Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-3 (of 3 Records) |
Query Trace: Nduba V[original query] |
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Incidence of active tuberculosis and cohort retention among adolescents in western Kenya
Nduba V , Van't Hoog AH , Mitchell EMH , Borgdorff M , Laserson KF . Pediatr Infect Dis J 2017 37 (1) 10-15 SETTING: Siaya County, with the highest tuberculosis notification rates in Kenya. OBJECTIVE: To determine the incidence of active tuberculosis and one year cohort retention in 12-18 year old adolescents, in preparation for Phase III tuberculosis vaccine trials. METHODS: Adolescents were enrolled and followed up for 1-2 years to determine tuberculosis incidence. Adolescents with a positive tuberculin skin test (TST), history of cohabitation with a tuberculosis case, or at least one tuberculosis symptom received clinical and sputum examination and a chest radiograph. Definite tuberculosis cases were bacteriologically confirmed and clinical cases diagnosed by a clinician based on a suggestive chest radiograph and having clinical symptoms. Risk factors were explored using Poisson regression. RESULTS: Among 4934 adolescents without tuberculosis at baseline, 26 tuberculosis cases were identified during follow up with a corresponding incidence density of 4.4 (95% CI, 3.0-6.4) events per 1000 person years of observation, 12 definite tuberculosis cases; incidence density of 2.0 (95% CI, 0.9-3.1). Having previous tuberculosis (RR= 12.5, CI 1.8, 100) and presence of TST conversion (RR=3.4, CI 1.5, 7.7) were significantly associated with higher risk of tuberculosis. Overall (4086/4925) 83.0% of adolescents were retained in the study after 1 year of follow up. Being female, older, out of school and being orphaned were significant risk factors for loss to follow up. CONCLUSION: The tuberculosis incidence in adolescents will help inform future tuberculosis vaccine trial sample size calculations for this setting. The predictive factors for tuberculosis and retention can be further explored in future trials. |
A double-blind, randomised, placebo-controlled, dose-finding trial of the novel tuberculosis vaccine AERAS-402, an adenovirus-vectored fusion protein, in healthy, BCG-vaccinated infants
Tameris M , Hokey DA , Nduba V , Sacarlal J , Laher F , Kiringa G , Gondo K , Lazarus EM , Gray GE , Nachman S , Mahomed H , Downing K , Abel B , Scriba TJ , McClain JB , Pau MG , Hendriks J , Dheenadhayalan V , Ishmukhamedov S , Luabeya AK , Geldenhuys H , Shepherd B , Blatner G , Cardenas V , Walker R , Hanekom WA , Sadoff J , Douoguih M , Barker L , Hatherill M . Vaccine 2015 33 (25) 2944-54 BACKGROUND: Several novel tuberculosis vaccines are currently in clinical trials, including AERAS-402, an adenovector encoding a fusion protein of Mycobacterium tuberculosis antigens 85A, 85B, and TB10.4. A multicentred trial of AERAS-402 safety and immunogenicity in healthy infants was conducted in three countries in sub-Saharan Africa, using an adaptive design. METHODS: In a double-blind, randomised, placebo-controlled, dose-finding trial, we enrolled BCG-vaccinated, HIV-uninfected infants aged 16-26 weeks. Infants in the safety/dose-finding phase received two doses of AERAS-402 across three dose levels, or placebo, intramuscularly on days 0 and 28. Infants in the expanded safety phase received three doses of the highest dose level, with the 3rd dose at day 280. Follow up for safety and immunogenicity was for up to two years. RESULTS: We enrolled 206 infants (52 placebo and 154 AERAS-402 recipients) into the dose-finding phase and 281 (141 placebo and 140 AERAS-402 recipients) into the expanded safety phase. Safety data were acceptable across all dose levels. No vaccine-related deaths were recorded. A single serious adverse event of tachypnoea was deemed related to study vaccine. Antibodies directed largely against Ag85A and Ag85B were detected. Low magnitude CD4+ and CD8+ polyfunctional T cell responses were observed at all dose levels. The addition of a third dose of AERAS-402 at the highest dose level did not increase frequency or magnitude of antibody or CD8+ T cell responses. CONCLUSIONS: AERAS-402 has an acceptable safety profile in infants and was well tolerated at all dose levels. Response rate was lower than previously seen in BCG vaccinated adults, and frequency and magnitude of antigen-specific T cells were not increased by a third dose of vaccine. |
Prevalence of tuberculosis in adolescents, western Kenya; implications for control programs
Nduba V , Hoog AH , Mitchell E , Onyango P , Laserson K , Borgdorff M . Int J Infect Dis 2015 35 11-7 OBJECTIVE: The aim was to determine the prevalence of tuberculosis in adolescents in Western Kenya. METHODS: We conducted a cohort study of 5004 adolescents aged 12-18 years. Adolescents were screened for prevalent tuberculosis using clinical criteria, history of TB contact, and a mantoux test. TB suspects were investigated through 2 sputum examinations (microscopy and liquid culture), and chest radiography. RESULTS: Out of 5004 adolescents enrolled, 1960 (39.2%) were identified as a TB suspect including 1544 with a positive mantoux (prevalence 1544/4808 32.1%), 515 having symptoms suggestive of TB (10.3%) and 144 (2.9%) with household TB contact. Sixteen culture-confirmed (definite) and 18 probable pulmonary TB (PTB) cases were identified reflecting a prevalence estimate of 3.2/1,000 (definite) and 6.8/1,000 all PTB respectively. Only one smear-positive case was detected. The case notification rate among 12-18 year old adolescents for all TB was 101/100,000 yielding a patient diagnostic rate of 0.13 (95% CI 0.03,3.7) cases detected per person-year for all TB. CONCLUSION: The prevalence of PTB among adolescents is high with the majority of cases not detected routinely. Innovative active case finding including wider use of Xpert MTB/RIF is needed, to detect smear-negative TB among adolescents. |
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