Mukabana W.R.,University of Nairobi |
Omusula P.,Jaramogi Oginga Odinga Teaching and Referral Hospital |
Van Loon J.J.A.,Wageningen University |
Takken W.,Wageningen University
Journal of Chemical Ecology | Year: 2016
The deployment of odor-baited tools for sampling and controlling malaria vectors is limited by a lack of potent synthetic mosquito attractants. A synthetic mixture of chemical compounds referred to as “the Mbita blend” (MB) was shown to attract as many host-seeking malaria mosquitoes as attracted to human subjects. We hypothesized that this effect could be enhanced by adding one or more attractive compounds to the blend. We tested changes in the capability of MB (ammonia + L-lactic acid + tetradecanoic acid +3-methyl-1-butanol + carbon dioxide) to attract host-seeking malaria mosquitoes by addition of selected dilutions of butyl-2-methylbutanoate (1:10,000), 2-pentadecanone (1:100), 1-dodecanol (1:10,000), and butan-1-amine (1:10,000,000). The experiments were conducted in semi-field enclosures and in a village in western Kenya. In semi-field enclosures, the attraction of Anopheles gambiae sensu stricto females to MB-baited traps was not enhanced by adding butyl-2-methylbutanoate. There was, however, an increase in the proportion of An. gambiae caught in traps containing MB augmented with the selected dilutions of butan-1-amine, 2-pentadecanone, and 1-dodecanol. When tested in the village, addition of butan-1-amine to MB enhanced catches of female An. gambiae sensu lato, An. funestus, and Culex mosquitoes. 1-Dodecanol increased attraction of An. gambiae s.l. to the MB, while addition of 2-pentadecanone improved trap catches of An. funestus and Culex mosquitoes. This study demonstrates the possibility of enhancing synthetic odor blends for trapping the malarial mosquitoes An. gambiae s.l. and An. funestus, as well as some culicine species. The findings provide promising results for the optimization and utilization of synthetic attractants for sampling and controlling major disease vectors. © 2016, Springer Science+Business Media New York.
Buckle G.C.,University of Massachusetts Medical School |
Collins J.P.,Case Western Reserve University |
Sumba P.O.,Kenya Medical Research Institute |
Nakalema B.,Uganda Cancer Institute |
And 6 more authors.
Infectious Agents and Cancer | Year: 2013
Background: Survival rates for children diagnosed with Burkitt lymphoma (BL) in Africa are far below those achieved in developed countries. Late stage of presentation contributes to poor prognosis, therefore this study investigated factors leading to delays in BL diagnosis and treatment of children in Uganda and western Kenya. Methods. Guardians of children diagnosed with BL were interviewed at the Jaramogi Oginga Odinga Teaching and Referral Hospital (JTRH) and Uganda Cancer Institute (UCI) from Jan-Dec 2010. Information on sociodemographics, knowledge, attitudes, illness perceptions, health-seeking behaviors and prior health encounters was collected using a standardized, pre-tested questionnaire. Results: Eighty-two guardians were interviewed (20 JTRH, 62 UCI). Median «total delay» (1st symptoms to BL diagnosis) was 12.1 weeks [interquartile range (IQR) 4.9-19.9] in Kenya and 12.9 weeks (IQR 4.3-25.7) in Uganda. In Kenya, median «guardian delay» (1st symptoms to 1st health encounter) and «health system delay» (1st health encounter to BL diagnosis) were 9.0 weeks (IQR 3.6-15.7) and 2.0 weeks (IQR 1.6-5.8), respectively. Data on guardian and health system delay in Uganda were only available for those with < 4 prior health encounters (n = 26). Of these, median guardian delay was 4.3 weeks (range 0.7-149.9), health system delay 2.6 weeks (range 0.1-16.0), and total delay 10.7 weeks (range 1.7-154.3). Guardians in Uganda reported more health encounters than those in Kenya (median 5, range 3-16 vs. median 3, range 2-6). Among Kenyan guardians, source of income was the only independent predictor of delay, whereas in Uganda, guardian delay was influenced by guardians' beliefs on the curability of cancer, health system delay, by guardians' perceptions of cancer as a contagious disease, and total delay, by the number of children in the household and guardians' role as caretaker. Qualitative findings suggest financial costs, transportation, and other household responsibilities were major barriers to care. Conclusions: Delays from symptom onset to BL treatment were considerable given the rapid growth rate of this cancer, with guardian delay constituting the majority of total delay in both settings. Future interventions should aim to reduce structural barriers to care and increase awareness of BL in particular and cancer in general within the community, as well as among health professionals. © 2013 Buckle et al.; licensee BioMed Central Ltd.
Young M.R.,Emory University |
Adera F.,Nyanza Reproductive Health Society |
Mehta S.D.,University of Illinois at Chicago |
Jaoko W.,University of Nairobi |
And 6 more authors.
AIDS and Behavior | Year: 2016
Several countries scaling-up adult medical male circumcision (MMC) for HIV prevention intend to introduce early infant male circumcision (EIMC). To assess preference for EIMC in a community with a mature adult MMC program, we conducted a cross-sectional survey of a representative sample of mothers (n = 613) and fathers (n = 430) of baby boys (“index son”) at 16 health facilities in western Kenya. Most (59 %) were for EIMC, generally. Just 29 % were for circumcising the index son. Pain and protection from HIV were the most frequently cited barrier and facilitator to EIMC, respectively. In multivariable logistic regression, ever talking with the partner about EIMC and positive serostatus were associated with preference for EIMC for the index son. Attitudes towards EIMC are favorable. Willingness to circumcise an infant son is modest. To facilitate EIMC uptake, education about EIMC pain management and encouraging discussion between parents about EIMC during pregnancy should be integrated into programs. © 2016 Springer Science+Business Media New York
Sickle cell trait is not associated with endemic Burkitt lymphoma: An ethnicity and malaria endemicity-matched case-control study suggests factors controlling EBV may serve as a predictive biomarker for this pediatric cancer
Mulama D.H.,Kenya Medical Research Institute |
Mulama D.H.,Maseno University |
Bailey J.A.,University of Massachusetts Medical School |
Foley J.,University of Massachusetts Medical School |
And 7 more authors.
International Journal of Cancer | Year: 2013
Endemic Burkitt lymphoma (eBL) is associated with Epstein-Barr virus (EBV) and Plasmodium falciparum coinfections. Malaria appears to dysregulate immunity that would otherwise control EBV, thereby contributing to eBL etiology. Juxtaposed to human genetic variants associated with protection from malaria, it has been hypothesized that such variants could decrease eBL susceptibility, historically referred to as "the protective hypothesis." Past studies attempting to link sickle cell trait (HbAS), which is known to be protective against malaria, with protection from eBL were contradictory and underpowered. Therefore, using a case-control study design, we examined HbAS frequency in 306 Kenyan children diagnosed with eBL compared to 537 geographically defined and ethnically matched controls. We found 23.8% HbAS for eBL patients, which was not significantly different compared to 27.0% HbAS for controls [odds ratio (OR) = 0.85; 95% confidence interval (CI) 0.61-1.17; p-value = 0.33]. Even though cellular EBV titers, indicative of the number of latently infected B cells, were significantly higher (p-value < 0.0003) in children residing in malaria holoendemic compared to hypoendemic areas, levels were not associated with HbAS genotype. Combined, this suggests that although HbAS protects against severe malaria and hyperparasitemia, it is not associated with viral control or eBL protection. However, based on receiver operating characteristic curves factors that enable the establishment of EBV persistence, in contrast to those involved in EBV lytic reactivation, may have utility as an eBL precursor biomarker. This has implications for future human genetic association studies to consider variants influencing control over EBV in addition to malaria as risk factors for eBL. © 2013 UICC.
Inzaule S.,Kenya Medical Research Institute |
Inzaule S.,Makerere University |
Otieno J.,Jaramogi Oginga Odinga Teaching and Referral Hospital |
Kalyango J.,Makerere University |
And 7 more authors.
PLoS ONE | Year: 2014
Background: Limited antiretroviral treatment regimens in resource-limited settings require long-term sustainability of patients on the few available options. We evaluated the incidence and predictors of combined antiretroviral treatment (cART) modifications, in an outpatient cohort of 955 patients who initiated cART between January 2009 and January 2011 in western Kenya. Methods: cART modification was defined as either first time single drug substitution or switch. Incidence rates were determined by Poisson regression and risk factor analysis assessed using multivariate Cox regression modeling. Results: Over a median follow-up period of 10.7 months, 178 (18.7%) patients modified regimens (incidence rate (IR); 18.6 per 100 person years [95% CI: 16.2-21.8]). Toxicity was the most common cited reason (66.3%). In adjusted multivariate Cox piecewise regression model, WHO disease stage III/IV (aHR; 1.82, 95%CI: 1.25-2.66), stavudine (d4T) use (aHR; 2.21 95%CI: 1.49-3.30) and increase in age (aHR; 1.02, 95%CI: 1.0-1.04) were associated with increased risk of treatment modification within the first year post-cART. Zidovudine (AZT) and tenofovir (TDF) use had a reduced risk for modification (aHR; 0.60 95%CI: 0.38-0.96 and aHR; 0.51 95%CI: 0.29-0.91 respectively). Beyond one year of treatment, d4T use (aHR; 2.75, 95% CI: 1.25-6.05), baseline CD4 counts ≤350 cells/mm3 (aHR; 2.45, 95%CI: 1.14-5.26), increase in age (aHR; 1.05 95%CI: 1.02-1.07) and high baseline weight >60kg aHR; 2.69 95% CI: 1.58-4.59) were associated with risk of cART modification. Conclusions: Early treatment initiation at higher CD4 counts and avoiding d4T use may reduce treatment modification and subsequently improve sustainability of patients on the available limited options. © 2014 Inzaule et al.
Matey E.J.,Kanazawa University |
Matey E.J.,Kenya Medical Research Institute |
Tokoro M.,Kanazawa University |
Nagamoto T.,Kanazawa University |
And 9 more authors.
AIDS | Year: 2016
A cross-sectional molecular epidemiological study of Entamoeba species was conducted among asymptomatic Kenyan children with (n=123) and without (n=111) HIV infection. The prevalence of E. histolytica was low (0.4%). Entamoeba species infection was inversely related with HIV infection [HIV(+): 29.3% vs. HIV(-): 55.0%, P<0.001]: multiple-species infection was related to higher CD4+ T-cell counts. Thus, HIV infection is not a risk factor for amebic infection, and multiple-species infection can be an indicator of better immune status. © 2016 Wolters Kluwer Health, Inc.
Anaemia in HIV-infected pregnant women receiving triple antiretroviral combination therapy for prevention of mother-to-child transmission: a secondary analysis of the Kisumu breastfeeding study (KiBS)
PubMed | Kenya Medical Research Institute, Jaramogi Oginga Odinga Teaching and Referral Hospital and Centers for Disease Control and Prevention
Type: Journal Article | Journal: Tropical medicine & international health : TM & IH | Year: 2016
The prevalence of anaemia during pregnancy is estimated to be 35-75% in sub-Saharan Africa and is associated with an increased risk of maternal mortality. We evaluated the frequency and factors associated with anaemia in HIV-infected women undergoing antiretroviral (ARV) therapy for prevention of mother-to-child transmission (PMTCT) enrolled in The Kisumu Breastfeeding Study 2003-2009.Maternal haematological parameters were monitored from 32 to 34 weeks of gestation to 2 years post-delivery among 522 enrolled women. Clinical and laboratory assessments for causes of anaemia were performed, and appropriate management was initiated. Anaemia was graded using the National Institutes of Health Division of AIDS 1994 Adult Toxicity Tables. Data were analysed using SAS software, v 9.2. The Wilcoxon two-sample rank test was used to compare groups. A logistic regression model was fitted to describe the trend in anaemia over time.At enrolment, the prevalence of any grade anaemia (Hb < 9.4 g/dl) was 61.8%, but fell during ARV therapy, reaching a nadir (7.4%) by 6 months post-partum. A total of 41 women (8%) developed severe anaemia (Hb < 7 g/dl) during follow-up; 2 (4.9%) were hospitalised for blood transfusion, whereas 3 (7.3%) were transfused while hospitalised (for delivery). The greatest proportion of severe anaemia events occurred around delivery (48.8%; n = 20). Anaemia (Hb 7 and < 9.4 g/dl) at enrolment was associated with severe anaemia at delivery (OR 5.87; 95% CI: 4.48, 7.68, P < 0.01). Few cases of severe anaemia coincided with clinical malaria (24.4%; n = 10) and helminth (7.3%; n = 3) infections.Resolution of anaemia among most participants during study follow-up was likely related to receipt of ARV therapy. Efforts should be geared towards addressing common causes of anaemia in HIV-infected pregnant women, prioritising initiation of ARV therapy and management of peripartum blood loss.
PubMed | University of Amsterdam, Centers for Disease Control and Prevention, National Center for HIV, Jaramogi Oginga Odinga Teaching and Referral Hospital and 2 more.
Type: Clinical Trial | Journal: PloS one | Year: 2015
Anemia results in increased morbidity and mortality, underscoring the need to better understand its pathophysiology amongst HIV-exposed and infected children in sub-Saharan Africa, the region where most infant HIV exposure and infections occur.This analysis used samples obtained from children in the Kisumu Breastfeeding Study (KiBS). KiBS was a longitudinal phase IIB, open-label, one-arm clinical trial, designed to investigate the safety, tolerability and effectiveness of a maternal triple-antiretroviral (ARV) regimen for prevention of mother-to-child transmission (PMTCT) of HIV, during late pregnancy and early infancy while breastfeeding. Blood samples from 482 children were obtained at birth, 2, 6, 10 and 14 weeks and 6, 9, 12, 18 and 24 months. Severity of anemia was graded using the NIH Division of AIDS (DAIDS) toxicity tables. We describe the proportion of children with anemia and anomalies in red blood cell parameters at various time points over 24 months and compare rates of anemia between HIV-infected and HIV-uninfected children and by mothers ARV regimen and infant malaria infection.The proportion of children with anemia significantly increased after the breastfeeding period in both HIV-infected and HIV-uninfected children with higher proportion among HIV-infected children compared to HIV-uninfected children (RR: 1.72; CI: 1.22-2.44, p = 0.002). Maternal triple-antiretroviral regimen was not associated with infant anemia (p = 0.11). There was no significant difference in mean hemoglobin between HIV-uninfected children with and without malaria at each time point except at 24 months.A relatively lower proportion of children with severe anemia during the breastfeeding period suggest that exposure to mothers triple antiretroviral combinations through breast milk, posed minimal risk of hematologic toxicity.
PubMed | Jaramogi Oginga Odinga Teaching and Referral Hospital, Indiana University, Kenya Medical Research Institute, Direct Relief and 2 more.
Type: Journal Article | Journal: International journal of cancer | Year: 2016
Discovering how to improve survival and establishing clinical reference points for children diagnosed with endemic Burkitt lymphoma (eBL) in resource-constrained settings has recaptured international attention. Using multivariate analyses, we evaluated 428 children with eBL in Kenya for age, gender, tumor stage, nutritional status, hemoglobin, lactate dehydrogenase (LDH), Epstein-Barr virus (EBV) and Plasmodium falciparum prior to induction of chemotherapy (cyclophosphamide, vincristine, methotrexate and doxorubicin) to identify predictive and prognostic biomarkers of survival. During this 10 year prospective study period, 22% died in-hospital and 78% completed six-courses of chemotherapy. Of those, 16% relapsed or died later; 31% achieved event-free-survival; and 31% were lost to follow-up; the overall one-year survival was 45%. After adjusting for covariates, low hemoglobin (<8 g/dL) and high LDH (>400 mU/ml) were associated with increased risk of death (adjusted Hazard Ratio (aHR)=1.57 [0.97-2.41]) and aHR=1.84, [0.91-3.69], respectively). Anemic children with malaria were 3.55 times more likely to die [1.10-11.44] compared to patients without anemia or malarial infection. EBV load did not differ by tumor stage nor was it associated with survival. System-level factors can also contribute to poor outcomes. Children were more likely to die when inadvertently overdosed by more than 115% of the correct dose of cyclophosphamide (a HR=1.43 [0.84-2.43]) or doxorubicin (a HR=1.25, [0.66-2.35]), compared with those receiving accurate doses of the respective agent in this setting. This study codifies risk factors associated with poor outcomes for eBL patients in Africa and provides a benchmark by which to assess improvements in survival for new chemotherapeutic approaches.
PubMed | Jaramogi Oginga Odinga Teaching and Referral Hospital, University of Zürich, Rhode Island Hospital, Uniformed Services University of the Health Sciences and 2 more.
Type: Journal Article | Journal: PloS one | Year: 2016
Deficiencies in Epstein-Barr virus (EBV)-specific T cell immunosurveillance appear to precede the development of endemic Burkitt lymphoma (eBL), a malaria-associated pediatric cancer common in sub-Saharan Africa. However, T cell contributions to eBL disease progression and survival have not been characterized. Our objective was to investigate regulatory and inflammatory T cell responses in eBL patients associated with clinical outcomes. By multi-parameter flow cytometry, we examined peripheral blood mononuclear cells from 38 eBL patients enrolled in a prospective cohort study in Kisumu, Kenya from 2008-2010, and 14 healthy age-matched Kenyan controls. Children diagnosed with eBL were prospectively followed and outcomes categorized as 2-year event-free survivors, cases of relapses, or those who died. At the time of diagnosis, eBL children with higher CD25+Foxp3+ regulatory T (Treg) cell frequencies were less likely to survive than patients with lower Treg frequencies (p = 00194). Non-survivors also had higher absolute counts of CD45RA+Foxp3lo nave and CD45RA-Foxp3hi effector Treg subsets compared to survivors and healthy controls. Once patients went into clinical remission, Treg frequencies remained low in event-free survivors. Patients who relapsed, however, showed elevated Treg frequencies months prior to their adverse event. Neither concurrent peripheral blood EBV load nor malaria infection could explain higher Treg cell frequencies. CD8+ T cell PD-1 expression was elevated in all eBL patients at time of diagnosis, but relapse patients tended to have persistently high PD-1 expression compared to long-term survivors. Non-survivors produced more CD4+ T-cell IL-10 in response to both Epstein-Barr Nuclear Antigen-1 (EBNA-1) (p = 0026) and the malaria antigen Plasmodium falciparum Schizont Egress Antigen-1 (p = 00158) compared to survivors, and were concurrently deficient in (EBNA-1)-specific CD8+ T-cell derived IFN- production (p = 0002). In addition, we identified the presence of Foxp3-IL10+ regulatory Type 1 cells responding to EBNA-1 in contrast to the malaria antigen tested. These novel findings suggest that poor outcomes in eBL patients are associated with a predominantly immuno-regulatory environment. Therefore, Treg frequencies could be a predictive biomarker of disease progression and manipulation of Treg activity has potential as a therapeutic target to improve eBL survival.