A Model of Tuberculosis Transmission and Intervention Strategies in an Urban Residential Area

The model herein aims to explore the dynamics of the spread of tuberculosis (TB) in an informal settlement or township. The population is divided into households of various sizes and also based on commuting status. The model dynamics distinguishes between three distinct social patterns: the exposure of commuters during travel, random diurnal interaction and familial exposure at night. Following the general SLIR models, the population is further segmented into susceptible (S), exposed/latently infected (L), active/infectious (I), and recovered (R) individuals. During the daytime, commuters travel on public transport, while non-commuters randomly interact in the community to mimic chance encounters with infectious persons. At night, each family interacts and sleeps together in the home. The risk of exposure to TB is based on the proximity, duration, and frequency of encounters with infectious persons. The model is applied to a hypothetical population to explore the effects of different intervention strategies including vaccination, wearing of masks or scarves during the commute, prophylactic treatment of latent infections and more effective case-finding and treatment. The most important findings of the model are: (1) members of larger families are responsible for more disease transmissions than those from smaller families, (2) daily commutes on public transport provide ideal conditions for transmission of the disease, (3) improved diagnosis and treatment has the greatest impact on the spread of the disease, and (4) detecting TB at the first clinic visit, when patients are still smear negative, is key

A Model of Tuberculosis Transmission and Intervention Strategies in an Urban Residential Area

The model herein aims to explore the dynamics of the spread of tuberculosis (TB) in an informal settlement or township. The population is divided into households of various sizes and also based on commuting status. The model dynamics distinguishes between three distinct social patterns: the exposure of commuters during travel, random diurnal interaction and familial exposure at night. Following the general SLIR models, the population is further segmented into susceptible (S), exposed/latently infected (L), active/infectious (I), and recovered (R) individuals. During the daytime, commuters travel on public transport, while non-commuters randomly interact in the community to mimic chance encounters with infectious persons. At night, each family interacts and sleeps together in the home. The risk of exposure to TB is based on the proximity, duration, and frequency of encounters with infectious persons. The model is applied to a hypothetical population to explore the effects of different intervention strategies including vaccination, wearing of masks or scarves during the commute, prophylactic treatment of latent infections and more effective case-finding and treatment. The most important findings of the model are: (1) members of larger families are responsible for more disease transmissions than those from smaller families, (2) daily commutes on public transport provide ideal conditions for transmission of the disease, (3) improved diagnosis and treatment has the greatest impact on the spread of the disease, and (4) detecting TB at the first clinic visit, when patients are still smear negative, is key

Treatment and outcomes of invasive fusariosis: review of 65 cases from the PATH Alliance ® registry

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109347/1/myc12212.pd

Management and prophylaxis of infections after BMT/SCT

Management of febrile neutropenia page 357 Empiric antibiotic treatment for febrile neutropenia 357 Management of continued febrile neutropenia in the absence of documented infection (fever of unknown origin) 359 Treatment of specific infections and localizing signs and symptoms of infection 360 Prevention of infections in HSCT patients 366 Antiviral prophylaxis 368 Transplant-related considerations for hepatitis B and C 369 Management of infections 370 Management of specific infections 370 Interstitial pneumonitis 373 Further reading 378 Management of febrile neutropenia Empiric antibiotic treatment for febrile neutropenia Neutropenia as a consequence of cytoreductive chemotherapy is associated with increased risk of serious infections. This risk starts to increase when the absolute neutrophil count (ANC) decreases to less than 1000 cells/mm3 and further increases dramatically when it is less than 500 cells/mm3. A bloodstream infection develops in approximately 10%–20% with neutrophil counts less than 100 cells/mm3. Less often, pneumonia, cellulitis, catheter-related infections, or herpesvirus reactivations occur, causing fever. Fungal infections rarely cause initial fever during neutropenia; they typically occur after a week or more of neutropenia. Notably, fewer than half of all initial episodes of fever and neutropenia are “fever of undetermined origin” (FUO), with no identifiable source of infection despite examination, radiographs, and cultures. FUO patients cannot be reliably distinguished from those with documented infections on presentation, through signs or symptoms or blood tests. Therefore, all neutropenic patients should be treated immediately with a specific regimen of broad-spectrum antibiotics if there is any suspicion of infection, and especially if fever occurs, as there is danger of rapidly progressive sepsis

Mucor circinelloides Was Identified by Molecular Methods as a Cause of Primary Cutaneous Zygomycosis

A case of primary cutaneous zygomycosis caused by Mucor circinelloides is described. Histopathology showed typical hyphae along with chlamydospores. The isolate was identified by molecular and phenotypic methods. The utility of sequence analysis of the internal transcribed spacer region is highlighted; however, further studies are needed to assess species genetic heterogeneity

Valganciclovir for cytomegalovirus prevention in solid organ transplant patients: an evidence-based reassessment of safety and efficacy.

BACKGROUND:Several anti-viral drugs have demonstrated efficacy in preventing Cytomegalovirus (CMV) infections in solid organ transplant (SOT) patients. The recently approved valganciclovir is the most commonly used and most expensive drug for CMV prevention. The safety and efficacy data have been drawn from a single trial. We hypothesized that valganciclovir may not be as safe as nor more effective than other therapies for CMV prevention. METHODS:All experimental and analytical studies that compared valganciclovir with other therapies for prevention of CMV infection after SOT were selected. Based on meta-analytic and multivariate regression methodologies we critically analyzed all available evidence. FINDINGS:Nine studies were included (N = 1,831). In trials comparing valganciclovir with ganciclovir, the risk for CMV disease is 0.98 (95% Confidence Interval (95%CI) 0.67 to 1.43; P = 0.92; I(2) = 0%). Valganciclovir was significantly associated with the risk of absolute neutropenia (<1,500/mm(3)) compared with all therapies (Odds Ratio (OR) 3.63 95%CI 1.75 to 7.53; P = 0.001; I(2) = 0%); with ganciclovir only (OR 2.88, 95%CI 1.27 to 6.53; P = 0.01; I(2) = 0%); or with non-ganciclovir therapies (OR 8.30, 95%CI 1.51 to 45.58; P = 0.01; I(2) = 10%). For a neutropenia cut-off of <1,000/mm(3), the risk remained elevated (OR 1.97, 95%CI 1.03 to 3.67; P = 0.04; I(2) = 0%). For every 24 patients who receive valganciclovir prophylaxis, one more will develop neutropenia compared to other therapies. The risk of late-onset CMV disease with valganciclovir was similar to ganciclovir and higher than those with non-ganciclovir therapies (OR 8.95, 95%CI 1.07 to 74.83; P = 0.04; I(2) = 0%]. One more patient will develop late-onset CMV disease for every 25 who receive valganciclovir compared to treatment with non-ganciclovir therapies. The risk of CMV tissue-invasive disease in liver recipients receiving valganciclovir was 4.5 times the risk seen with ganciclovir [95%CI 1.00 to 20.14] (p = 0.04). All results remained consistent across different study designs, valganciclovir doses, and CMV serostatus. CONCLUSIONS:Valganciclovir shows no superior efficacy and significantly higher risk of absolute neutropenia, CMV late-onset disease, and CMV tissue-invasive disease compared to other standard therapies. Due to the availability of efficacious, safer, and lower cost drugs (high-dose acyclovir, valacyclovir, ganciclovir), our results do not favor the use of valganciclovir as a first-line agent for CMV preemptive or universal prophylaxis in SOT patients

Use of a Panfungal PCR Assay for Detection of Fungal Pathogens in a Commercial Blood Culture System

A panfungal PCR assay was used to evaluate the ability of the ESP blood culture system to detect fungemia. The results showed that the ESP system is reliable for the detection of fungi and showed the applicability of using a molecular-based assay as a potential rapid and reliable method for the identification of fungi