An analysis of the utilisation of chemoprophylaxis against Pneumocystis jirovecii pneumonia in patients with malignancy receiving corticosteroid therapy at a cancer hospital

Pneumocystis jirovecii pneumonia (PCP) is associated with high mortality in immunocompromised patients without human immunodeficiency virus infection. However, chemoprophylaxis is highly effective. In patients with solid tumours or haematologic malignancy, several risk factors for developing PCP have been identified, predominantly corticosteroid therapy. The aims of this study were to identify the potentially preventable cases of PCP in patients receiving corticosteroid therapy at a tertiary care cancer centre and to estimate the frequency of utilisation of chemoprophylaxis in these patients. Two retrospective reviews were performed. Over a 10-year period, 14 cases of PCP were identified: no cases were attributable to failed chemoprophylaxis, drug allergy or intolerance. During a 6-month period, 73 patients received high-dose corticosteroid therapy (⩾25 mg prednisolone or ⩾4 mg dexamethasone daily) for ⩾4 weeks. Of these, 22 (30%) had haematologic malignancy, and 51 (70%) had solid tumours. Fewer patients with solid tumours received prophylaxis compared to patients with haematologic malignancy (3.9 vs 63.6%, P<0.0001). Guidelines for PCP chemoprophylaxis in patients with haematologic malignancy or solid tumours who receive corticosteroid therapy are proposed. Successful primary prevention of PCP in this population will require a multifaceted approach targeting the suboptimal prescribing patterns for chemoprophylaxis

The Effect of Recurrent Floods on Genetic Composition of Marble Trout Populations

A changing global climate can threaten the diversity of species and ecosystems. We explore the consequences of catastrophic disturbances in determining the evolutionary and demographic histories of secluded marble trout populations in Slovenian streams subjected to weather extremes, in particular recurrent flash floods and debris flows causing massive mortalities. Using microsatellite data, a pattern of extreme genetic differentiation was found among populations (global FST of 0.716), which exceeds the highest values reported in freshwater fish. All locations showed low levels of genetic diversity as evidenced by low heterozygosities and a mean of only 2 alleles per locus, with few or no rare alleles. Many loci showed a discontinuous allele distribution, with missing alleles across the allele size range, suggestive of a population contraction. Accordingly, bottleneck episodes were inferred for all samples with a reduction in population size of 3–4 orders of magnitude. The reduced level of genetic diversity observed in all populations implies a strong impact of genetic drift, and suggests that along with limited gene flow, genetic differentiation might have been exacerbated by recurrent mortalities likely caused by flash flood and debris flows. Due to its low evolutionary potential the species might fail to cope with an intensification and altered frequency of flash flood events predicted to occur with climate change

Biotypes of oral Candida albicans isolates in human immunodeficiency virus-infected patients from diverse geographic locations

11-96% of patients with HIV infection develop oral candidosis at some point during the progression of HIV infection to AIDS. In the early stages of HIV infection, the development of oral candidosis is highly predictive of worsening immunodeficiency. Despite its importance as a sentinel opportunistic infection in HIV disease, however, little is known about the epidemiology of the major etiological agent, Candida albicans, associated with the disease. The authors conducted a study to identify the different biotypes of C. albicans isolated from oral samples of HIV-infected patients from Hong Kong, Australia, Germany, and England, and to gain insight into their geographic distribution. 33 isolates from Hong Kong, 37 from Australia, 30 from Germany, and 17 from England were characterized using a biotyping system based upon enzyme profiles, carbohydrate assimilation patterns, and boric acid resistance of the yeasts. 44 biotypes were identified. A1R and A1S were the two major biotypes, accounting for 17.9% and 11.1% of all isolates, respectively, isolated from all the regions studied. Some other biotypes were unique to individual countries. This study therefore found that there are many different sub-strains of oral Candida albicans in HIV-infected patients, some of which are globally prevalent.link_to_subscribed_fulltex