September 2014

Emerging Infectious Diseases Journal

Highlights: Emerging Infectious Diseases, Vol. 20, No. 9, (September 2014)


The articles of interest summarized below will appear in the September 2014 issue of Emerging Infectious Diseases, CDC’s monthly peer-reviewed public health journal. This issue will feature emerging pathogens.

Note: Not all articles published in EID represent work done at CDC. In your stories, please clarify whether a study was conducted by CDC (“a CDC study”) or by another institution (“a study published by CDC”). The opinions expressed by authors contributing to EID do not necessarily reflect the opinions of CDC or the institutions with which the authors are affiliated.

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1. Encephalitis Caused by Pathogens Transmitted through Organ Transplants, United States 2002–2013, Sridhar V. Basavaraju et al.

Although medical advancements have led to increased success of organ transplantations, the risk for transmission of infectious agents (such as viruses) through solid organ or tissue transplantation remains a worldwide public health problem. Since 2002, infection of the brain, a condition called encephalitis, has been reported with increasing frequency after transplantation of solid organs. However, these infections among transplant recipients are rare and might not be recognized by doctors, resulting in delayed treatment. A recent review of the agents known to cause transplant-transmitted encephalitis highlighted several diagnostic and clinical challenges. For example, diagnosing transplant-transmitted encephalitis in the patient can be difficult because the hallmark symptoms resemble those of other severe illnesses. And tracking the infection to the donor can be difficult because of geographic distance separating transplant recipients, and lack of prompt recognition and reporting systems. Thus, investigation of such infections requires rapid communication among transplant physicians, organ procurement organizations, and public health authorities. Until active tracking systems (surveillance) can be established, timely communication and use of traditional and new diagnostic tests are crucial for identifying unusual and emerging infections in transplant recipients.

Contact Sridhar V. Basavaraju via:
CDC Press Office

2. Incidence of Cronobacter spp. Infections, USA, 2003–2009, Mary E. Patrick et al.

Cronobacter are bacteria known to cause serious infections, especially in infants who consume contaminated powdered infant formula. However, Cronobacter can come from a variety of sources and affect other age groups. By reviewing laboratory records collected by FoodNet (a multiagency program that tracks foodborne diseases), researchers learned that the highest rate of invasive infection occurs in the very young (newborn to infant), and older adults (80 years and older). Older adults also have high isolation rates from the urinary tract. Rates varied by location and were highest for Minnesota. Increased understanding of sources of infection and populations at risk can help guide future prevention and control efforts.

 Contact Mary E. Patrick via:
CDC Press Office

3. Distance from Construction Site and Risk for Coccidioidomycosis, Arizona, USA, Janis E. Blair, et al.

Coccidioidomycosis is a fungal disease that affects the respiratory system.  Disease severity varies from person to person: some patients require prolonged medical evaluation, time away from work or school, treatment, or hospitalization. The fungi, which live in soil in the southwestern United States, can become airborne when the soil is disrupted, and humans who inhale the spores can become infected. Risk for infection is increased by situations and activities that increase exposure to dust, such as dust storms, earthquakes, construction work, outdoor occupations or activities, and military maneuvers. Thus, when the Mayo Clinic in Arizona began building a new medical facility in a previously undisturbed native desert area, researchers compared the risk for employees near the construction site with risk for those at another facility 13 miles away. They found that working next to this construction project soil did not increase the risk for infection. Possible explanations are successful dust control at the construction site, differing amounts of fungus in the soil at the 2 study sites, differing exposure at the employees’ residences, and varying outdoor exposure (e.g., walking for exercise) of the 2 groups of employees.

Contact Janis E. Blair via:
Lynn Closway
Mayo Clinic Public Affairs

4. Feeding Period Required by Amblyomma aureolatum Ticks for Transmission of Rickettsia rickettsii to Vertebrate Hosts, Hakan Leblebicioglu et al.

Rocky Mountain spotted fever is the deadliest known rickettsial (a type of bacteria) disease spread by ticks. Throughout the Americas, different types of ticks carry rickettsia and transmit them to hosts they feed on, such as dogs and humans. So how long does a tick need to be attached before it can infect its host?  By studying a tick common in Brazil, researchers recently determined that this window of time varies according to whether the tick is engorged (has recently fed). Although to infect their host, unfed ticks need to be attached to the host for 10 hours or more, recently fed ticks need to be attached for only 10 minutes.  The conventional wisdom is that a tick needs to be attached for 2 or more hours before it can infect humans or dogs, which might discourage people from immediately removing them and result in transmission of these lethal bacteria. People entering wooded or grassy areas should frequently inspect themselves and their children and pets for ticks and immediately remove any ticks found.

Marcelo B. Labruna
University of São Paulo, Preventive Veterinary Medicine



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