The burden of typhoid fever in low- and middle-income countries: A meta-regression approach

Abstract

BackgroundUpcoming vaccination efforts against typhoid fever require an assessment of the baseline burden of disease in countries at risk. There are no typhoid incidence data from most low- and middle-income countries (LMICs), so model-based estimates offer insights for decision-makers in the absence of readily available data.MethodsWe developed a mixed-effects model fit to data from 32 population-based studies of typhoid incidence in 22 locations in 14 countries. We tested the contribution of economic and environmental indices for predicting typhoid incidence using a stochastic search variable selection algorithm. We performed out-of-sample validation to assess the predictive performance of the model.ResultsWe estimated that 17.8 million cases of typhoid fever occur each year in LMICs (95% credible interval: 6.9–48.4 million). Central Africa was predicted to experience the highest incidence of typhoid, followed by select countries in Central, South, and Southeast Asia. Incidence typically peaked in the 2–4 year old age group. Models incorporating widely available economic and environmental indicators were found to describe incidence better than null models.ConclusionsRecent estimates of typhoid burden may under-estimate the number of cases and magnitude of uncertainty in typhoid incidence. Our analysis permits prediction of overall as well as age-specific incidence of typhoid fever in LMICs, and incorporates uncertainty around the model structure and estimates of the predictors. Future studies are needed to further validate and refine model predictions and better understand year-to-year variation in cases.

Small alarmones (p)ppGpp regulate virulence associated traits and pathogenesis ofSalmonella entericaserovar Typhi

“…The global burden of typhoid is increasing, with 26.9 million new infections and more than 200,000 deaths reported annually (Antillon et al, 2017). Nearly 1% of the infected individuals eventually become asymptomatic carriers, who serve as the major reservoir of infection and shed the bacteria in the stool.…”

Dengue coinfection in a case of enteric fever: a diagnostic and therapeutic dilemma

“…11 On the other hand, 17.8 million cases of typhoid fever occur each year in Low and Middle Income Countries (LMICs). 12 In Bangladesh, the incidence of typhoid fever was 3.9 and 2.0 episodes/1,000 person-years in an urban slum in 2000-2001 13 and 2003-2004 14 , respectively. On the other hand, since 2000, regular outbreaks of dengue occur in Bangladesh.…”

Functional analysis of Salmonella Typhi adaptation to survival in water

“…Water is of particular importance to the transmission of S. enterica serovar Typhi (S. Typhi), the aetiological agent of typhoid fever. Typhoid fever remains a significant cause of mortality and morbidity in low income countries, principally in Africa and Southeast and South Asia, with an estimated 20.6 million annual cases resulting in approximately 200,000 deaths (Buckle et al, 2012;Antillon et al, 2017;Kassebaum et al, 2017;Kim et al, 2017;Marks et al, 2017). The emergence and worldwide spread of multidrug resistant (MDR) S. Typhi, in part driven by the global spread of the H58 haplotype, has created enormous challenges for typhoid therapy and disease control in general (Wong et al, 2015;Klemm et al, 2018).…”