The spread of mosquito-borne Zika virus from South through Central America and into North America, while re-emerging in Africa and Asia, is meeting with resistance from East China. There, particularly in Zhejiang province, mosquito net makers are trying to stem the tide.

Dongren Knitters in Huzhou, Zhejiang, one of the largest makers of mosquito nets for export, has improved its products to try to meet the challenge, General Manager Tong Jian-fang said on Thursday.

The company now infuses the nets with a mosquito repellent to increase users' protection.

"Each year, we provide about 5 million mosquito nets for the World Health Organization and World Children's Fund. We have continuously upgraded our technology to provide the best possible defense," Tong said.

People infected with Zika often show no serious symptoms, but when contracted by a pregnant woman, the virus may cause microcephaly－an abnormally small brain－in the fetus and other brain abnormalities.

From October to January, 4,000 babies were born in Brazil with microcephaly.

The virus is spread princi-pally by the Aedes aegypti mosquito, which also spreads dengue.

The march of Zika virus through the Americas cut through many developing nations, where the last line of defense for residents who could not seal themselves off in air-conditioned homes is the mosquito net.

Chinese mosquito net makers have seen their exports rise by 10 to 20 percent.

Netmaker Fuermei Knitter saw its exports increase by 10 percent last year.

"Before, wemainly export-ed to Southeast Asia, and now we have expanded our business and received a large number of orders from the Middle East and South America," said Zhou Jian-quan, general manager of Fuermei Knitter.

Tong, of Dongren Knitters, said, "We focus on tropical countries, as they have demand all year around, and we won't be affected by the seasons."

Because the dramatic spread of Zika began last year in Brazil, the virus became a point of concern regarding the safety of the Summer Olympic Games inRio de Janeiro.

However, despite the name of the sports extravaganza, Brazil, in the Southern Hemi-sphere, is in its winter season, when there are relatively few mosquitoes.

Because of that, the WHO announced in June that there is "very little risk" of the Rio Olympics aiding the spread of Zika virus.