Research Interests

  1. As a Pediatrician with particular interest in HIV infection, understanding outcomes of children in HIV care is important for designing healthcare services for these children. Using the clinical care data collected during clinic visits, we have conducted retrospective analysis of data to describe the outcomes of children and adolescents who have been seen in care including those who are co-infected with TB. These analyses have informed the care that is provided within the AMPATH program. Several articles are available for adoption by various programs working in similar setups.My publications have focused in addressing issues related to disclosure and its impact on adherence to treatment and care among children and adolescents infected with HIV.  With wide access to ART, children who are perinatally infected with HIV are now surviving to adolescence. This group poses new challenges, including disclosure and their care needs to be tailored to meet their needs. Our team has been in the forefront in providing information on adherence and disclosure issues being faced by adolescents and children. The publications below summarize the work that we had done and are continuing to do. The publications guide healthcare providers and policy makers on various ways of overcoming challenges among children and adolescents in provision of HIV care.  By providing evidence and simple clinical approaches, our work has changed the standards of care for children and adolescents and will continue to provide guidance in relevant HIV care settings well into the future.
    1. Nyandiko W, Vreeman R, Liu H, Shangani S, Sang E, Ayaya S, Braitstein P. Nonadherence to clinic appointments among HIV-infected children in an ambulatory care program in western Kenya.JAIDS (2013); 63(2):e49-55. doi: 10.1097/QAI.0b013e31828e1e2c
    2. Nyandiko WM, Vreeman RC, Mwangi A, Ayaya S,  Kiptoon P, Musick B, Braitstein P, Abuya JM, Koech J, Hogan J. Survival and Loss to Follow-up Among HIV and Tuberculosis Co-infeced Children Below 3 Years of Age Initiating Anti-Tuberculosis Treatment in Western Kenya. International Journal of Advanced Research (2014), Volume 2, Issue 8, 249-262
    3. Braitstein P, Songok J, Vreeman R, Wools-Kaloustian K, Koskei P, Walusuna L, Ayaya S, Nyandiko W, Yiannoutsos C. 'Wamepotea' (They have become lost): Outcomes of HIV-positive and HIV-exposed children lost to follow-up from a large HIV treatment program in western Kenya. JAIDS March 9th 2011
    4. Nyandiko WM, Otieno-Nyunya B, Musick B, Bucher-Yiannoutsos S, Akhaabi P, Lane K, Yiannoutsos C.T, Wools-Kaloustian K. Outcomes of HIV-exposed children in western Kenya: efficacy of prevention of mother to child transmission in a resource-constrained setting. J Acquir Immune Defic Syndr 2010;54:42–50.
  2. My publications have focused in addressing issues related to disclosure and its impact on adherence to treatment and care among children and adolescents infected with HIV.  With wide access to ART, children who are perinatally infected with HIV are now surviving to adolescence. This group poses new challenges, including disclosure and their care needs to be tailored to meet their needs. Our team has been in the forefront in providing information on adherence and disclosure issues being faced by adolescents and children. The publications below summarize the work that we had done and are continuing to do. The publications guide healthcare providers and policy makers on various ways of overcoming challenges among children and adolescents in provision of HIV care.  By providing evidence and simple clinical approaches, our work has changed the standards of care for children and adolescents and will continue to provide guidance in relevant HIV care settings well into the future. 
    1. Rachel C. Vreeman, Michael L. ScanloN, Ann Mwangi, Matthew Turissini, Samuel O. Ayaya, Constance Tenge, Winstone M. Nyandiko. A Cross-Sectional Study of Disclosure of HIV Status to Children and Adolescents in Western Kenya. Plose one. 2014 January; 9:1. http://dx.plos.org/10.1371/journal.pone.0086616
    2. Vreeman RC, Gramelspacher AM, Gisore PO, Scanlon ML, Nyandiko WM. Disclosure of HIV status to children in resource-limited settings: a systematic review. J Int AIDS Soc. 2013 May 27;16:18466. doi: 10.7448/IAS.16.1.18466
    3. Yoder RB, Nyandiko WM, Vreeman RC, Ayaya SO, Gisore PO, Braitstein P, Wiehe SE. Long-term impact of the Kenya postelection crisis on clinic attendance and medication adherence for HIV-infected children in western Kenya. J Acquir Immune DeficSyndr. 2012 Feb 1;59(2):199-206. doi: 10.1097
    4. Rachel C. Vreeman, Winstone M. Nyandiko, Samwel O. Ayaya, Eunice G. Walumbe, David G. Marrero, Thomas S. Inui.  The perceived impact of disclosure of pediatric HIV status on pediatric antiretroviral therapy adherence, child well-being, and social relationships in a resource-limited setting. AIDS Patient Care and STDs. October 2010, 24(10): 639-649.
  3. In addition to the contributions described above, with a team of collaborators, we have developed and validated a tool to measure adherence of ART in pediatrics. Measuring and sustaining children’s adherence to antiretroviral is a challenge in pediatric care provision but we have developed a validated tool that should be used in provision of pediatric care in HIV care settings. Description of this work is found in the following articles.  
    1. Rachel Vreeman RC, Winstone Nyandiko, Hai Liu, Wanzhu Tu, Michael Scanlon, James Slaven, Samuel Ayaya, Thomas Inui. Measuring adherence to antiretroviral therapy in children and adolescents in western Kenya. Journal of the International AIDS Society (2014), 17:19227
    2. Rachel Vreeman RC, Winstone Nyandiko, Edward Liechty, Naftali Busakhala, Imke Bartelink, Rada Savic, Michael Scanlon, Samuel Ayaya, and Terry F. Blaschke. Impact of adherence and Anthropometric Characteristics on Nevirapine Pharmacokinetics and Exposure Among HIV-Infected Kenyan Children. Journal of Acquired Immune Def Syndr (2014), Volume 67: 277-286
    3. Vreeman RC, WM Nyandiko, H. Liu, W.Tu, M. Scanlon, JE Slaven, SO Ayaya, TS Inui. Comprehensive Evaluation of caregiver-Reported Antiretroviral therapy adherence for HIV infected Children. AIDS Behav,2015.19(4):p626-34
  4. Orphans and vulnerable children is also an area that I have made contribution to. Our work in this area has been disseminated to the policy-makers and supports the continuation of the government’s cash transfer programme, and registration of charitable children’s institutions which have been shown to provide care as good as that in other environments.
    1. Ayuku, D., Embleton, L., Koech, J., Atwoli, L., Hu, L., Ayaya, S., Hogan, J., Nyandiko, W., Vreeman, R.C., Kamanda, A., Braitstein, P. The Government of Kenya Cash Transfer for Orphaned and Vulnerable Children: Cross-sectional comparison of household and individual characteristics of those with and without. BMC International Health and Human Rights 2014; 14:25 doi:10.1186/1472-698X-14-25
    2. Embleton, L., Ayuku, D., Kamanda, A., Atwoli, L., Ayaya, S., Vreeman, R., Nyandiko, W., Gisore, P., Koech, J., Braitstein, P. Models of care for orphaned and separated children and children’s rights: cross-sectional evidence from western Kenya. BMC Health and Human Rights 2014; 14:9 doi:10.1186/1472-698X-14-9
    3. Paula Braitstein, Samuel Ayaya, Winstone M. Nyandiko, Allan Kamanda, Julius Koech, Peter Gisore, Lukoye Atwoli, Rachel C. Vreeman, Corey Duefield, David O. Ayuku. Nutritional Status of Orphaned and Separated Children and Adolescents Living in Community and Institutional Environments in UasinGishu County, Kenya. Plos One.July 2013; Volume 8; Issue;  e70054
    4. Rachel T. Thompson, Eric M. Meslin, Paula K. A. Braitstein, Winstone M. Nyandiko, Samuel O. Ayaya, Rachel C. Vreeman: The Vulnerabilities of Orphaned Children Participating in Research: A Critical Review and Factors for Consideration for Participation in Biomedical and Behavioral Research. Journal of Empirical Research on Human Research Ethics, Vol. 7, No. 4, pp. 56–66. print issn 1556-2646, online issn 1556-2654. © 2012
  5. The vulnerable group of neonates had been another area of our research that has contributed to scientific knowledge and policy. Below are some of the studies we have published.
    1. Felicitas Okwako, Winstone Nyandiko, Eren Oyungu. Short term survival of premature infants admitted to the new born unit at Moi Teaching and Referral Hospital, Kenya, EAMJ vol: 94 no 10. October 2017
    2. Nyandiko WM,Ng’etich E, Sara NE. Outcomes and associated factors among premature neonates with respiratory distress syndrome managed at Moi Teaching and Referral Hospital, Eldoret, Kenya. East African Medical Journal. 2018;95(1):1098-107.