Browsing by Author "Hussey, Gregory D."
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- ItemCulture-confirmed childhood tuberculosis in Cape Town, South Africa : a review of 596 cases(BioMed Central, 2007-11) Schaaf, H. Simon; Marais, Ben J.; Whitelaw, Andrew; Hesseling, Anneke C.; Eley, Brian; Hussey, Gregory D.; Donald, Peter R.Background: The clinical, radiological and microbiological features of culture-confirmed childhood tuberculosis diagnosed at two referral hospitals are described. Methods: Cultures of Mycobacterium tuberculosis from children less than 13 years of age at Tygerberg and Red Cross Children's Hospitals, Cape Town, South Africa, were collected from March 2003 through February 2005. Folder review and chest radiography were performed and drug susceptibility tests done. Results: Of 596 children (median age 31 months), 330 (55.4%) were males. Of all children, 281 (47.1%) were HIV-uninfected, 133 (22.3%) HIV-infected and 182 (30.5%) not tested. Contact with infectious tuberculosis adults was recorded in 295 (49.5%) children. Missed opportunities for chemoprophylaxis were present in 117/182 (64.3%) children less than 5 years of age. Extrathoracic TB was less common in HIV-infected than in HIV-uninfected children (49/133 vs. 156/281; odds ratio 0.50, 95% confidence interval 0.32–0.78). Alveolar opacification (84/126 vs. 128/274; OR 1.85, 95%CI 1.08–3.19) and cavitation (33/126 vs. 44/274; OR 2.28, 95%CI 1.44–3.63) were more common in HIV-infected than in HIV-uninfected children. Microscopy for acid-fast bacilli on gastric aspirates and sputum was positive in 29/142 (20.4%) and 40/125 (32.0%) children, respectively. Sixty-seven of 592 (11.3%) children's isolates showed resistance to isoniazid and/or rifampicin; 43 (7.3%) were isoniazid-monoresistant, 2 (0.3%) rifampicin-monoresistant and 22 (3.7%) multidrug-resistant. Death in 41 children (6.9%) was more common in HIV-infected children and very young infants. Conclusion: HIV infection and missed opportunities for chemoprophylaxis were common in children with culture-confirmed TB. With cavitating disease and sputum or gastric aspirates positive for acid-fast bacilli, children may be infectious. Transmission of drug-resistant TB is high in this setting.
- ItemImproving vaccination uptake among adolescents(Cochrane, 2015-09-29) Wiysonge, Charles Shey Umaru; Abdullahi, Leila H.; Kagina, Benjamin M. N.; Hussey, Gregory D.This is the protocol for a review and there is no abstract. The objectives are as follows: To evaluate the effects of interventions to improve vaccine uptake among adolescents in low, middle and high-income countries.
- ItemKnowledge, attitudes and practices on adolescent vaccination among parents, teachers and adolescents in Africa : a systematic review protocol(BioMed Central, 2014-09) Abdullahi, Leila H.; Kagina, Benjamin M.; Cassidy, Tali; Adebayo, Esther F.; Wiysonge, Charles S.; Hussey, Gregory D.Background Vaccines are the most successful and cost-effective public health interventions available to avert vaccine-preventable diseases and deaths. Despite progress in the field of adolescent health, many young people in Africa still get sick and die from vaccine-preventable diseases due to lack of vaccination. Parents, adolescents and teachers are key players with regard to implementation of adolescent vaccination policies. Therefore, understanding their knowledge, attitudes and practices towards adolescent vaccination may provide clues on what can be done to improve vaccine uptake among adolescents. The aim of this study is to conduct a qualitative and quantitative systematic review on knowledge, attitudes and practices on adolescent vaccination among parents, teachers and adolescents in Africa. Methods We will include both quantitative and qualitative primary studies. Eligible quantitative studies include both intervention and observational studies. Qualitative studies to be included are focus group discussions, direct observations, in-depth interviews and case ethnographic studies. We will search PubMed, Cochrane Central Register of Controlled Trials, Scopus, Web of Science, WHOLIS, Africa Wide and CINAHL for eligible studies with no time and language limits. We will also check reference lists of included studies for other eligible reports. Two authors will independently screen the search output, select studies and extract data, resolving discrepancies by consensus and discussion. We will analyse qualitative data using thematic analysis where applicable, and quantitative studies findings will be presented in a narrative synthesis form based on the outcomes. Discussion The findings from this systematic review will guide the identification of gaps on knowledge, attitudes and practices among the key role players on adolescent vaccination. We anticipate that our findings will guide the development of adolescent-focused vaccination policy in Africa, which is virtually non-existent at present. Systematic review registration This review is registered with PROSPERO, registration number CRD42014010395.
- ItemMobile phone text messaging for promoting adherence to anti-tuberculosis treatment : a systematic review(BioMed Central, 2013-12-02) Nglazi, Mweete D.; Bekker, Linda-Gail; Wood, Robin; Hussey, Gregory D.; Wiysonge, Charles S.Background: Mobile phone text messaging (SMS) has the potential to promote adherence to tuberculosis treatment. This systematic review aims to synthesize current evidence on the effectiveness of SMS interventions in improving patients’ adherence to tuberculosis treatment. Methods: We searched electronic databases (PubMed, EMBASE, Science Citation Index), reference lists of relevant articles, conference proceedings, and selected websites for eligible studies available by 15 February 2013; regardless of language or publication status. Two authors independently screened selected eligible studies, and assessed risk of bias in included studies; resolving discrepancies by discussion and consensus. Results: We identified four studies that compared the outcomes of the SMS intervention group with controls. Only one of the four studies was a randomized controlled trial. This was conducted in Argentina and the SMS intervention did not significantly improve adherence to tuberculosis treatment compared to self-administration of tuberculosis treatment (risk ratio [RR] 1.49, 95% confidence intervals [CI] 0.90 to 2.42). One of the non-randomized studies, conducted in South Africa, which compared SMS reminders to directly observed therapy short course (DOTS) reported similar rates of tuberculosis cure (62.35% vs. 66.4%) and treatment success (72.94% vs. 69.4%). A second study from South Africa, utilized SMS reminders when patients delayed in opening their pill bottles and reported increased tuberculosis cure (RR 2.32, 95% CI 1.60 to 3.36) and smear conversion (RR 1.62, 95% CI 1.09 to 2.42) rates compared to DOTS. In the third non-randomized study, conducted in Kenya, use of SMS reminders increased rates of clinic attendance on scheduled days compared to standard care (RR 1.56, 95% CI 1.06 to 2.29). Using the GRADE approach, we rate the quality of the evidence as low, mainly because of the high risk of bias and heterogeneity of effects across studies. Conclusions: This systematic review indicates that there is a paucity of high-quality data on the effectiveness of SMS interventions for improving patients’ adherence to tuberculosis treatment. The low quality of the current evidence implies that further studies (in particular randomized trials) on the subject are needed. In the interim, if the intervention is implemented outside research settings an impact evaluation is warranted.
- ItemPublic stewardship of private for-profit healthcare providers in low- and middle-income countries(Cochrane, 2016-08-11) Wiysonge, Charles S.; Abdullahi, Leila H.; Ndze, Valantine N.; Hussey, Gregory D.Background: Governments use different approaches to ensure that private for-profit healthcare services meet certain quality standards. Such government guidance, referred to as public stewardship, encompasses government policies, regulatory mechanisms, and implementation strategies for ensuring accountability in the delivery of services. However, the effectiveness of these strategies in low- and middle-income countries (LMICs) have not been the subject of a systematic review. Objectives: To assess the effects of public sector regulation, training, or co-ordination of the private for-profit health sector in low- and middle income countries.
- ItemRifampin pharmacokinetics in children, with and without human immunodeficiency virus infection, hospitalized for the management of severe forms of tuberculosis(2009-04) Schaaf, H. Simon; Willemse, Marianne; Cilliers, Karien; Labadarios, Demetre; Maritz, Johannes Stephanus; Hussey, Gregory D.; McIlleron, Helen; Smith, Peter; Donald, Peter RoderickBackground: Rifampin is a key drug in antituberculosis chemotherapy because it rapidly kills the majority of bacilli in tuberculosis lesions, prevents relapse and thus enables 6-month short-course chemotherapy. Little is known about the pharmacokinetics of rifampin in children. The objective of this study was to evaluate the pharmacokinetics of rifampin in children with tuberculosis, both human immunodeficiency virus type-1-infected and human immunodeficiency virus-uninfected. Methods: Fifty-four children, 21 human immunodeficiency virus-infected and 33 human immunodeficiency virus-uninfected, mean ages 3.73 and 4.05 years (P = 0.68), respectively, admitted to a tuberculosis hospital in Cape Town, South Africa with severe forms of tuberculosis were studied approximately 1 month and 4 months after commencing antituberculosis treatment. Blood specimens for analysis were drawn in the morning, 45 minutes, 1.5, 3.0, 4.0 and 6.0 hours after dosing. Rifampin concentrations were determined by liquid chromatography tandem mass spectrometry. For two sample comparisons of means, the Welch version of the t-test was used; associations between variables were examined by Pearson correlation and by multiple linear regression. Results: The children received a mean rifampin dosage of 9.61 mg/kg (6.47 to 15.58) body weight at 1 month and 9.63 mg/kg (4.63 to 17.8) at 4 months after commencing treatment administered as part of a fixed-dose formulation designed for paediatric use. The mean rifampin area under the curve 0 to 6 hours after dosing was 14.9 and 18.1 μg/hour/ml (P = 0.25) 1 month after starting treatment in human immunodeficiency virus-infected and human immunodeficiency virus-uninfected children, respectively, and 16.52 and 17.94 μg/hour/ml (P = 0.59) after 4 months of treatment. The mean calculated 2-hour rifampin concentrations in these human immunodeficiency virus-infected and human immunodeficiency virus-uninfected children were 3.9 and 4.8 μg/ml (P = 0.20) at 1 month after the start of treatment and 4.0 and 4.6 μg/ml (P = 0.33) after 4 months of treatment. These values are considerably less than the suggested lower limit for 2-hour rifampin concentrations in adults of 8.0 μg/ml and even 4 μg/ml Conclusion Both human immunodeficiency virus-infected and human immunodeficiency virus-uninfected children with tuberculosis have very low rifampin serum concentrations after receiving standard rifampin dosages similar to those used in adults. Pharmacokinetic studies of higher dosages of rifampin are urgently needed in children to assist in placing the dosage of rifampin used in childhood on a more scientific foundation.
- ItemSafety of licensed vaccines in HIV-infected persons : a systematic review protocol(BioMed Central, 2014-09) Kagina, Benjamin M.; Wiysonge, Charles S.; Lesosky, Maia; Madhi, Shabir A.; Hussey, Gregory D.Background Safety of vaccines remains a cornerstone of building public trust on the use of these cost-effective and life-saving public health interventions. In some settings, particularly Sub-Saharan Africa, there is a high prevalence of HIV infection and a high burden of vaccine-preventable diseases. There is evidence suggesting that the immunity induced by some commonly used vaccines is not durable in HIV-infected persons, and therefore, repeated vaccination may be considered to ensure optimal vaccine-induced immunity in this population. However, some vaccines, particularly the live vaccines, may be unsafe in HIV-infected persons. There is lack of evidence on the safety profile of commonly used vaccines among HIV-infected persons. We are therefore conducting a systematic review to assess the safety profile of routine vaccines administered to HIV-infected persons. Methods/Design We will select studies conducted in any setting where licensed and effective vaccines were administered to HIV-infected persons. We will search for eligible studies in PubMed, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Africa-Wide, PDQ-Evidence and CINAHL as well as reference lists of relevant publications. We will screen search outputs, select studies and extract data in duplicate, resolving discrepancies by discussion and consensus. Discussion Globally, immunisation is a major public health strategy to mitigate morbidity and mortality caused by various infectious disease-causing agents. In general, there are efforts to increase vaccination coverage worldwide, and for these efforts to be successful, safety of the vaccines is paramount, even among people living with HIV, who in some situations may require repeated vaccination. Results from this systematic review will be discussed in the context of the safety of routine vaccines among HIV-infected persons. From the safety perspective, we will also discuss whether repeat vaccination strategies may be feasible among HIV-infected persons. Systematic review registration PROSPERO CRD42014009794.
- ItemTrends in the types and quality of childhood immunisations research output from Africa 1970-2010 : mapping the evidence base(BioMed Central, 2014-02) Machingaidze, Shingai; Hussey, Gregory D.; Wiysonge, Charles S.Background: Over the past four decades, extraordinary progress has been made in establishing and improving childhood immunization programmes around Africa. In order to ensure effective and sustainable positive growth of these childhood immunisations programmes, the development, adaptation and implementation of all interventions (programme activities, new vaccines, new strategies and policies) should be informed by the best available local evidence. Methods: An assessment of the peer-reviewed literature on childhood immunization research published in English from 1970 to 2010 was conducted in PubMed and Africa-Wide databases. All study types were eligible for inclusion. A standard form was used to extract information from all studies identified as relevant and entered into a Microsoft Access database for analysis. Results: Our initial search yielded 5436 articles from the two databases, from which 848 full text articles were identified as relevant. Among studies classified as clinical research (417), 40% were clinical trials, 24% were burden of disease/epidemiology and 36% were other clinical studies. Among studies classified as operational research (431), 77% related to programme management, 18% were policy related and 5% were related to vaccine financing. Studies were conducted in 48 African countries with six countries (South Africa, The Gambia, Nigeria, Senegal, Guinea-Bissau and Kenya) accounting for 56% of the total research output. Studies were published in 152 different journals with impact factors ranging from 0.192 to 53.29; with a median impact factor of 3.572. Conclusion: A similar proportion of clinical versus operational research output was found. However, an uneven distribution across Africa was observed with only six countries accounting for over half of the research output. The research conducted was of moderate to high quality, with 62% being published in journals with 2010 impact factors greater than two. Urgent attention should be given to the development of research capacity in low performing countries around Africa, with increased focus on the process of turning immunisations programme research evidence into policy and practice, as well as increased focus on issues relating to vaccine financing and sustainability in Africa.
- ItemUnderstanding interventions for improving routine immunization coverage in children in low- and middle-income countries : a systematic review protocol(BioMed Central, 2013-11) Machingaidze, Shingai; Rehfuess, Eva; Von Kries, Rudiger; Hussey, Gregory D.; Wiysonge, Charles S.Background: Virtually all low- and middle-income countries are dependent on the World Health Organization’s Expanded Program on Immunization for delivery of vaccines to children. The Expanded Program on Immunization delivers routine immunization services from health facilities free of charge. Understanding interventions for improving immunization coverage remains key in achieving universal childhood immunization. Methods: We will conduct a systematic review that aims to assess the effectiveness of the full range of potential interventions to improve routine immunization coverage in children in low- and middle-income countries. We will include intervention studies, as well as observational studies. We will search the Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, electronic databases for eligible studies published by 31 August 2013. At least two authors will independently screen search outputs, select studies, extract data and assess the risk of bias (using separate criteria for interventions and observational studies); resolving any disagreements by discussion and consensus. The use of logic models and the Cochrane Complexity Matrix will be explored in order to better understand and contextualize studies. We will express the result of each study as a risk ratio with its corresponding 95% confidence intervals for dichotomous data, or mean difference with its standard deviation for continuous data. We will conduct meta-analysis for the same type of participants, interventions, study designs, and outcome measures where homogeneity of data allows. Use of harvest plots may be explored as an alternative. Heterogeneity will be assessed using the χ2 test of heterogeneity, and quantified using the I2 statistic. This protocol has not been registered with PROSPERO. Discussion: This review will allow us to document evidence across a broad range of intervention types for improving routine immunization coverage in children and also distinguish between those that are well supported by evidence (to direct policy recommendations) and those that are not well supported (to direct research agenda).
- ItemThe use of supplementary immunisation activities to improve uptake of current and future vaccines in low-income and middle-income countries : a systematic review protocol(BMJ Publishing Group, 2014-01) Kagina, Benjamin M.; Wiysonge, Charles S.; Machingaidze, Shingai; Abdullahi, Leila H.; Adebayo, Esther; Uthman, Olalekan A.; Hussey, Gregory D.ENGLISH SUMMARY : Introduction: Immunisation coverage data in low-income and middle-income countries (LMICs) suggest that more strategies need to be implemented to achieve and sustain optimal vaccine uptake. Among possible strategies to improve immunisation coverage are supplementary immunisation activities (SIAs). We are therefore interested in conducting a systematic review to assess whether SIAs complement routine immunisation programmes to improve vaccination coverage and prevent disease outbreaks. Methods: Our systematic review will focus on studies conducted in LMICs. With the help of an information specialist, we will search for eligible studies in PubMed, Web of Science, Scopus, Africa-Wide, Cochrane Library, WHOLIS, CINAHL, PDQ-Evidence as well as reference lists of relevant publications. Additionally, we will contact relevant organisations such as WHO and GAVI. Two authors will independently extract data from eligible studies and independently assess risk of bias by assessing the adequacy of study characteristics. The primary meta-analysis will use random effects models due to expected interstudies heterogeneity. Dichotomous data will be analysed using relative risk and continuous data using weighted mean differences (or standardised mean differences), both with 95% CIs. Discussion: The findings from this systematic review will be discussed in the context of strengthening routine childhood immunisation services, routine adolescent immunisation services and introduction of future vaccines against tuberculosis and HIV/AIDS. Study strengths: Unbiased selection of many studies conducted in different settings. This will strengthen the validity of the review results. Study limitations: Heterogeneity of the study settings of the low-income, lower-middle-income and upper-middle-income countries as well as heterogeneity in study designs.