PubMed HealthSearch

Biomedical subjects

J D Abbott

Publications and source records attributed to J D Abbott.

At least 19 recordsLinked to original sources

Application of three typing schemes (Penner, Lior, Preston) to strains of Campylobacter spp. isolated from three outbreaks.

Campylobacters isolated from human, animal and environmental sources during the investigation of a milk-borne outbreak, an incident involving goats' milk and an outbreak associated with puppies were serotyped using the Penner and Lior schemes and biotyped using the Preston scheme. Application of these three methods to the incident strains demonstrated that heterogenicity amongst similar strains exists. This study has confirmed the need to use at least two typing methods when investigating epidemiologically-related strains and we suggest that a combination of a serotyping scheme and an extended biotyping scheme is the most useful.

Animals

Serotyping of Campylobacter species by combined use of two methods.

Five hundred strains of thermophilic Campylobacter spp. from sporadic cases of enteritis and from epidemiologically related infections connected with outbreaks were serotyped. The haemagglutination method of Penner and the slide agglutination method of Lior were used together. Greater discrimination was obtained by the use of two methods together than by either alone; 96% of sporadic strains were typed using a restricted set of typing sera. Of the sporadic strains, 50% fell within five Penner serotypes and 50% fell within four Lior serotypes, so the increased discrimination obtained by using both methods was particularly useful amongst these most common serotypes. In outbreaks associated with one serotype both methods gave consistent results, and in outbreaks due to multiple serotypes the two methods complimented each other.

Agglutination Tests

The epidemiology of meningococcal infections in England and Wales, 1912-1983.

The epidemiology of meningococcal infections that arose in England and Wales during the period 1912-1983 has been reviewed. The outcome of meningococcal disease was dramatically improved when treatment with sulphonamides was introduced. With the emergence of sulphonamide-resistant strains, penicillin has become the drug of choice. Despite modern treatment, however, the mortality ratio during the last 30 years has remained about the same. Prompt diagnosis as well as immediate and effective treatment are cardinal needs. Even so, when infection is overwhelming there is little chance of saving the patient. Immunisation is probably the only effective answer but as yet there is not an effective vaccine to prevent group B infections which predominate in this country.

Age Factors

A comparison of biotypes and serotypes of Campylobacter sp. isolated from patients with enteritis and from animal and environmental sources.

The origin of sporadic campylobacter infections has been investigated by means of a collaborative study. From a total of 1152 cases reported in North West England in 1982, Campylobacter strains isolated during one month in each quarter of the year were biotyped and serotyped. For comparison, 875 strains of Campylobacter isolated from environmental and animal sources were similarly examined. Most strains from human beings were Campylobacter jejuni; about half of them were of three serotypes. Those serotypes commonly found in human infections were frequent among strains isolated from environmental and animal sources.

Adolescent

Diphtheria carriers in Manchester: simultaneous infection with toxigenic and non-toxigenic mitis strains.

A toxigenic strain of Corynebacterium diphtheriae mitis was isolated from a 10-week-old baby with membranous tonsillitis, and over the next 6 months thirty-nine symptom-free carriers of nitrate-positive mitis strains were found. All carriers were cleared by 14 days' treatment with erythromycin, though several relapsed after a 5-day course. Four contacts carried both toxigenic and non-toxigenic mitis strains; epidemiological evidence and phage studies suggest that these had a common origin. These findings have implications for the epidemiology of diphtheria and for the routine testing of isolates for toxigenicity.

Bacterial Toxins

An epidemic of meningococcal infection at Zaria, Northern Nigeria. 3. Meningococcal carriage.

Meningococcal carriage was studied in household contacts of patients with group A meningococcal disease and in controls. The carriage rate of group A meningococci among 1,098 household contacts was low (3.8%) and only slightly higher than the carriage rate found among 416 controls (2.6%). However, higher carrier rates were found among those in close contact with a patient. Carriage was found most frequently among children and young adults and was commoner in adult females than in adult males. Sulphonamides had no effect on carriage and all 60 strains tested in vitro were resistant to sodium sulphadiazine at a concentration of 10 micrograms/ml.

Adolescent

Nelson's syndrome: one disease or two?

We present a case of Nelson's syndrome in which the clinical, radiographic, and surgical findings are indicative of a discrete microadenoma rather than of diffuse pituitary hyperplasia. Ultrastructural analysis reveals this to be the first example of a sparsely granulated lesion in Nelson's syndrome and only the second such adrenocorticotropic hormone-secreting tumor reported. Unfortunately, there do not seem to be any firm ultrastructural features that differentiate between hyperplasia and discrete adenoma. Separation of the two entities may be important in delineating the pathogenesis and treatment of Nelson's syndrome; these are discussed.

Adenoma

The Canadian influenza decision, 1976.

This paper explains the Canadian decision process following the isolation and identification of A/New Jersey/8/76 at Fort Dix, New Jersey in February 1976. The cause for concern was the emergence of a swine-like strain related to that which caused the 1918-19 pandemic, together with proved man-to-man transmission. This concern was reinforced since all new influenza A strains known to have infected the number of persons involved at Fort Dix have become strains of epidemic importance. The Fort Dix outbreak gave sufficient warning to allow implementation of a national vaccination program, to prevent and protect against influenza. In the past such an opportunity had not occurred, and vaccine use had, at best, constituted an intervention in the course of an outbreak. The National Advisory Committee on Immunizing Agents had all available information when it reached its decision to recommend vaccination with bivalent (A/Victoria and A/New Jersey) or with monovalent (A/New Jersey) vaccine for selective, high-risk groups. This was an independent, scientifically based decision.

Adolescent

Meningococcal infections in Bolton, 1971-74.

Between December 1970, and the end of June, 1974, there were 82 cases of meningococcal infection, including 14 deaths, in the metropolitan borough of Bolton. This outbreak, caused by a sulphonamide-sensitive group-B strain, was characterised by a high attack-rate in young children, reaching a peak of 184 per 100,000 per year in the 6-11-month age-group. All the deaths were in children under 3 years of age. Nasopharyngeal carriage of the epidemic strain was found in 34% of close family contacts investigated before receiving sulphonamide prophylaxis.

Age Factors