Cases of Zika virus in Kerala rose to 14 on Friday after the National Institute of Virology confirmed that 13 more samples have tested positive for the mosquito-transmitted disease, reported PTI. The state has been put on alert.

All the cases have been reported from the Thiruvananthapuram district, according to The Indian Express. The first case was reported in a 24-year-old pregnant woman, who was admitted to a private hospital in Thiruvananthapuram on June 28 with symptoms like fever, headache and red marks on her skin. The woman is currently in stable condition and gave birth to a child on June 7.

On Friday, the state government said that 13 samples were found positive out of the 19 sent to the National Institute of Virology.

Health Minister Veena Geroge said that the government has created an action plan to control the spread of the disease. The minister also asked pregnant women to get themselves tested if they are suffering from fever.

The health minister told reporters that the monsoon rains have turned many areas into “breeding ground for the mosquitoes”, reported the BBC. The government has alerted all the district administrations to keep a close eye on cases of mosquito bites and to conduct fumigation drives.

Kerala Health Secretary Dr Rajan Khobragade told the BBC that the state government has sent teams for surveillance in outbreak areas and for spreading awareness about the disease.

According to the World Health Organization, Zika virus is transmitted primarily by Aedes mosquitoes, which bite during the day. The symptoms are usually mild and include fever, rash, conjunctivitis, muscle and joint pain, malaise or headache. The symptoms typically last for two to seven days. The global health body has also said that most people with Zika virus infection do not develop symptoms.

In 2018, more than 100 people were found infected with the virus in Rajasthan. In 2016-’17, Gujarat had also reported a Zika virus outbreak.