S. S. Y. Wong

Serodiagnosis of Penicillium marneffei infection.

Diagnosis of Penicillium marneffei infection is often made late. We evaluated an indirect immunofluorescent antibody test for P marneffei in serum from 103 patients with persistent fever and from 78 normal subjects. Germinating conidia (initial tissue-invasion phase) and yeast-hyphae (tissue multiplication phase) forms were used as antigen. All 8 documented P marneffei cases (8%) had an IgG titre of 160 or more; the other 95 patients and all the healthy controls had an IgG titre of 40 or below. Blood culture was positive in only 1 case with HIV infection. Biopsy and culture of tissues were necessary for confirmation in the other 7 cases. The test could provide rapid presumptive diagnosis and supplement conventional culture.

Human enterovirus 71 and hand, foot and mouth disease

Hand, foot and mouth disease (HFMD) is generally a benign febrile exanthematous childhood disease caused by human enteroviruses. The route of transmission is postulated to be faeco-oral in developing areas but attributed more to respiratory droplet in developed areas. Transmission is facilitated by the prolonged environmental survival of these viruses and their greater resistance to biocides. Serious outbreaks with neurological and cardiopulmonary complications caused by human enterovirus 71 (HEV-71) seem to be commoner in the Asian Pacific region than elsewhere in the world. This geographical predilection is unexplained but could be related to the frequency of intra- and inter-typic genetic recombinations of the virus, the host populations genetic predisposition, environmental hygiene, and standard of healthcare. Vaccine development could be hampered by the general mildness of the illness and rapid genetic evolution of the virus. Antivirals are not readily available; the role of intravenous immunoglobulin in the treatment of serious complications should be investigated. Monitoring of this disease and its epidemiology in the densely populated Asia Pacific epicentre is important for the detection of emerging epidemics due to enteroviruses.

A prospective study of symptomatic bacteremia following platelet transfusion and of its management

BACKGROUND: The danger of bacteremia due to contaminated platelets is not well known. There are also no established guidelines for the management of febrile reactions after platelet transfusion.

Bacteremia Caused by Escherichia coli producing Extended-spectrum Beta-lactamase: a Case-control Study of Risk Factors and Outcomes*

A case-control study was conducted in order to identify the risk factors associated with bloodstream infection caused by Escherichia coli producing extended-spectrum β-lactamase (ESBL) and to determine the outcomes of infected patients. Risk factors associated with ESBL production, according to univariate analysis, included a history of recent hospitalization [odds ratio (OR) 4.3, 95% confidence interval (CI) 2.1-8.9; p < 0.001], severe underlying diseases (OR 15, 95% CI 4.4-51.5; p < 0.001), prior exposure to urinary catheters (OR 8.3, 95% CI 3.2-21.7; p < 0.001) and nosocomial (OR 14.1, 95% CI 6.1-32.8; p < 0.001) or urinary (OR 3.6, 95% CI 1.7-7.4; p < 0.001) origin of the bacteria. Multivariate analysis revealed that severe underlying diseases (OR 31.2, 95% CI 6.7-144; p < 0.001) and nosocomial (OR 16.5, 95% CI 5.6-49; p < 0.001) and urinary origins (OR 7.8, 95% CI 2.6-23.8; p < 0.001) of the bacteria were independently associated with ESBL production in bacteremic E. coli. Crude mortality in case patients was more than twice as high as that in controls (p = 0.04). Production of ESBL increased the risk of inappropriate initial therapy (OR 95.6, 95% CI 27.4-334.2; p < 0.001). Treatment failed in 4/7 case patients treated with ceftazidime to which the isolate was susceptible in vitro. Our findings have implications for the choice of empirical therapy in nosocomial urinary tract infection.

Differential susceptibility of different cell lines to swine-origin influenza A H1N1, seasonal human influenza A H1N1, and avian influenza A H5N1 viruses

BACKGROUNDnThe novel swine-origin influenza A H1N1 virus (S-OIV) causes the current pandemic. Its tissue tropism and replication in different cell lines are not well understood.nnnOBJECTIVEnCompare the growth characteristics of cell lines infected by S-OIV, seasonal influenza A H1N1 (sH1N1) and avian influenza A H5N1 (H5N1) viruses and the effect of temperature on viral replication.nnnSTUDY DESIGNnCytopathic effect (CPE), antigen expression by immunofluorescence (IF) and viral load profile by quantitative RT-PCR in 17 cell lines infected by S-OIV, sH1N1 and H5N1 were examined. Comparison of their replication efficiency in chick embryo was performed. The effect of temperature on viral replication in Madin-Darby canine kidney (MDCK) cells was determined by TCID(50) at 33 degrees C, 37 degrees C and 39 degrees C for 5 consecutive days.nnnRESULTSnS-OIV replicated in cell lines derived from different tissues or organs and host species with comparable viral load to sH1N1. Among 13 human cell lines tested, Caco-2 has the highest viral load for S-OIV. S-OIV showed a low viral load with no CPE or antigen expression in pig kidney cell PK-15, H5N1 demonstrated the most diverse cell tropism by CPE and antigen expression, and the highest viral replication efficiency in both cell lines and allantoic fluid. All three viruses demonstrated best growth at 37 degrees C in MDCK cells.nnnCONCLUSIONnCell line growth characteristics of S-OIV, sH1N1 and H5N1 appear to correlate clinically and pathologically with involved anatomical sites and severity. Low replication of S-OIV in PK-15 suggests that this virus is more adapted to human than swine.

Differences in Clinical and Laboratory Diagnostic Characteristics of Penicilliosis Marneffei in Human Immunodeficiency Virus (HIV)- and Non-HIV-Infected Patients

ABSTRACT We compared the clinical and laboratory features of human immunodeficiency virus (HIV)- and non-HIV-infected patients with penicilliosis marneffei. HIV-infected patients had a higher incidence of fungemia. A total of 85.7% of the HIV-negative patients had underlying diseases including hematologic malignancies or had received therapy with corticosteroids or cytotoxic agents. By aPenicillium marneffei-specific mannoprotein Mp1p enzyme-linked immunosorbent assay, serum antigen titers were found to be higher in HIV-positive patients, whereas serum antibody levels were found to be higher in HIV-negative patients.

Immunorestitution diseases in patients not infected with HIV.

Abstractu2002The aim of this study was to assess the clinical spectrum of immunorestitution disease (IRD) in hospitalized patients over a 12-month period. In nine of 18 patients who presented with clinical deterioration during reduction or cessation of immunosuppressants (n=6) or bone marrow engraftment (n=3), IRD cases included the following infections: scabies infestation (n=1); gastric strongyloidiasis (n=1); hepatosplenic candidiasis (n=1); methicillin-resistant Staphylococcus aureus abscess formation (n=2); polyomavirus-related hemorrhagic cystitis (n=3); and influenza A pneumonitis (n=1). Immunopathological damage during withdrawal of immunosuppression is an incidental way to uncover an asymptomatic infectious disease. Serial monitoring of hematological and clinical profiles is essential in making a diagnosis of IRD.

Cellulitis complicating lymphoedema.

Abstractu2002In ten hospitalised patients with cellulitis complicating lymphoedema encountered over a 3-year period (1996–1998), the underlying diseases were carcinoma of the cervix (n=4), uterus (n=1), vagina (n=1), breast (n=2) and nasopharynx (n=1), and retroperitoneal squamous cell carcinoma (n=1). Three of the ten patients had positive blood cultures, compared to none of the 20 age-matched, sex-matched controls hospitalised for cellulitis without lymphoedema. The mean duration of fever, tachycardia and cellulitis was significantly longer in patients with lymphoedema than in those without (P<0.05, P<0.05, and P<0.005 respectively). Early treatment initiated by patients themselves may help stop bacterial replication in the initial stages and minimise further damage to the lymphatic system.

Disseminated Ochroconis gallopavum infection in a renal transplant recipient: The first reported case and a review of the literature

Ochroconis gallopavum is a potentially fatal dematiaceous fungus causing opportunistic infections in immunocompromised hosts. We report the first case of disseminated O. gallopavum infection in a 13-year-old renal transplant recipient, which involved the brain, lung and spleen. He was treated with amphotericin B, itraconazole and voriconazole, a new antifungal agent first used to treat such an infection. Besides antifungal treatment, all immunosuppressive agents were stopped and automated peritoneal dialysis was resumed. The initial infection was under control with both clinical and radiological improvements after treatment. However, the patient later acquired Acremonium spp. peritonitis; he failed to respond to high-dose amphotericin B, and finally succumbed. A total of 13 reported O. gallopavum human infections, including the one described here, are reviewed. The most common site of involvement is the brain and the crude mortality rate is up to 46%. As the disease is potentially lethal in immunocompromised hosts, empirical antifungal coverage should be considered in post-renal transplant recipients with suspected brain abscess. Early biopsy of lesion for histopathological and microbiological diagnosis would be essential in managing such cases.

Penicillium marneffei fungaemia in an allogeneic bone marrow transplant recipient

Penicillium marneffei is the most important thermal dimorphic fungus causing respiratory, skin and systemic mycosis in Southeast Asia.1, 2, 3 About 8% of AIDS patients in Hong Kong are infected with P. marneffei. Clinically, penicilliosis manifests as a systemic febrile illness, which results from intracellular infection of the reticuloendothelial cells by the yeast phase of the fungus. Besides HIV-positive patients, P. marneffei infections have been reported in other immunocompromised patients, such as renal transplant recipients, patients with systemic lupus erythematosus and patients who are receiving corticosteroid therapy.4, 5 Here, we describe the first case of P. marneffei infection in a bone marrow transplant recipient.