Monday, April 25, 2011

An Epidemiologist’s Delight

 

 

 

# 5518

 

 
Although today is World Malaria Day, Plasmodium isn’t the only mosquito borne disease of concern. Dengue Fever and Chikungunya both constitute significant public health threats and are increasing in incidence worldwide.

 

In recent years - up until 2009 - locally acquired Dengue fever in the U.S. had only occasionally been reported along the Texas-Mexico border during times when there were outbreaks in neighboring Mexican cities.

 

Otherwise Dengue was an imported disease.  One acquired in countries where the disease is endemic, and brought into the United States by international travelers.

 

All of that changed in August of 2009 when an astute New York Physician diagnosed a woman who had just returned from a Florida Keys vacation with Dengue Fever.   

 

The woman had no recent travel history outside of the United States, which is normally a criteria for diagnosing the illness.  A CDC follow up investigation determined she contracted the virus while in Key West. (see MMWR: Dengue Fever In Key West).

 

This signaled the return of Dengue to Florida after an absence of roughly 70 years.

 

Since then there have been more than 100 confirmed cases, and no doubt, many more undiagnosed mild or asymptomatic infections.

 

Last week the CDC’s  EID Journal published Upward Trend in Dengue Incidence among Hospitalized Patients, United States by J.A. Streit et al., which I highlighted in EID Journal:Vector-Borne Infections.

 

Today, with temperatures warming and mosquito season on its way - a bit of a follow up from the American Medical News (amednews.com) which is published for doctors and health care professionals by the AMA.

 

Doctors should be on lookout for dengue fever

With U.S. hospitalizations rising between 2000 and 2007, physicians are being asked to watch for trends of the disease.

By Christine S. Moyer, amednews staff. Posted Apr 25, 2011.

As cases of dengue infection escalate around the globe, authors of a new study are urging physicians to ask patients with fevers for travel histories. The mosquito-borne infection should be considered as a possible diagnosis for people who recently visited places where the disease is endemic, including Asia, the Caribbean, Central America and South America.

 

Doctors also should know the trends of the disease in the United States, the authors said.

 

Their study, published online April 13 in the Centers for Disease Control and Prevention's Emerging Infectious Diseases, found that more than three times as many people were hospitalized in the U.S. with dengue fever in 2007 than in 2000. Hospitalizations climbed from 81 cases in 2000 to 299 in 2007.

 

The study's authors attribute the increase, in part, to the growing number of worldwide dengue cases and the significant number of Americans who travel to areas where the disease is abundant. The global rise has been linked to climate change. Greater rainfall and warmer temperatures make it more conducive for infected mosquitoes to circulate.

(Continue . . . )

 

 

Back in the day, when I was a young paramedic, the following medical adage was drummed into us.

 

When you are in Central Park, and you hear hoof beats coming up behind you, think horses . . . not zebras.

 

In other words, don’t jump first to some exotic or obscure diagnosis when something perfectly ordinary and common fits the bill.

 

While still good advice most of the time, one need only glance at the table of contents of next months (May, 2011) edition of the EID journal to realize that the exotic, and unusual, are becoming more common in the United States.

 

Over the next month I’ll be highlighting a number of these articles. A few that are already available ahead of print include:

 

Vector-borne Infections
R. Rosenberg and C.B. Beard
(32 KB, 4 pages)

 

Evolution of New Genotype of West Nile Virus in North America
A.R. McMullen et al.

 

Babesiosis in Lower Hudson Valley, New York, USA
J.T. Joseph et al.


Rickettsia rickettsii Transmission by a Lone Star Tick, North Carolina
E.B. Breitschwerdt et al.

 

Probable Non–Vector-borne Transmission of Zika Virus, Colorado
B.D. Foy et al. (103 KB, 7 pages)

 

Bartonella spp. in Feral Pigs, Southeastern United States
A.W. Beard et al.

 

Rickettsia parkeri in Gulf Coast Ticks, Southeastern Virginia
C.L. Wright et al.

 

Upward Trend in Dengue Incidence among Hospitalized Patients, United States
J.A. Streit et al. (59 KB, 6 pages)

 

While not recommended for hypochondriacs, next month’s EID offerings make fascinating reading and are truly an epidemiologist's delight.