Archive for December, 2010

Infection With Transmissible Strains of Pseudomonas aeruginosa and Clinical Outcomes in Adults With Cystic Fibrosis.

JAMA. 2010 Nov 17 V.304 N.19 p.2145-2153.

Aaron SD, Vandemheen KL, Ramotar K, Giesbrecht-Lewis T, Tullis E, Freitag A, Paterson N, Jackson M, Lougheed MD, Dowson C, Kumar V, Ferris W, Chan F, Doucette S, Fergusson D.

Ottawa Hospital, General Campus, 501 Smyth Rd, Ottawa, ON, Canada, K1H 8L6.



Studies from Australia and the United Kingdom have shown that some patients with cystic fibrosis are infected with common transmissible strains of Pseudomonas aeruginosa.


To determine the prevalence and incidence of infection with transmissible strains of P aeruginosa and whether presence of the organism was associated with adverse clinical outcomes in Canada.


Prospective observational cohort study of adult patients cared for at cystic fibrosis clinics in Ontario, Canada, with enrollment from September 2005 to September 2008. Sputum was collected at baseline, 3 months, and yearly thereafter for 3 years; and retrieved P aeruginosa isolates were genotyped. Vital status (death or lung transplant) was assessed for all enrolled patients until December 31, 2009.


Incidence and prevalence of P aeruginosa isolation, rates of decline in lung function, and time to death or lung transplantation.


Of the 446 patients with cystic fibrosis studied, 102 were discovered to be infected with 1 of 2 common transmissible strains of P aeruginosa at study entry. Sixty-seven patients were infected with strain A (15%), 32 were infected with strain B (7%), and 3 were simultaneously infected with both strains (0.6%). Strain A was found to be genetically identical to the Liverpool epidemic strain but strain B has not been previously described as an epidemic strain. The incidence rate of new infections with these 2 transmissible strains was relatively low (7.0 per 1000 person-years; 95% confidence interval [CI], 1.8-12.2 per 1000 person-years). Compared with patients infected with unique strains of P aeruginosa, patients infected with the Liverpool epidemic strain (strain A) and strain B had similar declines in lung function (difference in decline in percent predicted forced expiratory volume in the first second of expiration of 0.64% per year [95% CI, -1.52% to 2.80% per year] and 1.66% per year [95% CI, -1.00% to 4.30%], respectively). However, the 3-year rate of death or lung transplantation was greater in those infected with the Liverpool epidemic strain (18.6%) compared with those infected with unique strains (8.7%) (adjusted hazard ratio, 3.26 [95% CI, 1.41 to 7.54]; P = .01).


A common strain of P aeruginosa (Liverpool epidemic strain/strain A) infects patients with cystic fibrosis in Canada and the United Kingdom. Infection with this strain in adult Canadian patients with cystic fibrosis was associated with a greater risk of death or lung transplantation.


December 29, 2010 at 11:11 pm Leave a comment

Long term risk for hypertension, renal impairment, and cardiovascular disease after gastroenteritis from drinking water contaminated with Escherichia coli O157:H7: a prospective cohort study.

BMJ. 2010 Nov 17; 341

Clark WF, Sontrop JM, Macnab JJ, Salvadori M, Moist L, Suri R, Garg AX.

Division of Nephrology, Department of Medicine, London Health Sciences Centre, London, ON, Canada.



To evaluate the risk for hypertension, renal impairment, and cardiovascular disease within eight years of gastroenteritis from drinking water contaminated with Escherichia coli O157:H7 and Campylobacter.


A prospective cohort study. Setting Walkerton, Ontario, Canada.


1977 adult participants in the Walkerton Health Study recruited between 2002 and 2005 after an outbreak of gastroenteritis in May 2000, when a municipal water system was contaminated, with no pre-outbreak history of outcome measures.


Information was collected annually via survey, physical examination, and laboratory assessment. Primary measures were acute gastroenteritis (diarrhoeal illness lasting >3 days, bloody diarrhoea, or >3 loose stools/day), hypertension (blood pressure ≥140/90 mm Hg), and renal impairment (microalbuminuria or estimated glomerular filtration rate <60 ml/min/1.73 m(2)). Self reported physician diagnosis of cardiovascular disease (myocardial infarction, stroke, or congestive heart failure) was a secondary outcome.


Acute gastroenteritis at the time of the outbreak was reported by 1067 (54%) of participants. Incident hypertension was detected in 697 (35%) (294 (32%) of group not exposed to acute gastroenteritis v 403 (38%) of exposed group). While 572 (29%) had at least one indicator of renal impairment (266 (29%) of unexposed v 306 (29%) of exposed), only 30 (1.5%) had both (8 (0.9%) of unexposed v 22 (2.1%) of exposed). Cardiovascular disease was reported by 33/1749 (1.9%). The adjusted hazard ratios for hypertension and cardiovascular disease after acute gastroenteritis were 1.33 (95% confidence interval 1.14 to 1.54) and 2.13 (1.03 to 4.43) respectively. The adjusted hazard ratio for the presence of either indicator of renal impairment was 1.15 (0.97 to 1.35) and was 3.41 (1.51 to 7.71) for the presence of both.


Gastroenteritis from drinking water contaminated with E coli O157:H7 and Campylobacter was associated with an increased risk for hypertension, renal impairment, and self reported cardiovascular disease. Annual monitoring of blood pressure and periodic monitoring of renal function may be warranted for individuals who experience E coli O157:H7 gastroenteritis.


December 29, 2010 at 11:09 pm Leave a comment

Expanded HIV Screening in the United States: What Will It Cost Government Discretionary and Entitlement Programs? A Budget Impact Analysis

Value Health 2010 Oct 15

Erika G. Martin PhD, MPH1,*, A. David Paltiel PhD2, Rochelle P. Walensky MD, MPH3,4,5, Bruce R. Schackman PhD6


The US Centers for Disease Control and Prevention (CDC) recently revised their HIV screening guidelines to promote testing and earlier entry to care. Prior analyses have examined the policy’s cost-effectiveness but have not evaluated its impact on government budgets.


We used a simulation model of HIV screening, disease, and treatment to determine the budget impact of expanded HIV screening to US government discretionary, entitlement, and testing programs. We estimated total and incremental testing and treatment costs over a 5-year time horizon under current and expanded screening scenarios. We used CDC estimates of HIV prevalence and annual incidence, and considered variations in screening frequency, test return rates, linkage to care, test characteristics, and eligibility for government screening and treatment programs.


Under current practice, 177,000 new HIV cases will be identified over 5 years. Expanded screening will identify an additional 46,000 cases at an incremental 5-year cost of $2.7 billion. The financial burden of expanded HIV screening will fall disproportionately on discretionary programs that fund care for newly identified patients and will not be offset by entitlement program savings. Testing will represent a small proportion (18%) of the total budget increase. Costs are sensitive to the frequency of screening and the proportion linked to care.


The expanded HIV screening program will have a large downstream impact on government programs that fund HIV care. Expanded HIV screening will not meet early treatment goals unless government programs have sufficient budgets to expand testing and provide care for newly identified cases.


December 29, 2010 at 11:06 pm Leave a comment

HIV-1 viral escape in cerebrospinal fluid of subjects on suppressive antiretroviral treatment.

J Infect Dis. 2010 Dec 15  V.202 N.12 p.1819-25

Edén A, Fuchs D, Hagberg L, Nilsson S, Spudich S, Svennerholm B, Price RW, Gisslén M.

Department of Infectious Diseases, The Sahlgrenska Academy at University of Gothenburg, Sweden.

Comment in:

J Infect Dis. 2010 Dec 15;202(12):1768-9.



Occasional cases of viral escape in cerebrospinal fluid (CSF) despite suppression of plasma human immunodeficiency virus type 1 (HIV-1) RNA have been reported. We investigated CSF viral escape in subjects treated with commonly used antiretroviral therapy regimens in relation to intrathecal immune activation and central nervous system penetration effectiveness (CPE) rank.


Sixty-nine neurologically asymptomatic subjects treated with antiretroviral therapy >6 months and plasma HIV-1 RNA <50 copies/mL were cross-sectionally included in the analysis. Antiretroviral therapy regimens included efavirenz, lopinavir/ritonavir or atazanavir/ritonavir combined with tenofovir, abacavir, or zidovudine and emtricitabine or lamivudine. HIV-1 RNA was analyzed with real-time polymerase chain reaction assays. Neopterin was analyzed by enzyme-linked immunosorbent assay.


Seven (10%) of the 69 subjects had detectable CSF HIV-1 RNA, in median 121 copies/mL (interquartile range, 54-213 copies/mL). Subjects with detectable CSF virus had significantly higher CSF neopterin and longer duration of treatment. Previous treatment interruptions were more common in subjects with CSF escape. Central nervous system penetration effectiveness rank was not a significant predictor of detectable CSF virus or CSF neopterin levels.


Viral escape in CSF is more common than previously reported, suggesting that low-grade central nervous system infection may continue in treated patients. Although these findings need extension in longitudinal studies, they suggest the utility of monitoring CSF responses, as new treatment combinations and strategies modify clinical practice


J Infect Dis. 2010 Dec 15 V.202 N.12 p.1768-9.

Viral escape in cerebrospinal fluid–an achilles heel of HIV therapy?

Clifford DB.

Comment on:

J Infect Dis. 2010 Dec 15;202(12):1819-25.


December 29, 2010 at 11:04 pm Leave a comment

New Delhi Metallo-β-Lactamase in Klebsiella pneumoniae and Escherichia coli, Canada

Emerging Infectious Diseases January 2011  V.17 N.1

Michael R. Mulvey,  Jennifer M. Grant, Katherine Plewes, Diane Roscoe, and David A. Boyd

Public Health Agency of Canada, Winnipeg, Manitoba, Canada (M.R. Mulvey, D.A. Boyd); and Vancouver General Hospital, Vancouver, British Columbia, Canada (J.M. Grant, K. Plewes, D. Roscoe)


Multidrug-resistant Klebsiella pneumoniae and Escherichia coli isolates harboring New Delhi metallo-b-lactamase (NDM-1) were isolated from a patient who had returned to Canada from India. The NDM-1 gene was found on closely related incompatibility group A/C type plasmids. The occurrence of NDM-1 in North America is a major public health concern.

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December 24, 2010 at 5:21 pm Leave a comment

Emergence of Rickettsia africae, Oceania

Emerging Infectious Diseases January 2011  V.17 N.1

Carole Eldin, Oleg Mediannikov, Bernard Davoust, Olivier Cabre, Nicolas Barré, Didier Raoult, and Philippe Parola

Université de la Méditerranée, Marseille, France (C. Eldin, O. Mediannikov, B. Davoust, D. Raoult, P. Parola); French Army Health Service, Marseille (B. Davoust, O. Cabre); and Institut Agronomique néo-Calédonien, Païta, New Caledonia (N. Barré)


We detected Rickettsia africae, the agent of African tick-bite fever (ATBF), by amplification of fragments of gltA, ompA, and ompB genes from 3 specimens of Amblyomma loculosum ticks collected from humans and birds in New Caledonia. Clinicians who treat persons in this region should be on alert for ATBF.

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December 24, 2010 at 5:20 pm Leave a comment

Identification of Rickettsial Infections by Using Cutaneous Swab Specimens and PCR

Emerging Infectious Diseases January 2011  V.17 N.1

Yassina Bechah, Cristina Socolovschi, and Didier Raoult

Université de la Méditerranée, Marseille, France


To determine the usefulness of noninvasive cutaneous swab specimens for detecting rickettsiae, we tested skin eschars from 6 guinea pigs and from 9 humans. Specimens from eschars in guinea pigs were positive for rickettsiae as long as lesions were present. Optimal storage temperature for specimens was 4°C for 3 days.

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December 24, 2010 at 5:18 pm Leave a comment

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