Safety and immunogenicity of ChAdOx1 85A prime followed by MVA85A boost compared with BCG revaccination among Ugandan adolescents who received BCG at birth: a randomised, open-label trial

BACKGROUND

BCG confers reduced, variable protection against pulmonary tuberculosis. A more effective vaccine is needed. We evaluated the safety and immunogenicity of candidate regimen ChAdOx1 85A-MVA85A compared with BCG revaccination among Ugandan adolescents.

METHODS

After ChAdOx1 85A dose escalation and age de-escalation, we did a randomised open-label phase 2a trial among healthy adolescents aged 12-17 years, who were BCG vaccinated at birth, without evident tuberculosis exposure, in Entebbe, Uganda. Participants were randomly assigned (1:1) using a block size of 6, to ChAdOx1 85A followed by MVA85A (on day 56) or BCG (Moscow strain). Laboratory staff were masked to group assignment. Primary outcomes were solicited and unsolicited adverse events (AEs) up to day 28 and serious adverse events (SAEs) throughout the trial; and IFN-γ ELISpot response to antigen 85A (day 63 [geometric mean] and days 0-224 [area under the curve; AUC).

FINDINGS

Six adults (group 1, n=3; group 2, n=3) and six adolescents (group 3, n=3; group 4, n=3) were enrolled in the ChAdOx1 85A-only dose-escalation and age de-escalation studies (July to August, 2019). In the phase 2a trial, 60 adolescents were randomly assigned to ChAdOx1 85A-MVA85A (group 5, n=30) or BCG (group 6, n=30; December, 2019, to October, 2020). All 60 participants from groups 5 and 6 were included in the safety analysis, with 28 of 30 from group 5 (ChAdOx1 85A-MVA85A) and 29 of 30 from group 6 (BCG revaccination) analysed for immunogenicity outcomes. In the randomised trial, 60 AEs were reported among 23 (77%) of 30 participants following ChAdOx1 85A-MVA85A, 31 were systemic, with one severe event that occurred after the MVA85A boost that was rapidly self-limiting. All 30 participants in the BCG revaccination group reported at least one mild to moderate solicited AE; most were local reactions. There were no SAEs in either group. Ag85A-specific IFN-γ ELISpot responses peaked on day 63 in the ChAdOx1 85A-MVA85A group and were higher in the ChAdOx1 85A-MVA85A group compared with the BCG revaccination group (geometric mean ratio 30·59 [95% CI 17·46-53·59], p<0·0001, day 63; AUC mean difference 57 091 [95% CI 40 524-73 658], p<0·0001, days 0-224).

INTERPRETATION

The ChAdOx1 85A-MVA85A regimen was safe and induced stronger Ag85A-specific responses than BCG revaccination. Our findings support further development of booster tuberculosis vaccines.

FUNDING

UK Research and Innovations and Medical Research Council.

TRANSLATIONS

For the Swahili and Luganda translations of the abstract see Supplementary Materials section.

Establishing a single-sex controlled human Schistosoma mansoni infection model for Uganda: protocol for safety and dose-finding trial

Control of schistosomiasis depends on a single drug, praziquantel, with variable cure rates, high reinfection rates, and risk of drug resistance. A vaccine could transform schistosomiasis control. Preclinical data show that vaccine development is possible, but conventional vaccine efficacy trials require high incidence, long-term follow-up, and large sample size. Controlled human infection studies (CHI) can provide early efficacy data, allowing the selection of optimal candidates for further trials. A Schistosoma CHI has been established in the Netherlands but responses to infection and vaccines differ in target populations in endemic countries. We aim to develop a CHI for Schistosoma mansoni in Uganda to test candidate vaccines in an endemic setting. This is an open-label, dose-escalation trial in two populations: minimal, or intense, prior Schistosoma exposure. In each population, participants will be enrolled in sequential dose-escalating groups. Initially, three volunteers will be exposed to 10 cercariae. If all show infection, seven more will be exposed to the same dose. If not, three volunteers in subsequent groups will be exposed to higher doses (20 or 30 cercariae) following the same algorithm, until all 10 volunteers receiving a particular dose become infected, at which point the study will be stopped for that population. Volunteers will be followed weekly after infection until CAA positivity or to 12 weeks. Once positive, they will be treated with praziquantel and followed for one year. The trial registry number is ISRCTN14033813 and all approvals have been obtained. The trial will be subjected to monitoring, inspection, and/or audits.

Knowledge, Attitudes, and Practices Regarding COVID-19 among Healthcare Workers in Uganda: A Cross-Sectional Survey

Healthcare workers (HCWs) are at high risk of COVID-19. However, data on HCWs' knowledge, attitudes, and practices (KAP) toward COVID-19 are limited. Between September and November 2020, we conducted a questionnaire-based COVID-19 KAP survey among HCWs at three hospitals in Uganda. We used Bloom's cut-off of ≥80% to determine sufficient knowledge, good attitude, and good practice, and multivariate Poisson regression with robust variance for statistical analysis. Of 717 HCWs invited to participate, 657 (91.6%) agreed and were enrolled. The mean age (standard deviation) of enrollees was 33.2 (10.2) years; most were clinical HCWs (64.7%) and had advanced secondary school/other higher-level education (57.8%). Overall, 83.9% had sufficient knowledge, 78.4% had a positive attitude, and 37.0% had good practices toward COVID-19. Factors associated with KAP were: Knowledge: being a clinical HCW (aRR: 1.12; 95% CI: 1.02-1.23) and previous participation in health research (aRR: 1.10; 95% CI: 1.04-1.17); Attitude: age > 35 years (aRR: 0.88; 95% CI: 0.79-0.98); Practice: being a clinical HCW (aRR: 1.91; 95% CI: 1.41-2.59). HCWs in Uganda have good knowledge and positive attitude but poor practices towards COVID-19. Differences in COVID-19 KAP between clinical and non-clinical HCWs could affect uptake of COVID-19 interventions including vaccination.

Willingness to participate in COVID-19 vaccine trials; a survey among a population of healthcare workers in Uganda

BACKGROUND

Healthcare workers (HCWs) are at high risk of acquiring SARS-CoV-2 and COVID-19 and may therefore be a suitable population for COVID-19 vaccine trials. We conducted a survey to evaluate willingness-to-participate in COVID-19 vaccine trials in a population of HCWs at three hospitals in Uganda.

METHODS

The survey was conducted between September and November 2020. Using a standardised questionnaire, data were collected on socio-demographics, previous participation in health research, COVID-19 information sources, underlying health conditions, and willingness-to-participate in COVID-19 vaccine trials. Data were analysed descriptively and a binomial generalised linear model with a log link function used to investigate factors associated with unwillingness to participate.

RESULTS

657 HCWs (female, 63%) were enrolled with a mean age of 33 years (Standard Deviation, 10). Overall willingness-to-participate was 70.2%. Key motivating factors for participation were: hope of being protected against COVID-19 (81.1%), altruism (73.3%), and the opportunity to get health care (26.0%). Selected hypothetical trial attributes reduced willingness-to-participate as follows: weekly-quarterly study visits over a 12-month period (70.2%-63.2%, P = 0.026); provision of approximately 50ml of blood at each study visit (70.2%-63.2%, P = 0.026); risk of mild-moderate local adverse reactions (70.2%-60.3%, P<0.001); chance of receiving candidate vaccine or placebo (70.2%-56.9%, P<0.001); and delay of pregnancy [Overall, 70.2%-57.1% P<0.001); Female, 62.8%-48.4% (P = 0.002); Male, 82.5%-71.5% (P = 0.003)]. Collectively, these attributes reduced willingness-to-participate from [70.2%-42.2% (P<0.001) overall; 82.5%-58.1% (P<0.001) in men; 62.8%-32.6% (P<0.001) in women]. Among individuals that were unwilling to participate, the commonest barriers were concerns over vaccine safety (54.6%) and fear of catching SARS-CoV-2 (31.6%). Unwillingness to participate was associated with being female (aRR 1.97, CI 1.46-2.67, P<0.001) and having university or other higher-level education (aRR 1.52, CI 1.05-2.2, P = 0.026).

CONCLUSIONS

Willingness-to-participate in COVID-19 vaccine trials among HCWs in Uganda is high but may be affected by vaccine trial requirements and concerns about the safety of candidate vaccines.

Analysis of the MUII-plus mentorship programme: reflections of Fellows’ experiences and lessons for other programmes

Background: The MUII mentorship programme began 11 years ago with a successful group mentorship model. Over the years, the programme has evolved and is presently anchored on the “GROW” approach. This model allows individuals to: set Goals (What I want?); Reflect (Where am I now?); think of Options (What can I do?); What to implement (my actions?). It is intended to help fellows (current, honorary, alumni) herein referred to as mentees achieve their short, medium, and long-term research, career and professional goals. Methods: A mixed methods study combining a cross-sectional survey, one focus group discussion and 11 in-depth key informant interviews were carried out between November 2018 and January 2019 to 1) assess the status of the mentorship programme, 2) perform a strength weakness opportunity and threats (SWOT) analysis, and 3) identify factors relevant for sustainability. Results: An open invitation was made to 52 fellows to participate in the survey, and 23 responded. Among respondents, the largest proportions were male [70% (16/23)], and PhD fellows [35% (8/23)]. The respondents rated the fellowship experience as excellent [65% (15/23)], and most [78% (18/23)] revealed they had benefitted greatly from the programme. The SWOT analysis revealed outstanding strengths of having regular fellows’ meetings for peer support, and availability of international collaborations, linkages and exposure. Opportunities identified included large pool of mentees within MUII-plus and evidence of fellows taking up leadership positions. The biggest threat to the mentorship programme was the busy schedule of mentors. Conclusions: The MUII-plus mentorship programme has strong potential to offer research and career mentorship to its fellows. To promote sustainability of the programme, there is a need for innovative ways to engage mentors; such as digital platforms (e-mentorship) for greater mentor-mentee interactions.

Population differences in vaccine responses (POPVAC): scientific rationale and cross-cutting analyses for three linked, randomised controlled trials assessing the role, reversibility and mediators of immunomodulation by chronic infections in the tropics

INTRODUCTION

Vaccine-specific immune responses vary between populations and are often impaired in low income, rural settings. Drivers of these differences are not fully elucidated, hampering identification of strategies for optimising vaccine effectiveness. We hypothesise that urban-rural (and regional and international) differences in vaccine responses are mediated to an important extent by differential exposure to chronic infections, particularly parasitic infections.

METHODS AND ANALYSIS

Three related trials sharing core elements of study design and procedures (allowing comparison of outcomes across the trials) will test the effects of (1) individually randomised intervention against schistosomiasis (trial A) and malaria (trial B), and (2) Bacillus Calmette-Guérin (BCG) revaccination (trial C), on a common set of vaccine responses. We will enrol adolescents from Ugandan schools in rural high-schistosomiasis (trial A) and rural high-malaria (trial B) settings and from an established urban birth cohort (trial C). All participants will receive BCG on day '0'; yellow fever, oral typhoid and human papilloma virus (HPV) vaccines at week 4; and HPV and tetanus/diphtheria booster vaccine at week 28. Primary outcomes are BCG-specific IFN-γ responses (8 weeks after BCG) and for other vaccines, antibody responses to key vaccine antigens at 4 weeks after immunisation. Secondary analyses will determine effects of interventions on correlates of protective immunity, vaccine response waning, priming versus boosting immunisations, and parasite infection status and intensity. Overarching analyses will compare outcomes between the three trial settings. Sample archives will offer opportunities for exploratory evaluation of the role of immunological and 'trans-kingdom' mediators in parasite modulation of vaccine-specific responses.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from relevant Ugandan and UK ethics committees. Results will be shared with Uganda Ministry of Health, relevant district councils, community leaders and study participants. Further dissemination will be done through conference proceedings and publications.

TRIAL REGISTRATION NUMBERS

ISRCTN60517191, ISRCTN62041885, ISRCTN10482904.

Impact of BCG revaccination on the response to unrelated vaccines in a Ugandan adolescent birth cohort: randomised controlled trial protocol C for the 'POPulation differences in VACcine responses' (POPVAC) programme

INTRODUCTION

There is evidence that BCG immunisation may protect against unrelated infectious illnesses. This has led to the postulation that administering BCG before unrelated vaccines may enhance responses to these vaccines. This might also model effects of BCG on unrelated infections.

METHODS AND ANALYSIS

To test this hypothesis, we have designed a randomised controlled trial of BCG versus no BCG immunisation to determine the effect of BCG on subsequent unrelated vaccines, among 300 adolescents (aged 13-17 years) from a Ugandan birth cohort. Our schedule will comprise three main immunisation days (week 0, week 4 and week 28): BCG (or no BCG) revaccination at week 0; yellow fever (YF-17D), oral typhoid (Ty21a) and human papillomavirus (HPV) prime at week 4; and HPV boost and tetanus/diphtheria (Td) boost at week 28. Primary outcomes are anti-YF-17D neutralising antibody titres, Salmonella typhi lipopolysaccharide-specific IgG concentration, IgG specific for L1-proteins of HPV-16/HPV-18 and tetanus and diphtheria toxoid-specific IgG concentration, all assessed at 4 weeks after immunisation with YF, Ty21a, HPV and Td, respectively. Secondary analyses will determine effects on correlates of protective immunity (where recognised correlates exist), on vaccine response waning and on whether there are differential effects on priming versus boosting immunisations. We will also conduct exploratory immunology assays among subsets of participants to further characterise effects of BCG revaccination on vaccine responses. Further analyses will assess which life course exposures influence vaccine responses in adolescence.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from relevant Ugandan and UK ethics committees. Results will be shared with Uganda Ministry of Health, relevant district councils, community leaders and study participants. Further dissemination will be done through conference proceedings and publications.

TRIAL REGISTRATION NUMBER

ISRCTN10482904.

Analysis of the MUII-plus mentorship programme: reflections of Fellows’ experiences and lessons for other programmes

Background: The MUII mentorship programme began 11 years ago with a successful group mentorship model. Over the years, the programme has evolved and is presently anchored on the “GROW” approach. This model allows individuals to: set Goals (What I want?); Reflect (Where am I now?); think of Options (What can I do?); What to implement (my actions?). It is intended to help fellows (current, honorary, alumni) herein referred to as mentees achieve their short, medium, and long-term research, career and professional goals. Methods: A mixed methods study combining a cross-sectional survey, one focus group discussion and 11 in-depth key informant interviews were carried out between November 2018 and January 2019 to 1) assess the status of the mentorship programme, 2) perform a strength weakness opportunity and threats (SWOT) analysis, and 3) identify factors relevant for sustainability. Results: An open invitation was made to 52 fellows to participate in the survey, and 23 responded. Among respondents, the largest proportions were male [70% (16/23)], and PhD fellows [35% (8/23)]. The respondents rated the fellowship experience as excellent [65% (15/23)], and most [78% (18/23)] revealed they had benefitted greatly from the programme. The SWOT analysis revealed outstanding strengths of having regular fellows’ meetings for peer support, and availability of international collaborations, linkages and exposure. Opportunities identified included large pool of mentees within MUII-plus and evidence of fellows taking up leadership positions. The biggest threat to the mentorship programme was the busy schedule of mentors. Conclusions: The MUII-plus mentorship programme has strong potential to offer research and career mentorship to its fellows. To promote sustainability of the programme, there is a need for innovative ways to engage mentors; such as digital platforms (e-mentorship) for greater mentor-mentee interactions.

Risk assessment for the implementation of controlled human Schistosoma mansoni infection trials in Uganda

Schistosomiasis is a parasitic infection highly prevalent in sub-Saharan Africa, and a significant cause of morbidity; it is a priority for vaccine development. A controlled human infection model for Schistosoma mansoni (CHI-S) with potential to accelerate vaccine development has been developed among naïve volunteers in the Netherlands. Because responses both to infections and candidate vaccines are likely to differ between endemic and non-endemic settings, we propose to establish a CHI-S in Uganda where Schistosoma mansoni is endemic. As part of a “road-map” to this goal, we have undertaken a risk assessment. We identified risks related to importing of laboratory vector snails and schistosome strains from the Netherlands to Uganda; exposure to natural infection in endemic settings concurrently with CHI-S studies, and unfamiliarity of the community with the nature, risks and rationale for CHI. Mitigating strategies are proposed. With careful implementation of the latter, we believe that CHI-S can be implemented safely in Uganda. Our reflections are presented here to promote feedback and discussion.

Risk assessment for the implementation of controlled human Schistosoma mansoni infection trials in Uganda

Schistosomiasis is a parasitic infection highly prevalent in sub-Saharan Africa, and a significant cause of morbidity; it is a priority for vaccine development. A controlled human infection model for Schistosoma mansoni (CHI-S) with potential to accelerate vaccine development has been developed among naïve volunteers in the Netherlands. Because responses both to infections and candidate vaccines are likely to differ between endemic and non-endemic settings, we propose to establish a CHI-S in Uganda where Schistosoma mansoni is endemic. As part of a "road-map" to this goal, we have undertaken a risk assessment. We identified risks related to importing of laboratory vector snails and schistosome strains from the Netherlands to Uganda; exposure to natural infection in endemic settings concurrently with CHI-S studies, and unfamiliarity of the community with the nature, risks and rationale for CHI. Mitigating strategies are proposed. With careful implementation of the latter, we believe that CHI-S can be implemented safely in Uganda. Our reflections are presented here to promote feedback and discussion.

Lessons from the first clinical trial of a non-licensed vaccine among Ugandan adolescents: a phase II field trial of the tuberculosis candidate vaccine, MVA85A

Background: A more effective vaccine for tuberculosis (TB) is a global public health priority. Vaccines under development will always need evaluation in endemic settings, most of which have limited resources. Adolescents are an important target population for a new TB vaccine and for other vaccines which are relevant at school-age. However, in most endemic settings there is limited experience of trials of investigational products among adolescents, and adolescents are not routinely vaccinated. Methods: We used Modified vaccinia Ankara-expressing Ag85A (MVA85A), a well-tolerated candidate vaccine for tuberculosis, to assess the effect of Schistosoma mansoni infection on vaccine immunogenicity among Ugandan adolescents in primary school. We describe here the challenges and lessons learned in designing and implementing this first clinical trial among Ugandan adolescents using a non-licensed vaccine. Results: The school based immunization study was feasible and adhered to Good Clinical Practice principles.  Engagement with the community and all stakeholders was critical for successful implementation of the trial. Creative and adaptable strategies were used to address protocol-specific, operational and logistical challenges. This study provided lessons and solutions that can be applied to other trials among adolescents in similar settings elsewhere, and to school-based immunization programs. Conclusion: Sufficient time and resources should be planned for community preparation and sensitization to ensure buy in and acceptance of a project of this kind. This trial shows that challenges to implementing early field trials in Africa are not insurmountable and that necessary well-planned high-quality ethical trials are feasible and should be encouraged. Trial Registration: ClinicalTrials.gov NCT02178748 03/06/2014.

Ethical and scientific considerations on the establishment of a controlled human infection model for schistosomiasis in Uganda: report of a stakeholders' meeting held in Entebbe, Uganda

Controlled human infection (CHI) models are gaining recognition as an approach to accelerating vaccine development, for use in both non-endemic and endemic populations: they can facilitate identification of the most promising candidate vaccines for further trials and advance understanding of protective immunity. Helminths present a continuing health burden in sub-Saharan Africa. Vaccine development for these complex organisms is particularly challenging, partly because protective responses are akin to mechanisms of allergy. A CHI model for Schistosoma mansoni (CHI-S) has been developed at Leiden University Medical Centre, the Netherlands. However, responses to schistosome infections, and candidate vaccines, are likely to be different among people from endemic settings compared to schistosome-naïve Dutch volunteers. Furthermore, among volunteers from endemic regions who have acquired immune responses through prior exposure, schistosome challenge can be used to define responses associated with clinical protection, and thus to guide vaccine development.  To explore the possibility of establishing the CHI-S in Uganda, a Stakeholders' Meeting was held in Entebbe in 2017. Regulators, community members, researchers and policy-makers discussed implementation challenges and recommended preparatory steps: risk assessment; development of infrastructure and technical capacity to produce the infectious challenge material in Uganda; community engagement from Parliamentary to grass-roots level; pilot studies to establish approaches to assuring fully informed consent and true voluntariness, and strategies for selection of volunteers who can avoid natural infection during the 12-week CHI-S; the building of regulatory capacity; and the development of study protocols and a product dossier in close consultation with ethical and regulatory partners. It was recommended that, on completion, the protocol and product dossier be reviewed for approval in a joint meeting combining ethical, regulatory and environment management authorities. Most importantly, representatives of schistosomiasis-affected communities emphasised the urgent need for an effective vaccine and urged the research community not to delay in the development process.

Ethical and scientific considerations on the establishment of a controlled human infection model for schistosomiasis in Uganda: report of a stakeholders' meeting held in Entebbe, Uganda

Controlled human infection (CHI) models are gaining recognition as an approach to accelerating vaccine development, for use in both non-endemic and endemic populations: they can facilitate identification of the most promising candidate vaccines for further trials and advance understanding of protective immunity. Helminths present a continuing health burden in sub-Saharan Africa. Vaccine development for these complex organisms is particularly challenging, partly because protective responses are akin to mechanisms of allergy. A CHI model for Schistosoma mansoni (CHI-S) has been developed at Leiden University Medical Centre, the Netherlands. However, responses to schistosome infections, and candidate vaccines, are likely to be different among people from endemic settings compared to schistosome-naïve Dutch volunteers. Furthermore, among volunteers from endemic regions who have acquired immune responses through prior exposure, schistosome challenge can be used to define responses associated with clinical protection, and thus to guide vaccine development.  To explore the possibility of establishing the CHI-S in Uganda, a Stakeholders' Meeting was held in Entebbe in 2017. Regulators, community members, researchers and policy-makers discussed implementation challenges and recommended preparatory steps: risk assessment; development of infrastructure and technical capacity to produce the infectious challenge material in Uganda; community engagement from Parliamentary to grass-roots level; pilot studies to establish approaches to assuring fully informed consent and true voluntariness, and strategies for selection of volunteers who can avoid natural infection during the 12-week CHI-S; the building of regulatory capacity; and the development of study protocols and a product dossier in close consultation with ethical and regulatory partners. It was recommended that, on completion, the protocol and product dossier be reviewed for approval in a joint meeting combining ethical, regulatory and environment management authorities. Most importantly, representatives of schistosomiasis-affected communities emphasised the urgent need for an effective vaccine and urged the research community not to delay in the development process.

The effect of current Schistosoma mansoni infection on the immunogenicity of a candidate TB vaccine, MVA85A, in BCG-vaccinated adolescents: An open-label trial

INTRODUCTION

Helminth infection may affect vaccine immunogenicity and efficacy. Adolescents, a target population for tuberculosis booster vaccines, often have a high helminth burden. We investigated effects of Schistosoma mansoni (Sm) on the immunogenicity and safety of MVA85A, a model candidate tuberculosis vaccine, in BCG-vaccinated Ugandan adolescents.

METHODS

In this phase II open label trial we enrolled 36 healthy, previously BCG-vaccinated adolescents, 18 with no helminth infection detected, 18 with Sm only. The primary outcome was immunogenicity measured by Ag85A-specific interferon gamma ELISpot assay. Tuberculosis and schistosome-specific responses were also assessed by whole-blood stimulation and multiplex cytokine assay, and by antibody ELISAs.

RESULTS

Ag85A-specific cellular responses increased significantly following immunisation but with no differences between the two groups. Sm infection was associated with higher pre-immunisation Ag85A-specific IgG4 but with no change in antibody levels following immunisation. There were no serious adverse events. Most reactogenicity events were of mild or moderate severity and resolved quickly.

CONCLUSIONS

The significant Ag85A-specific T cell responses and lack of difference between Sm-infected and uninfected participants is encouraging for tuberculosis vaccine development. The implications of pre-existing Ag85A-specific IgG4 antibodies for protective immunity against tuberculosis among those infected with Sm are not known. MVA85A was safe in this population.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02178748.

Feasibility of establishing a biosafety level 3 tuberculosis culture laboratory of acceptable quality standards in a resource-limited setting: an experience from Uganda

Background

Despite the recent innovations in tuberculosis (TB) and multi-drug resistant TB (MDR-TB) diagnosis, culture remains vital for difficult-to-diagnose patients, baseline and end-point determination for novel vaccines and drug trials. Herein, we share our experience of establishing a BSL-3 culture facility in Uganda as well as 3-years performance indicators and post-TB vaccine trials (pioneer) and funding experience of sustaining such a facility.

Methods

Between September 2008 and April 2009, the laboratory was set-up with financial support from external partners. After an initial procedure validation phase in parallel with the National TB Reference Laboratory (NTRL) and legal approvals, the laboratory registered for external quality assessment (EQA) from the NTRL, WHO, National Health Laboratories Services (NHLS), and the College of American Pathologists (CAP). The laboratory also instituted a functional quality management system (QMS). Pioneer funding ended in 2012 and the laboratory remained in self-sustainability mode.

Results

The laboratory achieved internationally acceptable standards in both structural and biosafety requirements. Of the 14 patient samples analyzed in the procedural validation phase, agreement for all tests with NTRL was 90% (P <0.01). It started full operations in October 2009 performing smear microscopy, culture, identification, and drug susceptibility testing (DST). The annual culture workload was 7,636, 10,242, and 2,712 inoculations for the years 2010, 2011, and 2012, respectively. Other performance indicators of TB culture laboratories were also monitored. Scores from EQA panels included smear microscopy >80% in all years from NTRL, CAP, and NHLS, and culture was 100% for CAP panels and above regional average scores for all years with NHLS. Quarterly DST scores from WHO-EQA ranged from 78% to 100% in 2010, 80% to 100% in 2011, and 90 to 100% in 2012.

Conclusions

From our experience, it is feasible to set-up a BSL-3 TB culture laboratory with acceptable quality performance standards in resource-limited countries. With the demonstrated quality of work, the laboratory attracted more research groups and post-pioneer funding, which helped to ensure sustainability. The high skilled experts in this research laboratory also continue to provide an excellent resource for the needed national discussion of the laboratory and quality management systems.

Electronic supplementary material

The online version of this article (doi:10.1186/1478-4505-13-4) contains supplementary material, which is available to authorized users.

Distinct T-cell responses when BCG vaccination is delayed from birth to 6 weeks of age in Ugandan infants

BACKGROUND

In Uganda, the tuberculosis vaccine BCG is administered on the first day of life. Infants delivered at home receive BCG vaccine at their first healthcare facility visit at 6 weeks of age. Our aim was to determine the effect of this delay in BCG vaccination on the induced immune response.

METHODS

We assessed CD4(+) and CD8(+) T-cell responses with a 12-hour whole-blood intracellular cytokine/cytotoxic marker assay, and with a 6-day proliferation assay.

RESULTS

We enrolled 92 infants: 50 had received BCG vaccine at birth and 42 at 6 weeks of age. Birth vaccination was associated with (1) greater induction of CD4(+) and CD8(+) T cells expressing either interferon γ (IFN-γ) alone or IFN-γ together with perforin and (2) induction of proliferating cells that had greater capacity to produce IFN-γ, tumor necrosis factor α (TNF-α), and interleukin 2 together, compared with delayed vaccination.

CONCLUSIONS

Distinct patterns of T-cell induction occurred when BCG vaccine was given at birth and at 6 weeks of age. We propose that this diversity might impact protection against tuberculosis. Our results differ from those of studies of delayed BCG vaccination in South Africa and the Gambia, suggesting that geographical and population heterogeneity may affect the BCG vaccine-induced T-cell response.

Species and genotypic diversity of non-tuberculous mycobacteria isolated from children investigated for pulmonary tuberculosis in rural Uganda

BACKGROUND

Smear microscopy, a mainstay of tuberculosis (TB) diagnosis in developing countries, cannot differentiate M. tuberculosis complex from NTM infection, while pulmonary TB shares clinical signs with NTM disease, causing clinical and diagnostic dilemmas. This study used molecular assays to identify species and assess genotypic diversity of non-tuberculous mycobacteria (NTM) isolates from children investigated for pulmonary tuberculosis at a demographic surveillance site in rural eastern Uganda.

METHODS

Children were investigated for pulmonary tuberculosis as part of a TB vaccine surveillance program (2009-2011). Two cohorts of 2500 BCG vaccinated infants and 7000 adolescents (12-18 years) were recruited and followed up for one to two years to determine incidence of tuberculosis. Induced sputum and gastric aspirates were processed by the standard N-acetyl L-cysteine (NALC)-NaOH method. Sediments were cultured in the automated MGIT (Becton Dickson) liquid culture system and incubated at 37°C for at least six weeks. Capilia TB assay was used to classify mycobacteria into MTC and NTM. The GenoType CM/AS assays were performed to identify species while Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR genotyping was used to assess genetic diversity of the strains within each species.

RESULTS

Among 2859 infants and 2988 adolescents screened, the numbers of TB suspects were 710 and 1490 infants and adolescents respectively. The prevalence of NTM in infant suspects was 3.7% (26/710) (95% CI 2.5-5.2) while that in adolescent suspects was 4.6% (69/1490) (95% CI 3.6-5.8). On culture, 127 isolates were obtained, 103 of which were confirmed as mycobacteria comprising of 95 NTM and eight M. tuberculosis complex. The Genotype CM/AS assay identified 63 of the 95 NTM isolates while 32 remained un-identified. The identified NTM species were M. fortuitum (40 isolates, 63.5%), M. szulgai (9 isolates, 14.3%), M. gordonae (6 isolates, 9.5%), M. intracellulare (3 isolates, 4.7%), M. scrofulaceum (2 isolates, 3.2%), M. lentiflavum (2 isolates, 3.2%), and M. peregrinum (1 isolate, 1.6%). Genotyping did not reveal any clustering in M. intracellulare, M. gordonae and M. szulgai species. M. fortuitum, on the other hand, had two clusters, one with three isolates of M. fortuitum 1 and the other with two isolates of M. fortuitum 2 subspecies. The remaining 35 of the 40 isolates of M. fortuitum had unique fingerprint patterns.

CONCLUSION

M. fortuitum is the most common cause of infection by NTM among Infants and adolescents in rural Uganda. There is a varied number of species and genotypes, with minimal clustering within species, suggesting ubiquitous sources of infection to individuals in this community.

Tuberculosis knowledge, attitudes and health-seeking behaviour in rural Uganda

OBJECTIVES

To assess tuberculosis (TB) knowledge, attitudes and health-seeking behaviour to inform the design of communication and social mobilisation interventions.

SETTING

Iganga/Mayuge Demographic Surveillance Site, Uganda.

DESIGN

Between June and July 2008, 18 focus group discussions and 12 key informant interviews were conducted, including parents of infants and adolescents and key informant interviews with community leaders, traditional healers and patients with TB.

RESULTS

People viewed TB as contagious, but not necessarily an airborne pathogen. Popular TB aetiologies included sharing utensils, heavy labour, smoking, bewitchment and hereditary transmission. TB patients were perceived to seek care late or to avoid care. Combining care from traditional healers and the biomedical system was common. Poverty, drug stock-outs, fear of human immunodeficiency virus (HIV) testing and length of TB treatment negatively affect health-seeking behaviour. Stigma and avoidance of persons with TB often reflects an assumption of HIV co-infection.

CONCLUSION

The community's concerns about pill burden, quality of care, financial barriers, TB aetiology, stigma and preference for pluralistic care need to be addressed to improve early detection. Health education messages should emphasise the curability of TB, the feasibility of treatment and the engagement of traditional healers as partners in identifying cases and facilitating adherence to treatment.

Population demographic indicators associated with incidence of pyloric stenosis

OBJECTIVES

To calculate incidence rates of pyloric stenosis (estimated by the rate of pyloromyotomy) among infants in Ontario and determine their association with population sociodemographic indicators.

METHODS

Pyloromyotomy rates were calculated from hospital discharge data from 1993 through 2000. Four-year data (1993-1996 and 1997-2000) were combined to ensure the stability of the rates. Small-area variations in pyloromyotomy rates and correlations between sociodemographic indicators were studied.

RESULTS

Approximately 84.0% of the patients were male infants (younger than 1 year). The sex-adjusted pyloromyotomy rates were 1.57 and 1.86 per 1000 with a 3.4-fold and 3.0-fold regional variation in 1993-1996 and 1997-2000, respectively. Urban areas consistently had the lowest pyloromyotomy rate (1.04 and 1.11 per 1000 in Metropolitan Toronto), but the highest rates were from more rural areas (3.30 and 3.38 per 1000 in Quinte, Kingston, Rideau). After adjusting for socioeconomic status and availability of surgeons in the region, living in a rural area remained a significant factor associated with a higher incidence of pyloromyotomy. The risk of pyloromyotomy for an infant who lives in a region with more than two thirds of its area classified as rural was 1.79 (95% confidence interval, 1.23-2.61; P<.005).

CONCLUSIONS

The observed changes in incidence and a higher rate among male infants are consistent with results from previous comparative studies conducted in North America and Sweden. The rural/urban differences suggest that environmental influences related to living in these areas may have a role in the etiology of pyloric stenosis. Further research is needed to evaluate these differences.

Effect of subspecialty training and volume on outcome after pediatric inguinal hernia repair

BACKGROUND/PURPOSE

Inguinal hernia repair is the most common operation performed in children. The aim of this study was to determine if there are any differences in outcome when this procedure is performed by subspecialist pediatric surgeons when compared with general surgeons.

METHODS

All pediatric inguinal hernias repaired in the province of Ontario between 1993 and 2000 were reviewed using a population-based database. Children with complex medical conditions or prematurity were excluded. Cases done by general surgeons were compared with those done by pediatric surgeons. The chi2 test was used for nominal data and the Student's t test was used for continuous variables. Probabilities were calculated based on a logistic regression model.

RESULTS

Of 20,545 eligible hernia repairs, 50.3% were performed by pediatric surgeons and 49.7% were performed by general surgeons. Pediatric surgeons operated on 62.4% of children younger than 2 years, 51.8% of children aged 26 years, and 37% of children older than 7 years. Duration of operation, length of hospital stay, and incidence of early postoperative complications were similar among pediatric and general surgeons. The rate of recurrent inguinal hernia was higher in the general surgeon group compared with pediatric surgeons (1.10% vs 0.45%, P < .001). Among pediatric surgeons, the estimated risk of hernia recurrence was independent of surgical volume. There was a significant inverse correlation between surgeon volume and recurrence risk among general surgeons, with the highest volume general surgeons achieving recurrence rates similar to pediatric surgeons.

CONCLUSIONS

Pediatric surgeons have a lower rate of recurrence after inguinal hernia repair in children. General surgeons with high volumes have similar outcomes to pediatric surgeons.

Activation of β‐Chemokines and CCR5 in Persons Infected with Human Immunodeficiency Virus Type 1 and Tuberculosis

Tuberculosis (TB) in human immunodeficiency virus type 1 (HIV-1)-infected persons is associated with progression of HIV-1 disease. The expression of macrophage inflammatory protein (MIP)-1alpha and CCR5 was assessed in HIV-1-infected patients with pulmonary TB (HIV-1/PTB) and without PTB (HIV-1/C), PTB patients not infected with HIV-1 (PTB), and control subjects. Mycobacterium tuberculosis (MTB)-induced MIP-1alpha production was lower in peripheral blood mononuclear cells (PBMC) of HIV-1/PTB patients than in those of PTB patients (P< .05) and was lower in PBMC of HIV-1/C patients than in those of control subjects (P< .005). However, MIP-1alpha production was higher in PBMC of HIV/PTB patients than in those of HIV-1/C patients (P< .01). The pattern of MTB-induced RANTES production was similar to that of MIP-1alpha. However, MTB induced greater expression of mRNA for CCR5 in PBMC of HIV-1/PTB patients than in those of HIV-1/C patients (P< .04). Furthermore, the MTB-induced HIV p24 antigen level in PBMC of HIV-1/PTB patients with a CD4 cell count <500 cells/microL was higher (P< .05) than that in HIV-1/C patients. Thus, perturbations in chemokine pathways in HIV-1/PTB patients may accelerate HIV-1 disease.

Macrophage‐Activating Cytokines in Human Immununodeficiency Virus Type 1–Infected and –Uninfected Patients with Pulmonary Tuberculosis

Tuberculosis (TB) is the most common opportunistic infection in human immunodeficiency virus type 1 (HIV-1)-infected patients globally and occurs throughout the course of HIV-1 disease. Here the production of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha by peripheral blood mononuclear cells (PBMC) of HIV-1-infected versus -uninfected patients with newly diagnosed pulmonary TB (PTB) was compared. Findings were correlated with cytokine profiles, clinical presentation, and expression of inducible nitric oxide (iNOS). Most HIV-1/PTB patients with a CD4 cell count of 200-500 cells/microL had high IFN-gamma production and radiographic evidence of atypical PTB. Low IFN-gamma production and radiographic evidence of reactivated PTB characterized both HIV-1/PTB patients with a CD4 cell count >or=500 cells/microL and HIV-1-uninfected patients. TNF-alpha levels were similar in all HIV-1/PTB patients, regardless of CD4 cell count. Induction of iNOS in PBMC was low and was associated with low IFN-gamma production. These data underscore the potential pathogenic role of macrophage-activating cytokines in TB in HIV-1-infected patients.

T cell activation, apoptosis and cytokine dysregulation in the (co)pathogenesis of HIV and pulmonary tuberculosis (TB)

Immune parameters were compared in four groups of Ugandan subjects: HIV-and HIV+ adult patients with active pulmonary TB (HIV- PTB n = 38; HIV+ PTB n = 28), patients with HIV infection only (n = 26) and PPD+ healthy controls (n = 25). Compared with healthy controls, CD4 and CD8 T cells from patients with HIV and/or PTB expressed more activation markers (HLA-DR, CD38); their CD8 T cells expressed more CD95 (pre-apoptosis) and less CD28 (co-stimulatory receptor). Peripheral blood mononuclear cells (PBMC) of patients with either HIV or PTB were impaired in interferon-gamma (IFN-gamma) production upon antigenic stimulation. PTB (with or without HIV) was characterized by monocytosis, granulocytosis, increased transforming growth factor-beta 1 production and PPD-induced apoptosis. In vivo CD4 T cell depletion, in vitro increased spontaneous CD4 T cell apoptosis and defects in IFN-gamma responses upon mitogenic stimulation were restricted to HIV+ subjects (with or without PTB). Overlapping and distinctive immune alterations, associated with PTB and HIV, might explain mutual unfavourable influences of both diseases.