SARS: Market, toilet, hospital, and laboratory

published_or_final_versio

Emerging infectious diseases in Hong Kong.

published_or_final_versio

Penicillium marneffei recombinant antigen Mp1p and penicilliosis marneffei in HIV and non-HIV patients

published_or_final_versio

Human infection by avian influenza A H5N1

The Southeast Asian outbreak of the highly lethal avian influenza A HSN1 infection in humans is unlikely to abate because of the enormous number of backyard farms providing poultry as the main source of food protein in developing countries. This increases the risk of the emergence of a reassortant pandemic influenza virus with improved human-to-human transmissibility. Currently triage of suspected cases by epidemiological risk factors remains the only practical way of case identification for laboratory investigation and infection control. The clinical usefulness of rapid diagnostic laboratory tests requires more vigorous evaluation. The lethality of this disease may reflect systemic viral dissemination, cytokine storm, or alveolar flooding due to inhibition of cellular sodium channels. The present circulating genotype Z is intrinsically resistant to amantadine and rimantadine. Prognosis may be improved by early treatment with a neuraminidase inhibitor with good systemic drug levels, and post-exposure prophylaxis for health care workers is recommended. The role of immunomodulators and other modalities of therapy requires evaluation in randomised controlled trials, with prospective monitoring of the viral load and cytokine profiles in various clinical specimens. In view of the high fatality of the disease, a combination of contact, droplet, and airborne precautions are recommended as long as resources allow despite the fact that the relative importance of these three modes in nosocomial transmission of avian influenza is still unknown.published_or_final_versio

Differential selection and mutation between dsDNA and ssDNA phages shape the evolution of their genomic AT percentage

Background: Bacterial genomes differ dramatically in AT%. We have developed a model to show that the genomic AT% in rapidly replicating bacterial species can be used as an index of the availability of nucleotides A and T for DNA replication in cellular medium. This index is then used to (1) study the evolution and adaptation of the bacteriophage genomic AT% in response to the differential nucleotide availability of the host and (2) test the prediction that double-stranded DNA (dsDNA) phage should exhibit better adaptation than single-stranded DNA (ssDNA) phage because the rate of spontaneous deamination, which leads to C→T or C→U mutations depending on whether C is methylated or not, is about 100-fold greater in ssDNA than in dsDNA. Results: We retrieved 79 dsDNA phage and 27 ssDNA phage genomes together with their host genomic sequences. The dsDNA phages have their genomic AT% better adapted to the host genomic AT% than ssDNA phage. The poorer adaptation of the ssDNA phage can be partially accounted for by the C→T(U) mutations mediated by the spontaneous deamination. For ssDNA phage, the genomic A% is more strongly correlated with their host genomic AT% than the genomic T%. Conclusion: A significant fraction of variation in the genomic AT% in the dsDNA phage, and that in the genomic A% and T% of the ssDNA phage, can be explained by the difference in selection and mutation between them. © 2005 Xia and Yuen; licensee BioMed Central Ltd.published_or_final_versio

Red imported fire ants in Hong Kong

published_or_final_versio

Avian influenza A/H5N1 virus: Management in human and bird

published_or_final_versio

Influenza vaccination: Options and issues

Currently available vaccines have similar efficacy if they are matched to the most prevalent circulating strains. They also have comparable adverse effect profiles. The choice of a specific preparation of vaccine therefore requires consideration of cost, purity of the vaccine preparation in terms of the amount of egg protein and endotoxin, allergy to different constituents of the vaccine, reactogenicity profiles, as well as the preferred route of administration. Intradermal injection of the vaccine appears to be a viable alternative to the traditional intramuscular administration with the additional benefit of requiring a smaller volume of vaccine. Despite the documented benefits in various community and institutional settings, influenza vaccination has been underutilised by most target groups. A major obstacle to broader coverage of vaccination is the perceived ineffectiveness of the vaccine and the relatively benign nature of the illness in most patients. Uptake of vaccine among target populations, especially health care workers, needs to be improved through a concerted effort between frontline clinicians and health authorities.published_or_final_versio

Infectious complications of liver transplantation

Sixteen (50%) of the 32 patients who received liver transplantations from October 1991 to March 1993 at Queen Mary Hospital, Hong Kong, developed viral, bacterial, or fungal infections. The viral infections were largely a result of immunosuppression while accidental bowel perforation, bile leak at the anastomosis, and delayed onset of stricture of the bile duct anastomosis were responsible for the intra-abdominal bacterial or fungal infections. Although the incidence of infectious complications was high, all patients were managed effectively and only one patient with lymphoproliferative disorder died. Infectious complications can lead to a prolonged hospital stay and a substantially increased hospital cost. The adoption of new immunosuppressive regimes that can better prevent acute graft rejection and adherence to meticulous surgical technique will help to reduce the infectious complications of liver transplantation in the future.published_or_final_versio

Live recombinant Salmonella oral vaccine against avian influenza viruses

published_or_final_versio