Zika Outbreaks

Zika Outbreaks 2024

Zika virus disease (ZIKV) was first recognized in Uganda in 1947, and outbreaks have been noted since 2007 and continue in 2024, according to the World Health Organization (WHO). Autochthonous (local) mosquito-borne transmission of ZIKV has been detected in 92 countries and territories globally. The United States, the United Kingdom, and Canada list countries that account for about 95% of Zika cases between 2014 and 2024. Scientists have reported that ZIKV RNA is detectable in the semen of infected men for months and is found in newborn children. Studies predict that 1.3 billion people could be impacted by Zika by 2050.

Zika Outbreaks The Americas

As of December 2024, the Pan American Health Organization (PAHO) confirmed local transmission of Zika in countries and territories in the Region of the Americas. The PAHO has reported over 40,694 ZIka cases and two related fatalities in the Americas in 2024, with the highest proportion of Zika cases reported in Brazil, Bolivia, Columbia, and Costa Rica. In November 2024, Brazil's Ministry of Health published weekly Zika case reports. The PAHO reported over 36,000 Zika cases in 2023.

Zika in the United States

As of December 2024, the U.S. CDC reported 28 non-congenital Zika cases (1 in Texas). In Puerto Rico, the Department of Health says 16 Zika cases have been reported in 2024. The U.S. CDC says Zika-spreading mosquitoes are found throughout Puerto Rico.

Zika in Asia

Since 2016, the Zika virus has been reported in India's 16 different states/union territories. In December 2024, there had been 148 AES cases, including 59 deaths in 2024. Those infected also included 63 pregnant women. The most affected Indian states are Maharashtra, Kerala, Chickballapur, and Karnataka. In 2024, the U.K. stated travelers should practice usual precautions when visiting India's Zika outbreak areas, such as Maharashtra and Madhya Pradesh. In August 2024, the U.S. CDC issued a Level 2 - Practice Enhanced Precautions regarding an ongoing Zika outbreak in Maharashtra.

The Kingdom of Cambodia's Ministry of Health confirmed its first case of the Zika virus since 2016. Thailand reported 742 Zika virus infections in 2023, with 160 recorded in Bangkok. This is a significant increase from the 190 Zika cases reported in 2022.

As of September 25, 2024, there is no active Zika cluster. Singapore reported 30 Zika cases in 2023. The female Aedes aegypti mosquito is Singapore's primary vector of Zika.

Zika in Europe

The European Centre for Disease Prevention and Control (ECDC) says the Zika virus is not endemic in mainland Europe. In November 2024, Italy reported 7 imported Zika cases this year. On September 11, 2024, France reported five imported cases of Zika in 3 departments colonized by Aedes albopictus. In 2022, the European CDC reported that 31,453 Zika patients were confirmed in 13 of 52 countries and territories. In addition, the WHO reported in 2019 that French authorities confirmed an autochthonous Zika virus case in Hyeres, Var department.

Zika Pacific Islands

As of May 2024, anti-ZIKV antibodies were found in 66% of the Cook Island test collective and 52% of the Vanuatu specimens. As of October 2023, the Solomon Islands reported 7 Zika cases.

Zika Thailand

Thailand has seen ongoing Zika transmission into 2024, with 148 confirmed cases reported as of December, following the high levels of transmission from 2023, when 777 cases were reported in Thailand.

Zika United Kingdom

As of December 2024, 8 Zika virus cases were reported between January and June 2024. This UKHSA data represents a 700% increase compared to the same period in 2023. Thailand (5 cases) and Singapore (2) were the most frequently reported travel countries. The U.K. Health Security Agency (UKHSA) issued a warning on March 21, 2024, concerning Zika outbreaks. Travel-related Zika cases in the U.K. peaked in 2016 with 725 cases.

Zika Virus and Dengue

A study published in Science Translational Medicine on May 29, 2024, found that primary ZIKV infection increased the risk of disease caused by DENV3 and DENV4 but not DENV1. This was also true for tertiary infections when individuals were previously infected with DENV and then ZIKV, but not when they were previously infected with ZIKV and then DENV.

Zika Virus Infections

According to the WHO, there is scientific consensus that the Zika virus is transmitted to people by mosquitoes of the genus Aedes. The WHO says two Zika virus lineages, the African lineage and the Asian lineage, have recently spread in the Pacific and the Region of the Americas. Zika infections can cause microcephaly, Guillain-Barré syndrome (GBS), and other central nervous system malformations. Although the Zika outbreak in southern Brazil has slowed in recent years, live births with microcephaly continue to be reported.

The U.S. Centers for Disease Control and Prevention (CDC) published Research, Volume 30, Number 2—February 2024: temporal phylogenetic analysis revealed limited within-host diversity among most ZIKV-persistent infected associated samples. The researchers detected unusual virus temporal diversity, uncovering the existence of divergent genomes within the same patient. During pregnancy, healthcare providers can monitor the fetus for signs of congenital Zika virus infection, says the CDC.