H5N1

CIDRAP: News scan for February 15

Via CIDRAP: NEWS SCAN: H5N1 reports from Nepal, possible H7N3 in Mexico, flu and RSV seasonality, NDM bacteria cluster. Excerpt:

Eight patients in a Denver hospital last year harbored Klebsiella pneumoniae carrying New Delhi metallo-beta-lactamase (NDM), an enzyme that confers resistance to many antimicrobials, marking the biggest such outbreak in the United States so far, according to the Centers for Disease Control and Prevention (CDC). 

The outbreak was first spotted with the detection of carbapenem-resistant K pneumoniae (CRKP) in respiratory samples from two patients in July and August, says an article in today's Morbidity and Mortality Weekly Report (MMWR). Review of records and surveillance cultures identified six more cases. 

The patients had been hospitalized for a median of 18 days before CRKP was identified. Three of them were treated for CRKP infections, and five were found to be asymptomatically colonized. All of them survived. Tests revealed that the initial isolates were resistant to all antimicrobials except tigecycline. 

An epidemiologic investigation suggested that multiple transmission events had occurred and that "undetected, asymptomatically colonized patients were involved in some transmission routes." 

How the pathogen got into the hospital was unclear. Before this outbreak, only 16 isolates of NDM-producing carbapenem-resistant Enterobacteriaceae (CRE) had been found in the United States, 14 of them in patients who had received medical care in South Asia. 

In a Health Alert Network advisory e-mailed to reporters today, the CDC said that, of the 37 unusual forms of CRE reported in the United States, 15 have been reported since July 2012. The agency called for healthcare providers to act aggressively to prevent the emergence and spread of these organisms.

Branswell: More than just flu this season

Via The Edmonton Journal, a report by Helen Branswell of The Canadian Press: It's not just flu, folks - plenty of viruses making the rounds. Excerpt:

After a couple of relatively mild seasons, this year the flu is really making headlines. 

But there are a lot of viruses making the rounds this winter. It's easy to mistake one for another — and hard even for doctors to tell some of them apart at times. 

This is, after all, the sick season. The cold-and-flu season. A time for the spread of viruses that make folks wheeze and sneeze and feel like crap. 

It's also a time for viruses that tether you to the bathroom. Let's take a look at some of the bugs that are making people sick these days.

Branswell deals concisely with influenza, respiratory syncytial virus, and norovirus. Not a story recommended for hypochondriacs.

Chile: 30% increase in respiratory illnesses in 2012

Thanks to FLUCARD.ORG for tweeting the link to this report from biobiochile.cl: Autoridades de salud revelan aumento de 30% de enfermedades respiratorias en 2012. [Health authorities report 30% increase in respiratory illnesses in 2012] Bear in mind that Chile is just coming out of the winter season. Excerpt, with my translation:

En 2012 se registró un 30 por ciento más de casos de personas afectadas por virus respiratorios que en 2011, siendo el Virus Sincicial el que produjo mayores problemas de salud durante esta temporada. Esto, según la evaluación del Ministerio de Salud posterior al cierre del Plan de Invierno 2012. 

In 2012, 30 per cent more persons with respiratory viruses were reported than in 2011, with syncytial virus causing major health problems during this season. This, according to the evaluation of the Ministry of Health after the close of the 2012 Winter Plan.

Como el año con el mayor número de consultas y hospitalizaciones por enfermedades respiratorias catalogó el Subsecretario de Salud Pública, Jorge Díaz, el 2012. Según la autoridad de salud, durante el Plan de Invierno de este año hubo un incremento en todas las variables de atención clínica. 

Jorge Díaz, subsecretary of Public Health, described 2012 as the year with the most consultations and hospitalizations over respiratory disease. According to him, this year's Winter Plan saw an increase in all the cases requiring clinical attention.

Además de estos altos índices, el peak de casos observados se retrasó, registrándose en 2011 el mayor número afectados por virus respiratorios en la semana epidemiológica número 23, mientras que en 2012 se registró en la semana 27.

In addition to these high numbers, the peak of high numbers has come later. In 2011 the largest numbers affected by respiratory viruses were in epidemiological week 23, while in 2012 they were recorded in week 27.

Viral infection and susceptibility to asthma

Via Nature Medicine:  Early infection with respiratory syncytial virus impairs regulatory T cell function and increases susceptibility to allergic asthma. The abstract:

Immune tolerance is instituted early in life, during which time regulatory T (Treg) cells have an important role. Recurrent infections with respiratory syncytial virus (RSV) in early life increase the risk for asthma in adult life. 

Repeated infection of infant mice tolerized to ovalbumin (OVA) through their mother's milk with RSV induced allergic airway disease in response to OVA sensitization and challenge, including airway inflammation, hyper-reactivity and higher OVA-specific IgE, as compared to uninfected tolerized control mice. 

Virus infection induced GATA-3 expression and T helper type 2 (TH2) cytokine production in forkhead box P3 (FOXP3)+ Treg cells and compromised the suppressive function of pulmonary Treg cells in a manner that was dependent on interleukin-4 receptor α (IL-4Rα) expression in the host. 

Thus, by promoting a TH2-type inflammatory response in the lung, RSV induced a TH2-like effector phenotype in Treg cells and attenuated tolerance to an unrelated antigen (allergen). 

Our findings highlight a mechanism by which viral infection targets a host-protective mechanism in early life and increases susceptibility to allergic disease.

BBC News has a useful report on this finding.