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1.
BMC Health Serv Res ; 17(Suppl 3): 829, 2017 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-29297352

RESUMO

BACKGROUND: The Doris Duke Charitable Foundation's African Health Initiative supported the implementation of Population Health Implementation and Training (PHIT) Partnership health system strengthening interventions in designated areas of five countries: Ghana, Mozambique, Rwanda, Tanzania, and Zambia. All PHIT programs included health system strengthening interventions with child health outcomes from the outset, but all increasingly recognized the need to increase focus to improve health and outcomes in the first month of life. This paper uses a case study approach to describe interventions implemented in newborn health, compare approaches, and identify lessons learned across the programs' collective implementation experience. METHODS: Case studies were built using quantitative and qualitative methods, applying the World Health Organization Health Systems Strengthening Framework, and maternal, newborn and child health continuum of care framework. We identified the following five primary themes in health systems strengthening intervention strategies used to target improvement in newborn health, which were incorporated by all PHIT projects with varying results: health service delivery at the community level (Tanzania), combining community and health facility level interventions (Zambia), participatory information feedback and clinical training (Ghana), performance review and enhancement (Mozambique), and integrated clinical and system-level improvement (Rwanda), and used individual case studies to illustrate each of these themes. RESULTS: Tanzania and Zambia included significant community-based components, including mobilization and sensitization for increased uptake of essential services, while Ghana, Mozambique, and Rwanda focused more efforts on improving the quality of services delivered once a patient enters a health facility. All countries included aspects that improved communication across levels of the health system, whether through district-wide data sharing and peer learning networks in Mozambique and Rwanda, or improved referral processes and systems in Tanzania, Zambia, and Ghana. CONCLUSION: Key lessons learned include the importance of focusing intervention components on addressing drivers of neonatal mortality across the maternal and newborn care continuum at all levels of the health system, matching efforts to improve service utilization with provision of high quality facility-based services, and the critical role of leadership to catalyze improvements in newborn health.


Assuntos
Serviços de Saúde da Criança/organização & administração , Saúde do Lactente , Gana , Pesquisa sobre Serviços de Saúde , Humanos , Recém-Nascido , Moçambique , Ruanda , Tanzânia , Zâmbia
2.
BMC Public Health ; 16: 312, 2016 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-27067003

RESUMO

BACKGROUND: A theoretically grounded formative research study was carried out to investigate behaviour related to the use of Oral Rehydration Salts (ORS) and zinc tablets. The purpose was to inform the design of the behaviour change component of the Programme for Awareness and Elimination of Diarrhoea in Lusaka Province, Zambia, which aims to reduce childhood morbidity and mortality from diarrhoeal disease. METHODS: Fourteen behaviour trials were conducted among caregivers of children under-five with diarrhoea. Caregivers were recruited from two clinics situated in rural and peri-urban Lusaka. Trials took ten days and data were captured using video, observation and repeated interviews. Additional data were collected through focus group discussions with mothers, observations in clinics and pharmacies and interviews with clinic and pharmacy staff. Findings were organised according to categories of behavioural determinants from Evo-Eco theory. RESULTS: Participants were all familiar with ORS and most knew its purpose. ORS use was motivated by symptoms of dehydration, rather than the start of a diarrhoea episode, and was stopped when the child had visibly recovered energy. Only four of 14 behaviour trial participants were observed to correctly prepare ORS. Errors were mainly associated with measurement, resulting in a solution that was too concentrated. ORS was not observed to be given to children at clinics. Although zinc was unknown in this population, it was positively received by mothers keen to learn whether zinc would work better than alternative treatments to stop diarrhoea. CONCLUSIONS: ORS was sub-optimally prepared and used at home. It was not used while waiting to be seen at a clinic. In homes, the behaviour change intervention should promote early and continued use of correctly prepared ORS. In the longer-term, these behaviours may best be encouraged by changing the product design or sachet size. Despite its unfamiliarity, this population was well disposed to the use of zinc as a treatment for diarrhoea; when zinc is new to a population, promoting zinc as a solution to stopping diarrhoea, which mothers seek, may drive initial trial. Ensuring the availability of zinc in public clinics and private pharmacies prior to commencement of any promotion activities is crucial.


Assuntos
Diarreia/terapia , Hidratação/métodos , Soluções para Reidratação/uso terapêutico , Sais/uso terapêutico , Zinco/uso terapêutico , Adolescente , Adulto , Cuidadores/psicologia , Cuidadores/estatística & dados numéricos , Pré-Escolar , Desidratação/psicologia , Desidratação/terapia , Feminino , Teoria Fundamentada , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Mães/psicologia , Mães/estatística & dados numéricos , Motivação , Farmácias , Pesquisa Qualitativa , Adulto Jovem , Zâmbia
3.
Lancet Glob Health ; 11(3): e373-e384, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36796984

RESUMO

BACKGROUND: Diarrhoeal disease is a leading cause of childhood illness and death globally, and Shigella is a major aetiological contributor for which a vaccine might soon be available. The primary objective of this study was to model the spatiotemporal variation in paediatric Shigella infection and map its predicted prevalence across low-income and middle-income countries (LMICs). METHODS: Individual participant data for Shigella positivity in stool samples were sourced from multiple LMIC-based studies of children aged 59 months or younger. Covariates included household-level and participant-level factors ascertained by study investigators and environmental and hydrometeorological variables extracted from various data products at georeferenced child locations. Multivariate models were fitted and prevalence predictions obtained by syndrome and age stratum. FINDINGS: 20 studies from 23 countries (including locations in Central America and South America, sub-Saharan Africa, and south and southeast Asia) contributed 66 563 sample results. Age, symptom status, and study design contributed most to model performance followed by temperature, wind speed, relative humidity, and soil moisture. Probability of Shigella infection exceeded 20% when both precipitation and soil moisture were above average and had a 43% peak in uncomplicated diarrhoea cases at 33°C temperatures, above which it decreased. Compared with unimproved sanitation, improved sanitation decreased the odds of Shigella infection by 19% (odds ratio [OR]=0·81 [95% CI 0·76-0·86]) and open defecation decreased them by 18% (OR=0·82 [0·76-0·88]). INTERPRETATION: The distribution of Shigella is more sensitive to climatological factors, such as temperature, than previously recognised. Conditions in much of sub-Saharan Africa are particularly propitious for Shigella transmission, although hotspots also occur in South America and Central America, the Ganges-Brahmaputra Delta, and the island of New Guinea. These findings can inform prioritisation of populations for future vaccine trials and campaigns. FUNDING: NASA, National Institutes of Health-The National Institute of Allergy and Infectious Diseases, and Bill & Melinda Gates Foundation.


Assuntos
Disenteria Bacilar , Criança , Humanos , Disenteria Bacilar/epidemiologia , Diarreia/epidemiologia , Diarreia/etiologia , África Subsaariana , Temperatura , Características da Família , Saúde Global
4.
Vaccine ; 39(31): 4266-4277, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-33965254

RESUMO

Diarrhoeal disease attributable to enterotoxigenic Escherichia coli (ETEC) causes substantial morbidity and mortality predominantly in paediatric populations in low- and middle-income countries. In addition to acute illness, there is an increasing appreciation of the long-term consequences of enteric infections, including ETEC, on childhood growth and development. Provision of potable water and sanitation and appropriate clinical care for acute illness are critical to reduce the ETEC burden. However, these interventions are not always practical and may not achieve equitable and sustainable coverage. Vaccination may be the most cost-effective and equitable means of primary prevention; however, additional data are needed to accelerate the investment and guide the decision-making process for ETEC vaccines. First, to understand and quantify the ETEC disease burden, additional data are needed on the association between ETEC infection and physical and cognitive stunting as well as delayed educational attainment. Furthermore, the role of inappropriate or inadequate antibiotic treatment of ETEC-attributable diarrhoea may contribute to the development of antimicrobial resistance (AMR) and needs further elucidation. An ETEC vaccine that mitigates acute diarrhoeal illness and minimizes the longer-term disease manifestations could have significant public health impact and be a cost-effective countermeasure. Herein we review the ETEC vaccine pipeline, led by candidates compatible with the general parameters of the Preferred Product Characteristics (PPC) recently developed by the World Health Organization. Additionally, we have developed an ETEC Vaccine Development Strategy to provide a framework to underpin priority activities for researchers, funders and vaccine manufacturers, with the goal of addressing globally unmet data needs in the areas of research, product development, and policy, as well as commercialization and delivery. The strategy also aims to guide prioritization and co-ordination of the priority activities needed to minimize the timeline to licensure and use of ETEC vaccines, especially in in low- and middle-income countries, where they are most urgently needed.


Assuntos
Escherichia coli Enterotoxigênica , Infecções por Escherichia coli , Vacinas contra Escherichia coli , Criança , Diarreia/epidemiologia , Diarreia/prevenção & controle , Infecções por Escherichia coli/prevenção & controle , Humanos , Organização Mundial da Saúde
5.
Vaccine ; 39(32): 4516-4523, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34217572

RESUMO

Two-dose killed oral cholera vaccines (OCV) are currently being used widely to control cholera. The standard dose-interval for OCV is 2 weeks; however, during emergency use of the vaccine, it may be more appropriate to use the available doses to quickly give a single dose to more people and give a delayed second dose when more vaccine becomes available. This study is an open label, randomized, phase 2 clinical trial of the vibriocidal response induced by OCV, comparing the responses when the second dose was given either 2 weeks (standard dose interval) or 6 months (extended dose interval) after the first dose. Vaccine was administered to healthy participants > 1 year of age living in the Lukanga Swamps area of Zambia. Three age cohorts (<5 years, 5-14 years, and ≥ 15 years) were randomized to the either dose-interval. The primary outcome was the vibriocidal GMT 14 days after the second dose. 156 of 172 subjects enrolled in the study were included in this analysis. The Inaba vibriocidal titers were not significantly different 14 days post dose two for a standard dose-interval GMT: 45.6 (32-64.9), as compared to the GMT 47.6 (32.6-69.3), for the extended dose-interval, (p = 0.87). However, the Ogawa vibriocidal GMTs were significantly higher 14 days post dose two for the extended-dose interval at 87.6 (58.9-130.4) compared to the standard dose-interval group at 49.7 (34.1-72.3), p = 0.04. Vibriocidal seroconversion rates (a > 4-fold rise in vibriocidal titer) were not significantly different between dose-interval groups. This study demonstrated that vibriocidal titers 14 days after a second dose when given at an extended\ dose interval were similar to the standard dose-interval. The findings suggest that a flexible dosing schedule may be considered when epidemiologically appropriate. The trial was registered at Clinical Trials.gov (NCT03373669).


Assuntos
Vacinas contra Cólera , Cólera , Administração Oral , Anticorpos Antibacterianos , Pré-Escolar , Cólera/prevenção & controle , Humanos , Zâmbia
6.
PLoS One ; 13(9): e0202889, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30192777

RESUMO

INTRODUCTION: Zambia has made substantial investments in health systems capacity, yet it remains unclear whether improved service quality improves outcomes. We investigated the association between health system capacity and use of prevention of mother-to-child HIV transmission (PMTCT) services in Zambia. MATERIALS AND METHODS: We analyzed data from two studies conducted in rural and semi-urban Lusaka Province in 2014-2015. Health system capacity, our primary exposure, was measured with a validated balanced scorecard approach. Based on WHO building blocks for health systems strengthening, we derived overall and domain-specific facility scores (range: 0-100), with higher scores indicating greater capacity. Our outcome, community-level maternal antiretroviral drug use at 12 months postpartum, was measured via self-report in a large cohort study evaluating PMTCT program impact. Associations between health systems capacity and our outcome were analyzed via linear regression. RESULTS: Among 29 facilities, median overall facility score was 72 (IQR:67-74). Median domain scores were: patient satisfaction 75 (IQR 71-78); human resources 85 (IQR:63-87); finance 50 (IQR:50-67); governance 82 (IQR:74-91); service capacity 77 (IQR:68-79); service provision 60 (IQR:52-76). Our programmatic outcome was measured from 804 HIV-infected mothers. Median community-level antiretroviral use at 12 months was 81% (IQR:69-89%). Patient satisfaction was the only domain score significantly associated with 12-month maternal antiretroviral use (ß:0.22; p = 0.02). When we excluded the human resources and finance domains, we found a positive association between composite 4-domain facility score and 12-month maternal antiretroviral use in peri-urban but not rural facilities. CONCLUSIONS: In these Zambian health facilities, patient satisfaction was positively associated with maternal antiretroviral 12 months postpartum. The association between overall health system capacity and maternal antiretroviral drug use was stronger in peri-urban versus rural facilities. Additional work is needed to guide strategic investments for improved outcomes in HIV and broader maternal-child health region-wide.


Assuntos
Atenção à Saúde , Infecções por HIV/prevenção & controle , Instalações de Saúde , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Qualidade da Assistência à Saúde , Fármacos Anti-HIV/uso terapêutico , Feminino , Humanos , Serviços de Saúde Materno-Infantil , Gravidez , População Rural , Zâmbia
7.
Am J Trop Med Hyg ; 77(6 Suppl): 282-8, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18165504

RESUMO

The African Malaria Network Trust (AMANET), whose mission is to promote capacity strengthening of African malaria research institutions, was founded in 2002 and is currently focusing on malaria vaccine development. AMANET has trained over 900 African malaria researchers at workshops relevant to clinical trials of candidate malaria vaccines that will meet scientific, ethical, and international Good Clinical Practice standards. African centers selected for developing malaria vaccines initially undergo a needs assessment, followed by filling gaps in short- and long-term training, provision of essential equipment, and infrastructure improvement. Four centers from different malaria ecoepidemiologic settings are being strengthened; two of these have been approved for carrying out malaria vaccine trials. Researchers from prospective trial sites are mentored at northern institutions undertaking Phase 1a and/or 2a trials; five researchers are undergoing doctoral training. AMANET has sponsored one successful Phase 1b trial; three more are underway. Expert site audits will precede launch of phase 2b trials. Several lessons have been learned: the building of comprehensive capacity, essential for undertaking internationally acceptable trials including their sponsorship, is complex and costly. AMANET has spent over US$ 1 million on capacity strengthening of its leading trial center. Despite the high costs, development of three other sites is underway and there are plans to develop two more sites. To succeed, genuine north-south collaboration based on mutual trust and sharing of available information and responsibilities has been essential. AMANET as a sponsor has assumed roles usually reserved for the pharmaceutical industry, yet is operating where regulatory authorities are generally weak or wanting.


Assuntos
Vacinas Antimaláricas , Malária/prevenção & controle , África , Humanos , Cooperação Internacional , Malária/parasitologia , Pesquisa
8.
Clin Vaccine Immunol ; 24(1)2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27847365

RESUMO

The role of maternal immunity, received by infants either transplacentally or orally from breast milk, in rotavirus vaccine (RV) performance is evaluated here. Breastfeeding withholding has no effect on vaccine responses, but higher levels of transplacental rotavirus-specific IgG antibody contribute to reduced vaccine seroconversion. The gaps in knowledge on the factors associated with low RV efficacy in low- and middle-income countries (LMIC) remain, and further research is needed to shed more light on these issues.


Assuntos
Imunidade Materno-Adquirida , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/administração & dosagem , Vacinas contra Rotavirus/imunologia , Anticorpos Antivirais/sangue , Países em Desenvolvimento , Humanos , Imunoglobulina G/sangue , Infecções por Rotavirus/imunologia , Resultado do Tratamento
9.
Vaccine ; 34(35): 4213-4220, 2016 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-27371102

RESUMO

BACKGROUND: Introduction of new vaccines in low- and lower middle-income countries has accelerated since Gavi, the Vaccine Alliance was established in 2000. This study sought to (i) estimate the costs of introducing pneumococcal conjugate vaccine, rotavirus vaccine and a second dose of measles vaccine in Zambia; and (ii) assess affordability of the new vaccines in relation to Gavi's co-financing and eligibility policies. METHODS: Data on 'one-time' costs of cold storage expansions, training and social mobilisation were collected from the government and development partners. A detailed economic cost study of routine immunisation based on a representative sample of 51 health facilities provided information on labour and vaccine transport costs. Gavi co-financing payments and immunisation programme costs were projected until 2022 when Zambia is expected to transition from Gavi support. The ability of Zambia to self-finance both new and traditional vaccines was assessed by comparing these with projected government health expenditures. RESULTS: 'One-time' costs of introducing the three vaccines amounted to US$ 0.28 per capita. The new vaccines increased annual immunisation programme costs by 38%, resulting in economic cost per fully immunised child of US$ 102. Co-financing payments on average increased by 10% during 2008-2017, but must increase 49% annually between 2017 and 2022. In 2014, the government spent approximately 6% of its health expenditures on immunisation. Assuming no real budget increases, immunisation would account for around 10% in 2022. Vaccines represented 1% of government, non-personnel expenditures for health in 2014, and would be 6% in 2022, assuming no real budget increases. CONCLUSION: While the introduction of new vaccines is justified by expected positive health impacts, long-term affordability will be challenging in light of the current economic climate in Zambia. The government needs to both allocate more resources to the health sector and seek efficiency gains within service provision.


Assuntos
Programas de Imunização/economia , Vacina contra Sarampo/economia , Vacinas Pneumocócicas/economia , Vacinas contra Rotavirus/economia , Criança , Custos e Análise de Custo , Humanos , Vacinas Conjugadas/economia , Zâmbia
10.
PLoS One ; 11(3): e0150100, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26974432

RESUMO

INTRODUCTION: Live attenuated oral vaccines against rotavirus (RV) have been shown to be less efficacious in children from developing countries. Reasons for this disparity are not fully understood. We assessed the role of maternal factors including breast milk RV-specific IgA, transplacentally acquired infant serum RV-specific IgG and maternal HIV status in seroconversion among Zambian infants routinely immunized with Rotarix™ (RV1). METHODS: 420 mother-child pairs were recruited at infant age 6-12 weeks in Lusaka. Clinical information and samples were collected at baseline and at one month following the second dose of RV1. Determination of breast milk RV-specific IgA and serum RV-specific IgA and IgG was done using standardized ELISA. Seroconversion was defined as a ≥ 4 fold rise in serum IgA titre from baseline to one-month post RV1 dose 2, while seropositivity of IgA was defined as serum titre ≥ 40 and antibody variables were modelled on log-base 2. Logistic regression was used to identify predictors of the odds of seroconversion. RESULTS: Baseline infant seropositivity was 25.5% (91/357). The seroconversion frequency was 60.2% (130/216). Infants who were IgA seropositive at baseline were less likely to seroconvert compared to their seronegative counterparts (P = 0.04). There was no evidence of an association between maternal HIV status and seroconversion (P = 0.25). Higher titres of breast milk rotavirus-specific IgA were associated with a lower frequency of seroconverson (Nonparametric test for trend Z = -2.84; P<0.01): a two-fold increase in breast milk RV-specific IgA titres was associated with a 22% lower odds of seroconversion (OR = 0.80; 95% CI = 0.68-0.94; P = 0.01). There was seasonal variation in baseline breast milk rotavirus-specific IgA titres, with significantly higher GMTs during the cold dry months (P = 0.01). CONCLUSION: Low immunogenicity of RV1 vaccine could be explained in part by exposure to high antibody titres in breast milk and early exposure to wild-type rotavirus infections. Potential interference of anti-RV specific IgA in breast milk and pre-vaccination serum RV specific-IgA and IgG titres with RV1 seroconversion and effectiveness requires further research.


Assuntos
Anticorpos Antivirais/imunologia , Aleitamento Materno , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/administração & dosagem , Anticorpos Antivirais/sangue , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Lactente , Recém-Nascido , Masculino , Infecções por Rotavirus/sangue , Infecções por Rotavirus/imunologia , Vacinas Atenuadas/administração & dosagem , Zâmbia
11.
Vaccine ; 34(38): 4536-4542, 2016 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-27477844

RESUMO

BACKGROUND: GMZ2 is a recombinant protein malaria vaccine, comprising two blood-stage antigens of Plasmodium falciparum, glutamate-rich protein and merozoite surface protein 3. We assessed efficacy of GMZ2 in children in Burkina Faso, Gabon, Ghana and Uganda. METHODS: Children 12-60months old were randomized to receive three injections of either 100µg GMZ2 adjuvanted with aluminum hydroxide or a control vaccine (rabies) four weeks apart and were followed up for six months to measure the incidence of malaria defined as fever or history of fever and a parasite density ⩾5000/µL. RESULTS: A cohort of 1849 children were randomized, 1735 received three doses of vaccine (868 GMZ2, 867 control-vaccine). There were 641 malaria episodes in the GMZ2/Alum group and 720 in the control group. In the ATP analysis, vaccine efficacy (VE), adjusted for age and site was 14% (95% confidence interval [CI]: 3.6%, 23%, p-value=0.009). In the ITT analysis, age-adjusted VE was 11.3% (95% CI 2.5%, 19%, p-value=0.013). VE was higher in older children. In GMZ2-vaccinated children, the incidence of malaria decreased with increasing vaccine-induced anti-GMZ2 IgG concentration. There were 32 cases of severe malaria (18 in the rabies vaccine group and 14 in the GMZ2 group), VE 27% (95% CI -44%, 63%). CONCLUSIONS: GMZ2 is the first blood-stage malaria vaccine to be evaluated in a large multicenter trial. GMZ2 was well tolerated and immunogenic, and reduced the incidence of malaria, but efficacy would need to be substantially improved, using a more immunogenic formulation, for the vaccine to have a public health role.


Assuntos
Antígenos de Protozoários/imunologia , Vacinas Antimaláricas/imunologia , Malária Falciparum/prevenção & controle , Proteínas de Protozoários/imunologia , Adjuvantes Imunológicos/administração & dosagem , Hidróxido de Alumínio/administração & dosagem , Anticorpos Antiprotozoários/sangue , Burkina Faso , Pré-Escolar , Feminino , Gabão , Gana , Humanos , Imunoglobulina G/sangue , Lactente , Masculino , Plasmodium falciparum , Proteínas Recombinantes de Fusão/imunologia , Uganda
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