The introduction of Zika virus in Brazil during 2015 and its subsequent spread throughout Central/South America, the Caribbean, and Mexico make it another travel-related arboviral infection of concern along with dengue and chikungunya. While most individuals infected with Zika virus have mild illness or remain asymptomatic, infection in pregnant women may lead to congenital infection that results in neurologic abnormalities or fetal loss.

Click here for more information on arboviruses including disease guidance and reporting information.

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Zika and Other Arbovirus Case Surveillance For 2016 - 2017 Season

Arboviral Infections 2016-2017 Philadelphia, PA:

Zika* Dengue Chikungunya
Cases** 59 3 0
2016 48 3 0
2017 11 0 0
Travel-related 59*** 3 0
Locally-acquired 0 0 0
Median Age (Range), y 34(<1-73) 35(11-58) -
Female, n (%) 43 (73) 1 (33) -
Foreign Born, n (%) 40 (68) 1 (33) -
*Revised Zika case definition implemented September 26, 2016. Unspecified flavivirus infections re-classified as probable Zika.
**Preliminary year to date data. Includes confirmed and probable cases.
***Two cases acquired through sexual contact with a returning traveler. Three cases were infants with probable, asymptomatic congenital infection and no identified birth defects. All others traveled to an affected area.

Travel Destinations: Arboviral Infections, Philadelphia, 2016 - 2017

Arboviral Infections By Travel Destination

Worldwide Distribution Reports

Aedes Species Mosquito Activity in Philadelphia, 2017 Season

Zika, dengue, and chikungunya viruses are spread by Aedes spp. mosquitoes, which are daytime biters and found around homes due to their short flight range. A.aegypti, a principle vector for transmission of these viruses is not found in Philadelphia. A. albopictus (Asian tiger mosquito), a less efficient vector are present and active during warmer months in Philadelphia. PDPH will continue to assess the presence of A. albopictus in Philadelphia and closely monitor human surveillance data to promptly identify local transmission should it occur.

Aedes Mosquito Activity 2017:

Mosquito Activity 2017 Philadelphia, PA
A. aegypti A. albopictus
Number of identifications since May 2017 0 1162
Median number of mosquitoes per trap (range) - 7 (1-814)
Percentage of all mosquito traps set during 2017 season - 64%
Percentage of residential zip codes with Aedes mosquitoes - 94%

A. albopictus Locations*, Philadelphia, 2017

Arboviral Infections By Travel Destination
***A. albopictus identified 1162 times at 430 locations.

Updated: 11/10/17 5:00pm