Monday, December 17, 2012

Disease Outbreaks in the United States 2012: A year in review

Once again not a specific animal related topic, but one that should be of great interest. A discussion of  the disease outbreaks in the United States in 2012. The link from the AVMA Pet Health SmartBrief.

(I have an interest in this type of information being a parent, of course, but as a veterinarian I try to keep abreast of various disease conditions occurring in the United States, as well as the potential to affect the animal population. My concentration for my Master's degree was parasitology, immunology, and medical entomology (study of bugs of medical significance).

Outbreaks in the United States 2012: A year in review

This was an active year for outbreaks in the United States, some more common than others. In this review, I will summarize what 2012 brought us in the world of infectious disease outbreaks (this list is by no means all inclusive).

Fungal Meningitis 
Photomicrograph showing fine branching tubes of Exserohilum rostratum/ CDC
Photomicrograph showing fine branching tubes of Exserohilum rostratum/ CDC
The United States was struck by a most unusual and preventable outbreak of fungal meningitis and related infections due to an injectable steroid called methylprednisolone acetate manufactured by the  Framingham, Massachusetts company, New England Compounding Center (NECC).

The outbreak, which started with a handful of cases in Tennessee in October, is now a 19 state outbreak that has infected 590 patients and killed at least 37 as of Dec. 10.

A variety of different molds were found to be contaminating the steroid including 112 cases of Exserohilum rostratum and 1 Aspergillus fumigatus, a variety of other fungi have also been identified in clinical specimens from fifteen case-patients: 5 otherAspergillus spp, 5 Cladosporium spp, 1 Bipolaris species, 1 coelomycete fungus, 1 Paecilomyces sp., 1 Penicillium sp, and 1 Stachybotrys chartarum.

As the investigation progressed, a whole host of events have happened–NECC recalled all their products, other companies were linked to the outbreak, a plethora of lawsuits, Congressional inquiries and  criticism of the FDA.

West Nile virus
Not since 2003 has the United States seen so many human cases of West Nile virus (WNV). According to the Centers for Disease Control and Prevention (CDC),  there were 5,387 cases of West Nile virus disease in people, including 243 deaths, according to the preliminary data for this year.

Dallas County, Texas was referred to as the “epicenter” of the outbreak. Eighty percent of the cases have been reported from 13 states (Texas, California, Louisiana, Illinois, Mississippi, South Dakota, Michigan, Oklahoma, Nebraska, Colorado, Arizona, Ohio, and New York) and a third of all cases have been reported from Texas.

A hantavirus outbreak linked to staying at the Signature Tent Cabins in Curry Village in Yosemite National Park received a lot of media attention in 2012.

According to the National Park Service (NPS), received confirmations from national and state public health agencies of hantavirus infection in 10 individuals who stayed one night or more in Yosemite since June of this year. Nine of the confirmed cases developed hantavirus pulmonary syndrome (HPS).

Three cases of HPS have resulted in fatality; the seven other individuals have recovered. The confirmed cases of hantavirus infection were in eight individuals from California, one from Pennsylvania, and one from West Virginia.

Although the focus of the outbreak was in the US, the NPS notified hundreds of thousands of visitors to the park worldwide of the risk.

H3N2v influenza “swine flu” 
This transmission electron micrograph (TEM) depicts some of the ultrastructural details displayed by H3N2 influenza virions. Image/CDC
Although the “new variant” of swine flu in the US did not get nearly the coverage as the above three outbreaks, it did infect some 309 people in 12 states. Indiana and Ohio saw the most cases.

The infection, mostly linked to exposure to pigs at county fairs this summer, killed one person and sent 16 to the hospital.

According to the CDC, there were at least a dozen Salmonella outbreaks, many multistate, investigated and reported on in 2012.

The source of the outbreaks covered a wide gamut to include small turtles, dry dog food, live poultry (chicks), ground beef, cantaloupe, hedgehogs and peanut butter this year.

In the 12 outbreaks investigated by the CDC, the bacterium resulted in 1,614 illnesses and 6 deaths.

A multistate outbreak of listeriosis resulted in 22 illnesses and four deaths in 2012. The outbreak was linked to Forever Cheese Frescolina Marte brand ricotta salata cheese.

The US was hit especially hard by pertussis or whooping cough this year. The latest provisional counts from the CDC reveals, as of Dec. 1, there were more than 38,000 cases of pertussis and 16 deaths in 2012.
Certain states saw marked increases in whooping cough in 2012 as compared to the year prior. For example, in Washington state, there have been 4,626 cases reported statewide through December 8, 2012, compared to 739 reported cases in 2011 during the same time period.

Minnesota was another one. As of November 29, 2012, 4,174 cases have been reported statewide. 661 pertussis cases were reported in 2011.

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