Recommendations
The broad distribution of the vector in the Americas combined with the high mobility of persons in and outside of this Region and worldwide, represent a risk for the spread of Zika virus in the Americas. PAHO/WHO reinforces the recommendations made previously regarding the same vector of dengue and chikungunya and urges Member States where the Aedes mosquito that transmits these diseases are present, to establish and maintain the capability to detect and confirm cases, manage cases, and implement an effective public communication strategy to reduce vector density.
Provided below are the key recommendations related to surveillance, case management, and prevention and control measures.
Surveillance
Zika fever surveillance should be set up based on the same existing surveillance system for dengue and chikungunya, taking into account differences in the clinical presentation. As appropriate to the epidemiological situation, surveillance should be directed to (i) determine if the Zika virus has been introduced to an area, (ii) to monitor the Zika virus once introduced, or (iii) to monitor the disease once it has been established.
In countries without autochthonous transmission of the Zika virus infection, it is recommended to:
- Test for Zika virus in a percentage of samples from patients presenting with fever and arthralgia or fever and arthritis with no known etiology (e.g., negative test for malaria, dengue, chikungunya, and febrile rash illnesses). Cross reactivity with dengue serology tests should be taken into account, especially if there has been prior dengue infection. Early detection will allow for proper response and characterization of the outbreak and identification of the circulating viral strains.
In countries with autochthonous transmission of Zika virus infection, it is recommended to:
- Monitor the spread of the virus to detect the introduction into new areas;
- Assess the clinical severity and impact on public health;
- Identify risk factors for Zika virus infection, and when the capacity exists;
- Identify circulating Zika virus lineages.
These efforts are the basis for developing effective control measures. Once the introduction of the virus is documented, ongoing surveillance should be continued to monitor changes in the epidemiology and in Zika virus vector transmission. Any changes detected by the surveillance system should be promptly communicated to the national authorities of prevention and control in order to ensure timely decisions for actions as warranted.