Update: Ongoing Zika Virus Transmission – Puerto Rico, November 1, 2015-July 7, 2016

Public Health Response

PRDH, in collaboration with CDC, implemented a Zika virus response strategy with three focus areas: protecting pregnant women, controlling the mosquito vector, and expanding access to the full range of voluntary contraceptive options for women and men. Health messaging, such as television and radio public service announcements, has been implemented, health education materials have been distributed at locations, including health care facilities and community events, and weekly arboviral surveillance reports with island-wide and municipal-level information have been posted online.**^,†† Outreach to travelers has included health messaging via television screens and flyers at ports of entry, hotels, and tourist places of interest as well as training airport and tourism personnel. Community intervention strategies have focused on pregnant women. PRDH has worked closely with Women, Infants, and Children (WIC) clinics, where 90% of pregnant women residing in Puerto Rico received services in 2015 (Dana Miró Medina, LND, WIC Puerto Rico, personal communication, 2016), to provide approximately 12,900 Zika prevention kits to pregnant women; the kits include insect repellent, bed nets, condoms, and larvicide to prevent mosquito breeding sites in water-holding containers around households. Since February 2016, approximately 21,000 pregnant women, representing approximately 67% of the estimated number of pregnant women per year based on 2015 birth rates, have been counseled about Zika virus prevention at WIC clinics. In addition, to reduce the risk for unintended pregnancies, the public health response includes community outreach and education about sexual transmission of Zika virus, distribution of male and female condoms, and an increase in the availability of the full range of voluntary contraceptive methods, including long-acting reversible contraceptives (11). PRDH and CDC have also implemented a representative, population-based survey of women aged 18–49 years to assess contraception use through the Behavioral Risk Factor Surveillance System.

Pregnant women across the island identified through WIC are offered vector control services carried out by a contracted pest control company; these services include source reduction of mosquito breeding sites, larvicide application, and residual indoor and outdoor insecticide spraying with deltamethrin. The Puerto Rico Public Housing Administration has led programs to incorporate residual insecticide spraying with deltamethrin and, in collaboration with Puerto Rico Department of Family Affairs, is working to install screens in the homes of pregnant women.

During February–March 2016, a CDC laboratory in Puerto Rico conducted an insecticide resistance study of Ae. aegypti mosquitoes to guide vector control strategies. Mosquitoes from across Puerto Rico were tested using the CDC bottle bioassay (12). Results from the laboratory study indicated widespread resistance to pyrethroids throughout the island with the exception of partial resistance to deltamethrin and full susceptibility to naled, an organophosphate insecticide. Insecticide resistance surveillance is ongoing in the CDC laboratory. Use of lethal adult mosquito traps, which have previously been associated with reduced Ae. aegypti numbers and incidence of arboviral infections in Puerto Rico, is also under consideration (13,14).

PRDH and CDC have collaborated to ensure that all public schools are sprayed with deltamethrin before the school year starts in early August. Furthermore, PRDH and the Puerto Rico Emergency Management Agency have collaborated with municipalities to initiate community cleanup campaigns using larvicide to prevent mosquito breeding in water-holding containers around households and to remove mosquito breeding sites, such as trash heaps and septic tanks. In addition, the Puerto Rico Emergency Management Agency and the Puerto Rico Environmental Quality Board have removed approximately 1.6 million rubber tires that could act as mosquito breeding sites.

Women with evidence of Zika virus infection during pregnancy and their exposed offspring are monitored for adverse maternal, fetal, neonatal, infant, and child health outcomes through the Zika Active Pregnancy Surveillance System. Puerto Rico’s Birth Defects Surveillance and Prevention System, in collaboration with maternal fetal medicine specialists, monitors the ultrasound findings of pregnant women infected with Zika virus. Beginning in January 2016, the Birth Defects Surveillance and Prevention System began identifying newborns with congenital microcephaly, including those born to women infected with Zika virus during pregnancy. All newborns of women with evidence of Zika virus infection during pregnancy are referred to the Children with Special Health Care Needs program for developmental surveillance and coordinated specialized services, for up to age 3 years as needed. All newborns with congenital microcephaly will be referred to Avanzando Juntos, Puerto Rico’s early intervention services system.

Quelle: CDC (Center for Disease Control and Prevention)