Cost of illness due to typhoid fever in five Asian countries

The cost of typhoid illness in low- and middle-income countries, a scoping review of the literature

Typhoid fever is responsible for a substantial health burden in low- and middle-income countries (LMICs). New means of prevention became available with the prequalification of typhoid conjugate vaccines (TCV) by the World Health Organization (WHO) in 2018. Policymakers require evidence to inform decisions about TCV. The economic burden related to typhoid fever can be considerable, both for healthcare providers and households, and should be accounted for in the decision-making process. We aimed to understand the breadth of the evidence on the cost of typhoid fever by undertaking a scoping review of the published literature. We searched scientific databases with terms referring to typhoid fever cost of illness to identify published studies for the period January 1st 2000 to May 24th 2024. We also conferred with stakeholders engaged in typhoid research to identify studies pending completion or publication. We identified 13 published studies reporting empirical data for 11 countries, most of them located in Asia. The total cost of a typhoid episode ranged from $23 in India to $884 in Indonesia (current 2022 United States Dollar [USD]). Household expenditures related to typhoid fever were characterized as catastrophic in 9 studies. We identified 5 studies pending completion or publication, which will provide evidence for 9 countries, most of them located in Africa. Alignment in study characteristics and methods would increase the usefulness of the evidence generated and facilitate cross-country and regional comparison. The gap in evidence across regions should be mitigated when studies undertaken in African countries are published. There remains a lack of evidence on the cost to treat typhoid in the context of increasing antimicrobial resistance. Decision-makers should consider the available evidence on the economic burden of typhoid, particularly as risk factors related to antimicrobial resistance and climate change increase typhoid risk. Additional studies should address typhoid illness costs, using standardized methods and accounting for the costs of antimicrobial resistance.

Typhoid Control in an Era of Antimicrobial Resistance: Challenges and Opportunities

Historically, typhoid control has been achieved with water and sanitation interventions. Today, in an era of rising antimicrobial resistance (AMR), two World Health Organization-prequalified vaccines are available to accelerate control in the shorter term. Meanwhile, water and sanitation interventions could be implemented in the longer term to sustainably prevent typhoid in low- and middle-income countries. This article first approaches typhoid control from a historical perspective, subsequently presents how vaccination could complement water and sanitation activities, and finally discusses the challenges and opportunities for impactful control of typhoid infection. It also addresses data blind spots and knowledge gaps to focus on for typhoid control and to ultimately progress towards elimination. This article presents a synthesis of discussions held in December 2021 during a roundtable session at the "12th International Conference on Typhoid and Other Invasive Salmonelloses".

Comparison of model predictions of typhoid conjugate vaccine public health impact and cost-effectiveness

Models are useful to inform policy decisions on typhoid conjugate vaccine (TCV) deployment in endemic settings. However, methodological choices can influence model-predicted outcomes. To provide robust estimates for the potential public health impact of TCVs that account for structural model differences, we compared four dynamic and one static mathematical model of typhoid transmission and vaccine impact. All models were fitted to a common dataset of age-specific typhoid fever cases in Kolkata, India. We evaluated three TCV strategies: no vaccination, routine vaccination at 9 months of age, and routine vaccination at 9 months with a one-time catch-up campaign (ages 9 months to 15 years). The primary outcome was the predicted percent reduction in symptomatic typhoid cases over 10 years after vaccine introduction. For three models with economic analyses (Models A-C), we also compared the incremental cost-effectiveness ratios (ICERs), calculated as the incremental cost (US$) per disability-adjusted life-year (DALY) averted. Routine vaccination was predicted to reduce symptomatic cases by 10-46 % over a 10-year time horizon under an optimistic scenario (95 % initial vaccine efficacy and 19-year mean duration of protection), and by 2-16 % under a pessimistic scenario (82 % initial efficacy and 6-year mean protection). Adding a catch-up campaign predicted a reduction in incidence of 36-90 % and 6-35 % in the optimistic and pessimistic scenarios, respectively. Vaccine impact was predicted to decrease as the relative contribution of chronic carriers to transmission increased. Models A-C all predicted routine vaccination with or without a catch-up campaign to be cost-effective compared to no vaccination, with ICERs varying from $95-789 per DALY averted; two models predicted the ICER of routine vaccination alone to be greater than with the addition of catch-up campaign. Despite differences in model-predicted vaccine impact and cost-effectiveness, routine vaccination plus a catch-up campaign is likely to be impactful and cost-effective in high incidence settings such as Kolkata.

Estimating the economic burden of typhoid in children and adults in Blantyre, Malawi: A costing cohort study

BACKGROUND

Typhoid causes preventable death and disease. The World Health Organization recommends Typhoid Conjugate Vaccine for endemic countries, but introduction decisions depend on cost-effectiveness. We estimated household and healthcare economic burdens of typhoid in Blantyre, Malawi.

METHODS

In a prospective cohort of culture-confirmed typhoid cases at two primary- and a referral-level health facility, we collected direct medical, non-medical costs (2020 U.S. dollars) to healthcare provider, plus indirect costs to households.

RESULTS

From July 2019-March 2020, of 109 cases, 63 (58%) were <15 years old, 44 (40%) were inpatients. Mean hospitalization length was 7.7 days (SD 4.1). For inpatients, mean total household and provider costs were $93.85 (95%CI: 68.87-118.84) and $296.52 (95%CI: 225.79-367.25), respectively. For outpatients, these costs were $19.05 (95%CI: 4.38-33.71) and $39.65 (95%CI: 33.93-45.39), respectively. Household costs were due mainly to direct non-medical and indirect costs, medical care was free. Catastrophic illness cost, defined as cost >40% of non-food monthly household expenditure, occurred in 48 (44%) households.

CONCLUSIONS

Typhoid can be economically catastrophic for families, despite accessible free medical care. Typhoid is costly for government healthcare provision. These data make an economic case for TCV introduction in Malawi and the region and will be used to derive vaccine cost-effectiveness.

Cost of Illness Due to Severe Enteric Fever in India

BACKGROUND

Lack of robust data on economic burden due to enteric fever in India has made decision making on typhoid vaccination a challenge. Surveillance for Enteric Fever network was established to address gaps in typhoid disease and economic burden.

METHODS

Patients hospitalized with blood culture-confirmed enteric fever and nontraumatic ileal perforation were identified at 14 hospitals. These sites represent urban referral hospitals (tier 3) and smaller hospitals in urban slums, remote rural, and tribal settings (tier 2). Cost of illness and productivity loss data from onset to 28 days after discharge from hospital were collected using a structured questionnaire. The direct and indirect costs of an illness episode were analyzed by type of setting.

RESULTS

In total, 274 patients from tier 2 surveillance, 891 patients from tier 3 surveillance, and 110 ileal perforation patients provided the cost of illness data. The mean direct cost of severe enteric fever was US$119.1 (95% confidence interval [CI], US$85.8-152.4) in tier 2 and US$405.7 (95% CI, 366.9-444.4) in tier 3; 16.9% of patients in tier 3 experienced catastrophic expenditure.

CONCLUSIONS

The cost of treating enteric fever is considerable and likely to increase with emerging antimicrobial resistance. Equitable preventive strategies are urgently needed.

Methodological Considerations for Cost of Illness Studies of Enteric Fever

This article presents a selection of practical issues, questions, and tradeoffs in methodological choices to consider when conducting a cost of illness (COI) study on enteric fever in low- to lower-middle-income countries. The experiences presented are based on 2 large-scale COI studies embedded within the Surveillance for Enteric Fever in Asia Project II (SEAP II), in Bangladesh, Nepal, and Pakistan; and the Severe Typhoid Fever Surveillance in Africa (SETA) Program in Burkina Faso, Ethiopia, Ghana, and Madagascar. Issues presented include study design choices such as controlling for background patient morbidity and healthcare costs, time points for follow-up, data collection methods for sensitive income and spending information, estimating enteric fever-specific health facility cost information, and analytic approaches in combining patient and health facility costs. The article highlights the potential tradeoffs in time, budget, and precision of results to assist those commissioning, conducting, and interpreting enteric fever COI studies.

Typhoid and Paratyphoid Cost of Illness in Bangladesh: Patient and Health Facility Costs From the Surveillance for Enteric Fever in Asia Project II

BACKGROUND

We conducted a cost of illness study to assess the economic burden of pediatric enteric fever (typhoid and paratyphoid) in Bangladesh. Results can inform public health policies to prevent enteric fever.

METHODS

The study was conducted at 2 pediatric health facilities in Dhaka. For the patient and caregiver's perspective, we administered questionnaires on costs incurred from illness onset until the survey dates to caregivers of patients with blood culture positive cases at enrollment and 6 weeks later to estimate the direct medical, direct nonmedical, and indirect costs. From the perspective of the health care provider, we collected data on quantities and prices of resources used by the 2 hospitals to estimate the direct medical economic costs to treat a case of enteric fever. We collected costs in Bangladeshi takas and converted them into 2018 US dollars. We multiplied the unit cost per procedure by the frequency of procedures in the surveillance case cohort to calculate the average cost per case.

RESULTS

Among the 1772 patients from whom we collected information, the median cost of illness per case of enteric fever from the patient and caregiver perspective was US $64.03 (IQR: US $33.90 -$173.48). Median direct medical and nonmedical costs per case were 3% of annual labor income across the sample. From the perspective of the healthcare provider, the average direct medical cost per case was US $58.64 (range: US $37.25 at Hospital B, US $73.27 at Hospital A).

CONCLUSIONS

Our results show substantial economic burden of enteric fever in Bangladesh, with higher costs for patients receiving inpatient care. As antimicrobial resistance increases globally, the cost of illness could increase, due to more expensive and potent drugs required for treatment.

Typhoid and Paratyphoid Cost of Illness in Pakistan: Patient and Health Facility Costs From the Surveillance for Enteric Fever in Asia Project II

BACKGROUND

The objective of this study was to estimate the cost of illness from enteric fever (typhoid and paratyphoid) at selected sites in Pakistan.

METHODS

We implemented a cost-of-illness study in 4 hospitals as part of the Surveillance for Enteric Fever in Asia Project (SEAP) II in Pakistan. From the patient and caregiver perspective, we collected direct medical, nonmedical, and indirect costs per case of enteric fever incurred since illness onset by phone after enrollment and 6 weeks later. From the health care provider perspective, we collected data on quantities and prices of resources used at 3 of the hospitals, to estimate the direct medical economic costs to treat a case of enteric fever. We collected costs in Pakistani rupees and converted them into 2018 US dollars. We multiplied the unit cost per procedure by the frequency of procedures in the surveillance case cohort to calculate the average cost per case.

RESULTS

We collected patient and caregiver information for 1029 patients with blood culture-confirmed enteric fever or with a nontraumatic terminal ileal perforation, with a median cost of illness per case of US $196.37 (IQR, US $72.89-496.40). The median direct medical and nonmedical costs represented 8.2% of the annual labor income. From the health care provider perspective, the estimated average direct medical cost per case was US $50.88 at Hospital A, US $52.24 at Hospital B, and US $11.73 at Hospital C.

CONCLUSIONS

Enteric fever can impose a considerable economic burden in Pakistan. These new estimates of the cost of illness of enteric fever can improve evaluation and modeling of the costs and benefits of enteric fever prevention and control measures, including typhoid conjugate vaccines.

Typhoid and Paratyphoid Cost of Illness in Nepal: Patient and Health Facility Costs From the Surveillance for Enteric Fever in Asia Project II

BACKGROUND

Enteric fever is endemic in Nepal and its economic burden is unknown. The objective of this study was to estimate the cost of illness due to enteric fever (typhoid and paratyphoid) at selected sites in Nepal.

METHODS

We implemented a study at 2 hospitals in Nepal to estimate the cost per case of enteric fever from the perspectives of patients, caregivers, and healthcare providers. We collected direct medical, nonmedical, and indirect costs per blood culture-confirmed case incurred by patients and their caregivers from illness onset until after enrollment and 6 weeks later. We estimated healthcare provider direct medical economic costs based on quantities and prices of resources used to diagnose and treat enteric fever, and procedure frequencies received at these facilities by enrolled patients. We collected costs in Nepalese rupees and converted them into 2018 US dollars.

RESULTS

We collected patient and caregiver cost of illness information for 395 patients, with a median cost of illness per case of $59.99 (IQR, $24.04-$151.23). Median direct medical and nonmedical costs per case represented ~3.5% of annual individual labor income. From the healthcare provider perspective, the average direct medical economic cost per case was $79.80 (range, $71.54 [hospital B], $93.43 [hospital A]).

CONCLUSIONS

Enteric fever can impose a considerable economic burden on patients, caregivers, and health facilities in Nepal. These new estimates of enteric fever cost of illness can improve evaluation and modeling of the costs and benefits of enteric fever-prevention measures.

A Multicenter Cost-of-Illness and Long-term Socioeconomic Follow-up Study in the Severe Typhoid Fever in Africa Program: Study Protocol

Background

There are limited data on typhoid fever cost of illness (COI) and economic impact from Africa. Health economic data are essential for measuring the cost-effectiveness of vaccination or other disease control interventions. Here, we describe the protocol and methods for conducting the health economic studies under the Severe Typhoid Fever in Africa (SETA) program.

Methods

The SETA health economic studies will rely on the platform for SETA typhoid surveillance in 4 African countries—Burkina Faso, Ethiopia, Ghana, and Madagascar. A COI and long-term socioeconomic study (LT-SES) will be its components. The COI will be assessed among blood culture–positive typhoid fever cases, blood culture–negative clinically suspected cases (clinical cases), and typhoid fever cases with pathognomonic gastrointestinal perforations (special cases). Repeated surveys using pretested questionnaires will be used to measure out-of-pocket expenses, quality of life, and the long-term socioeconomic impact. The cost of resources consumed for diagnosis and treatment will be collected at health facilities.

Results

Results from these studies will be published in peer-reviewed journals and presented at scientific conferences to make the data available to the wider health economics and public health research communities.

Conclusions

The health economic data will be analyzed to estimate the average cost per case, the quality of life at different stages of illness, financial stress due to illness, and the burden on the family due to caregiving during illness. The data generated are expected to be used in economic analysis and policy making on typhoid control interventions in sub-Saharan Africa.

A Review of the Economic Evidence of Typhoid Fever and Typhoid Vaccines

Typhoid places a substantial economic burden on low- and middle-income countries. We performed a literature review and critical overview of typhoid-related economic issues to inform vaccine introduction. We searched 4 literature databases, covering 2000–2017, to identify typhoid-related cost-of-illness (COI) studies, cost-of-delivery studies, cost-effectiveness analyses (CEAs), and demand forecast studies. Manual bibliographic searches of reviews revealed studies in the gray literature. Planned studies were identified in conference proceedings and through partner organization outreach. We identified 29 published, unpublished, and planned studies. Published COI studies revealed a substantial burden in Asia, with hospitalization costs alone ranging from $159 to $636 (in 2016 US$) in India, but there was less evidence for the burden in Africa. Cost-of-delivery studies are largely unpublished, but 1 study found that $671 000 in government investments would avert $60 000 in public treatment costs. CEA evidence was limited, but generally found targeted vaccination programs to be cost-effective. This review revealed insufficient economic evidence for vaccine introduction. Countries considering vaccine introduction should have access to relevant economic evidence to aid in decision-making and planning. Planned studies will fill many of the existing gaps in the literature.

Costing of Febrile Illness among Under Five Children, A Study in a Tertiary Care Teaching Hospital in Odisha, India

Objective

The objective of this study was to determine the cost of treatment, both direct and indirect costs, of febrile illness among under-five children in Odisha, India.

Methods

This was a cross-sectional study of thirty under-five children with febrile illness reporting to the pediatric outpatient (OP) department and thirty more under-five children admitted to the pediatric ward who were included in the study during January-April 2018. The parents/caretakers of the ailing children were interviewed using the WHO questionnaire contextualized to the local situation. Both direct (medicine, diagnostics, registration/doctor's fees, bed charges, and cost of personal medical appliances) and indirect (transportation, food, loss of income, and lodging) costs of febrile illness and pre-, during, and posthospital visit cost were estimated.

Results

The median direct and indirect costs for OP cases were Rs. 1201.00 and Rs. 1375.00, respectively. For the hospitalization (indoor patients), direct and indirect costs were Rs. 7015.00 and Rs. 5190.00, respectively. People also spent money in pre-, during, and posthospital visits for the same episode of febrile illness. Only four OP cases had some kind of medical insurance.

Conclusion

High expenditure on both OP and indoor patients calls for appropriate policy for provision of financial protection while seeking health-care services. Health facilities should be tuned to do cost analysis enabling comparison among health facilities.

Generating the Evidence for Typhoid Vaccine Introduction: Considerations for Global Disease Burden Estimates and Vaccine Testing Through Human Challenge

Typhoid fever has had a major impact on human populations, with the causative pathogen Salmonella enterica serovar Typhi implicated in many outbreaks through history. The current burden of disease is estimated at 11-18 million infections annually, with the majority of infections located in Africa and South Asia. Data that have been used to estimate burden are limited to a small number of blood-culture surveillance studies, largely from densely populated urban centers. Extrapolating these data to estimate disease burden within and across countries highlights the lack of precision in global figures. A number of approaches have been developed, characterizing different geographical areas by water-based risk factors for typhoid infection or broader measures of health and development to more accurately extrapolate incidence. Recognition of the substantial disease burden is essential for policy-makers considering vaccine introduction. Typhoid vaccines have been in development for >100 years. The Vi polysaccharide (ViPS) and Ty21a vaccines have had a World Health Organization (WHO) recommendation for programmatic use in countries with high burden for 10 years, with 1 ViPS vaccine also having WHO prequalification. Despite this, uptake and introduction of these vaccines has been minimal. The development of a controlled human infection model (CHIM) enabled the accelerated testing of the newly WHO-prequalified ViPS-tetanus toxoid protein conjugate vaccine, providing efficacy estimates for the vaccine, prior to larger field trials. There is an urgency to the global control of enteric fever due to the escalating problem of antimicrobial resistance. With more accurate burden of disease estimates and a vaccine showing efficacy in CHIM, that control is now a possibility.

Comparison of Strategies and Incidence Thresholds for Vi Conjugate Vaccines Against Typhoid Fever: A Cost-effectiveness Modeling Study

Background

Typhoid fever remains a major public health problem globally. While new Vi conjugate vaccines hold promise for averting disease, the optimal programmatic delivery remains unclear. We aimed to identify the strategies and associated epidemiologic conditions under which Vi conjugate vaccines would be cost-effective.

Methods

We developed a dynamic, age-structured transmission and cost-effectiveness model that simulated multiple vaccination strategies with a typhoid Vi conjugate vaccine from a societal perspective. We simulated 10-year vaccination programs with (1) routine immunization of infants (aged <1 year) through the Expanded Program on Immunization (EPI) and (2) routine immunization of infants through the EPI plus a 1-time catch-up campaign in school-aged children (aged 5–14 years). In the base case analysis, we assumed a 0.5% case-fatality rate for all cases of clinically symptomatic typhoid fever and defined strategies as highly cost-effective by using the definition of a low-income country (defined as a country with a gross domestic product of $1045 per capita). We defined incidence as the true number of clinically symptomatic people in the population per year.

Results

Vi conjugate typhoid vaccines were highly cost-effective when administered by routine immunization activities through the EPI in settings with an annual incidence of >50 cases/100000 (95% uncertainty interval, 40–75 cases) and when administered through the EPI plus a catch-up campaign in settings with an annual incidence of >130 cases/100000 (95% uncertainty interval, 50–395 cases). The incidence threshold was sensitive to the typhoid-related case-fatality rate, carrier contribution to transmission, vaccine characteristics, and country-specific economic threshold for cost-effectiveness.

Conclusions

Typhoid Vi conjugate vaccines would be highly cost-effective in low-income countries in settings of moderate typhoid incidence (50 cases/100000 annually). These results were sensitive to case-fatality rates, underscoring the need to consider factors contributing to typhoid mortality (eg, healthcare access and antimicrobial resistance) in the global vaccination strategy.

Cost-effectiveness of routine and campaign use of typhoid Vi-conjugate vaccine in Gavi-eligible countries: a modelling study

BACKGROUND

Typhoid fever is a major cause of morbidity and mortality in low-income and middle-income countries. In 2017, WHO recommended the programmatic use of typhoid Vi-conjugate vaccine (TCV) in endemic settings, and Gavi, The Vaccine Alliance, has pledged support for vaccine introduction in these countries. Country-level health economic evaluations are now needed to inform decision-making.

METHODS

In this modelling study, we compared four strategies: no vaccination, routine immunisation at 9 months, and routine immunisation at 9 months with catch-up campaigns to either age 5 years or 15 years. For each of the 54 countries eligible for Gavi support, output from an age-structured transmission-dynamic model was combined with country-specific treatment and vaccine-related costs, treatment outcomes, and disability weights to estimate the reduction in typhoid burden, identify the strategy that maximised average net benefit (ie, the optimal strategy) across a range of country-specific willingness-to-pay (WTP) values, estimate and investigate the uncertainties surrounding our findings, and identify the epidemiological conditions under which vaccination is optimal.

FINDINGS

The optimal strategy was either no vaccination or TCV immunisation including a catch-up campaign. Routine vaccination with a catch-up campaign to 15 years of age was optimal in 38 countries, assuming a WTP value of at least US$200 per disability-adjusted life-year (DALY) averted, or assuming a WTP value of at least 25% of each country's gross domestic product (GDP) per capita per DALY averted, at a vaccine price of $1·50 per dose (but excluding Gavi's contribution according to each country's transition phase). This vaccination strategy was also optimal in 48 countries assuming a WTP of at least $500 per DALY averted, in 51 with assumed WTP values of at least $1000, in 47 countries assuming a WTP value of at least 50% of GDP per capita per DALY averted, and in 49 assuming a minimum of 100%. Vaccination was likely to be cost-effective in countries with 300 or more typhoid cases per 100 000 person-years. Uncertainty about the probability of hospital admission (and typhoid incidence and mortality) had the greatest influence on the optimal strategy.

INTERPRETATION

Countries should establish their own WTP threshold and consider routine TCV introduction, including a catch-up campaign when vaccination is optimal on the basis of this threshold. Obtaining improved estimates of the probability of hospital admission would be valuable whenever the optimal strategy is uncertain.

FUNDING

Bill & Melinda Gates Foundation, Research Foundation-Flanders, and the Belgian-American Education Foundation.

The global burden of typhoid and paratyphoid fevers: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

Efforts to quantify the global burden of enteric fever are valuable for understanding the health lost and the large-scale spatial distribution of the disease. We present the estimates of typhoid and paratyphoid fever burden from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, and the approach taken to produce them.

METHODS

For this systematic analysis we broke down the relative contributions of typhoid and paratyphoid fevers by country, year, and age, and analysed trends in incidence and mortality. We modelled the combined incidence of typhoid and paratyphoid fevers and split these total cases proportionally between typhoid and paratyphoid fevers using aetiological proportion models. We estimated deaths using vital registration data for countries with sufficiently high data completeness and using a natural history approach for other locations. We also estimated disability-adjusted life-years (DALYs) for typhoid and paratyphoid fevers.

FINDINGS

Globally, 14·3 million (95% uncertainty interval [UI] 12·5-16·3) cases of typhoid and paratyphoid fevers occurred in 2017, a 44·6% (42·2-47·0) decline from 25·9 million (22·0-29·9) in 1990. Age-standardised incidence rates declined by 54·9% (53·4-56·5), from 439·2 (376·7-507·7) per 100 000 person-years in 1990, to 197·8 (172·0-226·2) per 100 000 person-years in 2017. In 2017, Salmonella enterica serotype Typhi caused 76·3% (71·8-80·5) of cases of enteric fever. We estimated a global case fatality of 0·95% (0·54-1·53) in 2017, with higher case fatality estimates among children and older adults, and among those living in lower-income countries. We therefore estimated 135·9 thousand (76·9-218·9) deaths from typhoid and paratyphoid fever globally in 2017, a 41·0% (33·6-48·3) decline from 230·5 thousand (131·2-372·6) in 1990. Overall, typhoid and paratyphoid fevers were responsible for 9·8 million (5·6-15·8) DALYs in 2017, down 43·0% (35·5-50·6) from 17·2 million (9·9-27·8) DALYs in 1990.

INTERPRETATION

Despite notable progress, typhoid and paratyphoid fevers remain major causes of disability and death, with billions of people likely to be exposed to the pathogens. Although improvements in water and sanitation remain essential, increased vaccine use (including with typhoid conjugate vaccines that are effective in infants and young children and protective for longer periods) and improved data and surveillance to inform vaccine rollout are likely to drive the greatest improvements in the global burden of the disease.

FUNDING

Bill & Melinda Gates Foundation.

Cost of Caregivers for Treating Hospitalized Diarrheal Patients in Bangladesh

INTRODUCTION

Diarrheal diseases are a global public health problem and one of the leading causes of mortality, morbidity and economic loss. The objective of the study is to estimate the economic cost of caregivers and cost distribution per diarrheal episodes in Bangladesh.

METHODS

This was a cross-sectional hospital-based study conducted in public hospitals in Bangladesh. A total of 801 diarrheal patients were randomly selected and interviewed during January to December 2015. Simple descriptive statistics including frequencies, percentage, mean with 95% CI and median are presented.

RESULTS

The overall average cost of caregivers was BDT 2243 (US$ 28.58) while only BDT 259 (US$ 3.29) was spent as out of pocket payments. Caregivers mostly spent money (US$ 1.63) for food, lodging, utility bills, and other lump sum costs followed by the transportation costs (US$ 1.57). The caregivers spent more (US$ 44.45) when they accompanied the patients who were admitted in inpatients care and almost 3.6 times higher than for out-patients care (US$ 12.42).

CONCLUSIONS

The study delivers an empirical evidence to the health-care programmers and policy makers about the economic cost of caregivers during diarrheal treatment care, which should be accounted for in designing future diarrheal prevention programme.

Modelling the cost-effectiveness of a rapid diagnostic test (IgMFA) for uncomplicated typhoid fever in Cambodia

Typhoid fever is a common cause of fever in Cambodian children but diagnosis and treatment are usually presumptive owing to the lack of quick and accurate tests at an initial consultation. This study aimed to evaluate the cost-effectiveness of using a rapid diagnostic test (RDT) for typhoid fever diagnosis, an immunoglobulin M lateral flow assay (IgMFA), in a remote health centre setting in Cambodia from a healthcare provider perspective. A cost-effectiveness analysis (CEA) with decision analytic modelling was conducted. We constructed a decision tree model comparing the IgMFA versus clinical diagnosis in a hypothetical cohort with 1000 children in each arm. The costs included direct medical costs only. The eligibility was children (≤14 years old) with fever. Time horizon was day seven from the initial consultation. The number of treatment success in typhoid fever cases was the primary health outcome. The number of correctly diagnosed typhoid fever cases (true-positives) was the intermediate health outcome. We obtained the incremental cost effectiveness ratio (ICER), expressed as the difference in costs divided by the difference in the number of treatment success between the two arms. Sensitivity analyses were conducted. The IgMFA detected 5.87 more true-positives than the clinical diagnosis (38.45 versus 32.59) per 1000 children and there were 3.61 more treatment successes (46.78 versus 43.17). The incremental cost of the IgMFA was estimated at $5700; therefore, the ICER to have one additional treatment success was estimated to be $1579. The key drivers for the ICER were the relative sensitivity of IgMFA versus clinical diagnosis, the cost of IgMFA, and the prevalence of typhoid fever or multi-drug resistant strains. The IgMFA was more costly but more effective than the clinical diagnosis in the base-case analysis. An IgMFA could be more cost-effective than the base-case if the sensitivity of IgMFA was higher or cost lower. Decision makers may use a willingness-to-pay threshold that considers the additional cost of hospitalisation for treatment failures.

Social and Economic Burden Associated With Typhoid Fever in Kathmandu and Surrounding Areas: A Qualitative Study

Typhoid fever is a significant contributor to infectious disease mortality and morbidity in low- and middle-income countries, particularly in South Asia. With increasing antimicrobial resistance, commonly used treatments are less effective and risks increase for complications and hospitalizations. During an episode of typhoid fever, households experience multiple social and economic costs that are often undocumented. In the current study, qualitative interview data from Kathmandu and surrounding areas provide important insights into the challenges that affect those who contract typhoid fever and their caregivers, families, and communities, as well as insight into prevention and treatment options for health providers and outreach workers. When considering typhoid fever cases confirmed by blood culture, our data reveal delays in healthcare access, financial and time costs burden on households, and the need to increase health literacy. These data also illustrate the impact of limited laboratory diagnostic equipment and tools on healthcare providers' abilities to distinguish typhoid fever from other febrile conditions and treatment challenges associated with antimicrobial resistance. In light of these findings, there is an urgent need to identify and implement effective preventive measures including vaccination policies and programs focused on at-risk populations and endemic regions such as Nepal.

Case Fatality Rate of Enteric Fever in Endemic Countries: A Systematic Review and Meta-analysis

Enteric fever is a febrile illness, occurring mostly in Asia and Africa, which can present as a severe and possibly fatal disease. Currently, a case fatality rate (CFR) of 1% is assumed when evaluating the global burden of enteric fever. Until now, no meta-analysis has been conducted to summarize mortality from enteric fever. Therefore, we conducted a systematic review and meta-analysis to aggregate all available evidence. We estimated an overall CFR of 2.49% (95% confidence interval, 1.65%-3.75%; n = 44), and a CFR in hospitalized patients of 4.45% (2.85%-6.88%; n = 21 of 44). There was considerably heterogeneity in estimates of the CFR from individual studies. Neither age nor antimicrobial resistance were significant prognostic factors, but limited data were available for these analyses. The combined estimate of the CFR for enteric fever is higher than previously estimated, and the evaluation of prognostic factors, including antimicrobial resistance, urgently requires more data.

Cost-effectiveness analysis of typhoid conjugate vaccines in five endemic low- and middle-income settings

BACKGROUND

Typhoid fever remains endemic in low- and middle-income countries. Programmatic use of existing vaccines is limited, but upcoming typhoid conjugate vaccines (TCVs) could warrant wider use. We evaluated the cost-effectiveness of five TCV delivery strategies in three urban areas (Delhi and Kolkata, India and Nairobi, Kenya) and two rural settings (Lwak, Kenya and Dong Thap, Vietnam) with varying incidence.

METHODS AND FINDINGS

We evaluated routine infant vaccination with and without catch-up campaigns among older individuals. We used a dynamic model of typhoid transmission to simulate cases, hospitalizations, deaths, disability-adjusted life-years (DALY) lost, treatment and intervention costs. We estimated cost-effectiveness (in terms of cost in international dollars (I$) per DALY averted) from the healthcare payer perspective, and assessed how it was influenced by uncertain model parameters. Compared to no vaccination, routine infant vaccination at I$1/dose was cost-saving in Delhi and Dong Thap, "very cost-effective" in Kolkata and Nairobi, and "cost-effective" in Lwak according to World Health Organization thresholds. However, routine vaccination was not the optimal strategy compared to strategies that included a catch-up campaign, which yielded the highest probability of being cost-saving in Delhi and Dong Thap and were most likely to provide a return on investment above a willingness-to-pay threshold of I$1440 in Kolkata, I$2300 in Nairobi, and I$5360 in Lwak. Vaccine price impacted the optimal strategy, and the number of doses required and rate of hospitalization were the primary sources of uncertainty.

CONCLUSION

Routine vaccination with TCV would be cost-effective in most settings, and additional one-time catch-up campaigns would also be economically justified.

Revisiting typhoid fever surveillance in low and middle income countries: lessons from systematic literature review of population-based longitudinal studies

Background

The control of typhoid fever being an important public health concern in low and middle income countries, improving typhoid surveillance will help in planning and implementing typhoid control activities such as deployment of new generation Vi conjugate typhoid vaccines.

Methods

We conducted a systematic literature review of longitudinal population-based blood culture-confirmed typhoid fever studies from low and middle income countries published from 1^st January 1990 to 31^st December 2013. We quantitatively summarized typhoid fever incidence rates and qualitatively reviewed study methodology that could have influenced rate estimates. We used meta-analysis approach based on random effects model in summarizing the hospitalization rates.

Results

Twenty-two papers presented longitudinal population-based and blood culture-confirmed typhoid fever incidence estimates from 20 distinct sites in low and middle income countries. The reported incidence and hospitalizations rates were heterogeneous as well as the study methodology across the sites. We elucidated how the incidence rates were underestimated in published studies. We summarized six categories of under-estimation biases observed in these studies and presented potential solutions.

Conclusions

Published longitudinal typhoid fever studies in low and middle income countries are geographically clustered and the methodology employed has a potential for underestimation. Future studies should account for these limitations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1351-3) contains supplementary material, which is available to authorized users.

A review of typhoid fever transmission dynamic models and economic evaluations of vaccination

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There are relatively few dynamic models or economic analyses of typhoid vaccination.

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The relative contribution of carriage to transmission is a key uncertainty.

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Published economic analyses use static models that omit indirect protection of vaccines.

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Nevertheless, vaccines appear highly cost-effective against WHO criteria in high-incidence settings.

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No economic model was found to compare vaccine and sanitation.

Despite a recommendation by the World Health Organization (WHO) that typhoid vaccines be considered for the control of endemic disease and outbreaks, programmatic use remains limited. Transmission models and economic evaluation may be informative in decision making about vaccine programme introductions and their role alongside other control measures. A literature search found few typhoid transmission models or economic evaluations relative to analyses of other infectious diseases of similar or lower health burden.

Modelling suggests vaccines alone are unlikely to eliminate endemic disease in the short to medium term without measures to reduce transmission from asymptomatic carriage. The single identified data-fitted transmission model of typhoid vaccination suggests vaccines can reduce disease burden substantially when introduced programmatically but that indirect protection depends on the relative contribution of carriage to transmission in a given setting. This is an important source of epidemiological uncertainty, alongside the extent and nature of natural immunity.

Economic evaluations suggest that typhoid vaccination can be cost-saving to health services if incidence is extremely high and cost-effective in other high-incidence situations, when compared to WHO norms. Targeting vaccination to the highest incidence age-groups is likely to improve cost-effectiveness substantially. Economic perspective and vaccine costs substantially affect estimates, with disease incidence, case-fatality rates, and vaccine efficacy over time also important determinants of cost-effectiveness and sources of uncertainty. Static economic models may under-estimate benefits of typhoid vaccination by omitting indirect protection.

Typhoid fever transmission models currently require per-setting epidemiological parameterisation to inform their use in economic evaluation, which may limit their generalisability. We found no economic evaluation based on transmission dynamic modelling, and no economic evaluation of typhoid vaccination against interventions such as improvements in sanitation or hygiene.

Willingness to pay for public health services in rural Central Java, Indonesia: methodological considerations when using the contingent valuation method

In the health sectors of low- and middle-income countries, contingent valuation method (CVM) studies on willingness to pay (WTP) have been used to gather information on demand variation or financial perspectives alongside price setting, such as the introduction of user fees and valuation of quality improvements. However, WTP found in most CVM studies have only explored the preferences that consumers express through their WTP without exploring whether they are actually able to pay for it. Therefore, this study examines the issues pertaining to WTP estimation for health services using the conventional CVM. We conducted 202 household interviews in 2008, in which we asked respondents about three types of public health services in Indonesia and assessed WTP estimated by the conventional CVM as well as in the scenario of "resorting to debt" to recognize their budget constraints. We find that all the demand curves for both WTP scenarios show gaps. Furthermore, the gap for midwife services is negatively affected by household income and is larger for the poor. These results prove that CVM studies on WTP do not always reveal WTP in the latter scenario. Those findings suggest that WTP elicited by the conventional CVM is different to that from the maximum price that prevents respondents from resorting to debt as their WTP. In order to bridge this gap in the body of knowledge on this topic, studies should improve the scenarios that CVM analyses use to explore WTP. Furthermore, because valuing or pricing health services based on the results of CVM studies on WTP alone can exacerbate the inequity of access to these services, information provided by such studies requires careful interpretation when used for this purpose, especially for the poor and vulnerable sections of society.

Prospects for prevention of Salmonella infection in children through vaccination

PURPOSE OF REVIEW

Strains of Salmonella enterica subsp. enterica are amongst the most commonly identified invasive bacterial pathogens in resource-poor settings, and cause significant mortality, particularly in children. In this study we review recent progress in the development of vaccines against S. Typhi, S. Paratyphi and nontyphoidal Salmonella for children.

RECENT FINDINGS

Typhoid remains common and S. Paratyphi A is increasingly recognized as a cause of enteric fever in Asia. In rural Africa, nontyphoidal salmonellae are among the most common invasive bacterial infections, although S. Typhi predominates in some urban centres. Licensed vaccines against typhoid have moderate but useful efficacy but neither of the two available vaccines can be used in infants. Although Ty21a may afford some cross-protection against S. Paratyphi B, there are no vaccines that specifically target paratyphoid or any nontyphoidal Salmonella. Several live attenuated vaccines are under development and may offer some advantages over Ty21a. Vi-conjugate vaccines should offer children excellent protection from typhoid once licensed.

SUMMARY

There are few effective vaccines against Salmonella sp. and those that do exist target only one serovar, S. Typhi. Research is urgently needed to combat emerging agents of enteric fever such as S. Paratyphi A as well as nontyphoidal serovars, which commonly cause invasive disease in Africa.

Vaccines for typhoid fever and other salmonelloses

PURPOSE OF REVIEW

This review summarizes the recent advances in vaccination against Salmonella enterica serovar Typhi and highlights the data supporting the development of next generation vaccines to address paratyphoid fever and invasive nontyphoidal Salmonella (iNTS) disease.

RECENT FINDINGS

There has been increasing awareness of the disease burden caused by S. Typhi particularly in Africa and greater recognition of S. Paratyphi A's contribution to enteric fever episodes throughout Asia. Groups have been working to improve the existing typhoid vaccines and provide comprehensive data on the feasibility of their implementation in endemic settings. These data have resulted in modifications to the recommendations for typhoid vaccination in traveller markets and endemic settings, and has also led to the development of S. Paratyphi A vaccine components that can be combined with existing typhoid vaccines to generate bivalent formulations against enteric fever. The epidemiology of iNTS serovars as cause of appreciable morbidity and mortality in Africa, and the need for vaccines, has also become more widely appreciated.

SUMMARY

Current typhoid vaccines, although moderately effective for short periods of time, cannot be used in all age groups and only target one of the clinically relevant Salmonella serovars. Greater effort must be placed on the development and implementation of improved vaccines for the disease burden resulting from Typhi, Paratyphi A or iNTS infections.

Costs of illness due to endemic cholera

Economic analyses of cholera immunization programmes require estimates of the costs of cholera. The Diseases of the Most Impoverished programme measured the public, provider, and patient costs of culture-confirmed cholera in four study sites with endemic cholera using a combination of hospital- and community-based studies. Families with culture-proven cases were surveyed at home 7 and 14 days after confirmation of illness. Public costs were measured at local health facilities using a micro-costing methodology. Hospital-based studies found that the costs of severe cholera were US$32 and US$47 in Matlab and Beira. Community-based studies in North Jakarta and Kolkata found that cholera cases cost between US$28 and US$206, depending on hospitalization. Patients' cost of illness as a percentage of average monthly income were 21% and 65% for hospitalized cases in Kolkata and North Jakarta, respectively. This burden on families is not captured by studies that adopt a provider perspective.

How valuable are environmental health interventions? Evaluation of water and sanitation programmes in India

OBJECTIVE

To evaluate and quantify the economic benefits attributable to improvements in water supply and sanitation in rural India.

METHODS

We combined propensity-score "pre-matching" and rich pre-post panel data on 9500 households in 242 villages located in four geographically different districts to estimate the economic benefits of a large-scale community demand-driven water supply programme in Maharashtra, India. We calculated coping costs and cost of illness by adding across several elements of coping and illness and then estimated causal impacts using a difference-in-difference strategy on the pre-matched sample. The pre-post design allowed us to use a difference-in-difference estimator to measure "treatment effect" by comparing treatment and control villages during both periods. We compared average household costs with respect to out-of-pocket medical expenses, patients' lost income, caregiving costs, time spent on collecting water, time spent on sanitation, and water treatment costs due to filtration, boiling, chemical use and storage.

FINDINGS

Three years after programme initiation, the number of households using piped water and private pit latrines had increased by 10% on average, but no changes in hygiene-related behaviour had occurred. The behavioural changes observed suggest that the average household in a programme community could save as much as 7 United States dollars per month (or 5% of monthly household cash expenditures) in coping costs, but would not reduce illness costs. Poorer, socially marginalized households benefited more, in alignment with programme objectives.

CONCLUSION

Given the renewed interest in water, sanitation and hygiene outcomes, evaluating the economic benefits of environmental interventions by means of causal research is important for understanding the true value of such interventions.