GHESKIO’s initial work defined the etiology of severe diarrhea and dehydration in Haitian infants.  GHESKIO introduced oral rehydration therapy which resulted in a decrease in the hospital infant mortality rate from 40% to <1% within two years.  Nationwide expansion of the GHESKIO program resulted in a 50% decrease in infant mortality in Haiti by the mid-1990s.  The studies of diarrhea in infants led to similar studies in adults and the recognition of AIDS in Haiti.   

GHESKIO published the first comprehensive description of AIDS in a tropical resource-poor setting in 1983 in the New England Journal of Medicine.  The story of HIV/AIDS in Haiti has since been inseparable from that of GHESKIO. GHESKIO has been the major source of information on the evolving AIDS epidemic in Haiti and a partner with the government and other organizations in combating the epidemic for over 30 years. GHESKIO researchers identified contaminated blood transfusions as a major mode of HIV transmission in 1985, and then worked with the Haitian Government to place the Haitian Red Cross in total control of blood banking. In the 1990’s GHESKIO conducted clinical trials to define effective therapeutic and preventive interventions for HIV. In 2005, GHESKIO documented the success of antiretroviral therapy (ART) in a resource-poor setting, and in 2010, GHESKIO published ART treatment initiation criteria, which prompted the WHO to change international guidelines.

GHESKIO opened the first HIV Voluntary Counseling and Testing (VCT) Center in Haiti in 1985.  The number of people seeking HIV testing at GHESKIO has continued to increase reaching 40,077 in 2013.  A GHESKIO-Ministry of Health project successfully reduced the rate of transmission of HIV from pregnant mother to child from 27% to <5% in 2009. As HIV care and prevention services have expanded, HIV prevalence has decreased from 6.2% (1993) to 2.2% in 2012. 

In 2003, the Haitian Government asked GHESKIO to expand its prevention and care model to a network of 42 hospitals throughout the country.  GHESKIO provides training, supervision, administrative support, financial oversight, and continuing quality control for all HIV and TB clinical services provided at these sites. Haiti reached near universal ART coverage with 50,078 patients on ART (June 2013), with 40% of them treated in the GHESKIO Network.