An M-antibody capture radioimmunoassay (MACRIA) for anti-rubella IgM was developed. Under optimum conditions positive serum specimens bound up to 20 times as much radioactivity as negative specimens. Positive reactions were expressed in arbitrary units/ml by comparison with a calibration curve derived from results obtained with dilutions of a standard serum.

The specificity of the assay was confirmed by testing IgM and IgG rich fractions of positive sera. One hundred and forty specimens from blood donors, patients whose sera contained rheumatoid factor and patients with acute, non-rubella, virus infections were tested by MACRIA. No significant non-specific reactions were detected.

Paired sera from acute rubella (25 patients) and individual sera from suspected rubella (69 patients) were tested for anti-rubella IgM by MACRIA and by haemagglutination inhibition following sucrose-density-gradient fractionation. There was close agreement between the two methods. The capture assay was more sensitive and could be used to detect the weak IgM response in women given RA 27/3 vaccine. After the natural infection, the MACRIA was strongly positive for two months and remained weakly so for a further two months. Repeat testing of sera demonstrated good reproducibility of the assay.

MACRIA proved a simple, sensitive and specific test for anti-rubella IgM and compared favourably with currently used techniques.

An epidemiological study and the simultaneous evaluation of anti-Hav antibody using radio immunoassay (RIA) and immunoadherence hemagglutination assay (IAHA) was performed during three hepatitis A epidemics in the Tours area (France). Fifty-seven sera from 35 subjects with viral hepatitis type A and 16 sera from nine children who did not develop any clinical signs of hepatitis were studied. The more explosive epidemic occurred in an institution for mentally retarded children (attack rate 68%). The two major outbreaks observed were due to the introduction in the institutions of individuals infected with hepatitis A virus. Two out of three of the index cases had a seafood dinner three to four weeks before onset of jaundice. Sera taken one week after jaundice were always found to be anti-HAV positive by both RIA and IAHA, and sera taken more than three days before the appearance of jaundice were negative by both methods. Sera taken at the peak of the transaminase elevation were anti-HAV positive by RIA but only one out of two were positive by Iaha. The anti-HAV titre by RIA increased from the time of the appearance of jaundice and the highest titres, over 1/20000 were seen only after several months. Observations of subjects in close contact with patients who seroconverted without any manifestation of hepatitis, confirmed the existence of clinically mute infections.

A solid phase M-antibody capture radioimmunoassay (MACRIA) and a serum fractionation method were used to quantitate the IgM response to the hepatitis B core antigen (IgM anti-HBc) in acute and chronic hepatitis B infections.

Antibody to the core antigen was predominantly of the IgM class during theacute phase of hepatitis B. Resolving acute infections remained positive by MACRIA, but at decreasing levels, for as long as 6 months. IgM anti-HBc persisted in HBsAg carriers but at levels very much lower than seen in acute infections. There was no correlation of IgM anti-HBc with severity of chronic liver disease in carriers.

Measurement of IgM anti-HBc by MACRIA enabled accurate identification of acute hepatitis B on single serum specimens.

Strains of Treponema hyodysenteriae capable of inducing swine dysentery in specific pathogen-free pigs were compared with other spirochaetes from the porcine alimentary tract by biochemical and serological tests and by electrophoresis of their proteins. Carbohydrate fermentation and esculin hydrolysis were similar in all the spirochaetes. Indole was produced by T. hyodysenteriae and by some of the other spirochaetes. Analysis of the fatty acids produced from glucose showed a difference between T. hyodysenteriae and other spirochaetes only in the amount of n-butyric acid produced. The indirect fluorescent antibody test showed extensive cross-reactions between all the spirochaetes unless antisera were first absorbed. A microtitre agglutination test and a growth-inhibition test were both more specific; strains of T. hyodysenteriae could be distinguished from the other spirochaetes using unabsorbed sera. Both tests revealed some antigenic heterogeneity among strains of T. hyodysenteriae. The cell proteins of a single strain of T. hyodysenteriae gave an electrophoretic pattern distinct from those of the other spirochaetes.

Two of the six spirochaetes not associated with swine dysentery, PWS/B and PWS/C, were indistinguishable serologically and electrophoretically. The other four strains were serologically distinct from one another and from PWS/B and PWS/C. Only two of these spirochaetes were examined electrophoretically, but each gave a different pattern from PWS/B and PWS/C. The diversity observed among spirochaetes not associated with swine dysentery indicates that their suggested inclusion in a single species, T. innocens, may prove to be unjustified.

The transfer of gentamicin resistance between a coagulase-negative S. hominis strain and various coagulase-positive S. aureus strains on human and murine skin in the absence of a selective agent is described. Transfer occurs at higher frequency on skin than in broth. Skin transfer may account for the apparently explosive occurrence of gentamicin resistant staphylococci in hospitals.

Klebsiella of capsular type K2 were investigated to find out whether a single epidemic clone was the source of many outbreaks of infection in different hospitals, in different areas over a period of five years. The klebsiellas studied were found to be very similar; they were of the same biotype, had similar klebecin sensitivity patterns and carried multiple drug-resistance plasmids; however, characterization of these plasmids showed that they were heterogeneous. Thus there was not a single epidemic bacterial clone.

Of 1242 samples of seagulls faeces examined, 12·9% were found to contain salmonellae. The number of positive samples was significantly higher (17–21%) near sewage outfalls. Twenty-seven serotypes were isolated, including a new serotype named Salmonella grampian. The range and frequency of serotypes carried by gulls was similar to those in the human population, suggesting sewage as a possible source of gull infection.

The number of salmonellae found in positive samples was low (0·18−191 g−1 faeces). This was similar to the numbers found in sewage, 10−80 l−1, suggesting gulls may only carry infected material without infecting themselves. Antibiotic resistance in the isolates was low, only 21 showing resistance to the antibiotics tested, although most of these were determined by resistance transfer plasmids.

A portable air purifier significantly reduced mal odour in a small room. If the atmosphere was deliberately contaminated with Serratia marcescens the unit rapidly removed this organism. However, if incorrectly sited, the purifier could disperse organisms into the atmosphere.

The prevalence of serum neutralizing antibodies to infectious bovine rhinotracheitis virus in 1152 serum samples from adult cattle in 114 dairy and beef herds in different regions of Scotland was 12%. In the Grampian region, the number of seropositive cattle in the self-contained herds was significantly less (P < 0·01) than in the ‘other’ herds. Holstein cattle had been introduced into five of these ‘other’ herds, and significantly more (P < 0·01) of the samples from these five herds were seropositive compared with the samples from the rest of the ‘other’ herds in the same region into which recently purchased cattle had been introduced. The introduction of Holstein cattle was also a major factor in the association between the prevalence of antibodies and herd size in the Grampian region. The prevalence of serum neutralizing antibodies to infectious bovine rhinotracheitis virus was significantly greater (P < 0·001) in this survey than in those previously undertaken in the United Kingdom.

The results of a three year study of the viruses isolated from sewage by means of five tissue culture types are reported. The enteroviruses identified demonstrated a seasonal pattern which was similar to that of clinical isolates. Echoviruses and coxsackieviruses displayed a changing pattern of dominant serotypes in both sewage and clinical isolates; echovirus 6, 19, 3 and coxsackievirus B4, B5, A9 successively became the most common serotypes. The poliovirus in sewage was all vaccine-like in character. Reovirus, type 2 was abundant; adenovirus, of several serotypes, were the least often identified.

During a survey in Jakarta, Indonesia, 158 cultures of Salmonella oranienburg, consisting of two phage types, were obtained from 150 hospitalized patients with diarrhoea. Phage type I, though found notably in young children, was found in all age groups while phage type II was found almost exclusively in young children aged 0–7 years. Phage type I may produce a more severe clinical picture affecting all age groups alike, while phage type II may result in hospitalization of only the very young, who are more susceptible to dehydration. Phage type I was significantly more resistant than phage type II to the individual antibiotics: tetracycline, chloramphenicol, kanamycin and neomycin. However, there was no difference in their respective antibiotic resistance patterns as measured by disk and MIC assay. All cultures were sensitive to gentamicin and trimethoprimsulphamethoxazole 1:19.