Zika Virus In Bolivia: Tracking Cases And Outbreaks

Bolivia has reported cases of the Zika virus, with the first laboratory-confirmed case of locally-acquired infection reported in January 2016. The virus has been circulating in the country's tropical regions, with varying levels of seroprevalence in different areas. In 2023, Bolivia reported 881 cases of the Zika virus, a significant increase from the previous year. The virus has been associated with severe complications, particularly in pregnant women, and has the potential for further spread in certain regions.

Zika cases in Bolivia in 2023

In 2023, Bolivia reported 881 cases of the Zika virus, a notable increase from the 190 infections recorded in 2022. The South American country experienced its highest number of Zika infections in 2017 and 2018, with 1,736 cases each year.

Zika is a mosquito-borne disease transmitted mainly through the bites of the Aedes aegypti mosquito, which is also associated with dengue fever. The disease can also be sexually transmitted and can be acquired through blood transfusions. While symptoms are often mild, including fever, headache, rashes, and joint pain, Zika infections during pregnancy can cause congenital disorders such as microcephaly, which disrupts brain growth and can lead to intellectual and motor impairments in newborns.

In response to the Zika virus, Bolivian health authorities have implemented several measures, including intensified surveillance activities, vector control measures, and public education campaigns to raise awareness about the risks associated with the virus.

In recent years, Latin America has seen a rise in Zika infections, with Brazil reporting the highest number of cases in 2023, followed by Bolivia and Belize. However, there is still no specific cure, vaccine, or treatment for Zika, and prevention remains a crucial strategy in combating the spread of the disease.

First Zika case in Bolivia

On the 16th of January 2016, the Ministry of Health of Bolivia notified the Pan American Health Organisation/World Health Organisation (PAHO/WHO) of the first laboratory-confirmed case of locally-acquired Zika virus infection in the country. The case was a 32-year-old pregnant woman from Portachuelo, Santa Cruz Department, with the onset of symptoms on the 8th of January. She had no recent history of travel.

On the 12th of January, samples of the patient were sent to the National Center for Tropical Diseases for testing. On the 14th of January, the case was confirmed by polymerase chain reaction (PCR) (viral genome detection).

In response, health authorities in Bolivia took several measures, including intensifying surveillance activities, implementing vector control measures, and educating the public about the risks associated with the Zika virus. They also encouraged people to take precautions against mosquito bites, as the proximity of mosquito vector breeding sites to human habitation is a significant risk factor for Zika virus infection.

Zika virus transmission

In addition to mosquito-borne transmission, Zika virus can also be transmitted through several other routes:

• Sexual transmission: Zika virus can be passed from a person with Zika to their sex partners. The use of condoms can reduce the risk of Zika transmission during sexual intercourse.
• Mother-to-child transmission: Zika virus can be passed from a pregnant person to their baby, potentially resulting in serious consequences such as miscarriage, stillbirth, or severe birth defects like microcephaly.
• Blood transfusion and organ transplantation: Although rare, Zika virus transmission can occur through blood transfusion and organ transplantation.

To prevent Zika virus transmission, it is crucial to avoid mosquito bites, especially in areas with active Zika virus transmission. This can be achieved by wearing long-sleeved shirts and long pants, using insect repellents, staying in screened-in or air-conditioned rooms, and sleeping under mosquito nets if necessary.

In Bolivia, the first laboratory-confirmed cases of locally acquired Zika virus infection were reported in January 2016. Since then, there have been fluctuations in the number of Zika cases in the country, with 2017 and 2018 being the years with the highest number of infections.

Zika virus circulation in Bolivia

Zika virus disease (Zika) is transmitted to humans by Aedes mosquitoes and is related to dengue and yellow fever viruses. The first autochthonous case of Zika in Bolivia was reported in January 2016. Since then, Bolivia has reported Zika cases every year, with the exception of 2022.

In 2023, Bolivia reported 881 cases of Zika, a significant increase from the 190 cases reported in 2021. The highest number of Zika cases in Bolivia was recorded in 2017 and 2018, with 1,736 cases each year.

A seroprevalence study conducted in 2016-2017 revealed that Zika circulation occurred in tropical areas of Bolivia, such as Beni (39%) and Santa Cruz de la Sierra (21.5%), but not in the highlands (~0% in Cochabamba, La Paz, and Tarija). The spread of Zika in Bolivia was influenced by the activity of Aedes aegypti mosquitoes and was not limited by prior immunity to dengue.

The proximity of mosquito breeding sites to human habitation poses a significant risk for Zika infection. To prevent and control the spread of Zika, it is crucial to reduce mosquito breeding sites and protect against mosquito bites.

Preventing Zika virus infection

Zika is primarily transmitted to people through mosquito bites, specifically from female Aedes aegypti mosquitoes. These mosquitoes are mostly active during the daytime and can also transmit other diseases such as dengue, chikungunya, and yellow fever. Aedes aegypti mosquitoes can be found in warm, tropical climates and do not survive in cooler temperatures. Zika can also be transmitted by the Aedes albopictus mosquito, although it is still contested how effective this is in transmitting the disease.

To prevent Zika virus infection, it is important to take precautions to avoid mosquito bites, especially during the daytime when mosquitoes are most active. Here are some measures to prevent mosquito bites:

• Use mosquito repellent in accordance with the instructions on the product label. It is recommended to use an Environmental Protection Agency (EPA)-registered insect repellent with active ingredients such as oil of lemon eucalyptus (para-menthane-diol).
• Wear long-sleeved shirts and long trousers to cover your skin. Light-colored clothing is preferable.
• Sleep or rest in screened or air-conditioned rooms to keep mosquitoes out.
• Empty and remove containers that can collect water, as these can serve as mosquito breeding sites.

In addition to preventing mosquito bites, it is important to be aware of other modes of Zika transmission and take appropriate precautions:

• Zika can be transmitted through sexual contact, including vaginal, anal, and oral sex, as well as the sharing of sex toys. To reduce the risk of sexual transmission, it is recommended to use condoms consistently and correctly. Abstaining from sex eliminates the risk of getting Zika from sexual transmission.
• Zika can be transmitted from mother to child during pregnancy, and it can cause severe birth defects such as microcephaly and other fetal brain defects. Pregnant women or those planning to become pregnant should take extra precautions to avoid mosquito bites and exposure to Zika.
• There is evidence of possible Zika transmission through blood transfusion. Travellers returning from Zika-affected areas are advised not to donate blood until at least 28 days after their return to ensure the risk of infection has passed.

Frequently asked questions