Cost-effectiveness and public health impact of typhoid conjugate vaccine introduction strategies in Bangladesh.

PURPOSE: Typhoid fever causes substantial morbidity and mortality in Bangladesh. The government of Bangladesh plans to introduce typhoid conjugate vaccines (TCV) in its expanded program on immunization (EPI) schedule. However, the optimal introduction strategy in addition to the costs and benefits of such a program are unclear. METHODS: We extended an existing mathematical model of typhoid transmission to integrate cost data, clinical incidence data, and recently conducted serosurveys in urban, semi-urban, and rural areas. In our primary analysis, we evaluated the status quo (i.e., no vaccination) and eight vaccine introduction strategies including routine and 1-time campaign strategies, which differed by age groups targeted and geographic focus. Model outcomes included clinical incidence, seroincidence, deaths, costs, disability-adjusted life years (DALYs), and incremental cost-effectiveness ratios (ICERs) for each strategy. We adopted a societal perspective, 10-year model time horizon, and 3 % annual discount rate. We performed probabilistic, one-way, and scenario sensitivity analyses including adopting a healthcare perspective and alternate model time horizons. RESULTS: We projected that all TCV strategies would be cost saving compared to the status quo. The preferred strategy was a nationwide introduction of TCV at 9-12 months of age with a single catch-up campaign for children ages 1-15, which was cost saving compared to all other strategies and the status quo. In the 10 years following implementation, we projected this strategy would avert 3.77 million cases (95 % CrI: 2.60 - 5.18), 11.31 thousand deaths (95 % CrI: 3.77 - 23.60), and save $172.35 million (95 % CrI: -14.29 - 460.59) compared to the status quo. Our findings were broadly robust to changes in parameter values and willingness-to-pay thresholds. CONCLUSIONS: We projected that nationwide TCV introduction with a catch-up campaign would substantially reduce typhoid incidence and very likely be cost saving in Bangladesh.

Community-based asthma assessment in young children: adaptations for a multicentre longitudinal study in South Asia.

Background: Systematic assessment of childhood asthma is challenging in low- and middle-income country (LMIC) settings due to the lack of standardised and validated methodologies. We describe the contextual challenges and adaptation strategies in the implementation of a community-based asthma assessment in four resource-constrained settings in Bangladesh, India, and Pakistan. Method: We followed a group of children of age 6-8 years for 12 months to record their respiratory health outcomes. The study participants were enrolled at four study sites of the 'Aetiology of Neonatal Infection in South Asia (ANISA)' study. We standardised the research methods for the sites, trained field staff for uniform data collection and provided a 'Child Card' to the caregiver to record the illness history of the participants. We visited the children on three different occasions to collect data on respiratory-related illnesses. The lung function of the children was assessed in the outreach clinics using portable spirometers before and after 6-minute exercise, and capillary blood was examined under light microscopes to determine eosinophil levels. Results: We enrolled 1512 children, 95.5% (1476/1512) of them completed the follow-up, and 81.5% (1232/1512) participants attended the lung function assessment tests. Pre- and post-exercise spirometry was performed successfully in 88.6% (1091/1232) and 85.7% (1056/1232) of children who attempted these tests. Limited access to health care services, shortage of skilled human resources, and cultural diversity were the main challenges in adopting uniform procedures across all sites. Designing the study implementation plan based on the local contexts and providing extensive training of the healthcare workers helped us to overcome these challenges. Conclusion: This study can be seen as a large-scale feasibility assessment of applying spirometry and exercise challenge tests in community settings of LMICs and provides confidence to build capacity to evaluate children's respiratory outcomes in future translational research studies.

Ensuring the global COVID-19 vaccine equity: Universal vaccine access strategy in the context of low and-middle-income countries.

ABSTRACTLockdowns and other COVID-19 containment measures enforced to kerb the pandemic have had a massive impact on the overall growth of the world. Income-generating activities have been reduced, but the impact is more consequential among the low- and middle-income countries. The disproportionate access to vaccines between wealthy and poor countries has resulted in 'vaccine apartheid.' An 'every-country-for-itself' approach or 'vaccine nationalism' coupled with 'vaccine hesitancy' has contributed to disproportionate access to and uptake of the COVID-19 vaccines. This paper argues that it is time for the decision-makers to adopt a Universal Vaccine Access Strategy (UVAS). The authors argue that sharing resources by establishing local production of vaccines wherever possible, timely donation of unused COVID-19 vaccines to developing countries and addressing vaccine hesitancy have become imperative to interrupt the emergence of new variants.

Invasive Bacterial Vaccine-Preventable Disease Surveillance: Successes and Lessons Learned in Bangladesh for a Sustainable Path Forward.

We have made considerable progress in setting and scaling up surveillance systems to drive evidence-based policy decisions, but the recent epidemics highlight that current systems are not optimally designed. Good surveillance systems should be coordinated, comprehensive, and adaptive. They should generate data in real time for immediate analysis and intervention, whether for endemic diseases or potential epidemics. Such systems are especially needed in low-resource settings where disease burden is the highest, but tracking systems are the weakest here due to competing priorities and constraints on available resources. In this article, using the examples of 3 large, and mostly successful, infectious disease surveillance studies in Bangladesh, we identify 2 core limitations-the pathogen bias and the vaccine bias-in the way current surveillance programs are designed for low-resource settings. We highlight the strengths of the current Global Invasive Bacterial Vaccine Preventable Disease Surveillance Network of the World Health Organization and present case studies from Bangladesh to illustrate how this surveillance platform can be leveraged to overcome its limitations. Finally, we propose a set of criteria for building a comprehensive infectious disease surveillance system with the hope of encouraging current systems to use the limited resources as optimally as possible to generate the maximum amount of knowledge.

Addressing power asymmetries in global health: Imperatives in the wake of the COVID-19 pandemic.

Seye Abimbola and co-authors argue for a transformation in global health research and practice in the post-COVID-19 world.

Epidemiology of Otitis Media With Otorrhea Among Bangladeshi Children: Baseline Study for Future Assessment of Pneumococcal Conjugate Vaccine Impact.

BACKGROUND: Otitis media (OM) poses a high disease burden on Bangladeshi children, but little is known about its etiologies. We conducted a surveillance study in the largest pediatric hospital to characterize pathogens responsible for OM. METHODS: In the outpatient ear-nose-throat department of Dhaka Shishu Hospital, which serves 0 to 18-year-old children, we collected ear swabs from OM children with otorrhea from April 2014 to March 2015. We cultured all specimens for bacterial pathogens and assessed serotype and antimicrobial susceptibility of Streptococcus pneumoniae (Spn) and Haemophilus influenzae (Hi) isolates. RESULTS: We recorded 1111 OM episodes; 88% (981/1111) involved otorrhea, and we collected samples from 91% (891/981) of these children. Fifty-one percent (452/891) were culture positive (contaminants excluded), with Hi (21%, 187/891) and Spn (18%, 164/891) most commonly detected. Overall, 45 distinct single and mixed pathogens were revealed. Dominant pneumococcal serotypes were 19A, 19F, 3 and 14; 98% of Hi isolates were nontypeable. Pneumococcal conjugate vaccine (PCV)10 and PCV10 + 6A serotypes accounted for 8% and 9% of all OM and 46% and 49% of pneumococcus-positive cases, respectively, and were more likely to be nonsusceptible to at least 1 antibiotic (erythromycin and/or trimethoprim-sulfamethoxazole) than nonvaccine serotypes (91% vs. 77%). Staphylococcus aureus (9%, 83/891) and Pseudomonas aeruginosa (4%, 38/891) were also found. CONCLUSIONS: Nontypeable Hi (NTHi) and Spn are predominant causes of OM in Bangladesh. PCV10, introduced in March 2015, is likely to reduce pneumococcal and overall OM burden. Data collected post-PCV10 will provide comprehensive insight into the effects of this vaccine on these pathogens.

Integration of enteric fever surveillance into the WHO-coordinated Invasive Bacterial-Vaccine Preventable Diseases (IB-VPD) platform: A low cost approach to track an increasingly important disease.

BACKGROUND: Lack of surveillance systems and accurate data impede evidence-based decisions on treatment and prevention of enteric fever, caused by Salmonella Typhi/Paratyphi. The WHO coordinates a global Invasive Bacterial-Vaccine Preventable Diseases (IB-VPD) surveillance network but does not monitor enteric fever. We evaluated the feasibility and sustainability of integrating enteric fever surveillance into the ongoing IB-VPD platform. METHODOLOGIES: The IB-VPD surveillance system uses WHO definitions to enroll 2-59 month children hospitalized with possible pneumonia, sepsis or meningitis. We expanded this surveillance system to additionally capture suspect enteric fever cases during 2012-2016, in two WHO sentinel hospitals of Bangladesh, by adding inclusion criteria of fever ≥102°F for ≥3 days, irrespective of other manifestations. Culture-positive enteric fever cases from in-patient departments (IPD) detected in the hospital laboratories but missed by the expanded surveillance, were also enrolled to assess completion. Costs for this integration were calculated for the additional personnel and resources required. PRINCIPAL FINDINGS: In the IB-VPD surveillance, 5,185 cases were enrolled; 3% (N = 171/5185) were positive for microbiological growth, of which 55% (94/171) were culture-confirmed cases of enteric fever (85 Typhi and 9 Paratyphi A). The added inclusion criteria for enteric fever enrolled an additional 1,699 cases; 22% (358/1699) were positive, of which 85% (349/358) were enteric fever cases (305 Typhi and 44 Paratyphi A). Laboratory surveillance of in-patients of all ages enrolled 311 additional enteric fever cases (263 Typhi and 48 Paratyphi A); 9% (28/311) were 2-59 m and 91% (283/311) >59 m. Altogether, 754 (94+349+311) culture-confirmed enteric fever cases were found, of which 471 were 2-59 m. Of these 471 cases, 94% (443/471) were identified through the hospital surveillances and 6% (28/471) through laboratory results. Twenty-three percent (170/754) of all cases were children <2 years. Additional cost for the integration was USD 44,974/year, a 27% increase to the IB-VPD annual expenditure. CONCLUSION: In a setting where enteric disease is a substantial public health problem, we could integrate enteric fever surveillance into the standard IB-VPD surveillance platform at a modest cost.