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D J Merry

Publications and source records attributed to D J Merry.

6 recordsLinked to original sources
PubMed1997

Evaluation of a commercial enzyme-linked immunosorbent assay for detection of immunoglobulin M antibody in diagnosis of human leptospiral infection.

The PanBio Leptospira immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) is a commercially available screening test for the diagnosis of acute leptospiral infection. The ability of the test to diagnose early or recent Leptospira interrogans infection was assessed by testing sera with known microagglutination test (MAT) titers to serovars pomona, hardjo, copenhageni, and australis. The IgM ELISA detected all 41 cases of early or recent leptospiral infection (sensitivity, 100%), with a positive ELISA result seen in many cases before MAT antibody titers reached 1:50. Thirty-eight of 41 patients showed seroconversion (fourfold or greater increase in titer by MAT, 2 of 41 patients had a single sample with elevated titer, and 1 patient from whom leptospires were isolated from a blood sample failed to show MAT titers, despite a seroconversion (negative to positive result) in the ELISA. Follow-up sera obtained from 8 of 12 patients (67%) for 3 to 48 months after the acute stage of illness showed persisting IgM antibody. However, the range of levels detected in these samples (maximum ELISA ratio, 2.0) was lower than the range seen when infection was recent. Reactivity in the IgM ELISA was observed for only 1 of 59 serum samples from asymptomatic donors (specificity, 98%) and 16 of 233 serum samples from patients with Ross River virus, brucella, Epstein-Barr virus, cytomegalovirus, mycoplasma, Q-fever, toxoplasma, hepatitis A virus, Treponema pallidum, or Borrelia burgdorferi infection (specificity, 93%), with the majority of these patients showing lower levels of IgM in comparison to those in patients with leptospiral infection. We conclude that this ELISA is sufficiently sensitive for use as an initial screen for leptospiral infections, with subsequent confirmation of positive test results by MAT.

Analysis of Variance↗
PubMed1992

The use of suckling mice to isolate and grow Giardia from mammalian faecal specimens for genetic analysis.

A simple technique is described for preparation of Giardia cysts from faecal samples, the growth of trophozoites in suckling mice and the isolation of trophozoites for genetic analysis by allozyme electrophoresis. In total, 125 new isolates of Giardia have been collected from human and animal sources over a wide geographical area of South Australia and the Northern Territory of Australia. A number of long-established axenized isolates of G. intestinalis belonging to Groups I and II also adapted to grow in suckling mice. These findings indicate that suckling mice are permissive hosts for a variety of genetically dissimilar but morphologically similar organisms of the G. duodenalis type and that this in vivo technique may be less selective than isolation by in vitro culture. The use of suckling mice has revealed that infections can be composed of mixed genotypes and that isolation and purification techniques can be selective. Allozymic interpretation is essential to reveal the genetic complexity of such mixtures.

Alleles↗
PubMed1985

Hydatid cyst: an unusual cause of diplopia.

A 59-year-old man presented with double vision due to vertical displacement of one eye by an infraorbital mass that indented the globe. Some 10 years previously he had had a Caldwell-Luc antrostomy for chronic sinusitis. Following investigation, the antrostomy was revised and an orbital cyst with a histological appearance suggestive of a mucocele was excised via an anterior inferior orbitotomy. The orbital mass recurred with identical symptoms some 18 months later with a second mass confluent with the first, presenting subcutaneously through his zygoma. A further radical antrostomy was performed enabling a diagnosis of a hydatid cyst of the antrum to be made. The unusual features of this rare cause of diplopia are discussed and illustrated. The literature on orbital hydatid cysts is reviewed and recommendations made as regards adequate surgical exposure and not irrigating orbital cysts with noxious agents.

Diplopia↗
PubMed1980

Legionnaires' disease in South Australia. Prevalence and diagnosis.

Legionella pneumophila was successfully isolated from sputum, and from respiratory secretions obtained by tracheal aspiration, of two patients with Legionnaires' disease by means of guinea pigs and charcoal yeast extract agar. Direct culture of lung tissue from one of these patients gave a pure growth of L. pneumophila. In both cases, legionellas were isolated from specimens which were collected several days after treatment with erythromycin began. Direct fluorescent antibody tests on these specimens gave positive results. This test can result in the rapid diagnosis of legionellosis in carefully selected patients. Serological diagnosis by demonstrating a greater than fourfold rise in antibody level, particularly that of IgM antibody, is the method of choice for making the diagnosis of legionellosis in patients who do not have life-threatening infections or in whom a definitive bacteriological diagnosis cannot be made. Serological studies suggest that infection with L. pneumophila is endemic in South Australia.

Adult↗
PubMed1975

The VDRL test in a blood transfusion service.

A survey has been made of the results of 12 months' VDRL screening in a blood transfusion service. Positive VDRL tests were found on 318 of the 73 350 blood donations collected during 1974. Thirty-four tests confirming specific treponemal infection were found in 24 donors. A battery of confirmatory tests showed the remaining 284 positive VDRL reactions from 235 donors to be biological false positive (BFP) results, and, of these, one-third were considered entirely negative by the reference laboratory. BFP reactions were commoner in female donors than in males, and a higher incidence than expected was observed in younger female donors and older male donors. A marked seasonal incidence was noted, 65% of all BFP tests from the transfusion service being found in the four colder months of May to August. Although some differences exist between the group as a whole and the 36 donors (15.3%) found to have BFP results on more than one occasion during the year, there is little evidence from these studies to suggest that regular blood donation per se is a contributing factor to the finding of a BFP result in VDRL screening. It is probable that the population tested regularly by the blood transfusion service reflects a small but representative sample of the community as a whole.

Blood Donors↗