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Vector-borne diseases (VBD) are viruses and bacteria spread by vectors, such as mosquitoes, ticks and fleas, and they can cause a variety of illnesses in humans. ​​The vectors ingest the microorganisms from an infected host and transmit to a new host through a bite. Many public health laboratories test for VBDs that are endemic (see list below) as well as those emerging or re-emerging in the US.

APHL works with CDC and public health laboratories to promote best practices, develop guidance and hold important laboratory trainings related to the most commonly found vector-borne diseases in the country. Public health laboratories are integral to performing high quality testing to assess regional disease burden and inform the nation's response to vector-borne diseases.

Chikungunya virus (CHIKV) 

APHL continues to monitor increased Chikungunya virus activity internationally and is working with federal partners to monitor for local transmission in the US. Level Two travel health notices have been released for Cuba, China and for islands in the Indian Ocean. For chikungunya virus protocols, visit APHL's Emerging Infectious Disease Protocols (member access only).  

Other Vector-borne Diseases of Public Health Concern 

In addition to Chikunguyna virus mentioned above, there are other vector-borne diseases of public health concern globally. Domestically, these viruses are predominantly seen in travelers returning to the US. Some local transmission can and has occurred. Many public health laboratories maintain capability to test for one or more of these pathogens. 

  • Dengue virus (DENV): APHL continues to monitor the unprecedented number of dengue cases in 2024–2025 (CDC Situation Summary) State and local public health laboratories diagnose suspected dengue cases through molecular methods and serology, including PRNT. There are five FDA-cleared (or EUA-authorized) tests available; two nucleic acid amplification tests (NAAT) from CDC Trioplex Real-Time RT-PCR Assay (EUA) and CDC DENV 1-4 rRT-PCR Multiplex Assay (510K), two serologic assays from InBios International-IgM ELISA and NS1 ELISA and the BioFire global fever panel. The CDC NAAT methods are currently available to public health laboratories (DenguePCROrdering@cdc.gov) while the other assays are commercially available. Commercial laboratories also offer testing for DENV.
  • Oropouche virus (OROV): Following a number of cases in 2024-2025 in the US, a few public health laboratories have implemented testing capacity in-house (molecular or PRNT) as well as CDC to detect suspected oropouche cases in-house. Commercial testing is also available at:
  • Zika virus (ZIKV): Following the Zika virus response, APHL published a book highlighting the experiences of public health laboratories keeping up with the Zika outbreak and the challenges they faced during the response. 

​Endemic Vector-borne Di​seases

There are several endemic VBDs of public health concern within the US. These VBDs are not equally distributed nationally, therefore testing at any given public health laboratory will vary. The most commonly recognized endemic VBDs include the following: 

  • Borrelia burgdorferi (Lyme Disease)​

  • Colorado tick fever virus (CTFV)

  • Eastern equine encephalitis virus (EEEV)

  • Jamestown Canyon virus (JCV)

  • LaCrosse encephalitis virus (LCV)

  • Powassan virus

  • St. Louis encephalitis virus (SLEV)

  • West Nile virus (WNV)

APHL Resources

Vector-borne Diseases Training and Educational Resources​

APHL, in collaboration with CDC, has developed training and educational resources to promote competency, quality and safety in vector-borne disease testing practices. These resources are primarily designed for laboratorians interested in learning more about the several testing methods available for testing for vector-borne diseases. Most of these trainings are available in APHL's Learning Center. 

Access the APHL Learning Center

Recorded Webinars and Trainings ​