At least 98 people, including 17 children, have tested positive for the Zika virus in the Indian City of Kanpur in the Northern state of Uttar Pradesh. The surge in cases is concerning, reminiscent of the Zika epidemic that affected Brazil and other South American countries in late 2015.
Zika infection is often asymptomatic, with 80 percent of the cases being mild. Usual symptoms involve skin rash, fever, muscle pain, red eyes, and joint pain. The virus is mostly transmitted by mosquitoes, but can also be transmitted sexually.
"There has been a surge in cases of the Zika virus and the health department has formed several teams to contain the spread," Dr Nepal Singh, chief medical officer of Kanpur, told Reuters. "There is one woman who is pregnant and we are paying special attention towards her.”
Zika is concerning for pregnant people as it can lead to fetal abnormalities. In fact, the epidemic in Brazil became clear due to an increased number of infants born with microcephaly, with some 4,000 cases reported back then. Microcephaly is the condition for which the skull of the infant is much smaller than what it should be and there is delayed or arrested brain growth.
The link between Zika and microcephaly is not exactly certain. There is plenty of circumstantial evidence showing that increases in microcephaly peaks in areas of increased Zika spread. Genetic material from the Zika virus has also been found in amniotic fluid, placentas, tissues of infants who have died with microcephaly, and in infants of mothers who have had Zika virus infection during pregnancy, according to several reports.
Microcephaly is caused also by other factors. Some genetic disorders – plus exposure to drugs, alcohol, and chemical toxins – can cause it. However, infections such as rubella, herpes simplex virus infections, syphilis, and toxoplasmosis can contribute. Some other viruses also spread by mosquitoes can be linked to the condition.
Mosquitoes as disease vectors are a particular concern in Uttar Pradesh, India’s most populous state. The region, ruled by Prime Minister Modi's Hindu nationalist Bharatiya Janata Party, saw a mysterious fever killing children just a few months ago.
The two most likely causes were dengue fever and Japanese encephalitis, both of which are carried by mosquitoes. The increase in these diseases over the recent decades has been blamed on weakened and ineffective mosquito control programs, as well as the rise of insecticide-resistant vectors.