Infectious Disease Update – from CDC newsletters, 5.18.12

MRSA News – for Background see my book review on blog: search for MRSA.


New article from CDC newsletter: Some trends show decreases but its still present and serious and now the learning edge is the community acquired infections.

Trends in Invasive Infection with Methicillin-ResistantStaphylococcus aureus, Connecticut,USA, 2001–2010

A summary of data from 2005, the first full year of EIP invasive disease surveillance, was published in 2007 and revealed the full magnitude of invasive MRSA in the United States: ≈94,360 persons had invasive infections in 2005, and 18,650 patients died while hospitalized (12). This study also demonstrated that most MRSA infections (85%) were health care–associated, with 69% occurring in the community rather than in the hospital.

Excerpts from:

In contrast, controlling community strains that occur outside the hospital is not as easy. Although proactive control efforts in institutions, including correctional facilities and sports facilities, should minimize the potential for institutional outbreaks, much community transmission occurs outside such settings. Thus, one could expect the sustained prevalence and continued transmission of community strains in the community with regular introduction in proportion to their incidence into health care settings and that their proportion of all MRSA infections would increase.


Report on Rhickettsia in dogs inLouisiana



The association between companion animals and tick-borne rickettsial disease has long been recognized and can be essential to the emergence of rickettsioses. We tested whole blood from dogs in temporary shelters by using PCR for rickettsial infections. Of 93 dogs, 12 (13%) were positive for Rickettsia parkeri, an emerging tick-borne rickettsiosis.

Tick-borne spotted fever group (SFG) rickettsioses are maintained in tick populations through vertical transmission of the rickettsial agent and horizontal transmission among vectors by a vertebrate host. Companion animals, specifically dogs, can serve as vertebrate hosts for arthropod vectors and SFG rickettsia (1), as shown by a report of a Rickettsia parkeri–infected dog in South America (2). Likewise, cases of rickettsioses in humans have been associated with cases in companion animals (3). Because of a substantial increase in tick-borne rickettsial diseases in the past decade, much effort has been directed to identifying the rickettsial agents present in ticks (4). On the basis of findings from field surveys of rickettsial infections in ticks and characterization of rickettsioses in humans, most cases of what is considered Rocky Mountain spotted fever, a disease caused by R. rickettsii, are likely caused by infections with rickettsial species other than R. rickettsii (5).


Info on Whooping cough


Bordetella pertussis, the causative agent of whooping cough, continues to circulate among children and adolescents even in regions with high vaccine coverage. Antimicrobial drug treatment contributes substantially to controlling transmission of the disease. In France, the treatment of choice is clarithromycin or azithromycin, which eliminate the bacterium from the respiratory tract of the infected patient and their close contacts (1). To date, erythromycin resistance in B. pertussis has been described only in the United States (24). The erythromycin-resistant B. pertussis isolates in theUnited States carry an A-to-G transition at nucleotide position 2047 of the 23S rRNA gene, in a region critical for erythromycin binding.


Iatrogenic Creutzfeldt-Jakob Disease, Final Assessment


The era of iatrogenic Creutzfeldt-Jakob disease (CJD) has nearly closed; only occasional cases with exceptionally long incubation periods are still appearing. The principal sources of these outbreaks are contaminated growth hormone (226 cases) and dura mater grafts (228 cases) derived from human cadavers with undiagnosed CJD infections; a small number of additional cases are caused by neurosurgical instrument contamination, corneal grafts, gonadotrophic hormone, and secondary infection with variant CJD transmitted by transfusion of blood products. No new sources of disease have been identified, and current practices, which combine improved recognition of potentially infected persons with new disinfection methods for fragile surgical instruments and biological products, should continue to minimize the risk for iatrogenic disease until a blood screening test for the detection of preclinical infection is validated for human use.


Detection of European Strain of Echinococcus multilocularis in North America

To the Editor: In 2009, an alveolar hydatid cyst, the intermediate stage of the cestode Echinococcus multilocularis, was detected in the liver of a dog from Quesnel, British Columbia (BC), Canada (1), 600 km west of the nearest known record of this parasite in central North America (Figure). Alveolar hydatid cysts normally occur in rodent intermediate hosts. However, humans can serve as aberrant intermediate hosts; cysts generally originate in the liver and, in about one third of cases, metastasize throughout the body (2). Detection of the larval stage of this pathogen in an unusual host in a new geographic region required application of multiple molecular epidemiologic techniques to determine if this was range expansion of a native strain or introduction of a new strain of veterinary and public health concern. end


Book Review: Superbug, The Fatal Menace of MRSA

Superbug, The Fatal Menace of MRSA, by Mary McKenna. Free Press, N.Y. N.Y. 271 pp., 2010

Review by Wm Olkowski, PhD

What’s MRSA and Why is it Important?

Methicillin Resistant Staphylococcus aureus (MRSA) is a strain of the common bacteria we all carry on our skin and mucus membranes like those in the nose.  Normally this commensal causes no problem but sometimes an infection develops that becomes very serious, cannot be treated with the commonly used antibiotics (AB’s) and can cause a horrible death.

AB resistance occurs when an infection is challenged repeatedly with an antibiotic.  The AB kills off the susceptible bacteria leaving the resistant.  A mutation is believed to be involved in developing resistance.  As a result the species changes to one that cannot be killed by that AB.  It is said to be resistant.  There is now so much resistance to ABs a tragedy looms.  And that’s the theme for this book.

Some History

The first big AB was penicillin.  The AB methicillin was the next choice when people got resistant to penicillin.  It’s a related substance hence the similarity in spelling, but very different in structure from penicillin and that was why it worked for so long.  Penicillin was a wonder drug as it worked on a whole range of bacteria and saved millions of lives.  Its very success caused its downfall, as the more it was used the faster resistance developed. And it was overused, for example, people were given this and other ABs when viruses were the cause and ABs don’t kill viruses.

Methicillin (first used in 1960) worked for a while.  Then SA got resistant to it and these strains could not be controlled and an epidemic would ensue.   Hospital stays got more complicated, longer and some people would die of what first would appear to be minor infections.  Some of these deaths were horrible pus filled infections dissolving skin, muscles and bones.

As more doctors were unable to treat MRSA infections successfully the seriousness of this situation began to be appreciated.  McKenna was a reporter who investigated a hospital epidemic of MRSA and then worked with the Kaiser Family Foundation making observations in ERs as part of a media fellowship program.  In every city she found MRSA everywhere she looked.  The range of infections ran from minor skin infections to gaping pus filled wounds in bones and muscles, and pneumonias that would kill.  She started a blog, called “Superbug” for reporting on such cases and developing epidemics.  This book documents her discoveries and is instructive in many ways.

It’s not just a Hospital Infection

At first MRSA was considered only a hospital acquired infection, but later different strains were found not associated with hospitals.  In the early stages infections were noted in nurseries in hospitals, as new mothers would return after a few weeks with their infected babies, many of which died horrible deaths.  Thus was born MRSA hospital infection epidemics.  Even today MRSA is believed by many to be only a hospital infection.

Although MRSA strains from the community are very different from the hospital strains, the source of these community strains is unknown.  They may be hospital strains that have established somewhere in the community and then mutated to appear different to the immune system and that is a big threat as MRSA, with its large arsenal of toxins is a terrible way of death.

One of the most important lessons from this phenomenon is the need and importance of detection and hand washing.  Note that there is still no national surveillance system for reporting MRSA cases.  The Dutch and other European health systems had such a system in place decades ago and have not experienced the same sort of epidemics we in the US have.  The Dutch also cultured every hospital patient to detect MRSA strains upon entry to the hospital.  In cases where no obvious infection was present but the organism was detected each patient was treated to remove such “colonized patients”.  When every patient in the hospital is decolonized there is no epidemic.

Consequently each hospital afflicted with MRSA cases in our country had to go at detection and control with their own personnel and labs, a rather poor response to the suffering inflicted by this tragedy.  One wonders why people persist in insisting on keeping health care in an industry whose goal is profit.  Stupidities abound when ignorance masquerades as ideology.  Do you notice that those who insist on how bad government is segregate out the military, the largest and most error prone part of government from their view of our political systems defects?

McKenna examines programs run by hospitals to detect and treat patients and their ability to contain these local epidemics.  In one case she describes how a hospital put a nurse with sufficient authority to monitor compliance for hand washing by physicians and staff.  The nurse documented that in too many cases compliance was less than 50%.  Repeatedly the nurse found physicians going from patient to patient without washing their hands.

When compliance rose to 97% or more the epidemic was stopped and no further cases were noted.  Fortunately a simple nose swab and culture detects these strains.  But this costs a hospital not the insurance industry.  Such fragmentation is unbelievable, especially when one knows it’s such a terrible process of treatment and when it fails a horrible death.  So wash hands and make sure your doctor washes his/her hands before he touches you.

Next is a most amazing story of a cure.  Decades ago I read a great book called “Man Adapting” by the famous microbiologist Rene Dubois.  He proposed adding benign strains of SA to newborn babies so these inoculations would adapt and prevent infections by more damaging strains.  At that time such a suggestion was an advanced idea.  Now comes an example of just how such a procedure could work.

One of the hospitals tracking the source of the infective strain of MRSA traced it to a nursery where no baby had been found to be infected by a deadly MRSA strain then rampant in the hospital.  Then after swabbing all the hundreds of staff one nurse in the nursery was found with a benign strain, labeled as 502a.  Two investigators working to find useful treatments tried an experiment on a small family who had repeated MRSA infections and a few years of misery of unsuccessful but intermittent repeated infections.  Apparently their MRSA strain would hide and then reinfect.  So the two investigators set up an AB course to knock back the infection, treating with an AB mix for 12 days.  After that they inoculated the family with 502a and the colonization was successful, as no reinfections occurred.  But this experiment was never repeated as the two investigators separated and joined other institutions.

This story affirms an approach which Dubois suggested decades ago, but has never been adequately followed up.

So beware of hospital infections.  Before admission look into their infection control systems and check on compliance for hand washing.  It would help if hospitals were required to publish their infection rates and compliance with sanitation practices, but that seems just too much for a system running on profit.

Wishing MRSA on those who oppose a public healthcare system or even a public option would provide some incentive, albeit too late for prevention.  But the decision makers in our congress don’t have to worry as they have a publically supported health care system which they denied the rest of us, even as an option.

“When will we ever learn?”