks in which the illnesses occurred. No evidence of Norwalk infection was found at any other time. These studies confirmed the epidemiological findings of the major outbreak of gastroenteritis in 1978, and showed that only Georges River oysters caused Norwalk virus infections and that depuration as carried out in 1979 was not entirely satisfactory.

Antibodies, Viral

An Australia-wide outbreak of gastroenteritis from oysters caused by Norwalk virus.

At least 2000 persons were involved in an Australia-wide outbreak of oyster-associated food poisoning in June and July, 1978. At the time, this episode presented a major health risk to the community as a whole and has subsequently posed a serious economic problem for the oyster farming and distributing industry. Although bacteriological investigations indicated some batches of oysters were contaminated by sewage, no bacterial cause could be established. The causative organism was shown to be Norwalk virus, a known cause of acute non-bacterial gastroenteritis. This virus was found in 39% of faecal specimens examined by electron microscopy and an antibody response was demonstrated by immune electron microscopy in 75% of paired sera tested. Norwalk virus has not been identified previously outside the United States of America and has not been linked to food-borne gastroenteritis before. Purification of oysters and other measures have been instituted to prevent a recurrence of the outbreak.

Antibodies, Viral

Parvovirus gastroenteritis--a new entity for Australia.

An outbreak of acute gastroenteritis occurred in a primary school southwest of Sydney in August, 1977. Two hundred and eight pupils and nine teachers were affected over a one-month period. Electron microscopy revealed parvovirus-like particles in faecal extracts of 14 of 23 persons tested during the acute phase of illness. The virus was still present in the faeces of four individuals six weeks later. The appearance of specific antibodies was demonstrated by immune electron microscopy in five persons. No other cause for the outbreak could be found despite exhaustive investigations.

Antibodies, Viral

Medical aspects of the Granville Rail Disaster.

The paper outlines the Granville Rail Disaster incident, and the Sydney Metropolitan Disaster Programme which was operational for the first time. The nature of casualties (their triage, resuscitation and evacuation) is discussed, together with a description of the medical response. Difficulties confronting rescuers are mentioned and conclusions are drawn.

Accidents