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