Counter-current immunoelectrophoresis for the diagnosis of pneumococcal chest infection.

Counter-current immunoelectrohporesis is a rapid sensitive method for detecting pneumococcal capsular antigens in sputum. A result can be obtained within 45 minutes. The optimum conditions for performing the test are given. Counter-current immunoelectrophoresis works with all the 33 pneumococcal antigens tested except type 14. Better precipitin lines are obtained when the gel-support is acid (pH 6-6) than when it is alkaline (pH 8-6). Omniserum is as effective as group-specific sera for the identification of pneumococcal capsular antigens. The findings suggest that pneumococcal infection was present in 44% of 300 unselected suspected chest infections. Culture for pneumococci was positive in only 15% of these cases. The clinical importance of these findings is still being studied but our experience has shown that patients with chest infections should have effective antipneumococcal antibiotics as part of their regimen and that the laboratory diagnosis may be made quickly and accurately by counter-current immunoelectrophoresis.

Postoperative urinary infections caused by Escherichia coli.

Serological and biochemical classification of Esch. coli from the rectum and vagina of patients who developed a urinary infection after operation and the insertion of a self-retaining catheter showed that 13/20 urinary infections were caused by a type which had been present before operation in the rectum, vagina, or both.

A study of workload units in five microbiology laboratories.

A study of a modified Canadian unit system of measuring laboratory workload was undertaken in five joint Public Health Laboratory Service and hospital microbiology laboratories. Ten percent of the specimens received over six months were sampled, the number of units expended on each was recorded, and the results were analysed on a central computer. The process of gathering information in the absence of laboratory computers was time consuming and, despite careful planning, differences were found in the recording practices of the laboratories. The analysis of results did not lead to major changes in data gathering techniques because the same information about laboratory workload could be obtained by collecting numbers of clearly defined specimens. Analysis of workload units could be useful for particular purposes, such as comparing differences between laboratories using different techniques for the same investigation or assessing the possible benefits of automation. It must be appreciated, however, that workload units are measures of quantity not of laboratory performance.

Diphtheria: the logistics of mass swabbing.

Although diphtheria is a rare disease it is necessary to swab contacts of all cases in order to identify carriers. The selection of individuals who should be swabbed and the organisation of mass swabbing so that there is the minimum of delay between collection, culture and reporting are described. With this organisation it is possible for a laboratory to culture at least 1000 swabs in any one day.

Incidence of HBsAg in blood samples submitted to the metropolitan police forensic science laboratory.

In survey carried out at the Metropolitan Police Forensic Science Laboratory, the frequency of HBsAg positive blood samples, being submitted for grouping purposes, was estimated to be 1.6%. This figure is significantly higher than that quoted for the general population.

A new citrated formulation of nalidixic acid (Mictral U.K.) for the treatment of acute cystitis.

A 3-day course of a new citrated formulation of nalidixic acid (Mictral) was assessed in fifty-four women presenting with acute uncomplicated cystitis. Over 96% of women with a significant Gram-negative bacteriuria were cured of the infection following a course of treatment. Only two relapses occurred in this group during the follow-up period. Relief of symptoms occurred in nearly 90% of infected patients and generally by the second day of treatment. Although the incidence of side-effects was about 20% they were not considered serious.

A double outbreak of exfoliative toxin-producing strains of Staphylococcus aureus in a maternity unit.

This report describes a double outbreak of staphylococcal scalded skin syndrome (SSSS) in which two distinct tetracycline-resistant strains of Staphylococcus aureus producing different exfoliative toxins were involved. In the first phase the daytime staff of the delivery unit and eczematous skin conditions in midwives were implicated as the probable source. In the second phase a source within a post-natal ward was suggested with local cross-infection. In the final phase both sources were epidemiologically linked to cases of SSSS. Because early discharge was the policy of the unit many cases presented in the community rather than in the hospital. Confirmation of epidemiological findings was provided by additional laboratory studies. Two distinct strains of S. aureus could be defined, differing in phage-typing patterns, the exfoliative toxin produced, plasmid profile, cadmium resistance and bacteriocin production. Strict care in hand washing with a chlorhexidine-containing detergent was an important control measure.

Transrectal biopsy of the prostate and bacteraemia.

Bacteraemia and urinary tract infection are well-recognized complications of urological procedures. This paper compares, for the first time, the incidence of bacteraemia after cystoscopy and transrectal biopsy of the prostate with that following cystoscopy alone. The incidence of bacteraemia in those undergoing biopsy was 73 per cent; following cystoscopy alone the incidence was 13 per cent. In view of this high incidence we recommend prophylactic antibiotic cover of transrectal prostatic biopsy.

Pneumococcal antigen in pneumonia. A post-mortem study with the histological and bacteriological findings.

Pneumococcal capsular antigens can be detected in lung tissue by counter-current immunoelectrophoresis even when, following antibiotics, post-mortem bacterilogy suggests that Escherichia coli has replaced pneumococci. The results suggest that antipneumococcal therapy would benefit at least 55% of patients critically ill with lung infection and that the potentially toxic drugs directed at coliform bacteria may be unnecessary.

Hemolytic-uremic syndrome associated with neuraminidase-producing microorganisms: treatment by exchange transfusion.

In two infants with pneumonia, Coombs test positive hemolytic anemia and hemolytic uremic syndrome (HUS), exposure of the Thomsen cryptantigen, probably due to the action of circulating neuraminidase, was demonstrated. Reaction between the exposed T-antigen and anti-T agglutinin, normally present in human blood, can lead to difficulties in serological testing and during blood transfusion. The place of exchange transfusions using washed RBC or heparinized whole blood in the management of this subgroup of HUS is discussed.

Outbreak of Salmonella napoli infection caused by contaminated chocolate bars.

An outbreak of Salmonella napoli infection in England and Wales in 1982 was detected by the surveillance of routine reports of salmonella infections from hospital and public-health laboratories. Epidemiological investigation quickly identified two types of small chocolate-covered bars, imported from Italy, as the vehicles of infection, and subsequently both were found to be contaminated with the organism. The prompt recognition of this outbreak and rapid identification of the vehicle of infection enabled four-fifths of the consignment of contaminated chocolate to be withdrawn from the market. The 245 reported cases resulted from the sale of 600 000 bars; as these were presumably only a small fraction of the total number of cases, it is likely that many thousands of infections were prevented.

The problem of infection after prostatic biopsy: the case for the transperineal approach.

The incidence of infection after needle biopsy of the prostate by different techniques was compared in 45 patients. Aerobic and anaerobic culture was made of the biopsy needle, prostate, urine and blood. In addition, endotoxin assays were determined by a new chromogenic method using Limulus lysate. All of the patients undergoing transrectal biopsy were found to have a bacteraemia; 27% were symptomatic and 87% had a post-operative urinary tract infection. A double-blind controlled trial using cefamandole with the premedication showed a significant reduction in the incidence of bacteraemia to 53% and the prevention of a urinary tract infection. Following transperineal biopsy, although the incidence of bacteraemia was 40% and urinary tract infection 27%, none of these patients was symptomatic and the organisms causing the bacteraemia were predominantly skin contaminants. The endotoxin assays showed differences between the groups with higher endotoxin values in the unprotected transrectal group.

Detection of rubella-specific IgM in subclinical rubella reinfection in pregnancy.

Seven cases of asymptomatic rubella reinfection in early pregnancy are described. In each, there was a history of exposure to a rubelliform illness and low levels of rubella-specific IgM subsequently appeared in the serum. Four of the women had been immunised, after having been shown to be susceptible to rubella, one had been immunised at school without previous antibody screening, and two were uncertain about immunisation. One pregnancy was terminated and rubella virus was not isolated from the products of conception. Six pregnancies went to term and the infants showed no evidence of intrauterine infection. In a further case it was impossible to discriminate between reinfection and primary infection, and termination of pregnancy was offered.