72-year-old Kanemasa Ito (L) puts a GPS tracking necklace on his 68-year-old wife Kimiko who was diagnosed with dementia 11 years ago, on a sofa at their home in Kawasaki, south of Tokyo, Japan, April 6, 2016. Encouraging people with dementia to speak out is part of Japan's effort to ease the negative image of a disorder that affects nearly 5 million citizens and is forecast to affect 7 million, or one in five Japanese age 65 or over, by 2025. REUTERS/Issei Kato SEARCH "JAPAN DEMENTIA" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES TPX IMAGES OF THE DAY TPX IMAGES OF THE DAY

A health worker prepares insecticide before fumigating a neighborhood in San Juan, in this January 27, 2016, file photo. Researchers around the world are now convinced the Zika virus can cause the birth defect microcephaly as well as Guillain-Barre syndrome, a rare neurological disorder that can result in paralysis, the World Health Organization said on March 31, 2016. REUTERS/Alvin Baez/Files 

Lucas, 4-months old, who is Miriam Araujos's second child and born with microcephaly, sleeps on a hammock at their house, in Sao Jose dos Cordeiros, Brazil early February 17, 2016. Picture taken on February 17, 2016. REUTERS/Ricardo Moraes 

Miriam Araujo, 25, holds Lucas, her 4-months old child born with microcephaly as her mother Joana, 51, observes and her daughter Maisa, 6, looks on, as the stand outside their house, in Sao Jose dos Cordeiros, Brazil February 16, 2016. Picture taken on February 16, 2016. REUTERS/Ricardo Moraes 

Miriam Araujo, 25, caresses Lucas, her 4-months old child born with microcephaly as he sleeps on a hammock inside their house, in Sao Jose dos Cordeiros, Brazil February 16, 2016. Picture taken on February 16, 2016. REUTERS/Ricardo Moraes 

Miriam Araujo, 25, holds Lucas, her 4-months old child born with microcephaly as her daughter Maisa, 6 looks on, outside their house, in Sao Jose dos Cordeiros, Brazil, February 16, 2016. Picture taken on February 16, 2016. REUTERS/Ricardo Moraes 

Physiotherapist Jeime Lara Leal does exercises with Lucas, 4-months old, who is Miriam Araujo's second child and born with microcephaly in Pedro I hospital in Campina Grande, Brazil , February 17, 2016. Picture taken on February 17, 2016. REUTERS/Ricardo Moraes 

Miriam Araujo, 25, packs as Lucas, her 4-months old child born with microcephaly sleeps on a hammock at their house, in Sao Jose dos Cordeiros, Brazil February 16, 2016. Picture taken on February 16, 2016. REUTERS/Ricardo Moraes 

Miriam Araujo, 25, holds Lucas, her 4-months old child born with microcephaly at their house, in Sao Jose dos Cordeiros, Brazil February 16, 2016. Picture taken on February 16, 2016. REUTERS/Ricardo Moraes 

Miriam Araujo (L), 25, holds Lucas, her 4-months old child born with microcephaly as her mother Joana, 51, and her brother Israel, 34, observe outside their house, in Sao Jose dos Cordeiros, Brazil February 16, 2016. Picture taken on February 16, 2016. REUTERS/Ricardo Moraes 

Lucas, 4-months old, who is Mariam Araujo's second child and born with microcephaly sleeps on the legs of his sister Maisa, 6 at their house, in Sao Jose dos Cordeiros, Brazil, early February 17, 2016. Picture taken on February 17, 2016. REUTERS/Ricardo Moraes 

Lucas, 4-months old, who is Mariam Araujo's second child and born with microcephaly sleeps on the legs of his sister Maisa, 6 at their house, in Sao Jose dos Cordeiros, Brazil, early February 17, 2016. Picture taken on February 17, 2016. REUTERS/Ricardo Moraes 

Mariam Araujo, 25, reacts as she holds Lucas, her 4-months old child and born with microcephaly as they get inside a van in Sao Jose dos Cordeiros as they start a trip to Campina Grande, Brazil, early February 17, 2016. Picture taken on February 17, 2016. REUTERS/Ricardo Moraes 

Mariam Araujo, 25, holds Lucas, her 4-months child and born with microcephaly as woman plays with him, as they arrive to Pedro I hospital after a trip from Sao Jose dos Cordeiros and Campina Grande, Brazil, February 17, 2016. Picture taken on February 17, 2016. REUTERS/Ricardo Moraes 

Mariam Araujo, 25, holds Lucas, her 4-months old second child and born with microcephaly as they wait for a physiotherapy session in Pedro I hospital in Campina Grande, Brazil, February 17, 2016. Picture taken on February 17, 2016. REUTERS/Ricardo Moraes 

Mariam Araujo, 25, plays with Lucas, her 4-months old second child and born with microcephaly as they wait for a physiotherapy session in Pedro I hospital in Campina Grande, Brazil, February 17, 2016. Picture taken on February 17, 2016. REUTERS/Ricardo Moraes 

Miriam Araujo, 25, holds Lucas, her 4-months old second child and born with microcephaly as her daughter Maisa, 6 caresses him, outside their house, in Sao Jose dos Cordeiros, Brazil , February 16, 2016. Picture taken on February 16, 2016. REUTERS/Ricardo Moraes TPX IMAGES OF THE DAY

Physiotherapist Jeime Lara Leal does exercises with Lucas, 4-months old, who is Miriam Araujo's second child and born with microcephaly in Pedro I hospital in Campina Grande, Brazil , February 17, 2016. Picture taken on February 17, 2016. REUTERS/Ricardo Moraes 

Mariam Araujo (R), 25, holds Lucas, her 4-months old second child and born with microcephaly as she attends a group therapy with others mothers who also had babies born with microcephaly, in Pedro I hospital in Campina Grande, Brazil, February 17, 2016. Picture taken on February 17, 2016. REUTERS/Ricardo Moraes 

Physiotherapist Jeime Lara Leal does exercises with Lucas, 4-months old, who is Miriam Araujo's second child and born with microcephaly in Pedro I hospital in Campina Grande, Brazil , February 17, 2016. Picture taken on February 17, 2016. REUTERS/Ricardo Moraes TPX IMAGES OF THE DAY

Miriam Araujo, 25, holds Lucas, 4-months old, who is her second child and born with microcephaly as her mother Joana, 51 and her brother Israel, 34, look out of their house, in Sao Jose dos Cordeiros, Brazil February 16, 2016. Picture taken on February 16, 2016. REUTERS/Ricardo Moraes 

Vanessa, 32, types a text message on her mobile phone as she holds her daughter Valentina, who is 5-months-old and born with microcephaly, inside of their house in Jaboatao, near Recife, Brazil, February 12, 2016. The Zika virus may be particularly adept at entrenching itself in parts of the body that are shielded from the immune system, making it harder to fight off and possibly lengthening the timeframe in which it can be transmitted, top U.S. experts said on Friday. Picture taken February 12, 2016. REUTERS/Nacho Doce

Daniele Santos, 29, holds her son Juan Pedro who is 2-months-old and born with microcephaly, after bathing him at their house in Recife, Brazil, February 9, 2016. The Zika virus may be particularly adept at entrenching itself in parts of the body that are shielded from the immune system, making it harder to fight off and possibly lengthening the timeframe in which it can be transmitted, top U.S. experts said on Friday. Picture taken February 9, 2016. REUTERS/Nacho Doce

Vanessa, 32, bathes her daughter Valentina, who is 5-months old and born with microcephaly, at the entrance of their house in Jaboatao, near Recife, Brazil, February 12, 2016. The suspected link between the Zika virus and two neurological disorders, the birth defect microcephaly and Guillain-Barre syndrome, could be confirmed within weeks, the World Health Organisation (WHO) said on Friday. REUTERS/Nacho Doce 

Vanessa, 32, feeds her daughter Valentina who is 5-months old and born with microcephaly, with a bottle under a mosquito net, inside their house in Jaboatao, near Recife, Brazil, February 12, 2016. The suspected link between the Zika virus and two neurological disorders, the birth defect microcephaly and Guillain-Barre syndrome, could be confirmed within weeks, the World Health Organisation (WHO) said on Friday. REUTERS/Nacho Doce TPX IMAGES OF THE DAY

Vanessa, 32, holds her daughter Valentina, who is 5-months old and born with microcephaly, at the entrance of their house in Jaboatao, near Recife, Brazil, February 12, 2016. The suspected link between the Zika virus and two neurological disorders, the birth defect microcephaly and Guillain-Barre syndrome, could be confirmed within weeks, the World Health Organisation (WHO) said on Friday. REUTERS/Nacho Doce 

Vanessa, 32, feeds her daughter Valentina who is 5-months old and born with microcephaly, with a bottle under a mosquito net, inside their house in Jaboatao, near Recife, Brazil, February 12, 2016. The suspected link between the Zika virus and two neurological disorders, the birth defect microcephaly and Guillain-Barre syndrome, could be confirmed within weeks, the World Health Organisation (WHO) said on Friday. REUTERS/Nacho Doce 

Gustavo Henrique who is 2-months old and born with microcephaly, reacts to stimulus during an evaluation session with the physiotherapist Marcia (R) at the Altino Ventura rehabilitation center in Recife, Brazil, February 11, 2016. Recent laboratory analyses identified Zika virus infections in three people who died in Brazil last year, the health ministry said on Thursday, although authorities could not confirm that Zika alone was responsible for their deaths. REUTERS/Nacho Doce 

Gustavo Henrique who is 2-months old and born with microcephaly, during a session to stimulate the development of his eyesight with a physiotherapist at the Altino Ventura rehabilitation center in Recife, Brazil, February 11, 2016. Recent laboratory analyses identified Zika virus infections in three people who died in Brazil last year, the health ministry said on Thursday, although authorities could not confirm that Zika alone was responsible for their deaths. REUTERS/Nacho Doce 

Gustavo Henrique who is 2-months old and born with microcephaly, reacts to stimulus during an evaluation session with a physiotherapist at the Altino Ventura rehabilitation center in Recife, Brazil, February 11, 2016. Recent laboratory analyses identified Zika virus infections in three people who died in Brazil last year, the health ministry said on Thursday, although authorities could not confirm that Zika alone was responsible for their deaths. REUTERS/Nacho Doce 

Geovane, 32, holds his son Gustavo Henrique who is 2-months old and born with microcephaly, as they wait for a session with a physiotherapist at the Altino Ventura rehabilitation center in Recife, Brazil, February 11, 2016. Recent laboratory analyses identified Zika virus infections in three people who died in Brazil last year, the health ministry said on Thursday, although authorities could not confirm that Zika alone was responsible for their deaths. REUTERS/Nacho Doce 

Gustavo Henrique who is 2-months old and born with microcephaly, reacts to stimulus during an evaluation session with a physiotherapist at the Altino Ventura rehabilitation center in Recife, Brazil, February 11, 2016. Recent laboratory analyses identified Zika virus infections in three people who died in Brazil last year, the health ministry said on Thursday, although authorities could not confirm that Zika alone was responsible for their deaths. REUTERS/Nacho Doce 

Geovane, 32, holds his son Gustavo Henrique who is 2-months old and born with microcephaly, as they wait for a session with a physiotherapist at the Altino Ventura rehabilitation center in Recife, Brazil, February 11, 2016. Recent laboratory analyses identified Zika virus infections in three people who died in Brazil last year, the health ministry said on Thursday, although authorities could not confirm that Zika alone was responsible for their deaths. REUTERS/Nacho Doce TPX IMAGES OF THE DAY 

Geovane, 32, holds his son Gustavo Henrique who is 2-months old and born with microcephaly, as they wait for a session with a physiotherapist at the Altino Ventura rehabilitation center in Recife, Brazil, February 11, 2016. Recent laboratory analyses identified Zika virus infections in three people who died in Brazil last year, the health ministry said on Thursday, although authorities could not confirm that Zika alone was responsible for their deaths. REUTERS/Nacho Doce 

Jackeline, 30, feeds her son Gustavo Henrique who is 2-months old and born with microcephaly, with a bottle as they wait for a session with a physiotherapist at the Altino Ventura rehabilitation center in Recife, Brazil, February 11, 2016. Recent laboratory analyses identified Zika virus infections in three people who died in Brazil last year, the health ministry said on Thursday, although authorities could not confirm that Zika alone was responsible for their deaths. REUTERS/Nacho Doce 

Daniele Santos, 29, holds her son Juan Pedro who is 2-months old and born with microcephaly, after bathing him at their house in Recife, Brazil, February 9, 2016. The mosquito-borne virus, which is widespread in Brazil and has been linked to birth defects, has prompted concern among athletes and sports officials around the world as they prepare for the Olympic Games in Rio de Janeiro. REUTERS/Nacho Doce 

Daniele Santos, 29, holds her son Juan Pedro who is 2-months old and born with microcephaly, as his great-grandmother Maria Jose (R), 66, holds the pacifier for him in front of their house in Recife, Brazil, February 9, 2016. The mosquito-borne virus, which is widespread in Brazil and has been linked to birth defects, has prompted concern among athletes and sports officials around the world as they prepare for the Olympic Games in Rio de Janeiro. REUTERS/Nacho Doce 

Daniele Santos, 29, combs the hair of her son Juan Pedro who is 2-months old and born with microcephaly, after bathing him at their house in Recife, Brazil, February 9, 2016. The mosquito-borne virus, which is widespread in Brazil and has been linked to birth defects, has prompted concern among athletes and sports officials around the world as they prepare for the Olympic Games in Rio de Janeiro. REUTERS/Nacho Doce 

Daniele Santos, 29, bathes her son Juan Pedro who is 2-months old and born with microcephaly, at their house in Recife, Brazil, February 9, 2016. The mosquito-borne virus, which is widespread in Brazil and has been linked to birth defects, has prompted concern among athletes and sports officials around the world as they prepare for the Olympic Games in Rio de Janeiro. REUTERS/Nacho Doce 

Daniele Santos, 29, holds her son Juan Pedro who is 2-months old and born with microcephaly, as she picks up a towel at their house in Recife, Brazil, February 9, 2016. The mosquito-borne virus, which is widespread in Brazil and has been linked to birth defects, has prompted concern among athletes and sports officials around the world as they prepare for the Olympic Games in Rio de Janeiro. REUTERS/Nacho Doce 

Daniele Santos, 29, holds her son Juan Pedro who is 2-months old and born with microcephaly, at their house in Recife, Brazil, February 9, 2016. The mosquito-borne virus, which is widespread in Brazil and has been linked to birth defects, has prompted concern among athletes and sports officials around the world as they prepare for the Olympic Games in Rio de Janeiro. REUTERS/Nacho Doce 

Daniele Santos, 29, holds her son Juan Pedro who is 2-months old and born with microcephaly, at their house in Recife, Brazil, February 9, 2016. The mosquito-borne virus, which is widespread in Brazil and has been linked to birth defects, has prompted concern among athletes and sports officials around the world as they prepare for the Olympic Games in Rio de Janeiro. REUTERS/Nacho Doce 

Daniele Santos, 29, holds her son Juan Pedro who is 2-months old and born with microcephaly, as she talks with a neighbour (not pictured) in front of their house in Recife, Brazil, February 9, 2016. The mosquito-borne virus, which is widespread in Brazil and has been linked to birth defects, has prompted concern among athletes and sports officials around the world as they prepare for the Olympic Games in Rio de Janeiro. REUTERS/Nacho Doce 

Great-grandfather Wilson (L), 77, kisses his great-grandson Juan Pedro who is 2-months old and born with microcephaly, as his mother Daniele Santos, 29, holds him on a street in front of their house in Recife, Brazil, February 9, 2016. The mosquito-borne virus, which is widespread in Brazil and has been linked to birth defects, has prompted concern among athletes and sports officials around the world as they prepare for the Olympic Games in Rio de Janeiro. REUTERS/Nacho Doce TPX IMAGES OF THE DAY

Daniele Santos, 29, cleans her son Juan Pedro's ear who is 2-months old and born with microcephaly, after bathing him at their house in Recife, Brazil, February 9, 2016. The mosquito-borne virus, which is widespread in Brazil and has been linked to birth defects, has prompted concern among athletes and sports officials around the world as they prepare for the Olympic Games in Rio de Janeiro. REUTERS/Nacho Doce TPX IMAGES OF THE DAY

Luana Vieira, 4 months old, who was born with microcephaly, is carried by her mother Rosana Vieira Alves, as Rosana walks with her other daughters to school, in Olinda, Brazil, February 4, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. REUTERS/Ueslei Marcelino 

Luana Vieira, 4 months old, who was born with microcephaly, is carried by her mother Rosana Vieira Alves, as Rosana walks with her other daughters to school, in Olinda, Brazil, February 4, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. REUTERS/Ueslei Marcelino 

Luana Vieira, 4 months, who was born with microcephaly, is held by her mother Rosana Vieira Alves as they ride the subway after a doctor's appointment in Recife, Brazil, February 3, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. Picture taken February 3. REUTERS/Ueslei Marcelino 

Luana Vieira, 4 months, who was born with microcephaly, is carried by her mother Rosana Vieira Alves, as Rosana walks with her other daughters to school, in Olinda, Brazil, February 4, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. REUTERS/Ueslei Marcelino 

Rosana Vieira Alves holds her 4-month-old daughter Luana Vieira, who was born with microcephaly, in the sea in Olinda, Brazil, February 4, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. REUTERS/Ueslei Marcelino 

Rosana Vieira Alves holds her 4-month-old daughter Luana Vieira, who was born with microcephaly, at their house in Olinda, Brazil, February 3, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. Picture taken February 3. REUTERS/Ueslei Marcelino 

Rosana Vieira Alves, bathes her 4-month-old daughter Luana Vieira, who was born with microcephaly, at their house in Olinda, Brazil, February 3, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. Picture taken February 3. REUTERS/Ueslei Marcelino 

Rosana Vieira Alves stretches her back while washing the clothes of her 4-month-old daughter Luana Vieira, who was born with microcephaly, in their house in Olinda, Brazil, February 3, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. Picture taken February 3. REUTERS/Ueslei Marcelino 

Luana Vieira, 4 months old, who was born with microcephaly, reacts to stimulus during an evaluation session with a physiotherapist at the Altino Ventura rehabilitation center in Recife, Brazil, February 3, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. Picture taken February 3. REUTERS/Ueslei Marcelino 

Luana Vieira, 4 months old, who was born with microcephaly, is held by her mother Rosana Vieira Alves as they ride the subway after a doctor's appointment in Recife, Brazil, February 3, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. Picture taken February 3. REUTERS/Ueslei Marcelino 

Luana Vieira, 4 months old, and born with microcephaly, is seen on the beach in Olinda, Brazil, February 4, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. REUTERS/Ueslei Marcelino TPX IMAGES OF THE DAY

Rosana Vieira Alves holds her 4-month-old daughter Luana Vieira, who was born with microcephaly, at their house in Olinda, Brazil, February 3, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. Picture taken February 3. REUTERS/Ueslei Marcelino 

Rosana Vieira Alves holds her 4-month-old daughter Luana Vieira, who was born with microcephaly, at their house in Olinda, Brazil, February 3, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. Picture taken February 3. REUTERS/Ueslei Marcelino 

X-ray of Rosana Vieira Alves's daughter Luana Vieira, who is 4 months old with microcephaly, is pictured at their house in Olinda, Brazil, February 3, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. Picture taken February 3. REUTERS/Ueslei Marcelino 

Vitoria Evillen (obscured) holds her sister 4-month-old Luana Vieira, who was born with microcephaly, at their house in Olinda, Brazil, February 3, 2016. Brazil is investigating more than 4,000 suspected cases of microcephaly, a condition in which infants are born with abnormally small heads and can suffer developmental problems, that may be linked to the Zika outbreak. Picture taken February 3. REUTERS/Ueslei Marcelino TPX IMAGES OF THE DAY