Emerging Infectious Diseases Journal

Highlights: EID, Vol. 17, No. 3 (March 2011)

1. Mycobacterium tuberculosis Cluster with Developing Drug Resistance, New York, New York, USA, 2003–2009

B.R. Perri, et al.

"Naming names" is tough for hard-to-reach populations. But identifying people who have been exposed to TB (contact tracing) is a crucial part of TB control. Typically, TB patients are asked to name their close contacts. Some patients, however, are reluctant to give names for fear of revealing illicit activities or undocumented immigrants. They also may not know or remember names or may know only an alias or street name. As an alternate approach in a New York City outbreak investigation, patients were asked to identify contacts by photographs (shown with patient permission or taken from public record). This approach combined with molecular testing and drug resistance testing provided valuable information about the outbreak. For example, although the strain at first was treatable with drugs, it later became drug resistant. The approach also revealed that this drug-resistant strain was most common in people who had been born in the United States and who used illegal drugs. With this information, investigators were able to explore the social networks in which this resistant strain of TB was spreading and learn how specific drug-use practices may have contributed to its spread.

Contact Bianca R. Perri, MPH, via:
Press Office
New York City Department of Health and Mental Hygiene, Bureau of Tuberculosis Control
New York, NY, USA
212-788-5290
pressoffice@health.nyc.gov

2. Tuberculosis Outbreak Investigations in the United States, 2002–2008

Kiren Mitruka, et al.

To better understand the characteristics of TB outbreaks that pose some of the biggest challenges to local public health, CDC researchers conducted a retrospective review of outbreak investigations where CDC was asked by state and local health officials to assist. Investigations were included in the analysis if they occurred between 2002 and 2008 and involved at least three related culture-confirmed TB cases; twenty-seven out of 51 investigations met these criteria. Most of the outbreaks that were included in the review involved U.S.-born persons who abused substances; drug houses were locations of TB spread in approximately two-thirds of the outbreaks. A prolonged contagious period resulting from delayed TB diagnosis was a major contributing factor in the outbreaks. Healthcare providers should maintain vigilance for TB among persons who abuse substances, to prevent delays in diagnosis and to ensure early intervention at the beginning of a potential outbreak. Substance abuse remains one of the greatest challenges to TB control in the United States, both because it can increase risk for TB transmission, and because it can challenge the ability of local health officials to detect and investigate outbreaks among this hard-to-reach population. Researchers caution that these results may not be representative of all TB outbreaks occurring in the U.S.

Contact Dr. Kiren Mitruka via:
CDC NCHHSTP News Media Office
404-639-8895
NCHHSTPMediaTeam@cdc.gov

3. Active Tuberculosis among Homeless Persons, Toronto, Canada, 1998-2007

K. Khan, et al.

Homelessness often means more than just a lack of stable housing. It can also mean that subsistence needs, for example food and shelter, are prioritized over accessing needed health services. Compared to the general population, homeless people often experience a high burden of chronic health conditions, mental health problems, and substance use and are at high risk for developing active tuberculosis (TB). A recent study in Toronto found that many homeless people with TB have highly contagious, advanced disease and that one-fifth die within a year of diagnosis. It also found that TB in the homeless is increasing among those born outside of Canada, which increases the risk that drug-resistant strains from overseas will be introduced into homeless shelters. To control TB in homeless populations, the authors recommend stepped-up ventilation at shelters, greater focus on early detection of latent and active TB, and treatment of active TB by experienced providers and clinics.

Contact:
Kamran Khan, MD, MPH, FRCPC
St. Michael's Hospital, Toronto, Ontario, Canada
416-864-6060, Ext. 77441
KhanK@smh.ca

4. Elephant-to-Human Transmission of Tuberculosis, 2009

R. Murphree, et al.

The elephant in the room… doesn't have to actually be in the room to spread TB. Since the late 1990s, it has been suggested that TB can spread from infected elephants to people who work in direct contact with them. Recently, however, TB spread to people not in close contact with elephants. Among eight elephant-refuge employees with evidence of TB infection, three of them didn't even work with the elephants. They were administrative employees who worked in a building connected to the elephant quarantine barn (where an elephant with confirmed TB disease was housed). The investigators believe that TB bacteria expelled by the elephant or aerosolized in spray from pressure washing or dust from sweeping the barn got into shared air space and was inhaled by the administrative employees. Thus, infection control practices should address TB spread by both direct and indirect contact.

Contact Rendi Murphree, PhD via:
Press Officer Andrea Turner
Tennessee Department of Health
Nashville, Tennessee
615-741-3446
Or via email: rendi.murphree@tn.gov

5. Surveillance for Invasive Meningococcal Disease in Children, US–Mexico Border

E. Chacon-Cruz, et al.

Invasive meningococcal disease is a severe bacterial infection of the brain. It mainly affects children, resulting in brain damage, hearing loss, learning disabilities, or death. Fortunately, it can be prevented with vaccine or treated with antibiotics, if given promptly. The seemingly good news is that in Mexico, few cases are reported; the bad news is that the actual number of cases is higher than reported. A recent study in Tijuana found that along the US–Mexico border, the case and death rates (number per 100,000 people) for each country are about the same. Although doctors in Mexico are seeing patients with symptoms of this disease, they don't always run the lab tests needed to confirm the diagnosis. Vaccination would be an effective way to prevent such cases in Mexico.

Contact:
Enrique Chacon-Cruz, MD
Hospital General de Tijuana
Tijuana, Baja-California, Mexico
+52-664-6346820
echacon88@hotmail.com

6. An Integrated Approach to Identify International Foodborne Norovirus Outbreaks

L. Verhoef, et al.

Noroviruses are the most common viral cause of food poisoning, but they are also hard to track because they spread rapidly among many people. By the time an outbreak is recognized, it's often so far from the source that it's hard to tell whether it was even caused by food, let alone determine which food or where it came from. Verhoef and colleagues used a new approach to re-examine past norovirus outbreaks in Europe. By linking two types of data (epidemiologic and molecular) from these outbreaks, researchers found that five times more of these outbreaks had actually spread to other countries than previously thought. This approach, combined with international collaboration, may greatly increase the number of international food-borne outbreaks that are identified and solved.

Contact:
National Institute for Public Health and the Environment (RIVM)
Bilthoven, the Netherlands

Linda PB Verhoef
+31-30-274 2605
linda.verhoef@rivm.nl

Harald Wychgel
+31-30-274 3005
Harald.Wychgel@rivm.nl

The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.

 

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