Detection of human norovirus in intestinal biopsies from immunocompromised transplant patients

Human noroviruses (HuNoVs) can often cause chronic infections in solid organ and haematopoietic stem cell transplant (HSCT) patients. Based on histopathological changes observed during HuNoV infections, the intestine is the presumed site of virus replication in patients; however, the cell types infected by HuNoVs remain unknown. The objective of this study was to characterize histopathological changes during HuNoV infection and to determine the cell types that may be permissive for HuNoV replication in transplant patients. We analysed biopsies from HuNoV-infected and non-infected (control) transplant patients to assess histopathological changes in conjunction with detection of HuNoV antigens to identify the infected cell types. HuNoV infection in immunocompromised patients was associated with histopathological changes such as disorganization and flattening of the intestinal epithelium. The HuNoV major capsid protein, VP1, was detected in all segments of the small intestine, in areas of biopsies that showed histopathological changes. Specifically, VP1 was detected in enterocytes, macrophages, T cells and dendritic cells. HuNoV replication was investigated by detecting the non-structural proteins, RdRp and VPg. We detected RdRp and VPg along with VP1 in duodenal and jejunal enterocytes. These results provide critical insights into histological changes due to HuNoV infection in immunocompromised patients and propose human enterocytes as a physiologically relevant cell type for HuNoV cultivation.

Prevalence and risk factors of acquiring Strongyloides stercoralis infection among patients attending a tertiary hospital in Thailand

OBJECTIVES

We aimed to determine the prevalence and risk factors for Strongyloides stercoralis infection in adult patients attending Siriraj Hospital, a tertiary hospital in Thailand.

METHODS

A case-control study was carried out between July 2008 and April 2010. Case and control were identified from 6022 patients for whom results of faecal examination were available. A case was a patient who had S. stercoralis larva detected from faecal examination. Control was randomly selected from patients without S. stercoralis larvae detected in three consecutive faecal examinations. The proportion of control to case was 2 : 1. Demographic and clinical data for the day of diagnosis and retrospectively up to 15 days preceding the date of faecal examination were reviewed from their medical records.

RESULTS

Overall, 149 (2.47%) patients had S. stercoralis larvae positive. There were 105 males (70.5%), with the mean (SD) age of 53.9 (17.2) years. A total of 300 controls were selected. Male gender (odds ratio (OR)  =  2.79, 95% confidence interval (CI) 1.78-4.27)), human immunodeficiency virus (HIV) infection (OR  =  3.23, 95% CI 1.43-7.29), and eosinophilia (OR  =  1.81, 95% CI 1.33-2.47) were found to be independent risk factors associated with S. stercoralis infection in this setting. Corticosteroid or other immunosuppressive treatment, and other concomitant illnesses were not associated with increased risk of S. stercoralis infection.

CONCLUSION

In this setting, strongyloidiasis was seen more often in male patients with eosinophilia and with HIV infection. Prevention of fatal complication caused by S. stercoralis by regular faecal examination, or serology for early detection and treatment of undiagnosed S. stercoralis infection, is warranted in these high-risk patients.

Isolated intradural-extramedullary spinal cysticercosis: a case report

Spinal cysticercosis is an uncommon manifestation of neurocysticercosis (NCC). We present a case of isolated lumbar intradural-extramedullary NCC. The patient was treated successfully with the surgical removal of the cyst. Spinal NCC should be considered in the differential diagnosis in high-risk populations with new symptoms suggestive of a spinal mass lesion.

Serum procalcitonin in diagnosis of bacteremia

OBJECTIVE

To (a) determine the diagnostic value of procalcitonin (PCT) in differentiating sepsis with or without bacteremia, (b) evaluate the correlation of PCT levels to severity of sepsis, (c) establish the prognostic value in predicting the outcome of sepsis and (d) evaluate the correlation among different assays.

MATERIAL AND METHOD

A prospective study was carried out from August through November 2007. Blood for PCT levels and culture were drawn simultaneously.

RESULTS

Fifty-six patients with clinical suspicious of sepsis were enrolled in the study; bacteremia (n = 30) and non-bacteremia (n = 26). There were good correlations between the PCT levels measured by three assays (p < 0.001). At the threshold of 0.5 ng/mL, PCT had > 90% sensitivity for diagnosis of bacteremia. Of the bacteremic group, median PCT levels measured by Kryptor and VIDAS assays were 12.4 and 16.6 ng/mL respectively. In the non-bacteremic group, median PCT levels measured by Kryptor and VIDAS were 4.2 and 4.9 ng/mL respectively. PCT levels were significantly higher in the bacteremic group (p = 0.04). The optimum thresholds to discriminate between these two groups were found to be 5, 6.5 and 2 ng/mL for Kryptor, VIDAS and PCT-Q, respectively. In addition, correlations of PCT and increasing values of the APACHE II score were observed. PCT levels in the severe sepsis and MOD group were also found to be significantly higher

CONCLUSION

PCT was highly sensitive in detecting bacteremia, although not very accurate in differentiating bacteremic from non-bacteremic SIRS in adult patients.

Fulminating influenza pneumonia in the elderly: a case demonstration

An 82-year-old male Bangkokian with hypertension, diabetes mellitus, end-stage renal disease, and coronary artery disease for many years, was hospitalized due to deterioration of a 3-day influenza-like-illness with one-day chest oppression and respiratory failure. At the emergency room, oxygen saturation was 79% on room air Chest X-ray revealed bilateral diffuse pulmonary infiltrates. He was intubated and hemodialysis was initiated. Emergency coronary angiography revealed patent coronary artery. Sputum gram stain revealed numerous leukocytes with no bacteria. On day three of hospitalization, empiric treatment with oseltamivir and clarithromycin was administered Seventy-two hours later his clinical condition began to improve and fever subsided 7 days later Rapid test of tracheal secretion with immunofluorescence assay was positive for moderate amount of influenza A virus. Viral isolation yielded influenza A virus subtype H1N1. Review of in-patient records at this hospital using ICD-10 codes as J10 and J11 during 1995-2005, discovered 32 cases with claim diagnosis of influenza. However this is the first case with proven influenza pneumonia that was given empiric oseltamivir. Rapid deterioration of influenza-like illness due to human influenza virus in the elderly and pathogenesis of pulmonary in this case are discussed to alert physicians to recognize this dreadful illness and treat it in timely fashion.

Comparison of clinical features and survival between cryptococcosis in human immunodeficiency virus (HIV)-positive and HIV-negative patients

Cryptococcosis is a life-threatening fungal infection among human immunodeficiency virus (HIV)-positive patients and also occurs frequently in HIV-negative patients. A retrospective cohort study was conducted among patients with cryptococcosis. Clinical manifestations, laboratory findings, treatment, and outcomes for 149 HIV-positive and 29 HIV-negative patients were compared. Neurological involvement occurred more frequently in HIV-positive patients (91.9 versus 20.7%, P<0.001), whereas pulmonary involvement was more frequently observed in HIV-negative patients (34.5 versus 2.7%, P<0.001). Ninety percent of HIV-positive patients and 74% of HIV-negative patients had positive serum cryptococcal antigen (P=0.119). HIV-positive patients were more likely to have a cerebrospinal fluid (CSF) preparation that is positive for India ink staining (81 versus 50%, P<0.001) and a CSF cryptococcal antigen titer of > or =1:1,024 (61.1 versus 16.7%, P=0.038). Most of the patients in both groups received amphotericin B as the primary therapy. Cryptococcosis-related mortality was high and did not differ between the two groups (22.2 versus 34.5%, P=0.162). Kaplan-Meier analysis revealed that HIV-positive patients had a higher relapse rate (P=0.011), especially among those lacking antiretroviral therapy. In conclusion, clinical presentation of cryptococcosis among HIV-negative patients varies and differs from that of HIV-positive patients. Awareness and prompt management are crucial for establishing a diagnosis and initiating proper treatment.

Cryptococcal meningoradiculitis: an atypical presentation after initiation of antiretroviral therapy

Atypical presentations of cryptococcal infection have been described as clinical manifestations of immune reconstitution inflammatory syndrome (IRIS) in HIV-infected patients following commence of antiretroviral therapy (ART). The authors describe a patient presenting with cryptococcal meningoradiculitis two weeks after initiation of ART. In patients with advanced HIV disease, immune reconstitution induced by ART can precipitate onset of atypical clinical manifestations in those patients with latent cryptococcal infection of the central nervous system.

Impact of Antiretroviral Therapy on the Relapse of Cryptococcosis and Survival of HIV-Infected Patients with Cryptococcal Infection

BACKGROUND

Cryptococcosis is an opportunistic infection with morbidity and mortality in HIV-infected patients. Impact of antiretroviral therapy (ART) on the relapse of cryptococcosis and survival of HIV-infected patients with cryptococcosis has not been well established.

METHODS

A retrospective cohort study of HIV-infected patients with cryptococcosis during 1997-2005 was conducted. Relapse and survival rates with corresponding risk factors were determined.

RESULTS

There were 149 patients with a mean age of 33.5+/-7.4 years and 57% were male. Median CD4 cell count was 22 cells/mm(3). After exclusion of patients who died or were lost to follow-up during the first two weeks, 127 patients were eligible for the analysis of the effect of ART on relapse and survival rates. Of 127 patients, 52 received ART. The demographic data between the two groups were similar. Median time of ART initiation after cryptococcal diagnosis was 2.6 months. The most frequent ART used was NNRTI-based regimen (88.4%). Median CD4 change at six months of ART was 97 cells/mm(3) and 87.9% achieved undetectable HIV-RNA. The cumulative 75% survival (free) from relapse duration was 10.4 months in no-ART group and 41.9 months in ART group (P<0.01). The 75% survival from cryptococcal-related mortality in no-ART group was 6.4 months whereas >54 months for ART group (P<0.01). In Cox proportional hazards model, ART was the only factor that associated with lower relapse and mortality rate (P<0.01).

CONCLUSIONS

ART significantly reduced relapse and mortality rate from cryptococcosis in HIV-infected patients. ART is strongly recommended in this population and should not be delayed.