Health experts are warning that the capital Hanoi and northern Vietnam are at risk from the Zika virus following two new non-travel-related cases in the southern part of the country reported last week by the Ministry of Health.
The new cases, one in Thuan An District in the southern province of Binh Duong and one Ho Chi Minh City's District 9, bring the total number of Zika cases recorded in Vietnam so far to five.
Vietnam’s health sector has taken measures to prevent a potential outbreak, including testing samples and setting up quarantine zones. The sector has been placed on high alert since two Vietnamese women in Nha Trang and Khanh Hoa became the first confirmed cases of the virus in the country in April.
Prof. Nguyen Van Kinh, director of the National Hospital of Tropical Diseases, said the possibility of the mosquito-borne virus spreading to the north is very high as the Aedes species of mosquito is very common in most provinces and cities in the region.
Zika is spread mostly by the bite of an infected Aedes mosquito. Statistics show that 584 communes and wards in Hanoi are home to this type of mosquito, which can spread dengue fever, Zika, yellow fever and other viruses and diseases.
Kinh added that the majority of Vietnamese people have never been exposed to the virus before, meaning they have lower immunity and with 80 percent of cases showing no symptoms.
Tran Dac Phu, head of the General Department of Preventive Medicine, said the cases of the Zika virus in Vietnam have not displayed any significant symptoms. But that poses a major concern as the victims typically do not know they are carrying the virus and there is a high risk of transmission to people exposed to these "silent carriers".
In Hanoi, 55 suspected cases of Zika have been detected and monitored, but test results have all come back negative for the virus, said Hoang Duc Hanh, deputy director of Hanoi's Health Department. “From now until November, the course of dengue fever may become complicated and the Zika virus may also appear in Hanoi,” said Hanh.
According to the local Health Department, there are 50-60 international flights on average with about 7,000 to 8,000 passengers arriving in Hanoi via Noi Bai International Airport every day. In order to prevent and control the virus, the airport has deployed two body-temperature monitors to detect passengers suspected of carrying Zika.
In July, Vietnam confirmed its third case of Zika in the southern province of Phu Yen. In April, two Vietnamese women became the first confirmed cases of the virus in Nha Trang and Ho Chi Minh City.
Authorities have also discovered a number of foreigners with the Zika virus in recent months.
The Zika virus is transmitted to humans by mosquitoes. Zika virus infections have been linked to the birth defect microcephaly and miscarriages, posing a significant threat to pregnant women, according to the World Health Organization (WHO).
There is no vaccine or effective treatment for Zika, and companies and scientists are racing to develop a vaccine. However, that is unlikely to be ready for widespread use for at least two or three years.
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