The Zika Virus

Response to Policy Order #5, adopted 2/1/2016

Excerpt of Order: That the City Manager be and hereby is requested to confer with the Department of Public Health, the Cambridge Health Alliance, local hospitals and the medical community on appropriate strategies for public outreach, education, and support for residents who may be concerned about the Zika virus, and report back to the City Council in a timely manner. Full text: https://cambridgema.iqm2.com/Citizens/Detail_LegiFile.aspx?ID=1910

Zika virus outbreaks have occurred in areas of Africa, Southeast Asia, and the Pacific Islands, according to the Centers for Disease Control and Prevention (CDC). In 2015, Zika virus was found in South America for the first time. Since then, it has spread to many countries in Central America, South America, and the Caribbean, as well as Mexico.

Zika virus is primarily spread to people through the bite of the infected Aedes species mosquito. The illness is usually mild with symptoms lasting from several days to a week. People usually don’t get sick enough to go to the hospital, and they very rarely die of Zika.

The worldwide concern over Zika is largely focused on pregnant women. Zika virus can be transmitted from a pregnant woman who has been bitten by an infected mosquito to her fetus during pregnancy or around the time of birth. Infection during pregnancies may be linked to birth defects in babies.

Zika Virus in the United States

Human Cases

As of February 10, no locally acquired vector-borne Zika cases had been reported in the continental United States. Local transmission means that mosquitoes in the area have been infected with Zika virus and can transmit it to humans.

However, cases have been reported in travelers to the United States. A travel-related case, or “imported” case, refers to Zika virus disease in a person who became infected outside the United States and then traveled to the United States. 2

As of Feb. 10, 2016:  52 travel-associated Zika virus cases in people returning to the U.S. had been reported to the CDC, including two cases in Massachusetts.

In December 2015, the Commonwealth of Puerto Rico (a U.S. territory) reported its first confirmed locally transmitted Zika virus case. Cases of local transmission have recently been confirmed in two other U.S. territories: the U.S. Virgin Islands and American Samoa.

As of Feb. 10, 2016:  10 cases had been reported in U.S. territories (1 case was travel-related; 9 cases were locally acquired.)

With the recent outbreaks in the Americas, the number of Zika cases among travelers visiting or returning to the United States will likely increase, according to the CDC. These imported cases may result in limited local spread of the virus in some areas of the United States.

Aedes Species Mosquito Population in the U.S.

The U.S. mainland does have the Aedes species mosquitoes that could become infected with and spread Zika virus. The primary vector in the current Zika virus outbreaks is considered to be the Aedes aegypti mosquito, which has been found in the southeastern United States, Arizona, and California.

While another Aedes species (Aedes albopictus), a possible Zika vector, has been found in isolated areas in Massachusetts, it is extremely unlikely at this time that someone would become infected with Zika virus from a mosquito bite in the Commonwealth, according to the Massachusetts Department of Public Health.

The CDC is not able to predict how much Zika virus would spread in the continental United States. Many areas in the United States have the type of mosquitoes that can become infected with and transmit Zika virus. However, recent chikungunya and dengue outbreaks in the continental United States suggest that Zika outbreaks in the continental United States may be relatively small and limited to a small area.

State and Local Response to Zika Virus

Massachusetts

The CDC is working closely with states to monitor Zika virus and other mosquito-borne diseases. The CDC is providing comprehensive, up-to-date information to state and local health departments, health care providers, and the public via its Zika website, http://www.cdc.gov/zika/index.html.

The Massachusetts Department of Public Health issued clinical advisories on Zika virus on Jan. 21 and Feb. 6. Both the CDC and the state health department recommend that all 3

pregnant women consider postponing travel to areas where Zika virus transmission is ongoing, given that there is neither a vaccine nor prophylactic medications available to prevent Zika virus infection.

The state’s clinical advisories also offer guidance to Massachusetts health care providers about laboratory testing for Zika in pregnant women with recent travel to an area with Zika virus transmission. At this time, all testing is being performed at the CDC.

As an arboviral disease, Zika is nationally notifiable. This means that health care providers are required to report suspected cases to their state or local health departments to facilitate diagnosis and mitigate the risk of local transmission.

Cambridge

The Cambridge Public Health Department and the city’s two health care systems—

Cambridge Health Alliance and Mount Auburn Hospital—are closely monitoring the Zika

virus outbreaks in the Americas and staying abreast of the latest information and protocols from the CDC and the Massachusetts Department of Public Health.

Cambridge Public Health Department

The Cambridge Public Health Department (CPHD) is primarily focused on preparing for the likelihood of travel-associated Zika virus cases in Cambridge. Since late January, CPHD has been in frequent contact with the Massachusetts Department of Public Health and the CDC regarding Zika virus.

If notified of a Cambridge resident with suspected Zika virus infection, CPHD’s public health nurses and epidemiologists would work with the patient’s physician and the state health department to facilitate diagnosis and laboratory testing. Staff would also conduct a thorough case investigation to assist in determining the likely time and location of exposure.

Other CPHD activities:

 Posting Zika virus information on the cambridgepublichealth.org website. Links to the CDC and the Massachusetts Department of Public Health were posted on the CPHD homepage in early February.  Continuing to work with the East Middlesex Mosquito Control Project and the city's

Department of Public Works and Inspectional Services Department to reduce mosquito

habitats and prevent mosquito-borne diseases.

Cambridge Health Alliance

Cambridge Health Alliance (CHA) is providing information about Zika virus to its staff and patients. CHA activities including the following:  Providing information to providers on a dedicated Zika page on the CHA intranet.  Distributing a Zika virus informational handout for maternity and primary care patients, which has been translated into multiple languages. 4