Tick-, Mosquito-Borne Diseases Tripled in US, CDC says

Vector-borne diseases are known to be major causes of illness and death worldwide, but according to a new report from the Centers for Disease Control and Prevention (CDC), they are an especially large and growing health problem in the United States.

In fact, cases of vector-borne diseases have tripled in the United States since 2004, the report said.

This finding emerged from an analysis of data reported to the National Notifiable Diseases Surveillance System for 16 notifiable vector-borne diseases between 2004 and 2016. Findings from the analysis were tabulated according to disease, vector type, location, and year.

Ultimately, 642,602 cases were reported. Researchers at the CDC found that the number of annual reports of tick-borne bacterial and protozoan disease more than doubled from about 22,000 in 2004 to about 48,000 in 2016. Lyme disease was responsible for 82% of all tick-borne disease reports during this time period.

They also noted that the occurrence of mosquito-borne diseases was influenced by virus epidemics, with transmission in Puerto Rico, the US Virgin Islands, and American Samoa comprising most reports of dengue, chikungunya, and Zika virus diseases.

In the continental United States, West Nile virus was found to be endemic, and at times, epidemic.

These trends were found to be characterized by geographic specificity and frequent emergence and introduction of pathogens. Differences in distribution and transmission dynamics of tick-borne and mosquito-borne diseases were often attributable to biologic differences of the vectors, the researchers said.

“To effectively reduce transmission and respond to outbreaks will require major national improvement of surveillance, diagnostics, reporting, and vector control, as well as new tools, including vaccines,” the researchers concluded.

—Christina Vogt

Reference:

Rosenberg R, Lindsey NP, Fischer M, et al. Vital signs: trends in reported vectorborne disease cases —  United States and territories, 2004-2016 [Published online May 1, 2018]. MMWR Morb Mortal Wkly Rep. http://dx.doi.org/10.15585/mmwr.mm6717e1