Zika virus detected in Karnataka’s Chikkaballapura, health officials clarify there are ‘no cases in humans’

Zika virus is primarily transmitted to humans through the bite of infected Aedes mosquitoes, particularly Aedes aegypti and Aedes albopictus.

BySumit Jha

Published Nov 02, 2023 | 9:37 PMUpdatedNov 02, 2023 | 9:37 PM

Zika virus, a vector-borne disease, was reported in several Indian states, including Telangana and Kerala. (Wikimedia Commons)

Zika virus — primarily transmitted to humans through the bite of infected Aedes mosquitoes —  has been detected in a mosquito species in Chikkaballapura district of Karnataka. Following this, blood samples of people with high fever have been sent to the National Institute of Virology (NIV) in Pune for examination.

The NIV, in a statement, said that the virus was detected in Aedes aegypti mosquitoes after samples from six waterbodies in Chikkaballapura were collected and sent for examination in August last week.

Following confirmation of the presence of Zika virus in the mosquito samples collected from Thalakayalabetta in the district, an alert was issued in a five km radius of the area as a precautionary measure to contain the breeding.

It should be noted that the first case of Zika virus in the state was reported in December 2022, when a five year-old-girl in Raichur became infected with the virus.

Also read: First case of Zika virus reported in Karnataka’s Raichur

No cases in humans

The NIV officials stressed that the virus has been detected only in mosquito samples collected from the Thalakayalabetta waterbody and that no cases have been detected in people yet.

Karnataka Health Minister Dinesh Gundu Rao, in a statement, said that no person has tested positive for Zika virus yet.

“Health Department officials have held a special meeting and chalked out a plan to take necessary precautionary measures to prevent the spread of the virus. So far, the Zika virus has not been detected in humans,” Gundu Rao said.

He further added that as a precautionary measure, blood samples of those affected by high fever have been sent for further testing and the report will be received in three days.

“I request the public to not panic as the Zika virus is not as deadly as the Nipah virus. I request children and pregnant women to exercise caution and take precautionary measures,” said the Health Minister.

Also read: How to keep yourself safe from Zika virus? 

‘Monitoring the situation’

“We will be monitoring the situation. A few people were showing some symptoms of fever and rashes. They have been kept in the hospital and checked. Their samples have been sent. Some of them have also been discharged from the hospital. They are okay,” said the Health Minister.

Aedes aegypti mosquito, (Wikimedia Commons)

Aedes aegypti mosquito, (Wikimedia Commons)

“We will be looking into it. We are taking preventive measures. Our people are on the job. The only precaution we need to take is for pregnant women, where it might affect the child. So far, nothing of that sort is there. I request people not to panic. Our department is fully looking into it. Hopefully, there will be no breakout of it anywhere,” he told PTI.

Meanwhile, state Health Commissioner D Randeep iterated, “Samples of three patients with fever have been sent for testing to the National Institute of Virology. These patients are doing fine.”

Chikkaballapura District Health Officer Dr Mahesh Kumar said that mosquito samples were collected from six sites by the entomology team of the state government in August last week and “we received the reports on 25 October”.

According to reports, mosquito samples collected from five sites tested negative but those collected from the Thalakayalabetta waterbody in Shidlaghatta taluk were found to be positive for Zika virus.

Also read: Zika virus: Doctors asked to monitor scans of pregnant women

Alert issued around Thalakayalabetta

“Since the day we received reports, an alert was issued in the five km radius of Thalakayalabetta. We have taken all preventive measures at the field level. We formed 53 teams. Each team has two members who have been surveying 888 houses surrounding the five km radius of that area. We have been getting screenings done regularly,” Mahesh Kumar told PTI.

Aedes albopictus mosquito. (Wikimedia Commons)

Aedes albopictus mosquito. (Wikimedia Commons)

As a precautionary measure, blood samples of 33 patients have been sent to the NIV. Twenty nine of them are antenatal cases and four samples are of patients with high fever. “We are waiting for the results, which are expected to come in another 10 days,” he added.

“Samples are being collected regularly. All these patients whose blood samples have been sent are doing fine. Only one patient with a fever had to be admitted to the district hospital, but the patient has been discharged,” Kumar said.

According to health officials, all precautionary measures have been taken to control the mosquito breeding around houses. Health awareness is being created; people have been made to understand the importance of maintaining cleanliness and hygiene in and around houses.

Mosquito fogging is being done near the area where the Zika virus was detected and the Revenue Department has also been urged to cooperate with the Health Department and take necessary action to contain further spread of the virus.

Also read: Mosquito numbers, diseases to increase due to climate change

About Zika virus

Zika virus is a flavivirus, which is the same family of viruses that includes dengue, yellow fever, and West Nile virus. Zika virus is primarily transmitted to humans through the bite of infected Aedes mosquitoes, particularly Aedes aegypti and Aedes albopictus. These mosquitoes are commonly found in tropical and subtropical regions.


Many people infected with Zika virus may not develop any symptoms or they may experience mild symptoms such as fever, rash, joint pain, and conjunctivitis (red eyes). Symptoms, when present, are usually mild and last for several days to a week.

Pregnancy and Birth Defects

Zika virus infection during pregnancy can lead to serious birth defects in the developing foetus, including microcephaly (a condition where a baby is born with a smaller head and brain) and other neurological abnormalities. It is crucial for pregnant women to take precautions to avoid Zika virus exposure, especially in areas of active transmission.


Beside mosquito bites, Zika virus can also be transmitted through sexual contact with an infected partner. There have been cases of Zika virus transmission through blood transfusion and from mother to child during childbirth or breastfeeding.

Geographic Distribution

The Zika virus was initially identified in Uganda in 1947 and was historically found in Africa and Asia. However, it gained significant attention in 2015 when it was linked to a large outbreak in the Americas, including Brazil. It has since been reported in various parts of the world, including in Kerala.


Preventing mosquito bites is a key measure to reduce the risk of Zika virus infection, especially for pregnant women and individuals living in or travelling to areas with Zika transmission. Safe sexual practices, such as using condoms, can help prevent sexual transmission.

Vaccine and Treatment

There is no specific antiviral treatment for Zika virus and no vaccine is available. Research into vaccines and treatments for Zika virus are ongoing.