Prince Harry looks through a microscope at a sample of gonorrhoea as he visits the Burrell Street Sexual Health Clinic in London, Britain on July 14, 2016. REUTERS/Chris Jackson/Pool

U.S. ambassador to Guatemala Arnold Chacon attends a report on experiments on Guatemalans by U.S. researchers between 1946 and 1948, at the National Palace in Guatemala City December 7, 2011. Wednesday's report showed that 2,082 Guatemalans were infected with venereal diseases, gonorrhoea, syphilis and characinoid during experiments performed by ten American doctors in Guatemala. Chacon, who received a copy of the report titled "Damage Consent," reiterated the apology that U.S. President Barack Obama offered in October 2010. REUTERS/Jorge Dan Lopez (GUATEMALA - Tags: POLITICS HEALTH) 

U.S. ambassador to Guatemala Arnold Chacon is seen before a report on experiments on Guatemalans by U.S. researchers between 1946 and 1948, at the National Palace in Guatemala City December 7, 2011. Wednesday's report showed that 2,082 Guatemalans were infected with venereal diseases, gonorrhoea, syphilis and characinoid during experiments performed by ten American doctors in Guatemala. Chacon, who received a copy of the report titled "Damage Consent," reiterated the apology that U.S. President Barack Obama offered in October 2010. REUTERS/Jorge Dan Lopez (GUATEMALA - Tags: POLITICS HEALTH) 

Guatemala's President Alvaro Colom (C) shakes hands with U.S. ambassador to Guatemala Arnold Chacon as Vice President Rafael Espada looks on, before a report on experiments on Guatemalans by U.S. researchers between 1946 and 1948, at the National Palace in Guatemala City December 7, 2011. Wednesday's report showed that 2,082 Guatemalans were infected with venereal diseases, gonorrhoea, syphilis and characinoid during experiments performed by ten American doctors in Guatemala. Chacon, who received a copy of the report titled "Damage Consent," reiterated the apology that U.S. President Barack Obama offered in October 2010. REUTERS/Jorge Dan Lopez (GUATEMALA - Tags: POLITICS HEALTH) 

U.S. ambassador to Guatemala Arnold Chacon speaks during a report on experiments on Guatemalans by U.S. researchers between 1946 and 1948, at the National Palace in Guatemala City December 7, 2011. Wednesday's report showed that 2,082 Guatemalans were infected with venereal diseases, gonorrhoea, syphilis and characinoid during experiments performed by ten American doctors in Guatemala. Chacon, who received a copy of the report titled "Damage Consent," reiterated the apology that U.S. President Barack Obama offered in October 2010. REUTERS/Jorge Dan Lopez (GUATEMALA - Tags: POLITICS HEALTH) 

Guatemala's President Alvaro Colom speaks during a report on experiments on Guatemalans by U.S. researchers between 1946 and 1948, at the National Palace in Guatemala City December 7, 2011. Wednesday's report showed that 2,082 Guatemalans were infected with venereal diseases, gonorrhoea, syphilis and characinoid during experiments performed by ten American doctors in Guatemala. U.S. ambassador to Guatemala Arnold Chacon, who received a copy of the report titled "Damage Consent," reiterated the apology that U.S. President Barack Obama offered in October 2010. REUTERS/Jorge Dan Lopez (GUATEMALA - Tags: POLITICS HEALTH) 

Guatemala's President Alvaro Colom (L) sings the national anthem next to U.S. ambassador to Guatemala Arnold Chacon, before a report on experiments on Guatemalans by U.S. researchers between 1946 and 1948, at the National Palace in Guatemala City December 7, 2011. Wednesday's report showed that 2,082 Guatemalans were infected with venereal diseases, gonorrhoea, syphilis and characinoid during experiments performed by ten American doctors in Guatemala. Chacon, who received a copy of the report titled "Damage Consent," reiterated the apology that U.S. President Barack Obama offered in October 2010. REUTERS/Jorge Dan Lopez (GUATEMALA - Tags: POLITICS HEALTH)