Journal of Hygiene最新文献

The distribution of ticks of the Ornithodoros moubata complex in different habitats in Malawi, particularly pigsties and houses, was established from a four-phase survey undertaken between 1982 and 1985. The first phase consisted of preliminary interviews, the second phase consisted of a questionnaire to Veterinary Assistants (VAs) in rural areas, the third involved tick collections by VAs and the fourth involved both interviews and tick collections by members of the Central Veterinary Laboratory, Lilongwe. The area in which O. moubata is found in pigsties includes much of the African swine fever (ASF) enzootic area, and it seems likely that the enzootic area could become larger in future. The occurrence of O. moubata in warthog habitats was also investigated.

An outbreak of keratoconjunctivitis is described which involved at least 186 people; adenovirus type 8 was identified in 50 of the cases. Topical human fibroblast interferon was assessed in a double-blind, placebo-controlled study in which 34 patients participated. Seventeen of the 34 trial patients yielded adenovirus type 8; three were infected with adenovirus type 7. The outbreak was curtailed by control of infection measures: principally careful hand-washing by medical personnel between cases and by discouraging attendance of new cases at the Eye Infirmary. Consequently the trial numbers are small. In addition there was a wide interpatient variation in the severity of infection. Therefore it was not possible to make any statistically valid conclusions concerning the recovery rate of patients receiving interferon or placebo.

Five hundred strains of methicillin-resistant Staphylococcus aureus were tested against various anti-staphylococcal agents. Vancomycin, fusidic acid and fosfomycin were found to be the most effective. Only 1 strain out of 500 was resistant to fosfomycin. Three patients with methicillin-resistant Staphylococcus aureus septicaemia were successfully treated by fosfomycin. We conclude that fosfomycin could be the drug of choice for methicillin-resistant Staphylococcus aureus infection.

A total of 6593 serum samples from birds, received for diagnostic testing or surveys between 1974 and 1983, were titrated by direct complement fixation (CF) test against Chlamydia psittaci antigen. The percentage of positive reactions found was variable for domestic poultry, ranging from 1.5 in chickens to 22.2 in geese, and was highest in pigeons Columba livia (47.3) and collared doves Streptopelia decaocto (51.4). A moderate incidence was found for game birds (29.0), wild ducks (23.3) and imported birds of the order Psittaciformes (15.9). The highest titres were found in pigeons, collared doves and psittacines, confirming that infection is both frequent and active in these birds in Britain. Results of isolation of chlamydia from similar sources will be reported subsequently.

Fifty volunteers, treated with an inactivated trivalent influenza vaccine containing A/Bangkok/1/79 (H3N2), A/Brazil/11/78 (H1N1) and B/Singapore/222/79 virus, were subdivided according to the estimated first exposure to influenza in their lifetime (priming) and the presence of antibodies against the vaccine components in the pre-vaccination sera. The isotypic antibody response (IgG, IgA, IgM) was determined by means of an antibody capture haemadsorption immunosorbent technique. For all three vaccine components, previously seropositive subjects produced antibodies of the IgG- and IgA-class more frequently than previously seronegative persons. Subjects primed to one of the influenza A subtypes showed more IgG and IgA responses in comparison with those unprimed (prime-effect). In contrast, IgM antibodies occurred in only 19 and 11% of primed, but in 59 and 54% of unprimed subjects, for A (H3N2) and A (H1N1), respectively. The incidence of IgM titre rises was not influenced by the prevaccination state. However, the mean magnitude of anti-A (H1N1)-IgM titre rises was greater in those previously seronegative. The concepts of primary and reinfection and of 'original antigenic sin' are discussed, and it is suggested that age and, if possible, serological state prior to antigen-exposure should be taken into account when studying isotypic antibody responses after influenza infection or vaccination.

Nine monoclonal antibodies directed against the flagella of Campylobacter jejuni strain 81116 have been investigated for serotypic and cross-reacting activity using a panel of 17 Penner serotype strains of C. jejuni. Four monoclonal antibodies were exclusively specific for serotype-6 strains, which was the serotype of C. jejuni strain 81116. Two monoclonal antibodies cross-reacted with all the flagellated strains of C. jejuni tested. One of these cross-reacting monoclonal antibodies, CF5, was found to react with all other Campylobacter species except C. sputorum bulbulus but it did not react with other bacterial enteropathogens. An antigen-capture ELISA technique was established, using this monoclonal antibody, which could detect flagellar antigen in human faecal material. These anti-flagella monoclonal antibodies therefore may be valuable in the diagnosis and serotyping of C. jejuni in clinical material.

A total of 1531 diagnostic submissions from birds were examined by culture for the presence of Chlamydia psittaci between June 1976 and December 1984 by growth in NCTC 929 clone L mouse fibroblast cells, pretreated with an inhibitor of cell division, followed by direct immunofluorescence microscopy. Of these, 196 were found positive. The continued importance of psittacine birds as potential sources of infection was shown by the high number of positives (139) obtained from birds of that order. The percentage of submissions found positive was highest in parakeets (30.1) and was fairly high in psittacines as a group (16.6), but the latter figure was exceeded by the group of collared doves (Streptopelia decaocto) and wood pigeons (Columba palumbus) (25.0). Domestic poultry generally gave low rates, turkeys being the highest. Both the numbers of submissions and their rates of positives increased between 1980 and 1984. Comparing the isolation rates from the various organs sampled, the intestines gave the highest rate (20.4 per cent positive), closely followed by the other internal sites. The superficial swabbed sites (eye, nasal cavity, cloaca) gave lower rates.