Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 32-05: Other Systemic Viral Diseases + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Most infected persons asymptomatically seroconvert Clinical symptoms are akin to those of chikungunya virus infection but with less arthritis Complications include microcephalic infants and ocular abnormalities born to mothers infected during pregnancy as well as Guillain-Barré There is no effective antiviral or vaccine +++ General Considerations ++ Zika virus is a flavivirus, akin to the viruses that cause dengue fever, Japanese encephalitis, and West Nile infection Aedes species mosquitoes, particularly Aedes aegypti, are responsible for transmission of Zika virus The biodistribution of the species largely determines the area of prevalence for Zika virus Aedes species mosquitoes are found primarily in the southeastern United States, but one species Aedes albopictus (the Asian tiger mosquito known to sequester in tires) may be seen as far north as Pennsylvania Modes of transmission Sexual: reported from males and females to partners via vaginal, anal, or oral sex Vertical: from pregnant woman to fetus is prominent Via platelet transfusion has also been reported +++ Demographics ++ The virus was noted in Africa and Asia during the 1950s–1980s A large outbreak occurred in French Polynesia in 2013 A smaller outbreak occurred on Easter Island during 2014 Noted in Brazil in 2015; 239,742 cases were subsequently reported between 2015 and 2018 As of November 7, 2019, there have been 15 cases (14 in travelers and 1 laboratory-acquired case) in the United States and 51 (49 locally-acquired cases and 2 travel-associated cases) in the US territories + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Incubation period is about 3–14 days Most infections (50–80%) are asymptomatic Acute onset fever Maculopapular rash that is often pruritic Nonpurulent conjunctivitis Arthralgias Rash may outlast the fever but is not always present Symptoms last up to 7 days +++ Differential Diagnosis ++ Dengue Chikungunya virus infection + Diagnosis Download Section PDF Listen +++ ++ The CDC recommends that everyone with symptoms of Zika infection be tested if they have traveled to an endemic area with active transmission Diagnosis is made by detecting viral RNA (nucleic acid testing, NAT) in patients presenting with onset of symptoms less than 7 days NAT can be performed within 14 days of illness onset Persons being tested 14 days or more after symptom onset should be tested using IgM serology The Trioplex real-time PCR assay, which detects Zika virus, chikungunya virus, and dengue virus RNA, and the Zika MAC-ELISA, which detects Zika virus IgM antibodies (usually present up to 12 weeks after illness onset), are available Matched serum and urine specimens should be tested simultaneously + Treatment Download Section PDF Listen +++ ++ There are no effective antivirals against Zika virus Sofosbuvir Shows some ability to inhibit Zika replication and infection in vitro Appears to be synergistic with interferon-alpha and with interferon-beta Aspirin does not appear to be associated with major hemorrhagic complications as seen in dengue + Outcome Download Section PDF Listen +++ +++ Complications ++ Congenital microcephaly Ocular findings, including ocular lesions of chorioretinal atrophy and focal pigmented mottling of the retina Guillain-Barré syndrome Can persist in semen for months +++ Prevention ++ Environmental control of mosquitoes + References Download Section PDF Listen +++ + +Abbink P et al. Zika virus vaccines. Nat Rev Microbiol. 2018 Oct;16(10):594–600. [PubMed: 29921914] + +Bullard-Feibelman KM et al. The FDA-approved drug sofosbuvir inhibits Zika virus infection. Antiviral Res. 2017 Jan;137:134–40. [PubMed: 27902933] + +Gaudinski MR et al. Safety, tolerability, and immunogenicity of two Zika virus DNA vaccine candidates in healthy adults: randomised, open-label, phase 1 clinical trials. Lancet 2018 Feb 10;391(10120):552–62. [PubMed: 29217376] + +Giron S et al. Vector-borne transmission of Zika virus in Europe, southern France, August 2019. Eurosurveillance. 2019 Nov;24(45):1900655. [PubMed: 31718742] + +Kovacs A. Zika, the newest TORCH infectious disease in the Americas. Clin Infect Dis. 2020 Jun 10;70(12):2673–4. [PubMed: 31346608] + +Krow-Lucal ER et al. Association and birth prevalence of microcephaly attributable to Zika virus infection among infants in Paraíba, Brazil, in 2015-16: a case-control study. Lancet Child Adolesc Health 2018 Mar;2(3):205–13. [PubMed: 30169255] + +Musso D et al. Zika virus infection—after the pandemic. N Engl J Med. 2019 Oct 10;381(15):1444–57. [PubMed: 31597021] + +Sánchez-Montalvá A et al. Persistence of Zika virus in body fluids—final report. N Engl J Med. 2019 Jan 10;380(2):198. [PubMed: 30628425] + +Silva JVJ Jr et al. Current status, challenges and perspectives in the development of vaccines against yellow fever, dengue, Zika and chikungunya viruses. Acta Trop. 2018 Jun;182:257–63. [PubMed: 29551394] + +Stassen L et al. Zika virus in the male reproductive tract. Viruses. 2018 Apr 16;10(4):E198. [PubMed: 29659541] + +Stone L. Zika virus causes prostatitis. Nat Rev Urol. 2019 Dec;16(12):694. [PubMed: 31712766] + +World Health Organization. Laboratory testing for Zika virus infection: interim guidance. 2016 Mar 23. https://www.who.int/csr/resources/publications/zika/laboratory-testing/en/