Sunday, April 12, 2015

Punished for precision (or, too much information (TMI) from the micro lab!)

We recently had a patient's blood culture turn positive for a Gram-positive, catalase-positive, facultative diphtheroid. In the “pre-MALDI” era, we’d have called this isolate a “diphtheroid”. Taking into account other aspects of the case, the NHSN definition would have categorized this as a contaminant (diphtheroids being on the “common commensal” list maintained by NHSN). By virtue of the wonders of mass spectrometry, we are now able to identify the organism to species-level as Actinomyces neuii, an organism previously categorized as CDC group 1-like coryneform bacteria (also on the “common commensal” list). 

Actinomyces neuii isn’t anywhere on the NHSN organism lists. However, Actinomyces species (as a group) can be found on the “all organisms” list but NOT on the “common commensal” list. The NHSN rules tell us we have to categorize any organism on the “all organisms” list that isn’t also on the “common commensals” list as a pathogen, meaning this positive blood culture now helps define a central-line associated bloodstream infection (CLABSI).

And that’s the story of how a contaminated blood culture became a CLABSI. We’ve had other similar cases since we introduced MALDI-TOF. Before the CLABSI rate became worth millions of dollars to a hospital’s bottom line and reputation, this might have been easy to navigate. Now, though, it’s a much bigger deal. 

These and other issues regarding the impact of microbiological advances on infection prevention will be discussed at SHEA 2015 (ever heard of it?). Register now!

Friday, April 10, 2015

SHEA 2015: *New* Post-Acute and Long-Term Care Track
This is a special guest post by Dr. Silvia Munoz-Price, Enterprise Epidemiologist at Froedtert & Medical College of Wisconsin Institute for Health and Society and the Department of Medicine. She is co-directing the new SHEA Certificate Track in Post-Acute and Long-Term Care at the 2015 SHEA Meeting in Orlando.

In healthcare, we are in the process of transforming our approach from caring of an isolated individual to caring for the population as a whole. Similarly, we are slowly migrating from paying attention to single hospital encounters to focusing on the continuum of care of individuals. These facts are important in the fields of Infection Control and Hospital Epidemiology, as in order to control the spread of highly resistant pathogens we need to internalize that our hospital systems are interconnected through patient transfers. This is particularly evident in the interactions between acute care hospitals, long term care acute care hospitals (LTACHs), and nursing homes within regions. A few years ago, this interrelatedness was elegantly described by Won and colleagues in the midst of a regional outbreak of KPC Klebsiella pneumoniae in the Chicago area (Won et al CID 53: 532-540, figure below). Furthermore, controlling the spreadwithin the LTACH changed the whole transmission dynamic in the region (Munoz-Price Infect Control Hosp Epidemiol. 2010 Apr;31(4):341-7).

Research dealing with Infection Control practices in post-acute care settings is progressing, as recently described in this blog here, here and here. Given our interdependence, it is fundamental that providers in post-acute care --who deal directly with these infection control issues-- are knowledgeable and up to date. This year, SHEA’s Spring meeting will have a 2-day post-acute care track specifically designed to provide a general infection control overview to infection control personnel in post-acute care and LTACHs. The co-Director of this track, Dr. Nimalie Stone, is the Medical Epidemiologist for Long-term Care in the Division of Healthcare Quality Promotion (DHQP) at CDC. Additionally, we will have top notch speakers such as David Nace, Lona Mody, Curtis Donskey, among others. Upon completion, attendees will receive a certificate from SHEA.

A full description of the track can be found here. Participation and engagement of our post-acute care/LTACH colleagues is fundamental to succeed in our fight against hospital acquired infections.

We hope to meet you in Orlando!

Discounted registration ends April 17th (save $100), so register now!

Wednesday, April 8, 2015

Screening, Decolonization and Environmental Decontamination for MRSA in Nursing Homes Doesn't Work

Just in the past couple of weeks, we've written about pneumonia prevention bundles, MDRO prevention bundles, and spread of S. aureus - all in nursing homes.  It's like no one cares about acute care facilities any more! (humor) There is now more great data for those charged with managing infection control in nursing homes.

Cristina Bellini and colleagues from Lausanne University Hospital in Switzerland just published the results of cluster-randomized trial of an MRSA prevention bundle in 104 nursing homes (53 intervention, 51 control) in the April ICHE. All residents in intervention and control nursing homes (NH), who gave consent, were screened for MRSA carriage at study entry and 12 months thereafter on a single day in each NH. Newly admitted or readmitted residents were screened when admitted to the NH. Screening included nasal, groin and ulcer swabs along with urine cultures if residents had an indwelling catheter. In the intervention NHs MRSA colonized residents underwent decolonization along with environmental decontamination.

The primary decolonization bundle included 5 days of nasal mupirocin, 5 days of CHG oral rinse twice per day, 5 days of CHG showers including CHG shampoo on day 1 and 5. Environmental disinfection included daily clothing changes for 5 days, new linens on day 1 and day 5, and daily bed/table/phone/remote/wheelchair/walker disinfection with 70% alcohol. A lot of steps.

Unfortunately, the MRSA decolonization and decontamination bundle was not successful. The baseline prevalence of MRSA was 8.9% in both groups. The rate declined in intervention units to 5.8% in the intervention unit and 6.6% on the control units after 12 months (p=0.66) Full stratified results are in Table 3 below, and as you can see, no matter how they analyzed the intervention, the MRSA bundle intervention did not reduce MRSA prevalence compared to controls. This was despite the fact that the participation rate was 87%.

A limitation of this study was that they only measured prevalence and not individual level acquisition of MRSA. It is possible that by measuring prevalence they missed detecting benefits of the intervention related to reduced patient-to-patient transmission of MRSA. In any case, as I said last week about the study in CID, congratulations to the authors and journal (this time ICHE) for publishing this important negative study.

Monday, April 6, 2015

Vaccine Efficacy Trials During Ongoing Epidemics: Lessons from Ebola

Investigating the efficacy of vaccines during on-going epidemics poses numerous challenges, whether the infection is Middle East Respiratory Syndrome (MERS), novel influenza strains or Ebola. Beyond the public health urgency, there are issues such as variable and unpredictable incidence and limited vaccine supplies, which pose huge challenges for investigators (and governments). I wrote about some of these issues last October in a post titled, "Ebola vaccine - do we really need a placebo-controlled RCT." In the post, I described a stepped-wedge design, which we've used in health services research, but I made clear that I wasn't a vaccine trial expert.

Fortunately, more experienced vaccine trial experts have just published their thoughts on designing vaccine trials during emergencies with the ongoing West African Ebola outbreak providing context. Marc Lipsitch, Rebecca Grais and colleagues (COI - I'm a co-author), suggest three principles worth considering when designing vaccine trials during public health emergencies:

Principle 1: Block Randomization within small centers with analysis matched by center
    Some centers may have higher (or lower) incidence, so that it is better to randomize within a center (block randomization). In this way, exposed (vaccinated) and unexposed (controls) would be expected to have similar risk of infection.

Principle 2: Stepped Rollout
     This principle is a response to the urgency of the situation. An individual randomized trial would require waiting for all centers to come online before commencing a trial (see purple box in Figure A, above). In contrast, a stepped role-out allows each center to commence the trial as soon as they are ready (purple area in Figure B, above).

Principle 3: Adaptive Design
     Since vaccine trials require participants to be at some risk of infection after the've established immunity from vaccination, it is imperative to know if centers will have active transmission once they are included in the study. This is incredibly difficult to predict. Adaptive designs use pre-specified rules to add centers (green in Figure B) or extend follow-up periods (yellow in Figure B), which improve the chances that a trial will reach a successful conclusion.

There is more depth in the Science Policy Forum, if you're interested. A final note of thanks to Marc and the group for including me in this effort. I learned a great deal through many email discussions over the past 4-5 months.

Thursday, April 2, 2015

Pneumonia Prevention Bundle in Nursing Homes: A Cluster-randomized Trail

If you're looking for another infection prevention bundle in long-term care, look no further than the March 15th issue of CID that included a cluster-randomized trial of a pneumonia prevention bundle in 36 Connecticut nursing homes by Juthani-Mehta and colleagues at Yale. (full text free)  Residents in the intervention nursing homes with at least one risk factor (impaired oral hygiene or swallowing difficulty) received a bundle that included manual tooth/gum brushing plus 0.12% chlorhexidine oral rinse, twice per day, plus upright positioning during feeding.

The primary outcome was development of first pneumonia defined as "presence of (1) a compatible infiltrate on chest radiograph (CXR) (if previous CXR was available, the infiltrate had to be new or worsened) and (2) at least 2 of the following clinical features within 72 hours of the CXR-documented infiltrate: fever, pleuritic chest pain, respiratory rate over 25 breaths/minute, worsening functional status (ie, decline in level of consciousness or activities of daily living), or new or increased cough, sputum production, shortness of breath, or chest examination findings."  The secondary outcome was first lower respiratory tract infection (LRTI).

After enrolling 834 participants (434 to the intervention arm and 400 to the control arm), the DSMB terminated the study for futility. Results showed no significant differences for cumulative incidence of first pneumonia (Figure 2A, below) or first LRTI between intervention and control arms. In fact, you can see that the intervention arm appears to have higher incidence of first pneumonia, which is concerning. Of note, adherence was 87.9% to chlorhexidine, 75.0% to toothpaste and 100% for upright feeding position in the intervention facilities. The authors offer several explanations for the study's failure, none of which are entirely convincing. For example, adherence at these levels should have still shown some benefit and not a trend toward harm, so it's unlikely that compliance explains the results. For those interested in reading more, there is an excellent commentary by Lona Mody, who we also mentioned last week. And congratulations to the authors and journal for publishing this important negative study.

Sunday, March 29, 2015

For every rule, an exception

The current Ebola virus disease (EVD) epidemic has repeatedly confirmed a stark “gradient of infectivity”. On the one hand, those severely ill with EVD represent transmission risks so high that safe care can only be provided in the most well-prepared treatment units. On the other hand, those with few or no symptoms of EVD represent nearly zero transmission risk. The best evidence for this is that there have been over 850 health care worker EVD cases (and almost 500 deaths) since the beginning of this epidemic, yet of the several hundred community contacts of cases in the US, UK and Spain, there hasn’t been a single transmission event outside of an intensive care unit.

Thus the rule I’ve heard, and stated, at various times during the epidemic: “no symptoms, no transmission risk.”

Now the exception: sexual transmission. We’ve long known that filoviruses can be detected in semen for weeks and even months after disease recovery (a 1995 study reported Ebola virus RNA in seminal fluid for up to 101 days, and infectious virus up to 82 days, and in 1968 the sexual transmission of Marburg virus was reported 13 weeks into convalescence). Now a concerning case in Liberia has the WHO recommending indefinite safe sex practice for EVD survivors. From the New York Times article:
"The new guidelines came one day after the death of Liberia’s single confirmed patient with Ebola, Ruth Tugbah. Before her illness, the country had gone three weeks without a new Ebola diagnosis, and hopes had risen that Liberia was nearing the end of a yearlong epidemic that killed more than 4,000 people there. Ms. Tugbah’s only known risk factor was having a boyfriend who was an Ebola survivor. 
Scientists detected the genetic material of Ebola from a semen sample the boyfriend provided to infectious disease investigators, officials from two Ebola response agencies said, speaking on background because they were not authorized to speak publicly."
If further investigation confirms this transmission event, it would indicate that she was infected several months after his recovery from EVD (more than the three months currently suggested as the maximum time virus may be present in semen). Given the sheer number of cases that have occurred in the affected countries, this poorly-understood sexual transmission risk adds an unwelcome twist as the outbreak winds down.

Saturday, March 28, 2015

What's wrong with Indiana?

It's been a bad couple of weeks for Indiana. First, Indiana University and Butler were knocked out of the NCAA basketball tournament while their capital city was mocked in a widely-played television ad. (above) Then Indiana Governor Mike Pence signed a law allowing businesses to refuse service to same-sex couples. The NY Times suggests that the law might be part of the Governor's plans to run for President in 2016. There's been a backlash against the state with many crying for a boycott. Although most folks demanding such action have never been to Indiana and probably couldn't find it on a map, so it's unclear if it will have any effect.

If passing the 'Religious Freedom' bill is a sign that the Lord giveth, certainly the ongoing 79-person outbreak of HIV in rural Indiana is a sign that the Lord hath taken away. Thursday, the same Indiana Governor declared a public health emergency and approved a 30-day needle exchange program since all cases could be linked to intravenous drug use. Since Governor Pence has been a vocal opponent of needle exchange programs, this 180 must be quite humbling. But it's only funded for 30 days - so he has a political out and could still run for President.

From 538: "There were at least 194 needle exchange programs in 33 states in 2014, according to the Foundation for AIDS Research, and almost all were in states that have explicitly lifted or modified their laws. All of those programs are paid for by states, local governments or other organizations, since federal funding for needle exchange programs has been banned since 1980 (the ban was briefly lifted in 2009 by President Obama, and reinstated by Congress in 2012)"

A colleague mentioned to me today that it's nice that this program now exists to prevent HIV among rural folks but suspects that higher levels of HIV are occurring daily among urban Gary, Indiana residents and they'll never get even a temporary needle exchange program. America!! Perhaps Charles Barkley (above video) was smart to head to "In The Annapolis" instead of Indianapolis after all.

Addendum:  Notre Dame (Indiana) just lost in the NCAA tournament