It is now seven years since Cossart and her co-workers reported finding a novel parvovirus-like agent (PVLA) infecting man. Although this virus was found as a systemic infection in both Dr Cossart's eleven subjects and a further four subjects described subsequently (Paver & Clarke, 1976; Schneerson, Mortimer & Vandervelde, 1980) it was not until 1981 that a clearly defined clinical syndrome was identified as attributable to infection with this agent. Work in the Departments of Microbiology and Haematology, King's College Hospital Medical School and collaboration with the MRC laboratory at Kingston, Jamaica has shown that infection with the PVLA is the major cause of aplastic crisis in children with sickle cell anaemia (Sergeant et al. 1981, Anderson et al. 1982a, b).

An outbreak of streptococcal pyoderma in a military institution into which fresh susceptible recruits were regularly introduced involved more than 1300 persons over an eighteen-month period. Two M types were responsible for the great majority of the cases and an attack by one conferred immunity to that strain but not to the other. Lesions varied from trivial to disabling. Epidemiological studies indicated that contact – direct or indirect – through such things as gymnasium equipment and room dust was the means of transmission. The outbreak was eventually controlled by vigorous case finding, thorough treatment of cases and the strict application of hygienic principles to prevent spread. There were no late complications and throat streptococci were not involved. It is possible to control such an outbreak without isolation or the making of any significant concessions in the training programme even when large numbers of persons are living and working at close quarters.

A quantitative culture technique (hand washed in a glove containing broth for 30 s) was used to determine the frequency of hand carriage of aerobic Gram-negative rods by various groups of health care workers and 104 control subjects. Overall, 31 % of health care workers carried aerobic Gram-negative rods on their hands compared to 59% of control subjects (P < 0.001). Enterobacter agglomerans accounted for 40% of the isolates, and other Enterobacter spp. 7%. Other organisms included Acinetobacter calcoaceticus 21 %, Serratia spp. 11%, Klebsiella spp. 10%, Moraxella spp. 3%, Pseudomonas spp. 3%, Proteus spp. 1.5%, Escherichia coli 1%; Morganella morganii, Citrobacter freundii, Aeromonas sp. and an isolate that was not speciated accounted for 0.5% each. We conclude that endemic hand carriage of aerobic Gram-negative rods by health care personnel is common, but significantly less than that of control subjects. Enterobacter agglomerans is found so frequently on the hands of control subjects that it must be considered part of the normal hand flora.

In order to determine whether hand carriage of aerobic Gram-negative rods is continuous we used the glove-handwash technique to sample the hands of two groups (four each) of health care workers with normal hands (surgical intensive care unit, medical ward) and one group (four) with hand dermatitis (HD) and a group (five) of control subjects – secretaries with no exposure to patients. Each subject was sampled repeatedly over three to six weeks. The mean number of samples for each group was 25.2, 23.2, 19.8 and 25.8 respectively. The HD group had more samples positive for aerobic Gram-negative rods than did the other two groups of health care workers while the control group had more samples positive than any of the three health care groups.

Using various typing schemes and the following definition of continuous carriage (the isolation of an organism of the same serotype, pyocin type or biotype from more than two handwash samples) we found that 4 of 11 subjects from whom Klebsiella pseumoniae was isolated carried this organism continuously; 2 of 3 carried Pseudomonas aeruginosa continuously and 4 of 5 of the control subjects carried the same biotype of Enterobacter agglomerans continuously.

We conclude that continuous hand carriage of aerobic Gram-negative rods is common and, among health care workers, those with hand dermatitis carry Gram-negative rods more frequently and in greater numbers than health care workers without hand dermatitis.

Vibrio parahaemolyticus was isolated from 53 out of 584 samples (9·1%) of market fish. All strains were Kanagawa negative and were distributed as follows: sea fish 5 out of 370 samples (1·4%), shellfish 48 out of 214 samples (22·4%). Other fish spoilage microflora recovered were: Alcaligenes faecalis, Pseudomonas aeruginosa, Proteus vulgaris, Aeromonas spp. and Vibrio alginolyticus. Total aerobic counts and coliform counts per gram for the lake fish ranged from 2·6 × 102 to 6·6 × 107 and 10 to 1·0 × 102, respectively. Those from marine fish ranged from 1·0 × 105 to 8·8 × 105 and 2·0 × 103 to 1·6 × 104, respectively. Counts for marine fish gills alone ranged from 1·4 × 105 to 3·4 ×108 and 7·2 × 102 to 1·4 × 107, respectively. No hightemperature (44°) coliforms were recovered from either lake or marine samples.

Prisoners and attending staff from six houses of detention were screened for serum HBsAg, antiHBs, antiHBc and transaminases. Both prisoners and warders showed an increased prevalence of HBV serum markers with respect to age- and sex-matched general population control groups. The HBsAg carrier rate was 6·7% in prisoners and 6·6% in staff. Sixty-five per cent of the HBsAg-positive subjects were antiHBe-positive. When the blood samples were taken, all the HBsAg-positive subjects were asymptomatic; transaminases were normal in 80% and only slightly elevated in 20%.

Illicit drug abuse was found to be a relevant risk factor for HBV infection among prisoners under 35 years of age, but not in the older group, whereas no correlation emerged between presence of HBV serum markers and tattoos or admitted homosexuality. A high prevalence of HBV serum markers was also found among young warders who had been in service for a short time: most of them, however, come from areas of Italy with a particularly elevated HBV circulation.

Although the results suggest that many of the HBV infections are not recently acquired within the institution, this survey confirms that prisons should be regarded as high risk areas for HBV infection, both for prisoners and warders.

The bacterial colonization of the large bowel of 11 pre-term, low birth weight neonates who were nourished by expressed breast milk was examined by culturing serial faecal samples and compared to that observed in eight breast-fed and seven formula-fed full-term neonates.

Pre-term neonates were colonized by high counts of facultatively anaerobic bacteria from the first days of life while bifidobacteria colonized only six babies during the first week and appeared in only one baby before day 5. Bacteroides spp. and clostridia were isolated from seven and six pre-term babies respectively during week 1 and were first observed on day 2.

The intestinal colonization of pre-term infants differed from that in full-term breast-fed infants in the high counts of facultatively anaerobic bacteria and late appearance of bifidobacteria, and from both groups of full-term infants in the early stable colonization by Bacteroides spp.

It is postulated that the composition of the normal intestinal microflora of pre-term low birth weight babies contributes to their predisposition to neonatal necrotizing enterocolitis. Results are discussed in relation to the effect of infant feeding regimens on intestinal microbial populations.

The levels of faecal coliforms (FC), indole-positive FC (presumptive Escherichia coli), faecal streptococci (FS), Streptococcus faecalis and Clostridium perfringens in the natural water sources used by 29 rural settlements in Sierra Leone were investigated. Levels of the same indicators in human faeces were also investigated. The incidence of Salmonella spp. in both habitats and the temperature, pH and conductivity of water sources were also recorded. All water sources were contaminated with the indicator bacteria, mean numbers of which occurred in the relationship FC > presumptive E. coli ≏ FS ≏ C. perfringens > S. faecalis. FC were also predominant in human faeces, the relationship of means being FC ≏ presumptive E. coli > FS > S. faecalis > C. perfringens. The need for confirmation of FC counts obtained from water sources was indicated by the large number of positive tubes produced in the FC multiple-tube dilution test from some samples which could not be confirmed as presumptive E. coli. Salmonella spp. were isolated from 13 water sources and 6% of faecal samples. Mean water temperature was high (26·2 °C), pH low (5·04) and conductivity low (34μS cm−1). Presumptive E. coli was considered the most appropriate indicator of faecal pollution of the types of water investigated.

Four thousand, five hundred and sixteen rodents of 27 species were captured in widely separated localities in South Africa over a period of ten years. Samples of spleen, lung, heart, liver and rectal tissue with faeces were tested for the presence of zoonotic bacteria and 109 isolations of Pasteurella pneumotropica were made from 11 species. Latent infection with the organism was found to be widespread although there were temporal fluctuations in prevalence. Field and laboratory evidence suggest that P. pneumotropica may be associated with, but not the primary cause of, rodent epizootics in the wild.

The epidemiology in the United Kingdom of the influenza A H1N1 subtype which returned in 1977 after an absence of 20 years is described for the four winter seasons from 1977/8 to 1980/1. The age distribution of virus isolates and the evidence for antigenic variation is presented. The impact in the susceptible age groups year by year is shown by the change in the population with specific antibody. There was the expected increase of antibody in those under the age of 21 but also evidence for a significant amount of infection or re-infection in the older adult population.

The antibody responses of 194 volunteers were studied for up to 3 years after primary immunization with one, two or three doses of human diploid cell rabies vaccine, administered either in 0·1 ml volumes intradermally (i.d.) or as 1·0 ml intramuscularly (i.m.). Sero-conversion occurred in 95% of subjects after the first injection and in 100% after the second. The highest titres and most durable antibody responses were induced by three injections of vaccine.

Booster doses were administered either by the subcutaneous (s.c.) or i.d. route, after 6, 12 or 24 months to randomly grouped volunteers; these induced responses ≥ 5·0 i.u. per ml in 95% of subjects. The responses were rapid and were neither influenced by the primary regimen nor by the timing and route of the booster dose.

Antibody titres after i.d. immunization were only two-fold lower than those induced by the larger volume of vaccine. The findings suggest that the i.d. route is both effective and economic.

The relation of salmonella isolation efficiency and the size of inoculum introduced from a buffered peptone water culture of sewage polluted water into strontium chloride B medium was investigated. Two separate studies were made, one using enrichment at 37°C, the other at 43°C. From these trials, two inocula suitable for efficient salmonella isolation were determined. Using this information, strontium chloride B medium was compared with modified Rappaport's broth (R25). The inoculum used with R25 was 0·005 ml, determined in an earlier study. Two incubation temperatures were employed with strontium chloride enrichment (37 and 43°C). Rappaport's medium was incubated at 37°C only. Elevated temperature enrichment at 43°C improved the performance of strontium chloride B, but Rappaport's broth still gave significantly better results. This supports earlier studies on simplification of salmonella isolation and standardization of routine technique on a single enrichment medium: Rappaport broth (R25) incubated at 37°C.

Thirty-nine strains of klebsiella isolated from ankylosing spondylitis patients were examined by the methods of Cowan & Steel (1974), those described by Edmondson et al. (1980) and by capsular typing. No significant difference was detected by any of these methods between these strains and those examined by other workers from non-ankylosing spondylitis patients and other environments.

Of 120 specimens of garden fertilizers of animal origin purchased in retail shops, 40 (33·3%) were found to be contaminated with salmonella organisms. Untreated bone meal (53·1%) was the most heavily contaminated but 25% of specimens of this product classed as heat-treated or sterilized were positive. In all, 32 serotypes were identified.

A study of the ability of 49 strains of FMD virus to replicate in BHK-21 monolayer cells maintained under a standard agar overlay containing 5·2 mM guanidine hydrochloride and to withstand heat inactivation at 54°C for 1 h showed that strains belonging to serotypes C, O and Asia 1 were generally more resistant to guanidine and heat stable than the SAT 1, 2 and 3 serotypes. The type A viruses as a whole occupied an intermediate position between these two groups.

In vitro passage in BHK-21 cells influenced the guanidine sensitivity of 3(O, C and SAT 3) of the 7 FMD serotypes suggesting that this is not a stable genetic marker. Heat stability of the FMD viruses, however, did not change on passage, suggesting that this is a stable characteristic inherent in any homogeneous FMD virus population.

The aim of the study was first, to determine the prevalence of Neisseria meningitidis among the family members living with patients suffering from meningococcal infections, and second, to ascertain the distribution among these family members of strains epidemiologically related to those isolated from patients.

Forty-two family groups were studied and 135 nasopharyngeal samples were taken from family members living with patients.

Twenty family groups were found to contain meningococcal carriers, and of these 20, 13 contained a carrier of the strain that caused the infection (65%). Among the family members who were carriers, the mother and father most frequently yielded the strain which caused the illness.

The serotypes most frequently encountered both in patients and carriers were 2 and 8, as well as nontypable strains.

The polyacrylamide gel electrophoretic patterns (PAGE) most frequently found were II and IV. A notable feature of the study is the high resistance of the strains to sulphadiazine, since more than 90% of the strains found in patients and more than 75% of those from carriers possessed a minimum inhibitory concentration greater than or equal to 10μg/ml.

A single-tube confirmatory test that allows a result to be obtained in 4 h has been developed from the single-tube confirmatory test recommended by the Joint Committee of the Public Health Laboratory Service and the Standing Committee of Analysts (PHLS/SCA, 1980). A variety of river, lake and reservoir samples were examined for the presence of E. coli using either most probable number (MPN) or membrane filtration (MF) technique, and the PHLS/SCA recommended confirmatory medium (LTMB) was evaluated against traditional methods. To improve the performance of LTMB, the medium was modified and this modified medium when used in 0·1 ml volumes and incubated for 4 h at 44°C provided 99% agreement with traditional methods.

There are few data about the distribution of neutralizing antibodies (NA) against adenovirus types in the Italian population, especially the high-numbered ones. We tested the sera from 453 children and 51 young adults to evaluate NA against adenovirus prototypes 1–33. Using the microneutralization test, 338 (74·6%) of the children's sera were positive for at least one adenovirus type. Antibody to type 2 was the most frequently detected followed, in descending order, by antibody to types 5, 1 and 3. All these types are known to be associated with disease but antibody to type 7, a type also associated with disease, was less frequent than that to other serotypes such as 18 and 31, the pathogenicity of which in man is not clearly established. The antibody positivity rate rose with age for the more frequent types while it did not vary for the less frequent ones. The number of sera with NA against more than one adenovirus type increased with age. With regard to types 1–8, we found that their frequencies in Italy were similar to those found in the U.S.A.

An epidemiological study on Campylobacter jejuni enterocolitis was performed in an urban Swedish community. The study included 55 patients gathered during a six-month period. Forty-one of the 55 patients (75%) were infected outside Sweden. Campylobacter enterocolitis was rare among children within the country. Patients infected in Sweden had eaten chicken significantly more often than a corresponding control group. Seven out of nine chicken consuming campylobacter patients also had prepared the fresh chicken alone, and none of their family members became ill. Thus the preparation of food contaminated with Campylobacter seems to elevate the risk for contracting the disease. Sick household pets transmitted the campylobacter infection to two patients. Forty-six of the patients had a total of 85 close household members. Three definite secondary cases were found. There was no evidence of transmission of Campylobacter by food prepared by two cooks who were working while still being asymptomatic excreters. Clinical reinfection with Campylobacter was observed in one patient. No patients became long-term carriers of Campylobacter.

From October 1977 to May 1980, 243 stools collected in sedentary and semi-nomadic populations of the Ahaggar (Algerian Sahara) were examined using immunoelectronmicroscopy and tissue culture inoculation. Immunoelectron-microscopy revealed the presence of rotaviruses in 8, coronaviruses in 26, adenoviruses in 5 and small round viruses in 4. Enteroviruses were isolated in tissue culture from 24 stools.

Rotaviruses were present in the Ahaggar but were associated with little acute enteric disease. The high frequency of coronaviruses both in gastroenteritis patients and in patients without disease was surprising. The prevalence of enteroviruses in this hyperarid zone was similar to or higher than that found in noticeably more humid countries.

Further systematic bacterial, viral and parasitic examinations are required to clarify the role of the above viruses in the aetiology of gastroenteritis in this region.