Risk factors, clinical features and outcomes of visceral leishmaniasis in solid-organ transplant recipients: a retrospective multicenter case-control study.

Visceral leishmaniasis (VL) is a rare disease in solid-organ transplant (SOT) recipients. Therefore, little is known about the risk factors and disease behavior in the transplant setting. This multicenter, matched case-control study (1:2 ratio) was designed to determine the risk factors, clinical features and outcomes of VL among this population. Control and case subjects were matched by center, transplant type and timing. Thirty-six VL cases were identified among 25 139 SOT recipients (0.1%). VL occurred 5.7-fold more frequently in Brazil than in Spain, presenting a median time of 11 months after transplantation. High-dose prednisone in the preceding 6 months was associated with VL. Patients were diagnosed over 1 month after symptom onset in 25% of cases. Thirty-one patients (86%) were febrile upon diagnosis, 81% exhibited visceromegaly and 47% showed pancytopenia. Concomitant infection was common. Parasites were identified in 89% of patients; the remaining patients were diagnosed by serology. The majority of the patients received amphotericin B. Relapses occurred in 25.7% of cases, and the crude mortality rate was 2.8%. VL after SOT is related to the VL prevalence in the general population. Delayed diagnosis frequently occurs. Liposomal amphotericin is the most commonly used therapy; mortality is low, although relapses are common.

Predictors of the short- and long-term survival of HIV-infected patients admitted to a Brazilian intensive care unit.

The outcomes of HIV-infected patients requiring critical care have improved. However, in developing countries, information about HIV-infected patients admitted to intensive care units (ICUs) is scarce. We describe the prognosis of HIV-infected patients admitted to a Brazilian ICU and the factors predictive of short- and long-term survival. A historical cohort study, including HIV-infected patients admitted to a Brazilian ICU at an HIV/AIDS reference hospital, was conducted. Survivors were followed up for 24 months after ICU discharge. Demographic, clinical and laboratory data, disease severity scores and mortality were evaluated. Data were analysed using survival and regression models. One hundred and twenty-five patients were studied. In-ICU and in-hospital mortality rates were 46.4% and 68.0%, respectively. Multivariate analysis showed that the in-ICU mortality was significantly associated with APACHE (Acute Physiology and Chronic Health Evaluation) II scores (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.03-1.11), mechanical ventilation (OR, 6.39; 95% CI, 1.29-31.76), tuberculosis treatment (OR, 2.62; 95% CI, 1.03-6.71), use of antiretroviral therapy (OR, 0.19; 95% CI, 0.05-0.77) and septic shock (OR, 4.38; 95% CI, 1.78-10.76). Septic shock was also associated with long-term survival (hazard ratio, 3.0; 95% CI, 1.31-6.90). In-hospital and in-ICU mortality were higher than those reported for developed countries. ICU admission mostly due to AIDS-related diseases may explain these differences.

Hepatosplenic schistosomiasis in field-based studies: a combined clinical and sonographic definition.

A combined clinical and sonographic classification of hepatosplenic schistosomiasis mansoni to be used in field-based studies is proposed herein. Seven hundred forty one individuals out of 892 (83%), living in an area endemic for schistosomiasis in Brazil, have been submitted to clinical and ultrasound examinations. Based on two stool examinations the overall prevalence for schistosomiasis in this area was 73%. Abdominal palpation was performed with patients in dorsal decubit, during deep breath, by two experienced physicians and a portable ultrasound was used for the evaluation of liver fibrosis, portal collaterals and spleen size. Four groups of individuals were identified using data obtained by abdominal palpation and ultrasound examination: (1) palpable spleen and intense periportal thickening in 9 individuals (1.2%); (2) spleen not palpable and intense periportal thickening in 15 (2%); (3) palpable spleen with light to moderate periportal thickening in 32 (4.3%), and (4) palpable spleen with a normal liver on ultrasound in 30 (4%). The definition of hepatosplenic schistosomiasis in field-based studies as the finding of Schistosoma mansoni eggs in the stools in an individual with splenomegaly is not acceptable anymore. Abdominal ultrasound should be combined with clinical examination to accurately identify hepatosplenics in endemic areas for schistosomiasis.

Population dynamics of bacteria in Arctic sea ice.

The dynamics of bacterial populations in annual sea ice were measured throughout the vernal bloom of ice algae near Resolute in the Canadian Arctic. The maximum concentration of bacteria was 6.0·10(11) cells·m(-2) (about 2.0·10(10) cells·l(-1)) and average cell volume was 0.473 µm(3) in the lower 4 cm of the ice sheet. On average, 37% of the bacteria were epiphytic and were most commonly attached (70%) to the dominant alga,Nitzschia frigida (58% of total algal numbers). Bacterial population dynamics appeared exponential, and specific growth rates were higher in the early season (0.058 day(-1)), when algal biomass was increasing, than in the later season (0.0247 day(-1)), when algal biomass was declining. The proportion of epiphytes and the average number of epiphytes per alga increased significantly (P<0.05) through the course of the algal bloom. The net production of bacteria was 67.1 mgC·m(-2) throughout the algal bloom period, of which 45.5 mgC·m(-2) occurred during the phase of declining algal biomass. Net algal production was 1942 mgC·m(-2). Sea ice bacteria (both arctic and antarctic) are more abundant than expected on the basis of relationships between bacterioplankton and chlorophyll concentrations in temperate waters, but ice bacteria biomass and net production are nonetheless small compared with the ice algal blooms that presumably support them.