Mosquito-Borne Diseases Update, New Hampshire, 2021

NH DPHSOn June 28, 2021, NH DHHS issued a health alert regarding mosquito-borne diseases in NH in 2021.

Key Points and Recommendations:

  1. The first ever detection of Jamestown Canyon virus (JCV) in a mosquito has been detected from a batch of Aedes excrucians collected on 6/8/2021 in Bow, NH. During the 2020 season, one human case of JCV was identified in Bow. 
  2. Three different mosquito-transmitted infections can be acquired in New Hampshire: West Nile Virus (WNV), Eastern Equine Encephalitis Virus (EEEV), and JCV. 
  3. All three mosquito-borne diseases can cause a range of clinical symptoms including asymptomatic infection, non-specific febrile illness, and severe neurological disease including meningitis and encephalitis. 
  4. Clinicians should consider testing for WNV, EEEV, and JCV, especially in patients hospitalized with signs or symptoms of meningitis or encephalitis (e.g. confusion or altered mental status). 
  5. Testing for Powassan (POW) virus (a tickborne viral infection) should also be considered in patients presenting with unexplained neurologic illness. 
  6. Report all suspect or confirmed arboviral illnesses to the Division of Public Health Services (DPHS) within 24 hours at 603-271-4496 (after hours 603-271-5300 and ask for the public health nurse on call). 
  7. Clinicians should contact their reference laboratories for mosquito-borne disease testing for the 2021 season. DPHS will continue to coordinate testing for POW and JCV as well as confirmatory testing for EEEV and WNV through the CDC.

Read the full DHHS alert