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Clinical Infectious Diseases : An... Mar 2019Contemporary incidence estimates of typhoid fever are needed to guide policy decisions and control measures and to improve future epidemiological studies. (Meta-Analysis)
Meta-Analysis
BACKGROUND
Contemporary incidence estimates of typhoid fever are needed to guide policy decisions and control measures and to improve future epidemiological studies.
METHODS
We systematically reviewed 3 databases (Ovid Medline, PubMed, and Scopus) without restriction on age, country, language, or time for studies reporting the incidence of blood culture-confirmed typhoid fever. Outbreak, travel-associated, and passive government surveillance reports were excluded. We performed a meta-analysis using a random-effects model to calculate estimates of pooled incidence, stratifying by studies that reported the incidence of typhoid fever and those that estimated incidence by using multipliers.
RESULTS
Thirty-three studies were included in the analysis. There were 26 study sites from 16 countries reporting typhoid cases from population-based incidence studies, and 17 sites in 9 countries used multipliers to account for underascertainment in sentinel surveillance data. We identified Africa and Asia as regions with studies showing high typhoid incidence while noting considerable variation of typhoid incidence in time and place, including in consecutive years at the same location. Overall, more recent studies reported lower typhoid incidence compared to years prior to 2000. We identified variation in the criteria for collecting a blood culture, and among multiplier studies we identified a lack of a standardization for the types of multipliers being used to estimate incidence.
CONCLUSIONS
Typhoid fever incidence remains high at many sites. Additional and more accurate typhoid incidence studies are needed to support country decisions about typhoid conjugate vaccine adoption. Standardization of multiplier types applied in multiplier studies is recommended.
Topics: Africa; Asia; Global Health; Humans; Incidence; Salmonella typhi; Travel; Typhoid Fever; Typhoid-Paratyphoid Vaccines
PubMed: 30845336
DOI: 10.1093/cid/ciy1094 -
BMC Medicine Sep 2020In the absence of definitive diagnosis, healthcare providers are likely to prescribe empirical antibacterials to those who test negative for malaria. This problem is of...
BACKGROUND
In the absence of definitive diagnosis, healthcare providers are likely to prescribe empirical antibacterials to those who test negative for malaria. This problem is of critical importance in Southern Asia (SA) and South-eastern Asia (SEA) where high levels of antimicrobial consumption and high prevalence of antimicrobial resistance have been reported. To improve management and guide further diagnostic test development, better understanding is needed of the true causative agents of fever and their geographical variability.
METHODS
We conducted a systematic review of published literature (1980-2015) to characterise the spectrum of pathogens causing non-malarial febrile illness in SA and SEA. We searched six databases in English and French languages: MEDLINE, EMBASE, Global Health (CABI) database, WHO Global Health Library, PASCAL, and Bulletin de la Société Française de Parasitologie (BDSP). Selection criteria included reporting on an infection or infections with a confirmed diagnosis, defined as pathogens detected in or cultured from samples from normally sterile sites, or serological evidence of current or past infection.
RESULTS
A total of 29,558 records from 19 countries in SA and SEA were screened, of which 2410 (8.1%) met the selection criteria. Bacterial aetiologies were reported in 1235 (51.2%) articles, viral in 846 (35.1%), parasitic in 132 (5.5%), and fungal in 54 (2.2%), and 143 (6.0%) articles reported more than one pathogen group. In descending order of frequency, Salmonella Typhi, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and coagulase negative Staphylococcus were the commonly reported bacteria, while dengue virus, chikungunya virus, Japanese encephalitis virus, hepatitis B virus, and hepatitis C virus were common viral pathogens reported. Reports of rarely reported or emerging pathogens included a case report of Borrelia burgdorferi (Lyme disease) in India in 2010 and reports of Nipah virus in Singapore and India.
CONCLUSIONS
This review summarises the reported non-malaria pathogens that may cause febrile illness in SA and SEA. The findings emphasise the need of standardising the reporting of aetiological studies to develop effective, evidence-based fever management and improved surveillance. Research and development of diagnostic tools would benefit from up-to-date epidemiological reporting of the regional diversities of non-malaria fever aetiologies.
TRIAL REGISTRATION
PROSPERO registration, CRD42016049281.
Topics: Asia; Asia, Southeastern; Fever; History, 20th Century; History, 21st Century; Humans; Organizational Case Studies
PubMed: 32951591
DOI: 10.1186/s12916-020-01745-0 -
Antimicrobial Resistance and Infection... 2019Despite a high mortality rate in childhood, there is limited evidence on the causes and outcomes of paediatric bloodstream infections from low- and middle-income... (Meta-Analysis)
Meta-Analysis
Bacterial pathogens and resistance causing community acquired paediatric bloodstream infections in low- and middle-income countries: a systematic review and meta-analysis.
BACKGROUND
Despite a high mortality rate in childhood, there is limited evidence on the causes and outcomes of paediatric bloodstream infections from low- and middle-income countries (LMICs). We conducted a systematic review and meta-analysis to characterize the bacterial causes of paediatric bloodstream infections in LMICs and their resistance profile.
METHODS
We searched Pubmed and Embase databases between January 1st 1990 and October 30th 2019, combining MeSH and free-text terms for "sepsis" and "low-middle-income countries" in children. Two reviewers screened articles and performed data extraction to identify studies investigating children (1 month-18 years), with at least one blood culture. The main outcomes of interests were the rate of positive blood cultures, the distribution of bacterial pathogens, the resistance patterns and the case-fatality rate. The proportions obtained from each study were pooled using the Freeman-Tukey double arcsine transformation, and a random-effect meta-analysis model was used.
RESULTS
We identified 2403 eligible studies, 17 were included in the final review including 52,915 children (11 in Africa and 6 in Asia). The overall percentage of positive blood culture was 19.1% [95% CI: 12.0-27.5%]; 15.5% [8.4-24.4%] in Africa and 28.0% [13.2-45.8%] in Asia. A total of 4836 bacterial isolates were included in the studies; 2974 were Gram-negative (63.9% [52.2-74.9]) and 1858 were Gram-positive (35.8% [24.9-47.5]). In Asia, typhi (26.2%) was the most commonly isolated pathogen, followed by (7.7%) whereas in Africa, (17.8%) and (16.8%) were predominant followed by (10.7%). was more likely resistant to methicillin in Africa (29.5% vs. 7.9%), whereas was more frequently resistant to third-generation cephalosporins (31.2% vs. 21.2%), amikacin (29.6% vs. 0%) and ciprofloxacin (36.7% vs. 0%) in Asia. The overall estimate for case-fatality rate among 8 studies was 12.7% [6.6-20.2%]. Underlying conditions, such as malnutrition or HIV infection were assessed as a factor associated with bacteraemia in 4 studies each.
CONCLUSIONS
We observed a marked variation in pathogen distribution and their resistance profiles between Asia and Africa. Very limited data is available on underlying risk factors for bacteraemia, patterns of treatment of multidrug-resistant infections and predictors of adverse outcomes.
Topics: Adolescent; Africa; Anti-Bacterial Agents; Asia; Bacteremia; Bacteria; Child; Child Health; Child, Preschool; Community-Acquired Infections; Developing Countries; Drug Resistance, Bacterial; Humans; Infant; Microbial Sensitivity Tests; Observational Studies as Topic; Poverty; Sepsis
PubMed: 31893041
DOI: 10.1186/s13756-019-0673-5 -
PLoS Neglected Tropical Diseases Oct 2018The temporal and spatial change in trends of antimicrobial resistance (AMR) in typhoid have not been systematically studied, and such information will be critical for...
BACKGROUND
The temporal and spatial change in trends of antimicrobial resistance (AMR) in typhoid have not been systematically studied, and such information will be critical for defining intervention, as well as planning sustainable prevention strategies.
METHODOLOGY AND FINDINGS
To identify the phenotypic trends in AMR, 13,833 individual S. Typhi isolates, reported from 1973 to 2018 in 62 publications, were analysed to determine the AMR preponderance over time. Separate analyses of molecular resistance determinants present in over 4,000 isolates reported in 61 publications were also conducted. Multi-drug resistant (MDR) typhoid is in decline in Asia in a setting of high fluoroquinolone resistance while it is on the increase in Africa. Mutations in QRDRs in gyrA (S83F, D87N) and parC (S80I) are the most common mechanisms responsible for fluoroquinolone resistance. Cephalosporin resistant S. Typhi, dubbed extensively drug-resistant (XDR) is a real threat and underscores the urgency in deploying the Vi-conjugate vaccines.
CONCLUSION
From these observations, it appears that AMR in S. Typhi will continue to emerge leading to treatment failure, changes in antimicrobial policy and further resistance developing in S. Typhi isolates and other Gram-negative bacteria in endemic regions. The deployment of typhoid conjugate vaccines to control the disease in endemic regions may be the best defence.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Genes, Bacterial; Genotype; Global Health; Humans; Phenotype; Salmonella typhi; Typhoid Fever
PubMed: 30307935
DOI: 10.1371/journal.pntd.0006779 -
The Indian Journal of Medical Research Feb 2019The temporal trends in the development of antimicrobial resistance (AMR) among Salmonella Typhi and Salmonella Paratyphi in India have not been systematically reported....
BACKGROUND & OBJECTIVES
The temporal trends in the development of antimicrobial resistance (AMR) among Salmonella Typhi and Salmonella Paratyphi in India have not been systematically reported. We aimed to systematically review the temporal AMR trends (phenotypic and molecular mechanisms) in bacterial isolates from patients with enteric fever over two decades in India.
METHODS
To identify trends in AMR in India, resistance patterns among 4611 individual S. Typhi isolates and 800 S. Paratyphi A isolates, reported from 1992 to 2017 in 40 publications, were analysed. Molecular resistance determinants were extracted from 22 publications and also reviewed in accordance with the PRISMA guidelines. Articles were sourced using a predefined search strategy from different databases.
RESULTS
The analyses suggested that multidrug-resistant (MDR) enteric fever was declining in India and being replaced by fluoroquinolone (FQ) resistance. Mutations in gyrA and parC were key mechanisms responsible for FQ resistance, whereas MDR was largely driven by resistance determinants encoded on mobile genetic elements (plasmids, transposons).
INTERPRETATION & CONCLUSIONS
The results reflect the effect of antimicrobial pressure which has been driving AMR in typhoidal Salmonella in India. Understanding these trends is important in planning future approaches to therapy, which serve as a baseline for assessment of the impact of new typhoid conjugate vaccines against these resistant organisms.
Topics: Anti-Bacterial Agents; Ciprofloxacin; Drug Resistance, Bacterial; Fluoroquinolones; Humans; India; Microbial Sensitivity Tests; Paratyphoid Fever; Salmonella paratyphi A; Salmonella typhi
PubMed: 31219079
DOI: 10.4103/ijmr.IJMR_830_18 -
Clinical Infectious Diseases : An... Jun 2017Children bear a substantial proportion of the enteric fever disease burden in endemic areas. Controversy persists regarding which age groups are most affected, leading... (Meta-Analysis)
Meta-Analysis Review
Children bear a substantial proportion of the enteric fever disease burden in endemic areas. Controversy persists regarding which age groups are most affected, leading to uncertainty about optimal intervention strategies. We performed a systematic review and meta-analysis of studies in Asia and Africa to compare the relative proportion of children with enteric fever in the age groups <5 years, 5-9 years, and 10-14 years. Overall, studies conducted in Africa showed a relatively smaller occurrence of disease in the youngest age group, whereas in Asia the picture was more mixed with a very large degree of heterogeneity in estimates. The clinical features of enteric fever reviewed here differ between younger and older children and adults, likely leading to further uncertainty over disease burden. It is evident from our review that preschool children and infants also contribute a significant proportion of disease burden but have not been adequately targeted via vaccination programs, which have been focusing primarily on school-based vaccination campaigns.
Topics: Adolescent; Africa; Age Factors; Asia; Child; Child, Preschool; Cost of Illness; Female; Humans; Immunization Programs; Infant; Male; Paratyphoid Fever; Prevalence; Salmonella paratyphi A; Salmonella typhi; Typhoid Fever
PubMed: 28369224
DOI: 10.1093/cid/cix229 -
BMC Infectious Diseases Jan 2016The control of typhoid fever being an important public health concern in low and middle income countries, improving typhoid surveillance will help in planning and... (Meta-Analysis)
Meta-Analysis Review
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.
Topics: Databases, Factual; Developing Countries; Hospitalization; Humans; Incidence; Longitudinal Studies; Salmonella typhi; Typhoid Fever
PubMed: 26822522
DOI: 10.1186/s12879-016-1351-3 -
Clinical Infectious Diseases : An... Oct 2019Our current understanding of the burden and distribution of typhoid fever in Africa relies on extrapolation of data from a small number of population-based incidence...
BACKGROUND
Our current understanding of the burden and distribution of typhoid fever in Africa relies on extrapolation of data from a small number of population-based incidence rate estimates. However, many other records on the occurrence of typhoid fever are available, and those records contain information that may enrich our understanding of the epidemiology of the disease as well as secular trends in reporting by country and over time.
METHODS
We conducted a systematic review of typhoid fever occurrence in Africa, published in PubMed, Embase, and ProMED (Program for Monitoring Emerging Diseases).
RESULTS
At least one episode of culture-confirmed typhoid fever was reported in 42 of 57 African countries during 1900-2018. The number of reports on typhoid fever has increased over time in Africa and was highly heterogeneous between countries and over time. Outbreaks of typhoid fever were reported in 15 countries, with their frequency and size increasing over time.
CONCLUSIONS
Efforts should be made to leverage existing typhoid data, for example, by incorporating them into models for estimating the burden and distribution of typhoid fever.
Topics: Africa; Cost of Illness; Disease Outbreaks; Humans; Incidence; Paratyphoid Fever; Salmonella typhi; Typhoid Fever
PubMed: 31665777
DOI: 10.1093/cid/ciz525 -
The American Journal of Tropical... Feb 2023The occurrence and antimicrobial resistance (AMR) of typhoid fever in the WHO Eastern Mediterranean Region (EMR) are poorly characterized. Robust surveillance data are...
The occurrence and antimicrobial resistance (AMR) of typhoid fever in the WHO Eastern Mediterranean Region (EMR) are poorly characterized. Robust surveillance data are needed to inform strategies for typhoid control and prevention in the region. We conducted a systematic review of typhoid fever occurrence, complications, and AMR patterns in EMR countries. We identified 70 studies published from 1990 to 2021, including a total of 44,541 cases with blood culture confirmed typhoid fever in 12 EMR countries, with 48 (69%) studies and 42,008 cases from Pakistan. Among 56 studies with AMR data, fluroquinolone (68% of 13,013 tested isolates), and multidrug resistance (40% of 15,765 tested isolates) were common. Forty (57%) of the 56 studies were from Pakistan, and all reports of extensively drug resistant Salmonella Typhi (48% of 9,578 tested isolates) were from studies in Pakistan. Our findings support the need for continued efforts to strengthen surveillance and laboratory capacity for blood-culture detection of typhoid fever in the region, including data from an ongoing collaboration among CDC, the American University of Beirut, and the WHO EMR office.
Topics: Humans; Typhoid Fever; Anti-Bacterial Agents; Salmonella typhi; Pakistan; Laboratories
PubMed: 36538895
DOI: 10.4269/ajtmh.22-0075 -
The Lancet. Infectious Diseases Feb 2019Oral vaccines underperform in low-income and middle-income countries compared with in high-income countries. Whether interventions can improve oral vaccine performance... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Oral vaccines underperform in low-income and middle-income countries compared with in high-income countries. Whether interventions can improve oral vaccine performance is uncertain.
METHODS
We did a systematic review and meta-analysis of interventions designed to increase oral vaccine efficacy or immunogenicity. We searched Ovid-MEDLINE and Embase for trials published until Oct 23, 2017. Inclusion criteria for meta-analysis were two or more studies per intervention category and available seroconversion data. We did random-effects meta-analyses to produce summary relative risk (RR) estimates. This study is registered with PROSPERO (CRD42017060608).
FINDINGS
Of 2843 studies identified, 87 were eligible for qualitative synthesis and 66 for meta-analysis. 22 different interventions were assessed for oral poliovirus vaccine (OPV), oral rotavirus vaccine (RVV), oral cholera vaccine (OCV), and oral typhoid vaccines. There was generally high heterogeneity. Seroconversion to RVV was significantly increased by delaying the first RVV dose by 4 weeks (RR 1·37, 95% CI 1·16-1·62) and OPV seroconversion was increased with monovalent or bivalent OPV compared with trivalent OPV (RR 1·51, 95% CI 1·20-1·91). There was some evidence that separating RVV and OPV increased RVV seroconversion (RR 1·21, 95% CI 1·00-1·47) and that higher vaccine inoculum improved OCV seroconversion (RR 1·12, 95% CI 1·00-1·26). There was no evidence of effect for anthelmintics, antibiotics, probiotics, zinc, vitamin A, withholding breastfeeding, extra doses, or vaccine buffering.
INTERPRETATION
Most strategies did not improve oral vaccine performance. Delaying RVV and reducing OPV valence should be considered within immunisation programmes to reduce global enteric disease. New strategies to address the gap in oral vaccine efficacy are urgently required.
FUNDING
Wellcome Trust, Bill & Melinda Gates Foundation, UK Medical Research Council, and WHO Polio Research Committee.
Topics: Administration, Oral; Adolescent; Adult; Child; Child, Preschool; Cholera; Cholera Vaccines; Female; Humans; Immunogenicity, Vaccine; Infant; Infant, Newborn; Male; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral; Rotavirus; Rotavirus Infections; Rotavirus Vaccines; Salmonella typhi; Seroconversion; Treatment Outcome; Typhoid Fever; Typhoid-Paratyphoid Vaccines; Vaccination; Vibrio cholerae; Young Adult
PubMed: 30712836
DOI: 10.1016/S1473-3099(18)30602-9