Fighting the Zika virus

1. Fighting the Zika virus

2. A health ministry worker fumigates a house to kill mosquitoes during a campaign against dengue and chikungunya and to prevent the entry of Zika virus in Managua, Nicaragua January 26, 2016. The mosquito-borne Zika virus, which has been linked to brain damage in thousands of babies in Brazil, is likely to spread to all countries in the Americas except for Canada and Chile, the World Health Organization said on Monday.

3. People stand outside their house while a health ministry worker fumigates to kill mosquitoes in Managua, Nicaragua January 26, 2016. Brazil's Health Ministry said in November that Zika was linked to a fetal deformation known as microcephaly, in which infants are born with smaller-than-usual brains. REUTERS/Oswaldo Rivas

4. A transmission electron micrograph (TEM) shows the Zika virus, in an undated photo provided by the Centers For Disease Control in Atlanta, Georgia. Zika transmission has not yet been reported in the continental United States, although a woman who fell ill with the virus in Brazil later gave birth to a brain-damaged baby in Hawaii. REUTERS/CDC/Cynthia Goldsmith/Handout via Reuters

5. A public health technician inspects an Aedes aegyti mosquito in a research lab at the entomology department of the Ministry of Public Health, in Guatemala City, January 26, 2016. Brazil has reported 3,893 suspected cases of microcephaly, the WHO said last Friday, over 30 times more than in any year since 2010 and equivalent to 1-2 percent of all newborns in the state of Pernambuco, one of the worst-hit areas. REUTERS/Josue Decavele

6. A man walks away from his home with his son as health workers fumigates the Altos del Cerro neighborhood in Soyapango, El Salvador January 21, 2016. REUTERS/Jose Cabezas

7. A municipal worker touches his face as he finishes spraying insecticide at Sambodrome in Rio de Janeiro, Brazil, January 26, 2016. REUTERS/Pilar Olivares

8. A health agent collects blood from a child with a new test kit that rapidly diagnoses three different mosquito-borne viruses in Sao Paulo, Brazil, January 18, 2016. REUTERS/Rodrigo Paiva

9. A health agent uses a new test kit that rapidly diagnoses three different mosquito-borne viruses in Sao Paulo, Brazil, January 18, 2016. REUTERS/Rodrigo Paiva

10. Graph of the symptoms of the Zika virus is seen behind of Colombia's Health Minister Alejandro Gaviria (R) during a news conference in Bogota, Colombia, January 20, 2016. The Zika outbreak comes hard on the heels of the Ebola epidemic in West Africa, demonstrating once again how little-understood diseases can rapidly emerge as global threats. REUTERS/John Vizcaino

11. A Brazilian soldier searches for signs of mosquito larvae in a pool in Sao Paulo, Brazil, January 18, 2016. "We've got no drugs and we've got no vaccines. It's a case of deja vu because that's exactly what we were saying with Ebola," said Trudie Lang, a professor of global health at the University of Oxford. "It's really important to develop a vaccine as quickly as possible." REUTERS/Rodrigo Paiva

12. Municipal workers wait before spraying insecticide at Sambodrome in Rio de Janeiro, Brazil, January 26, 2016. The virus was first found in a monkey in the Zika forest near Lake Victoria, Uganda, in 1947, and has historically occurred in parts of Africa, Southeast Asia and the Pacific Islands. But there is little scientific data on it and it is unclear why it might be causing microcephaly in Brazil. REUTERS/Pilar Olivares

13. A municipal worker sprays insecticide at the neighborhood of Imbiribeira in Recife, Brazil, January 26, 2016. REUTERS/Ueslei Marcelino

14. A health worker fumigates the Altos del Cerro neighborhood in Soyapango, El Salvador January 21, 2016. Laura Rodrigues of the London School of Hygiene and Tropical Medicine said it was possible the disease could be evolving. REUTERS/Jose Cabezas

15. A woman walks away from her apartment as health workers fumigates the Altos del Cerro neighborhood in Soyapango, El Salvador January 21, 2016. If the epidemic was still going on in August, when Brazil is due to host the Olympic Games in Rio de Janeiro, then pregnant women should either stay away or be obsessive about covering up against mosquito bites, she said. REUTERS/Jose Cabezas

16. Municipal workers spray insecticide at Sambodrome in Rio de Janeiro, Brazil, January 26, 2016. The WHO advised pregnant women planning to travel to areas where Zika is circulating to consult a healthcare provider before traveling and on return. REUTERS/Pilar Olivares

17. A man and his son stand outside their house while a health ministry worker fumigates in Managua, Nicaragua January 26, 2016. The clinical symptoms of Zika are usually mild and often similar to dengue, a fever which is transmitted by the same Aedes aegypti mosquito, leading to fears that Zika will spread into all parts of the world where dengue is commonplace. REUTERS/Oswaldo Rivas

18. A woman sits outside her house while a health ministry worker fumigates in Managua, Nicaragua January 26, 2016. More than one-third of the world�s population lives in areas at risk of dengue infection, in a band stretching through Africa, India, Southeast Asia and Latin America. REUTERS/Oswaldo Rivas

19. World Health Organization Director-General Margaret Chan addresses the delegates during the WHO Executive Board meeting in Geneva, Switzerland, January 25, 2016. "Zika has been isolated in human semen, and one case of possible person-to-person sexual transmission has been described. However, more evidence is needed to confirm whether sexual contact is a means of Zika transmission," the WHO said.

20. A municipal health worker fumigates a home in Tegucigalpa, January 26, 2016. Like rubella, which also causes mild symptoms but can lead to birth defects, health experts believe a vaccine is needed to protect girls before they reach child-bearing age. REUTERS/Jorge Cabrera