The global prevalence of Zika virus infection has not been widely reported owing to asymptomatic clinical course, clinical resemblance to other infection with other flaviviruses (dengue, chikungunya), and difficulty in confirming diagnosis.
Based on outbreak reports, entomologic surveys, and seroprevalence surveys, Zika virus infection had been reported in various hosts, including humans, primates, and mosquitoes, in a total of 87 countries and territories across Africa, the Americas, Southeast Asia, and the Western Pacific, as of July 2019. [12]
The prevalence of Zika virus infection in Uganda was 6.1% in 1952 among a population of 99 residents. [13] The prevalence of Zika virus infection was 7.1% in Java, Indonesia, from 1977-1978 among patients who were hospitalized for fever. [14] A seroprevalence of around 20-22% was estimated based on study survey in Senegal, Mali and Gambia from 2007-2012. [2]
Since Zika virus was first isolated in 1947, the disease has spread outside of Africa, mainly into Southeast Asia and the Americas. Until 2007, sporadic cases of Zika virus illness in humans were reported. In 2007, Yap Island in Micronesia reported an outbreak of Zika virus infection transmitted via Aedes hensilli that sickened approximately 73% of the population. [5] Since 2013-2015, epidemics of Zika virus infection have occurred in French Polynesia, New Caledonia, the Cook Islands, the Easter Islands, and other Pacific Islands. [15] The outbreak in French Polynesia highlighted Guillian-Barre syndrome as a potential neurological complication associated with Zika.
In May 2015, Brazil reported the first outbreak of Zika virus infection in the Americas, accounting for around 205,578 cases, in 2016. The Asian lineage associated with the outbreak had potentially circulated in Brazil since 2013. Aedes aegypti (major) and Aedes albopictus (minor) were recognized as vectors for the transmission of Zika virus. The infection spread rapidly to several other countries and became a pandemic. During the outbreak in Brazil, a notable 22% rise in hospitalizations occured between 2014 to 2015 due to Zika-associated Guillain-Barré syndrome (GBS); confirmed or suspected cases of congenital Zika syndrome were reported in more than 5,000 newborns. [16, 17] Brazil reported a total of 6 deaths in 2015-2016. The incidence of new cases eventually decreased due to herd immunity.
Before 2015, only 14 travel-associated cases of Zika virus disease were reported in the United States. In 2016, around 5,168 laboratory-confirmed non-congenital Zika virus infections were reported in the United States. Most (95%) cases were imported as a result of travel to areas with ongoing outbreaks, 4% were potentially acquired via local vector-borne transmission in Florida and Texas, and 1% of the cases were acquired through other routes (sexual transmission, laboratory-acquired and unknown source). Guillain-Barré syndrome was reported in 0.3% of cases, of which 3% required hospitalization. Zika-associated birth defects occured in 10% of babies born to women in the United States. [18, 19]
United States territories such as Puerto Rico and the US Virgin Islands have reported around 37,188 symptomatic Zika virus disease cases, the majority of which were related to autochthonous transmission of the virus. Around 5% of babies born to women in US territories had Zika-associated birth defects. [18]
Outside of Americas and US states and territories, Cape Verde reported the first African Zika epidemic in 2015-2016. Ethiopia reported evidence of Zika virus infection in 2018. Multiple countries in Southeast Asia such as India, Indonesia, Mynamar, and Thailand have reported Zika virus cases and associated complications. [12]
Zika virus infections have been reported in Europe since 2013. The European CDC reported 71 cases of Zika virus infection in 2019, the majority (92%) of which were travel associated with few locally transmitted as a result of sexual contact or vertical transmission. The first 3 cases of vector-borne local transmission of ZIKV infection via Ae. albopictus were reported in France in October 2019. [20]
Laboratory-confirmed symptomatic Zika virus disease cases reported to ArboNET by states and territories - United States, 2017. Courtesy of the Centers for Disease Control and Prevention (CDC).
Laboratory-confirmed symptomatic Zika virus disease cases reported to ArboNET by states and territories - United States, 2017. Courtesy of the Centers for Disease Control and Prevention (CDC).
World map of areas with color-coded risk for Zika based on current or previously reported Zika cases, as of November 4, 2019. Courtesy of the Centers for Disease Control and Prevention (CDC).
World map of areas with color-coded risk for Zika based on current or previously reported Zika cases, as of November 4, 2019. Courtesy of the Centers for Disease Control and Prevention (CDC).
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Rash in a patient with Zika virus infection. Courtesy of Carolina O Barbosa, MD, and Antonio C Bandeira, MD, Salvador, Brazil.
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Rash in a patient with Zika virus infection. Courtesy of Carolina O Barbosa, MD, and Antonio C Bandeira, MD, Salvador, Brazil.
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Rash in a patient with Zika virus infection. Courtesy of Carolina O Barbosa, MD, and Antonio C Bandeira, MD, Salvador, Brazil.
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Rash in a patient with Zika virus infection. Courtesy of Carolina O Barbosa, MD, and Antonio C Bandeira, MD, Salvador, Brazil.
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Laboratory-confirmed symptomatic Zika virus disease cases reported to ArboNET by states and territories - United States, 2017. Courtesy of the Centers for Disease Control and Prevention (CDC).
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World map of areas with color-coded risk for Zika based on current or previously reported Zika cases, as of November 4, 2019. Courtesy of the Centers for Disease Control and Prevention (CDC).
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Diagnostic testing to interpret infection from Dengue and Zika virus. Courtesy of the Centers for Disease Control and Prevention (CDC).
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Dengue and Zika virus diagnostic testing interpretation in nonpregnant and pregnant patients. Courtesy of the Centers for Disease Control and Prevention (CDC).
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Testing algorithm for pregnant women with a clinically compatible illness and risk for Zika and Dengue virus. Courtesy of the Centers for Disease Control and Prevention (CDC).
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Dengue and Zika virus testing recommendations for nonpregnant persons with a clinically compatible illness and risk for infection with both viruses. Courtesy of the Centers for Disease Control and Prevention (CDC).
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Interpretation of results of laboratory testing of infant’s blood, urine, and/or cerebrospinal fluid for evidence of congenital Zika virus infection. Courtesy of the Centers for Disease Control and Prevention (CDC).
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Recommendations for the evaluation of infants with possible congenital Zika virus infection based on infant clinical findings, maternal testing results, and infant testing results - United States, October 2017. Courtesy of the Centers for Disease Control and Prevention (CDC).
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Consultations for infants with clinical findings consistent with congenital Zika syndrome - United States, October 2017. Courtesy of the Centers for Disease Control and Prevention (CDC).
