Browsing by Author "Kiptoo, Stephen"

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    A community-based approach to cervical cancer prevention in western Kenya: An AMPATH feasibility project
    (Sage, 2022-05-23) Orang’o, Omenge; Tonui, Philip; Muthoka, Kapten; Kiptoo, Stephen; Maina, Titus; Agosa, Mercy; Ermel, Aaron; Tong, Yan; Brown, Darron; Medicine, School of Medicine
    Objectives: Centralized programs have been ineffective in reducing the burden of cervical cancer among Kenyan women. A community-based pilot study was initiated to screen Kenyan women for cervical cancer and to vaccinate their children against human papillomavirus (HPV). Methods: Women were educated about cervical cancer prevention at community meetings. Women then provided self-collected vaginal swabs for oncogenic HPV testing using the Roche Cobas Assay. All women were then referred to the local clinic for Visual Inspection with Acetic Acid (VIA). Women were offered the quadrivalent HPV vaccine for their children if and when it became available for the study. Results: Women in western Kenya were invited to participate in community meetings. A total of 200 women were enrolled: 151 (75.5%) were HIV-uninfected and 49 (24.5%) were HIV-infected; the median age for all women was 42 years. High-risk (HR)-HPV types were detected in 49 of swabs from all 200 participants (24.5%) including 20.5% of HIV-uninfected women and 36.7% of HIV-infected women (P = .022). VIA was performed on 198 women: 192 had normal examinations and six had abnormal examinations. Five cervical biopsies revealed two cases of CIN 2 and one CIN 3. Although all mothers were willing to have their children (N = 432) vaccinated, the HPV vaccine could not be delivered to Kenya during the study period. Conclusions: Kenyan women were willing to attend community meetings to learn about prevention of cervical cancer, to provide self-collected vaginal swabs for HPV testing, to travel to the Webuye Clinic for VIA following the collection of swabs, and to have their children vaccinated against HPV. HR-HPV was prevalent, especially in HIV-infected women. As a result of this pilot study, this community-based strategy to prevent cervical cancer will be continued in western Kenya.
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    Detection and Concentration of Plasma Aflatoxin Is Associated With Detection of Oncogenic Human Papillomavirus in Kenyan Women
    (Oxford Academic, 2019-09-01) Zhang, Jianjun; Orang’o, Omenge; Tonui, Philip; Tong, Yan; Maina, Titus; Kiptoo, Stephen; Muthoka, Katpen; Groopman, John; Smith, Joshua; Madeen, Erin; Ermel, Aaron; Loehrer, Patrick; Brown, Darron R.; Department of Epidemiology, School of Public Health
    Abstract Background Cervical cancer is common in Kenyan women. Cofactors in addition to infection with oncogenic human papillomavirus (HPV) are likely to be important in causing cervical cancer, because only a small percentage of HPV-infected women will develop this malignancy. Kenyan women are exposed to dietary aflatoxin, a potent carcinogen and immunosuppressive agent, which may be such a cofactor. Methods Demographics, behavioral data, plasma, and cervical swabs were collected from 88 human immunodeficiency virus-uninfected Kenyan women without cervical dysplasia. Human papillomavirus detection was compared between women with or without plasma aflatoxin B1-lysine (AFB1-lys) and evaluated in relation to AFB1-lys concentration. Results Valid HPV testing results were available for 86 women (mean age 34.0 years); 49 women (57.0%) had AFB1-lys detected and 37 (43.0%) had none. The AFB1-lys detection was not associated with age, being married, having more than secondary school education, home ownership, living at a walking distance to healthcare ≥60 minutes, number of lifetime sex partners, or age of first sex. The AFB1-lys detection and plasma concentrations were associated with detection of oncogenic HPV types. Conclusions The AFB1-lys positivity and higher plasma AFB1-lys concentrations were associated with higher risk of oncogenic HPV detection in cervical samples from Kenya women. Further studies are needed to determine whether aflatoxin interacts with HPV in a synergistic manner to increase the risk of cervical cancer.
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    Detection of types of HPV among HIV-infected and HIV-uninfected Kenyan women undergoing cryotherapy or loop electrosurgical excision procedure
    (Wiley, 2020-11) Orang’o, Elkanah O.; Emont, Jordan P.; Ermel, Aaron C.; Liu, Tao; Omodi, Victor; Tong, Yan; Itsura, Peter M.; Tonui, Philip K.; Maina, Titus; Ong’echa, John M.; Muthoka, Kapten; Kiptoo, Stephen; Moormann, Ann; Hogan, Joseph; Loehrer, Patrick J.; Brown, Darron; Cu-Uvin, Susan; Medicine, School of Medicine
    Objective: To assess the baseline types of HPV infection among HIV-positive and HIV-negative women in western Kenya undergoing cryotherapy or loop electrosurgical excision procedure (LEEP) for cervical intraepithelial neoplasia. Methods: A prospective observational study was conducted of baseline HPV characteristics of women undergoing visual inspection with acetic acid (VIA) and cryotherapy or LEEP. After a positive VIA in HIV-positive and HIV-negative women, data on demographics, CD4 count, and use of antiretroviral therapy and a cervical swab were collected. HPV typing was performed using the Roche Linear Array. Results: Of 175 participants, 86 (49.1%) were HIV-positive and had a higher prevalence of low-risk HPV types (odds ratio [OR] 5.28, P=0.005) compared with HIV-negative women. The most common high-risk (HR)-HPV types in HIV-positive women were HPV 16 (13.9%) and HPV 18 (11.1%). HIV-positive women requiring LEEP were more likely to have HR-HPV types (OR 6.67, P=0.012) and to be infected with multiple HR-HPV types (OR 7.79, P=0.024) compared to those undergoing cryotherapy. Conclusion: HIV-positive women requiring LEEP versus cryotherapy had a higher prevalence of any HR-HPV type and multiple HR-HPV types. There were no such differences in HPV types identified among HIV-negative women.
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    Longer duration of anti-retroviral therapy is associated with decreased risk of human papillomaviruses detection in Kenyan women living with HIV
    (Sage, 2021-11) Ermel, Aaron; Tong, Yan; Tonui, Phillip; Omenge, O’rango; Muthoka, Kapten; Wong, Nelson; Titus, Manai; Kiptoo, Stephen; Loehrer, Patrick J.; Brown, Darron R.; Medicine, School of Medicine
    Objective: A longitudinal study was conducted among women living with HIV in Kenya to determine if duration of anti-retroviral (ART) usage altered detection and persistence of oncogenic (high-risk) human papillomaviruses (HR-HPV). Methods: Women living with HIV without cervical dysplasia were enrolled at a cervical cancer screening clinic. Three cervical swabs, HIV viral loads, and CD4 cell counts were obtained at enrollment and at two annual visits. HPV genotyping was performed on swabs (Roche Linear Array). Linear regression models assessed effects of ART duration on HR-HPV detection and persistence. Results: Seventy-seven women, median age 38 years, completed three study visits and were included in the analysis. The mean time from HIV diagnosis to enrollment was 9.6 years (SD 3.9 years). The mean ART duration was 6.2 years (SD 3.1 years). Most women had undetectable HIV viral loads and CD4 cell counts above 500 cells/L. Each additional year of ART use reduced the likelihood of detection of HR-HPV by 10-15% and persistent detection of A9 HR-HPV by 20%. Conclusion: Among Kenyan women living with HIV, longer duration of ART use was associated with significantly reduced risk of all detection and persistent detection of HR-HPV.
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    Persistence of oncogenic and non-oncogenic human papillomavirus is associated with human immunodeficiency virus infection in Kenyan women
    (SAGE, 2020-07-28) Tong, Yan; Tonui, Philip; Ermel, Aaron; Orang’o, Omenge; Wong, Nelson; Titus, Maina; Kiptoo, Stephen; Muthoka, Kapten; Loehrer, Patrick J; Brown, Darron R; Medicine, School of Medicine
    Objectives: Cervical cancer is caused by persistent infection with oncogenic, or “high-risk” types of human papillomaviruses, and is the most common malignancy in Kenyan women. A longitudinal study was initiated to investigate factors associated with persistent human papillomavirus detection among HIV-infected and HIV-uninfected Kenyan women without evidence of cervical dysplasia. Methods: Demographic/behavioral data and cervical swabs were collected from HIV-uninfected women (n = 82) and HIV-infected women (n = 101) at enrollment and annually for 2 years. Human papillomavirus typing was performed on swabs (Roche Linear Array). Logistic regression models of human papillomavirus persistence were adjusted for demographic and behavioral characteristics. Results: HIV-infected women were older and less likely to be married and to own a home and had more lifetime sexual partners than HIV-uninfected women. All HIV-infected women were receiving anti-retroviral therapy at enrollment and had satisfactory CD4 cell counts and HIV viral loads. One- and two-year persistent human papillomavirus detection was significantly associated with HIV infection for any human papillomavirus, high-risk human papillomavirus, International Agency for the Research on Cancer-classified high-risk human papillomavirus, and non-oncogenic “low-risk” human papillomavirus. Conclusion: Persistent detection of oncogenic and non-oncogenic human papillomavirus was strongly associated with HIV infection in Kenyan women with re-constituted immune systems based on satisfactory CD4 cell counts. In addition to HIV infection, factors associated with an increased risk of human papillomavirus persistence included a higher number of lifetime sex partners. Factors associated with decreased risk of human papillomavirus persistence included older age and being married. Further studies are needed to identify the immunological defects in HIV-infected women that allow human papillomavirus persistence, even in women receiving effective anti-retroviral therapy. Further studies are also needed to determine the significance of low-risk human papillomavirus persistence in HIV-infected women.
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    Reducing Geographic Barriers for Breast Cancer Diagnosis
    (American Society of Clinical Oncology, 2022-05-05) Adaniya, Emily; Bhatia, Manisha; Kiptoo, Stephen; Wabende, Lucy Najala; Kisilu, Nicholas; Kibiwot, Silvanus; Jepkirui, Sally; Awuor, Dorice Adhiambo; Loehrer, Patrick; Hunter-Squires, Joanna; Busakhala, Naftali; Medicine, School of Medicine
    Purpose: Increasing travel times to the nearest diagnostic facilities and cancer centers are correlated with decreasing prevalence of breast cancer diagnosis and increasing stage of cancer at diagnosis. Moi Teaching and Referral Hospital (MTRH), in Uasin Gishu County, houses the only public cancer center in western Kenya. A MTRH program, the Academic Model Providing Access to Healthcare Breast and Cervical Cancer Control Program (ABCCCP) hosted health fair breast cancer screening events and mentored nurses at local health facilities to complete clinical breast exams (CBEs). The objective is to understand the effect of the ABCCCP in reducing geographic barriers for breast cancer screening/early diagnosis. Methods: This is a retrospective review of the 61,392 patients who underwent breast cancer screening at a ministry of health facility in western Kenya from 2017-2021. ABCCCP hosted health fairs targeted at communities and mentored nurses at health facilities to complete clinical breast exams (CBEs) to target individual patients. Facility distances from MTRH were mapped via Google Maps. Descriptive analyses were performed to a significance of α < 0.05. Results: Two-thirds of the screening/early diagnosis CBEs occurred in five of the 22 counties in western Kenya: Busia, Uasin Gishu, Trans-Nzoia, Bungoma, and Kakamega. However, these five counties only had 25% of all ABCCCP screening sites in western Kenya. Only Uasin Gishu and Kakamega provided chemotherapy while Busia and Trans-Nzoia had additional programming promoting preventative healthcare through integration of community health volunteers. In these five counties, no association between the distance of the ministry of health facilities from MTRH and number of CBEs completed existed. Conclusion: ABCCCP programming reduced some geographic disparities in breast cancer screening/diagnosis in the top five counties. It may be result of the number of mentored nurses and health fair events. Further work should be completed to understand if a relationship between geographic distance from MTRH and the stage and treatment patterns of these patients is also reduced by ABCCCP.