Influenza virus load in hospitalised patients.

1. Hospitalised patients with severe influenza have persistently high viral loads, for whom a different therapeutic approach may be needed. 2. Active screening of influenza infection should be performed in all high-risk patients hospitalised with febrile respiratory illness. Early diagnosis and treatment to suppress the high viral load may maximise clinical benefit. 3. For late presenting high risk patients with severe symptoms, their viral load may remain high, and initiation of antiviral treatment may still be worthwhile. 4. More stringent infection control measures, including strict droplet precautions and preferably isolation for an extended period of time may be necessary owing to prolonged viral shedding. 5. Randomised, controlled trials are indicated to address timing and dosage of treatment for severe influenza infection.

Interferon gamma release assay for differentiating tuberculosis among pneumonia cases in acute healthcare setting.

OBJECTIVES: Early diagnosis of smear-negative tuberculosis remains challenging. The role of an interferon-gamma release assay (IGRA) in discriminating active pulmonary tuberculosis (PTB) among cases of 'pneumonia' was investigated. METHODS: Consecutive patients admitted to an acute hospital in Hong Kong (intermediate TB burden) during 2006-2008 because of pneumonia and suspected PTB were recruited for IGRA (Quantiferon-TB Gold, QFN-G) study. Diagnosis of tuberculosis was confirmed by mycobacterial culture or histology. RESULTS: Altogether 179 patients were recruited (median (IQR) age 59 (44-75), 68.7% male); active PTB was confirmed in 63 (35.2%). Among the AFB-smear-negative 'pneumonias' (n = 152), age>50 (OR 0.27, 95% CI 0.09-0.84), absence of weight loss (OR 0.30, 95% CI 0.10-0.88), and negative IGRA (OR 0.08, 95% CI 0.03-0.25) were independently associated with lower risks of PTB. The overall sensitivity, specificity, positive and negative predictive values for the IGRA in diagnosing active PTB were 60%, 87%, 72% and 80% respectively. Among smear-negative 'pneumonias' (n = 152), the performance values of IGRA were 64%, 87%, 62% and 88% respectively; in the absence of characteristic clinical or radiographic features of PTB, the negative predictive value (NPV) improved to 90-95%. CONCLUSIONS: The high NPV of QFN-G among smear-negative 'pneumonias' can be useful for risk stratification in hospitalized patients suspected of PTB. Further investigation on the role of these assays in patient management is warranted.

Outcomes of adults hospitalised with severe influenza.

BACKGROUND: The aim of this study was to investigate factors affecting clinical outcomes of adults hospitalised with severe seasonal influenza. METHODS: A prospective, observational cohort study was conducted over 24 months (2007-2008) in two acute, general hospitals. Consecutive, hospitalised adult patients were recruited and followed once their laboratory diagnosis of influenza A/B was established (based on viral antigen detection and virus isolation from nasopharyngeal aspirates collected per protocol). Outcomes studied included in-hospital death, length of stay and duration of oxygen therapy. Factors affecting outcomes were analysed using multivariate Cox proportional hazards models. Sequencing analysis on the neuraminidase gene was performed for available H1N1 isolates. RESULTS: 754 patients were studied (influenza A, n=539; >75% H3N2). Their mean age was 70+/-18 years; co-morbidities and serious complications were common (61-77%). Supplemental oxygen and ventilatory support was required in 401 (53.2%) and 41 (5.4%) patients, respectively. 39 (5.2%) patients died; pneumonia, respiratory failure and sepsis were the causes. 395 (52%) patients received antiviral (oseltamivir) treatment. Omission of antiviral treatment was associated with delayed presentation or negative antigen detection results. The mortality rate was 4.56 and 7.42 per 1000 patient-days in the treated and untreated patients, respectively; among those with co-morbidities, it was 5.62 and 11.64 per 1000 patient-days, respectively. In multivariate analysis, antiviral use was associated with reduced risk of death (adjusted HR (aHR) 0.27 (95% CI 0.13 to 0.55); p<0.001). Improved survival was observed with treatment started within 4 days from onset. Earlier hospital discharge (aHR 1.28 (95% CI 1.04 to 1.57); p=0.019) and faster discontinuation of oxygen therapy (aHR 1.30 (95% CI 1.01 to 1.69); p=0.043) was associated with early treatment within 2 days. Few (n=15) H1N1 isolates in this cohort had the H275Y mutation. CONCLUSIONS: Antiviral treatment for severe influenza is associated with reduced mortality and improved clinical outcomes.

The NCEP-ATPIII but not the IDF criteria for the metabolic syndrome identify Type 2 diabetic patients at increased risk of chronic kidney disease.

AIM: To examine the association between chronic kidney disease (CKD) and the metabolic syndrome (MetS) using both International Diabetes Federation (IDF) and National Cholesterol Education Program's Adult Treatment Panel III (NCEP-ATPIII) definitions in Chinese subjects with Type 2 diabetes. METHODS: Subjects with Type 2 diabetes were categorized according to the presence or absence of MetS by IDF or NCEP-ATPIII criteria. CKD was considered present if glomerular filtration rate, calculated using the abbreviated equation developed by the Modification of Diet in Renal Disease study with Chinese modification, was < 60 ml/min per 1.73 m2. Multivariate logistic regression analysis of the association between CKD and MetS by either definition was performed. RESULTS: Of 6350 subjects (mean age 55.1 +/- 13.3 years), 3439 (54.2%) and 3204 (50.5%) had MetS by IDF and NCEP-ATPIII definitions, respectively. Using the IDF definition, the presence of MetS was not associated with CKD [odds ratio (OR) 0.96, 95% confidence interval (CI) 0.71, 1.29, P = 0.784]. In contrast, the association with CKD was significant when MetS was defined by the NCEP-ATPIII definition (OR 1.75, 95% CI 1.37, 2.24, P < 0.001). In subjects who did not have MetS (n = 2911) as defined by IDF criteria, 997 fulfilled the MetS criteria of NCEP-ATP III. The association with CKD was stronger, after adjustment for covariates, in these subjects (OR 1.42, 95% CI 1.03, 1.97, P = 0.032) compared with subjects who met IDF criteria of MetS. CONCLUSION: In Type 2 diabetes, NCEP-ATPIII, but not the IDF definition of MetS, identifies a subgroup of patients who have a higher risk of CKD.

Cardiovascular risks and metabolic syndrome in Hong Kong Chinese women with polycystic ovary syndrome.

BACKGROUND: Women with polycystic ovary syndrome (PCOS) frequently exhibit central obesity, glucose intolerance, atherogenic dyslipidaemia and hypertension which are characteristic features of the metabolic syndrome (MetS). METHODS: A total of 295 premenopausal Chinese women with PCOS diagnosed by the Rotterdam criteria (mean age: 30.2 +/- 6.4 years) and 98 control subjects without PCOS were evaluated for prevalence of MetS and cardiovascular risk factors, including dyslipidaemia and dysglycaemia. RESULTS: Using the 2005 modified Adult Treatment Panel III criteria, MetS (presence of three or more risk factors) was found in 24.9% of PCOS women compared to 3.1% of controls. The prevalence of MetS in PCOS women increased from 16.7% at under 30 years of age to 53.3% at over 40 years. MetS was also more prevalent in overweight and obese (41.3%) than normal-weight PCOS women (0.9%). However, multivariate regression analysis showed that women with PCOS had a 5-fold increase in risk of MetS (odds ratio 4.90; 95% confidence interval: 1.35-17.84) compared with women without PCOS even after controlling for age and BMI, suggesting PCOS alone is an independent risk factor for MetS. CONCLUSIONS: There is high prevalence of MetS in Hong Kong Chinese women with PCOS despite their relatively young age. Recognition of these cardiometabolic risk factors requires a high level of awareness in conjunction with early and regular screening.

Islet autoimmunity status in Asians with young-onset diabetes (12-40 years): association with clinical characteristics, beta cell function and cardio-metabolic risk factors.

In this paper, the islet autoimmunity status and relation to clinical characteristics, beta cell function and cardio-metabolic risk factors in young-onset Asian diabetic patients are evaluated at baseline. The study population consisted of 912 patients (from China, India, Malaysia and Singapore) with age 12-40 years and diabetes duration <12 months. Autoantibodies to glutamic acid decarboxylase (GADA) and tyrosine phosphatase (IA-2A), beta cell function and cardio-metabolic risk parameters were assessed. Among our young patient cohort, 105 (11.5%) patients were GADA and/or IA-2A positives (Ab +ve). Ab +ve patients were younger, leaner, had more severe hyperglycaemia and lower beta cell function. The frequency of metabolic syndrome was significantly lower in Ab +ve patients (27%) compared to Ab -ve patients (54%). However, a substantial proportion of patients in both groups of patients had atherogenic dyslipidaemia, hypertension and albuminuria (micro or macro). In our study cohort, only one in 10 Asian youth with new-onset diabetes had evidence of islet autoimmunity. At least 60% of Ab +ve and 50% of Ab -ve patients demonstrated classical features of type 1 and type 2 diabetes respectively. Regardless of autoimmunity status, the cardio-metabolic risk factors, in particular atherogenic dyslipidaemia, hypertension and albuminuria were common in our patients with young-onset diabetes.

Co-circulation of human metapneumovirus and SARS-associated coronavirus during a major nosocomial SARS outbreak in Hong Kong.

BACKGROUND: The clinico-epidemiological significance of human metapneumovirus (hMPV) detected during the SARS outbreak is unknown. OBJECTIVES: To characterize a nosocomial hMPV outbreak during the 2003 SARS epidemic. STUDY DESIGN AND METHODS: All available nasopharyngeal aspirate (NPA) collected from confirmed patients during the first 8 weeks of the SARS outbreak in 2003 were tested for hMPV by a nested RT-PCR assay targeting the F-gene. Clinico-epidemiological information was used to analyze the relationship of hMPV co-infection to specific risk factors (demographics/symptoms/outcomes; status as health-care workers (HCWs)/patients; history of exposure/contact; ward location). Multivariate logistic regression analysis was performed to determine independent risk factors. RESULTS: An hMPV outbreak occurred during 6-16 March 2003 (first week of the Hong Kong SARS epidemic). hMPV RNA was detected in 31 of 155 (20%) NPAs from SARS patients. HCW status (OR 2.72, 95% CI 1.11-6.68; p=0.029) or epidemiological linkage to the SARS outbreak ward (OR 3.59, 95% CI 1.42-9.05; p=0.007) were independent factors associated with hMPV infection. Symptoms of cough and coryza were more common in co-infected individuals (22.6% vs. 15.9%) but this was not statistically significant. Other clinical manifestations and outcomes were not different in co-infected patients. CONCLUSIONS: A major nosocomial hMPV outbreak involving HCWs occurred during the early SARS epidemic. Patients with dual hMPV and SARS infection were not sicker than those with SARS infection only.

Hypercytokinemia and hyperactivation of phospho-p38 mitogen-activated protein kinase in severe human influenza A virus infection.

BACKGROUND: We postulate that hypercytokinemia plays a role in immunopathogenesis of severe human influenza. METHODS: We prospectively studied 39 consecutive patients who were hospitalized with severe influenza A virus infection. On laboratory confirmation of the diagnosis, paired acute-phase (obtained at hospital admission) and convalescent-phase (obtained >10 days after hospital admission) plasma samples were collected for assay of 11 cytokines and chemokines (interleukin [IL] 1 beta; IL-6; IL-10; IL-12p70; tumor necrosis factor alpha; IL-8; monokine induced by interferon [IFN]-gamma; IFN-inducible protein 10; monocyte chemoattractant protein 1; regulated upon activation, normal T cell-expressed and secreted; and IFN-gamma) using cytometric bead-array analysis and enzyme-linked immunosorbent assay. Simultaneously, virus concentration in the acute-phase nasopharyngeal aspirate was determined using real-time quantitative reverse-transcriptase polymerase chain reaction. Intracellular signaling molecules regulating lymphocyte activation, phospho-p38 mitogen-activated protein kinase and phospho-extracellular signal-regulated protein kinase in CD4+ and CD8+ T lymphocytes were studied in the acute-phase samples using flow cytometric analysis and were compared with results for samples from healthy control subjects. RESULTS: Statistically significant increases in plasma IL-6 (3.7-fold increase), IL-8 (2.6-fold increase), IFN-induced protein 10 (4.9-fold increase), and monokine induced by IFN-gamma (2.3-fold increase) concentrations were detected during acute illness (P < .01 for all, by Wilcoxon signed-rank test); the highest concentrations were observed on symptom days 3 and 4. Corresponding plasma cytokine and chemokine concentrations and nasopharyngeal viral loads showed statistically significant correlations (rho = 0.41, 0.49, 0.54, and 0.46, respectively; P < or = .01). Phospho-p38 mitogen-activated protein kinase expression in CD4+ lymphocytes was increased, correlating with cytokine concentrations (e.g., for IFN-induced protein 10, rho = 0.78; P < .01); phospho-extracellular signal-regulated protein kinase was suppressed. Advanced age and comorbidity were associated with aberrant IL-6, IL-8, and monokine induced by IFN-gamma responses (P < .05, by Mann-Whitney U test). An elevated IL-6 concentration was independently associated with prolonged hospitalization (hospitalization for >5 days; P = .02), adjusted for age, comorbidity, and virus load. CONCLUSIONS: Hypercytokinemia (of proinflammatory and T helper 1 cytokines) is detected in severe influenza, correlating with clinical illness and virus concentration. Hyperactivation of phospho-p38 mitogen-activated protein kinase (in T helper cells) is possibly involved. Early viral suppression may attenuate these potentially deleterious cytokine responses.

Interactive effect of retinopathy and macroalbuminuria on all-cause mortality, cardiovascular and renal end points in Chinese patients with Type 2 diabetes mellitus.

AIMS: To examine the effect of albuminuria and retinopathy on the risk of cardiovascular and renal events, and all-cause mortality in patients with Type 2 diabetes. METHODS: A post-hoc analysis of 4416 Chinese patients without macrovascular complications at baseline (age 57.6 +/- 13.3 years). Glomerular filtration rate (eGFR) was estimated by the abbreviated Modification of Diet in Renal Disease Study Group Formula, further adjusted for Chinese ethnicity. Clinical end points were all-cause mortality, cardiovascular events (heart failure or angina, myocardial infarction, lower limb amputation, re-vascularization procedures and stroke) and renal end points (reduction in eGFR by more than 50% or eGFR < 15 ml/min/1.73 m2 or death as a result of renal causes or need for dialysis). RESULTS: Compared with individuals without complications, subjects with retinopathy and macroalbuminuria had higher rates of cardiovascular events (14.1 vs. 2.4%), renal events (40.0 vs. 0.8%) and death (9.3 vs. 1.7%, P < 0.001). For composite event of death, cardiovascular and renal events, the presence of retinopathy, microalbuminuria alone, macroalbuminuria alone, retinopathy with microalbuminuria or retinopathy with macroalbuminuria increased the risk [hazard ratio (95% CI)] by 1.61 (1.05 to 2.47; P = 0.04), 1.93 (1.38 to 2.69; P < 0.001), 4.34 (3.02 to 6.22; P < 0.001), 2.59 [1.76 to 3.81; P < 0.001) and 6.83 (4.89 to 9.55; P < 0.001) fold, respectively. The relative excess risk as a result of interaction between retinopathy and macroalbuminuria was 15.31, implying biological interaction in the development of renal events. CONCLUSIONS: In Chinese patients with Type 2 diabetes, retinopathy interacts with macroalbuminuria to increase the risk of composite cardio-renal events.

A Chinese family with familial paraganglioma syndrome due to succinate dehydrogenase deficiency.

We report the genetic characteristics of a family with familial paraganglioma syndrome. The index patient was diagnosed with carcinoid tumour of the bronchus at the age of 30 years then later diagnosed with bilateral phaeochromocytoma. His sister had bilateral carotid body tumours. Mutational analyses of succinate dehydrogenase B and SDHD on the index patient showed him to be heterozygous for the M1I mutation of the SDHD gene. A genetic analysis revealed that his sister also had succinate dehydrogenase deficiency with the same mutation. Pre-symptomatic testing confirmed the genetic diagnosis, and led to a clinical diagnosis in an otherwise asymptomatic sibling. Comparison with other known cases of M1I mutation suggests that this is a founder mutation in the Chinese population. Genetic analysis of the succinate dehydrogenase genes can provide a specific diagnosis and allow for genetic screening of at-risk individuals.

Fecal viral concentration and diarrhea in norovirus gastroenteritis.

Fecal viral concentrations of 40 patients infected with norovirus genogroup GII.4 correlated with diarrhea duration and frequency of vomiting. Higher viral concentration and older age were independently associated with prolonged diarrhea (> or =4 days). These findings provide information on the pathogenesis and transmission of norovirus infections.

Role of laboratory variables in differentiating SARS-coronavirus from other causes of community-acquired pneumonia within the first 72 h of hospitalization.

The Centers for Disease Control and Prevention (CDC) recommend that SARS-coronavirus (SARS-CoV) testing be considered in epidemiologically high-risk patients hospitalized with community-acquired pneumonia (CAP) if no alternative diagnosis is identified after 72 h. The aim of this study was to identify routine laboratory variables that might indicate the need for SARS-CoV testing. Routine hematological/biochemical variables in patients with laboratory-confirmed SARS (2003) were compared with those in consecutive patients hospitalized June-December 2004 with radiologically confirmed CAP. Stepwise logistic regression analyses were performed to identify discriminating variables at baseline and by day 3 of hospitalization. Nasopharyngeal aspiration and antigen detection for influenza virus and respiratory syncytial virus using an immunofluorescence assay (IFA) were routinely performed in patients with CAP. Altogether, 181 patients with CAP (who remained undiagnosed by IFA) and 303 patients with SARS were studied. The mean intervals from symptom onset to admission were 3.1 and 2.8 days, respectively (p > 0.05). The etiological agent of CAP was identified retrospectively in only 39% of cases, the majority being bacterial pathogens. At baseline, age and absolute neutrophil count (ANC) were the only independent discriminating variables (p < 0.0001). Using a value of <4.4 x 10(9)/l as the cutoff for ANC, the sensitivity and specificity of ANC for discriminating SARS were 64 and 95%, respectively (AUC 0.90). By day 3 of hospitalization, age (p < 0.0001), change in ANC (p = 0.0003), and change in bilirubin (p = 0.0065) were discriminating variables. A model combining age <65 years, a change in ANC of >-3 x 10(9)/l, and a change in bilirubin of > or =0 mmol/l had a sensitivity of 43% and a specificity of 95% for SARS (AUC 0.90). There are only a few laboratory features (including lymphopenia) that clearly discriminate SARS from other causes of CAP. Nevertheless, when evaluating epidemiologically high-risk patients with CAP and no immediate alternative diagnosis, a low ANC on presentation along with poor clinical and laboratory responses after 72 h of antibiotic treatment may raise the index of suspicion for SARS and indicate a need to perform SARS-CoV testing.

End-stage renal disease risk equations for Hong Kong Chinese patients with type 2 diabetes: Hong Kong Diabetes Registry.

AIMS/HYPOTHESIS: The objective of the study was to investigate risk factors and develop risk equations for end-stage renal disease (ESRD) in Chinese patients with type 2 diabetes. SUBJECTS AND METHODS: A prospective cohort of 4,438 patients with type 2 diabetes mellitus and without ESRD (median observation period 2.9 years, interquartile range 1.6-4.1 years) was included in the analysis. The end-point (ESRD) was defined by: (1) death due to diabetes with renal manifestations or renal failure; (2) hospitalisation due to renal failure; (3) estimated GFR (eGFR) <15 ml min(-1) 1.73 m(-2). Cox proportional hazards regression was used to develop risk equations. The data were randomly and evenly divided into the training data for development of the risk equations and the test data for validation. The validation was performed using the area under the receiver operating characteristic curve (aROC), which takes into account follow-up time and censoring. RESULTS: During the observation period, 159 patients or 12.45 per 1,000 person-years (95% CI 10.52-14.37 per 1,000 person-years) developed ESRD. Known duration of diabetes, systolic blood pressure, log(10) total cholesterol:HDL cholesterol ratio and retinopathy were significant predictors of ESRD. After further adjusting for eGFR, log(10) spot albumin:creatinine ratio (ACR) and haematocrit, only eGFR, haematocrit and log(10) ACR remained as independent predictors of ESRD. The risk equation derived from these three independent predictors had good discrimination, with an aROC of 0.97. CONCLUSIONS/INTERPRETATION: Estimated GFR, haematocrit and ACR were independent predictors of ESRD and the derived risk equation performed well in Chinese patients with type 2 diabetes.

Chronic hepatitis B viral infection independently predicts renal outcome in type 2 diabetic patients.

AIMS/HYPOTHESIS: We examined the association between chronic hepatitis B virus (HBV) infection and clinical outcomes in a consecutive cohort of Chinese patients with type 2 diabetes. SUBJECTS, MATERIALS AND METHODS: Between 1995 and 1999, 2,838 type 2 diabetes patients underwent comprehensive assessments and blood screening for hepatitis B surface antigen (HBsAg). The risk of occurrence of cardiovascular events and end-stage renal disease (defined as need for dialysis, doubling of serum creatinine or serum creatinine > or =500 micromol/l) was compared between HBsAg-positive and HBsAg-negative groups. RESULTS: At baseline, HBV-infected patients (n=286, 10.1%) were younger (51.0+/-11.5 vs 53.7+/-12.7 years, p=0.004), had earlier onset of diabetes (51.0+/-11.5 vs 53.7+/-12.7 years, p=0.001) and a higher frequency of retinopathy (28 vs 22%, p=0.03) than non-HBV-infected patients. After a median follow-up of 3.5 years (interquartile range: 1.7-5.9 years) and adjustment of age, glycaemic control and other potential confounding factors, HBV-infected patients were more likely to develop end-stage renal disease than non-HBV infected patients (8.7 vs 6.4%) with a hazard ratio of 4.5 (95% CI 1.1-18.6). The difference in the frequency of cardiovascular endpoints was not statistically significant. CONCLUSIONS: In Chinese type 2 diabetes patients, chronic HBV infection was associated with increased risk of end-stage renal disease, and this was independent of other potential confounding factors. Early identification of HBV status and close surveillance of renal function are important in patients with type 2 diabetes who are living in areas where HBV is endemic or who are at risk of chronic HBV infection.

The efficacy and tolerability of fosinopril in Chinese type 2 diabetic patients with moderate renal insufficiency.

BACKGROUND: The renoprotective effect of angiotensin II antagonists has been demonstrated in type 2 diabetic patients with nephropathy but similar data on angiotensin-converting enzyme (ACE) inhibitors are limited. We examined the efficacy and tolerability of fosinopril, an ACE inhibitor with dual hepatic and renal clearance, in 38 type 2 diabetic patients with moderate renal impairment (plasma creatinine 130-300 micromol/l) over a 2-year period. METHODS: This was a single-centre, randomized, double-blinded, placebo-controlled trial comparing fosinopril 20 mg daily vs. placebo in addition to conventional antihypertensive treatment over a 2-year period. The primary endpoints were the rate of change and the percentage change in both 24-h urinary albumin excretion (UAE) and creatinine clearance (CrCl). RESULTS: The mean age of the patients was 65 +/- 6 years (range 47-76 years, median 66 years) and plasma creatinine 190 +/- 49 micromol/l. For similar blood pressure control, the percentage change of UAE in patients with microalbuminuria was greater in the fosinopril than the placebo group (-24.2 +/- 28.8 vs. 11.6 +/- 42.1%, p = 0.003 after adjustment for baseline covariates). In the fosinopril group, the rate of change of endogenous CrCl was slower than the placebo group (-0.07 +/- 0.19 vs. -0.24 +/- 0.35 ml/min/week, p = 0.026). The incidence of adverse events was similar between the two groups. CONCLUSIONS: Fosinopril treatment reduced albuminuria and rate of decline in renal function in type 2 diabetic patients with moderate renal insufficiency and did not increase the incidence of adverse events.

Cryptococcosis in apparently immunocompetent patients.

BACKGROUND: Few reports have described the clinical and microbiological features of cryptococcosis in immunocompetent patients. AIM: To compare clinical presentations and outcomes of cryptococcosis in immunocompetent vs. immunocompromised patients. DESIGN: Retrospective case series. METHODS: All culture- or histology-confirmed cases (n = 46) of cryptococcosis in two acute hospitals in Hong Kong (1995-2005) were included. Clinical presentations, rates of fungaemia, cerebrospinal fluid (CSF) parameters and clinical outcomes were recorded. RESULTS: Twenty patients (43.5%) were apparently immunocompetent, 17 (37.0%) had predisposing factors other than HIV infection, and 9 (19.6%) were HIV-positive. Thirty-one (67.4%) presented with meningitis, four (8.7%) with pulmonary cryptococcosis, and 11 (23.9%) with extraneural, extrapulmonary cryptococcosis. Of the immunocompetent patients with retrievable isolates (n = 8), three (37.5%) were Cryptococcus gattii; all isolates (n = 6) from immunocompromised patients were Cryptococcus neoformans var. grubii. Immunocompetent patients more commonly presented with meningitis (80.0% vs. 47.1%, p = 0.03), and tended toward lower rates of fungaemia (10.0% vs. 35.3%, p = 0.06) and mortality (25.0% vs. 52.9%, p = 0.06). Death was associated with fungaemia (p = 0.01) and underlying malignancy (p < 0.01). In cryptococcal meningitis, immunocompetent patients had longer mean time from illness onset to presentation (34.4 vs. 12.6 days, p = 0.02), more intense inflammatory responses (CSF: white blood cells 108 vs. 35 x 10(9)/l, p = 0.03; protein 1.61 g/l vs. 0.79 g/l, p = 0.07), less fungaemia (0% vs. 26.7%, p = 0.04) and more satisfactory clinical outcomes (81.3% vs. 46.7%, p = 0.04). DISCUSSION: A substantial proportion of patients with cryptococcosis are apparently immunocompetent. C. neoformans var. grubii and C. gattii are the common causes. Immunocompetent patients tend to present with localized, indolent neurological disease, with more intense inflammatory responses but better clinical outcomes.