Dalton Wamalwa

University of Nairobi, Nairoba, Nairobi Area, Kenya

Are you Dalton Wamalwa?

Claim your profile

Publications (45)149.19 Total impact

  • AIDS Research and Human Retroviruses 10/2014; 30 Suppl 1:A164. · 2.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Optimal pediatric HIV disclosure impacts illness and developmental experiences while improving access to timely treatment. However, disclosure rates in high HIV prevalence countries remain low and there are limited data on best practices. We conducted a qualitative study of disclosure practices and interviewed healthcare providers from five pediatric HIV clinics in Kenya. We identified themes central to disclosure practices, rationale for approaches, barriers to implementing disclosure, and creative strategies to overcome challenges. We used these insights to develop a practice-based framework for disclosure that is sensitive to practical challenges. Overall, providers had limited training but extensive experience in disclosure, endorsed individualized disclosure practices, invested substantial time on disclosure despite clinical burden, and noted adverse outcomes associated with unplanned or abrupt disclosure. Providers advocated for an approach to disclosure that is child-centered but respects caregiver fears and values. Caregiver support was provided to enable caregivers to be the person who ultimately disclosed HIV status to children. Unplanned or abrupt disclosure to children was reported to have severe and persistent adverse impact and was a stimulus to accelerate disclosure in scenarios when providers believed children may be suspecting their diagnosis. Based on these expert insights, the framework we developed incorporates concurrent evaluation of child and caregiver readiness, identifies cues to prompt disclosure discussions, includes caregiver education and support, and utilizes a gradual approach of unveiling HIV diagnosis to the child.
    AIDS PATIENT CARE and STDs 09/2014; · 3.58 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Infant HIV-1 infection is associated with impaired neurologic and motor development. Antiretroviral therapy (ART) has the potential to improve developmental outcomes but the relative contributions of pre-ART disease status, growth, treatment regimen, and ART response during infancy are unknown.
    The Pediatric Infectious Disease Journal 08/2014; · 3.14 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: There are limited data on the impact of cesarean section delivery on HIV-1 infected women in Sub-Saharan Africa. The purpose of this study was to assess the effect of mode of delivery on HIV-1 disease progression and postpartum mortality in a Kenyan cohort.
    BMC Pregnancy and Childbirth 08/2014; 14(1):257. · 2.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine neonatal immunologic factors that correlate with mother-to-child-transmission of HIV-1. This case-control study compared cord blood natural killer (NK) and T-cell populations of HIV-1 exposed infants who subsequently acquired infection by 1 month (cases) to those who remained uninfected by 1 year of life (controls). Control specimens were selected by proportional match on maternal viral load. Cryopreserved cord blood mononuclear cells (CBMCs) were thawed and stained for multiparameter flow cytometry to detect NK and T-cell subsets and activation status. CBMCs were also used in a viral suppression assay to evaluate NK cell inhibition of HIV-1 replication in autologous CD4 T cells. Cord blood from cases contained a skewed NK cell repertoire characterized by an increased proportion of CD16CD56 NK cells. In addition, cases displayed less-activated CD16CD56 NK cells and CD8 T cells, based on HLA-DRCD38 costaining. NK cell suppression of HIV-1 replication ex vivo correlated with the proportion of acutely activated CD68CD16CD56 NK cells. Finally, we detected a higher proportion of CD27CD45RA effector memory CD4 and CD8 T cells in cord blood from cases compared with controls. When controlled for maternal viral load, cord blood from infants who acquired HIV-1 had a higher proportion of CD16CD56 NK cells, lower NK cell activation and higher levels of mature T cells (potential HIV-1 targets) than control infants who remained uninfected. Our data provide evidence that infant HIV-1 acquisition may be influenced by both innate and adaptive immune cell phenotypes and activation status.
    AIDS (London, England) 04/2014; · 6.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper describes results from a cross-sectional study among HIV-infected children 15 months to 12 years of age who were receiving antiretroviral therapy. We found a low prevalence of measles IgG seropositivity (45.7%) and identified CD4% ≥ 25 as a predictor. Most HIV-infected children on ART were not measles seropositive and might benefit from revaccination.
    The Pediatric Infectious Disease Journal 03/2014; · 3.14 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We compared primary Epstein-Barr virus (EBV) infection and suppression between Kenyan HIV-infected infants starting nevirapine- versus lopinavir/ritonavir-based antiretroviral regimens. Although the rate of EBV infection was similar between groups, infants receiving lopinavir/ritonavir suppressed EBV more rapidly. Our findings suggest specific antiretrovirals may potentially impact the risk of future EBV-associated malignancies.
    Clinical Infectious Diseases 02/2014; · 9.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Half of Kenya's high infant and under five mortality rates is due to malnutrition. Proper implementation of World Health Organization's (WHO) Evidence Based Guidelines (EBG) in management of severe acute malnutrition can reduce mortality rates to less than 5%. The objectives were to establish the level of adherence to WHO guideline and the proportion of children appropriately managed for severe acute malnutrition (steps 1-8) as per the WHO protocol in the management of severe acute malnutrition. This was a short longitudinal study of 96 children, aged 6-59 months admitted to the pediatric ward with diagnosis of severe acute malnutrition.
    The Pan African medical journal. 01/2014; 17:214.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: Clinical Practice Guidelines for childhood illnesses including pneumonia in Kenya are contained in the Ministry of Health Basic Paediatric Protocols. In the presence of a cough and/ or difficulty in breathing and increased respiratory rate for age , pneumonia is diagnosed. In addition to these the presence of lower chest wall indrawing denotes severe pneumonia; The presence of cyanosis, inability to drink/ breast feed, grunting, level of consciousness using the AVPU scale less than A in addition to the aforementioned is classified as very severe pneumonia. Recommended management is intravascular Crystalline penicillin, gentamycin and oxygen for severe pneumonia, intravascular crystalline penicillin for severe pneumonia and oral amoxyl or cotrimaxole for pneumonia. These guidelines have been disseminated through the Emergency Triage And Treatment Plus (ETAT +) courses held since 2007. Implementation of guidelines into care has been shown to reduce case fatality from pneumonia by 36%. Objectives: Evaluate the level of adherence and factors affecting adherence to the National guidelines on management of pneumonia in children aged two to fifty nine months at Garissa provincial General Hospital, Kenya. Design: Retrospective hospital based cross sectional study. Setting: Paediatric department of Garissa Provincial General Hospital (PGH) in Kenya. Subjects: Hospital medical records of children aged two to fifty nine months diagnosed with pneumonia between January and June 2012 were reviewed. Data abstracted from the records included demographic information, recorded clinical signs and symptoms, disease classification and treatment. Results: Records of 91 children were reviewed. Their median age was 12 months (IQR 6 – 18 months). There were more boys than girls with a male to female ratio of 1.25:1. Forty-eight of the participants (52.8%) had severe pneumonia. Guideline adherence was assessed at three levels; assessment of clinical signs and symptoms reflected by their recording, correct disease severity classification and correct treatment prescribed. There were a minimum of two and a maximum of six clinical sign and symptoms recorded. The average level of adherence was 42.9% (SD ±17.3).Documented correct classification of disease severity was 56.6% and recommended treatment of pneumonia was 27.7%. The presence of a co-morbidity and severe disease was associated with better adherence to the assessment tasks (p = 0.033 and p = 0.021 respectively). Disease severity was associated with better adherence to the disease classification task (p = <0.001) and treatment task (p = 0.02). Conclusion: Adherence to guidelines was low at all assessed levels. Overall, disease severity was associated with better guideline adherence. Presence of co morbidities improved disease assessment.
    East African medical journal 01/2014; 91(1).
  • [Show abstract] [Hide abstract]
    ABSTRACT: Infants born to HIV-1 infected mothers may have increased risk for tuberculosis (TB), but the prevalence of TB infection in this population is undefined. In contrast to tuberculin skin tests that are confounded by recent BCG vaccination, TB interferon gamma release assays (IGRAs) do not cross-react with BCG and enable detection of TB infection in infancy. In a nested observational cohort of HIV-1 infected Kenyan mothers and their infants, we conducted T-SPOT.TB assays on cryopreserved peripheral blood mononuclear cells (PBMCs) from 6-month old infants without prior active TB. Maternal and infant correlates of infant TB infection were assessed. 182 infants were tested with T-SPOT.TB. Of 128 infants with determinate T-SPOT.TB results, the prevalence of a positive T-SPOT.TB was 10.9% (95% confidence interval [CI]: 6.1-17.7%). All infants were BCG-vaccinated and 7.0% were HIV-1 infected. Positive infant T-SPOT.TB was associated with maternal active TB (OR 15.5, [95% CI 1.3-184], p=.04) and prolonged infant fever (>1 month) (OR 18.8 [95% CI 1.6 - 223], p=.03). We observed a high prevalence of TB infection in 6-month old HIV-1 exposed infants. Improved TB detection and prevention is warranted in HIV-1 exposed infants at high risk for active TB disease.
    The Pediatric Infectious Disease Journal 12/2013; · 3.14 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Data on the prognostic utility of interferon-gamma release assays (IGRAs) for active tuberculosis (TB) among human immunodeficiency virus 1 (HIV-1) infected individuals are limited. Samples from a perinatal cohort of HIV-1-infected women in Kenya, obtained during pregnancy, were tested using T-SPOT®.TB IGRAs to detect Mycobacterium tuberculosis-specific interferon-gamma (IFN-γ) responses. IFN-γ (cut-off values of >0, ≥6 and ≥10 spot-forming cells [SFC]/well) and CD4 cell count (cut-off values of <250 and <350 cells/l) were evaluated to determine sensitivity and specificity using a time-dependent receiver operating characteristic curve and positive predictive value (PPV) using the Kaplan Meier method for future TB within 1 year postpartum. Of 327 women, 9 developed TB within 1 year postpartum (incidence rate 3.5/100 person-years of follow-up, 95%CI 1.66.7). IFN-γ ≥ 6 SFC/well was associated with an optimal trade-off between sensitivity (78%) and specificity (55%) and a PPV of 5.9%. In women with CD4 cell count of <250 cells/μl, the sensitivity and specificity of IFN- 6 SFC/well were respectively 89% and 63%, and the PPV was 19.2%. Among HIV-1 infected women, IFN-γ response (≥6 SFC/well) during pregnancy lacked a high PPV for postpartum TB, but had higher sensitivity and PPV among immunosuppressed women (CD4 cell count of <250 cells/μl).
    The International Journal of Tuberculosis and Lung Disease 12/2013; 17(12):1552-7. · 2.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We evaluated the association of single nucleotide polymorphisms (SNPs) in TLRs with infant HIV-1 acquisition and viral control. Infant HIV-1 outcomes were assessed in a Kenyan perinatal HIV-1 cohort. Infants were genotyped for six candidate and 118 haplotype-tagging polymorphisms in TLRs 2, 3, 4, 7, 8, and 9, MYD88 and TIRAP. Cox proportional hazards and linear regression were performed to assess associations with time to HIV-1 acquisition, time to infant mortality, and peak viral load. Among 368 infants, 56 (15%) acquired HIV-1 by month 1 and 17 (4.6%) between 1 and 12 months. Infants with the TLR9 1635A (rs352140) variant were more likely to acquire HIV-1 by 1 month [hazard ratio = 1.81, 95% confidence interval (CI) = 1.05-3.14, P = 0.033] and by 12 months (hazard ratio = 1.62, CI = 1.01-2.60, P = 0.044) in dominant models adjusted for maternal plasma HIV-1 RNA level and genetic ancestry. Among 56 infants infected at 1 month of age or less, at least one copy of the TLR9 1635A allele was associated with a 0.58 log10 copies/ml lower peak viral load (P = 0.002). Female infants with at least one copy of the TLR8 1G (rs3764880) variant had a 0.78 log10 copies/ml higher peak viral load (P = 0.0009) and having at least one copy of the C allele for a haplotype tagging TLR7 variant (rs1634319) was associated with a 0.80 log10 copies/ml higher peak viral load in female infants (P = 0.0003). In this African perinatal cohort, we found several TLR polymorphisms associated with HIV-1 acquisition and progression. Defining mechanisms for these TLR associations may inform HIV-1 prevention strategies that leverage innate responses.
    AIDS (London, England) 09/2013; 27(15):2431-9. · 6.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: HIV-exposed uninfected (HEU) infants have higher infectious disease morbidity and mortality than unexposed infants. We determined the incidence and risk factors for pneumonia, a leading cause of infant mortality worldwide, in a cohort of HEU infants. Identifying predictors of pneumonia among HEU infants may enable early identification of those at highest risk. A retrospective cohort of HEU infants participating in a Kenyan perinatal HIV study, enrolled between 1999 and 2002. Infants were followed monthly from birth to 12 months. Incidence of pneumonia diagnosed at monthly study visits, sick-child visits or by means of averbal autopsy was estimated with a 14-day window for new episodes. Cox proportional hazards regression was used to identify predictors of first pneumonia occurrence. Among 388 HEU infants with 328 person-years of follow-up, the incidence of pneumonia was 900/1000 child-years [95% confidence interval (CI) 800-1000]. Maternal HIV viral load at 32 weeks' gestation [hazard ratio 1.2 (1.0-1.5) per log10 difference] and being underweight (weight-for-age Z-score <-2) at the previous visit [hazard ratio 1.8 (1.1-2.8)] were associated with increased risk of pneumonia. Breastfed infants had a 47% lower risk of pneumonia than those never breastfed [hazard ratio 0.53 (0.39-0.73)], independent of infant growth, maternal viral load and maternal CD4%. Breastfeeding was also associated with a 74% lower risk of pneumonia-related hospitalization [hazard ratio 0.26 (0.13-0.53)]. The incidence of pneumonia in this cohort of HEU infants was high. Our observations suggest that maternal viral suppression and breastfeeding may reduce the burden of pneumonia among HEU infants.
    AIDS (London, England) 08/2013; · 6.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND:: Pooled viral load (VL) testing with two different testing strategies was evaluated as a potential cost-saving method to monitor antiretroviral therapy (ART) in HIV-infected children receiving ART in a resource-limited setting. METHODS:: Archived samples collected from 250 HIV-1 infected children on first-line ART at various time-points post-ART initiation were evaluated for pooled VL testing using a minipool+algorithm strategy. Additionally, samples collected in real-time from 125 children on ART were assessed for virologic failure using a minipool strategy for pooled viral load testing. Virologic failure was determined as HIV-1 RNA viral loads >1500 copies/ml. RESULTS:: Minipool+algorithm strategy for pooled VL testing of archived samples had estimated viral failure of 13.6%, with a relative efficiency (RE) of 23.6% (95% CI; 18.5, 29.4), and negative predictive value (NPV) of 88%. This testing strategy would have resulted in 24% fewer assays needed, for a cost savings of $1,180 per 100 samples. The minipool strategy for pooled viral load testing of samples obtained in real-time yielded an estimated 23.2% of samples with viral failure and a RE of 8.0 % (95% CI; 3.9, 14.2); however had a minipool+algorithm pooling strategy been used the RE would increase to 20%. CONCLUSIONS:: The minipool+algorithm strategy for pooled VL testing to detect virologic failure in HIV-1 infected children on ART was determined to be relatively efficient in detecting virologic failure, had high NPV, with substantial cost savings. Pooling strategies may be important components of cost-effect strategies to reduce rates of viral failure and resistance, thus improving clinical outcomes.
    JAIDS Journal of Acquired Immune Deficiency Syndromes 03/2013; · 4.39 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND:: Early highly active antiretroviral therapy (HAART) is recommended for HIV-1 infected infants. There are limited data on lipid changes during infant HAART. METHODS:: Non-fasting total (TC), low density lipoprotein (LDL), and high density lipoprotein (HDL) cholesterol, and triglycerides (TG) were measured at 0, 6 and 12 months. Correlates of lipid levels and changes post-HAART were assessed using linear regression. RESULTS:: Among 115 infants, pre-HAART median age was 3.8 months, CD4% was 19%, and weight-for-age z-score (WAZ) was -2.42. Pre-HAART median lipid levels were: TC, 108.7 mg/dl, LDL, 42.5 mg/dl, HDL, 29.4 mg/dl and TG, 186.9 mg/dl. Few infants had abnormally high TC (6.2%) or LDL (5.6%), but many had low HDL (76.5%) or high TG (69.6%). Higher pre-HAART WAZ and HAZ were each associated with higher pre-HAART TC (P=0.04 and P=0.01) and LDL (P=0.02 and P=0.008). From 0-6 months post-HAART, TC (P<0.0001), LDL (P<0.0001), and HDL (P<0.0001) increased significantly, and 23.1% (P=0.002), 14.0% (P=0.2), 31.3% (P<0.0001), and 50.8% (P=0.2) of infants had abnormally high TC, high LDL, low HDL, and high TG, respectively. Changes in TC and HDL were each associated with higher gain in WAZ (P=0.03 and P=0.01) and HAZ (P=0.01 and P=0.007). Increased change in LDL was associated with higher gain in HAZ (P=0.03). Infants on protease inhibitor (PI)-HAART had smaller HDL increase (P=0.004). CONCLUSIONS:: Infants had substantive increases in lipids, which correlated with growth. Increases in HDL were attenuated by PI-HAART. It is important to determine clinical implications of these changes.
    The Pediatric Infectious Disease Journal 02/2013; · 3.14 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Objective. This study aimed to examine hearing function in children admitted with bacterial meningitis to determine the risk factors for sensorineural hearing loss. Setting. The study was conducted in the audiology unit and paediatric wards of Kenyatta National Hospital. Subjects and Methods. The study involved 83 children between the ages of six months and twelve years admitted with bacterial meningitis. The median age for the children examined was 14. On discharge they underwent hearing testing to evaluate for presence and degree of hearing loss. Results. Thirty six of the 83 children (44.4%) were found to have at least a unilateral mild sensorineural hearing loss during initial audiologic testing. Of the children with hearing loss, 22 (26.5%) had mild or moderate sensorineural hearing loss and 14 (16.9%) had severe or profound sensorineural hearing loss. Significant determinants identified for hearing loss included coma score below eight, seizures, cranial nerve neuropathy, positive CSF culture, and fever above 38.7 degrees Celsius. Conclusions. Sensorineural hearing loss was found to be highly prevalent in children treated for bacterial meningitis. There is need to educate healthcare providers on aggressive management of coma, fever, and seizures due to their poor prognostic value on hearing.
    International Journal of Otolaryngology 01/2013; 2013:354725.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Disclosure to HIV-infected children regarding their diagnosis is important as expanding numbers of HIV-infected children attain adolescence and may become sexually active. In order to define correlates of pediatric disclosure and facilitate development of models for disclosure, we conducted a cross-sectional survey of primary caregivers of HIV-1 infected children aged 6-16 years attending a pediatric HIV treatment program in Nairobi, Kenya. We conducted focus group discussions with a subset of caregivers to further refine perceptions of disclosure. Among 271 caregiver/child dyads in the cross-sectional survey, median child age was 9 years (interquartile range: 7-12 years). Although 79% of caregivers believed children should know their HIV status, the prevalence of disclosure to the child was only 19%. Disclosure had been done primarily by health workers (52%) and caregivers (33%). Caregivers reported that 5 of the 52 (10%) who knew their status were accidentally disclosed to. Caregivers of older children (13 vs. 8 years; p<0.001), who were HIV-infected and had disclosed their own HIV status to the child (36% vs. 4%; p=0.003), or who traveled frequently (29% vs. 16%, p=0.03) were more likely to have disclosed. Children who had been recently hospitalized (25% vs. 44%, p=0.03) were less likely to know their status, and caregivers with HIV were less likely to have disclosed (p=0.03). Reasons for disclosure included medication adherence, curiosity or illness while reasons for nondisclosure included age and fear of inadvertent disclosure. Our study found that disclosure rates in this Kenyan setting are lower than observed rates in the USA and Europe but consistent with rates from other resource-limited settings. Given these low rates of disclosure and the potential benefits of disclosure, strategies promoting health worker trainings and caregiver support systems for disclosure may benefit children with HIV.
    AIDS Care 12/2012; · 1.60 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: HIV-infected children may require the use of combination antiretroviral treatment (cART) into adulthood. However, regimens are limited to first- and second-line in many African settings. Therefore, understanding the long-term rate of virologic failure and drug resistance during prolonged antiretroviral treatment is important for establishing treatment strategies in African pediatric cohorts. METHODS: Children ages 18 months to 12 years initiated first-line cART and were followed every 1-3 months, for up to 5.5 years. Treatment was switched to second-line based on clinical and immunologic criteria according to national guidelines. Virologic failure was determined retrospectively as defined by ≥2 viral loads >5000 copies/mL. Drug resistance was assessed during viral failure by population-based sequencing. RESULTS: Among 100 children on first-line cART followed for a median 49 months, 34% experienced virologic failure. Twenty-three (68%) of the 34 children with viral failure had detectable resistance mutations, of whom 14 (61%) had multi-class resistance. Fourteen (14%) children were switched to second-line regimens and followed for a median of 28 months. Retrospective analysis revealed that virologic failure had occurred a median of 12 months prior to the switch to second-line. During prolonged first-line treatment in the presence of viral failure, additional resistance mutations accumulated, however, only 1 (7%) of 14 children had persistent viremia during second-line treatment. DISCUSSION: Virologic suppression was maintained on first-line cART in two-thirds of HIV-infected children for up to 5 years. Switch to second-line based on clinical/immunologic criteria occurred ∼1 year after viral failure, but the delay did not consistently compromise second-line treatment.
    JAIDS Journal of Acquired Immune Deficiency Syndromes 11/2012; · 4.39 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: : Breast milk is a major route of infant HIV infection, yet the majority of breast-fed, HIV-exposed infants escape infection by unknown mechanisms. This study aimed to investigate the role of HIV-specific breast milk cells in preventing infant HIV infection. : A prospective study was designed to measure associations between maternal breast milk HIV-specific interferon-γ (IFN-γ) responses and infant HIV-1 detection at 1 month of age. : In a Kenyan cohort of HIV-infected mothers, blood and breast milk HIV-gag IFN-γ ELISpot responses were measured. Logistic regression was used to measure associations between breast milk IFN-γ responses and infant HIV infection at 1 month of age. : IFN-γ responses were detected in breast milk from 117 of 170 (69%) women. IFN-γ responses were associated with breast milk viral load, levels of macrophage inflammatory protein (MIP) 1α, MIP-1β, regulated upon activation, normal T-cell expressed, and secreted and stromal-cell derived factor 1 and subclinical mastitis. Univariate factors associated with infant HIV infection at 1 month postpartum included both detection and breadth of breast milk IFN-γ response (P = 0.08, P = 0.04, respectively), breast milk MIP-1β detection (P = 0.05), and plasma (P = 0.004) and breast milk (P = 0.004) viral load. In multivariate analyses adjusting for breast milk viral load and MIP-1β, breast milk IFN-γ responses were associated with an approximately 70% reduction in infant HIV infection [adjusted odds ratio (aOR) 0.29, 95% confidence interval (CI) 0.092-0.91], and each additional peptide pool targeted was associated with an approximately 35% reduction in infant HIV (aOR 0.65, 95% CI 0.44-0.97). : These data show breast milk HIV-gag-specific IFN-γ cellular immune responses are prevalent and may contribute to protection from early HIV transmission. More broadly, these data suggest breast milk cellular responses are potentially influential in decreasing mother-to-child transmission of viruses.
    AIDS (London, England) 08/2012; 26(16):2007-16. · 6.56 Impact Factor

Publication Stats

288 Citations
149.19 Total Impact Points


  • 2007–2014
    • University of Nairobi
      • • College of Health Sciences
      • • Department of Paedriatics
      • • Department of Medical Microbiology
      Nairoba, Nairobi Area, Kenya
    • Kenya Medical Research Institute
      • Centre for Clinical Research
      Nairobi, Nairobi Province, Kenya
  • 2009–2013
    • Fred Hutchinson Cancer Research Center
      • Division of Human Biology
      Seattle, Washington, United States
    • Kenyatta National Hospital
      Nairoba, Nairobi Area, Kenya
  • 2007–2012
    • University of Washington Seattle
      • • Department of Epidemiology
      • • Department of Medicine
      Seattle, WA, United States