Background: Modeling of the transmission dynamics of typhoid allows for an evaluation of the potential direct and indirect effects of vaccination; however, relevant typhoid models rooted in data have rarely been deployed.
Methodology/principal Findings: We developed a parsimonious age-structured model describing the natural history and immunity to typhoid infection. The model was fit to data on culture-confirmed cases of typhoid fever presenting to Christian Medical College hospital in Vellore, India from 2000-2012. The model was then used to evaluate the potential impact of school-based vaccination strategies using live oral, Vi-polysaccharide, and Vi-conjugate vaccines. The model was able to reproduce the incidence and age distribution of typhoid cases in Vellore. The basic reproductive number (R 0) of typhoid was estimated to be 2.8 in this setting. Vaccination was predicted to confer substantial indirect protection leading to a decrease in the incidence of typhoid in the short term, but (intuitively) typhoid incidence was predicted to rebound 5-15 years following a one-time campaign.
Conclusions/significance: We found that model predictions for the overall and indirect effects of vaccination depend strongly on the role of chronic carriers in transmission. Carrier transmissibility was tentatively estimated to be low, consistent with recent studies, but was identified as a pivotal area for future research. It is unlikely that typhoid can be eliminated from endemic settings through vaccination alone.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3886927 | PMC |
| http://dx.doi.org/10.1371/journal.pntd.0002642 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Contribution of domestic animals' feces to the occurrence of diarrhoea among children aged 6-48 months in Sidama region, Ethiopia: a laboratory-based matched case-control study.
BMJ Glob Health
December 2024
Division of Water and Health, Ethiopian Institute of Water Resources, Addis Ababa University, Addis Ababa, Ethiopia.
Background: In developing countries, due to improper management of domestic animals' exposures, under-five (U5) children have been affected by diarrhoea. However, there is no evidence that shows the presence of diarrhoea-causing pathogens in the faeces of U5 children and animals residing in the same houses in the Sidama region, Ethiopia.
Methods: A laboratory-based matched case-control study was conducted on children aged 6-48 months in the Sidama region of Ethiopia from February to June 2023.
Vi capsular polysaccharide of Salmonella enterica serovar Typhi disturbs autophagy to increase intracellular survival in macrophages.
Microb Pathog
December 2024
Department of Laboratory Medicine, Affiliated Hospital, Jiangsu University, Zhenjiang, Jiangsu 212001, China. Electronic address:
The autophagy pathway plays a crucial role in resistance to bacterial infection in the host. Salmonella enterica serovar Typhi (S. Typhi), a human restricted pathogen, causes a systemic infection known as typhoid fever.
View Article and Find Full Text PDFCharacterization of non-typhoidal Salmonella reveals the highly prevalent mcr-1-positive S. 1,4,[5],12:i:- within eggs are derived from chickens.
Int J Food Microbiol
December 2024
College of Veterinary Medicine, Qingdao Agricultural University, Qingdao 266109, China. Electronic address:
Salmonella is one of the most common foodborne pathogens. Antimicrobial-resistant Salmonella isolates, especially those resistant to colistin, pose a significant threat to public health worldwide. However, data about the prevalence of mcr-positive Salmonella in animals was few and the dissemination of mcr-positive Salmonella from animals to food, especially eggs, has not been fully addressed.
View Article and Find Full Text PDFZoonotic Gastroenteric Diseases of Exotic Animals.
Vet Clin North Am Exot Anim Pract
December 2024
Department of Clinical Sciences, North Carolina State University, College of Veterinary Medicine, Raleigh, NC, USA. Electronic address:
Exotic pet ownership has steadily increased over the last decade, and with increased numbers of these species in close contact with humans, the risk of gastrointestinal zoonoses has also increased. Non-typhoidal serovars of Salmonella enterica are one of the most prevalent and important zoonoses of exotic pets, and reptile and backyard poultry are common asymptomatic carriers of these bacteria. Outbreaks of reptile-associated salmonellosis have occurred yearly in the United States since 2019 but contact with backyard poultry has actually been associated with more Salmonella outbreaks in the United States than any other animal species to date.
View Article and Find Full Text PDFThe First-Ever Encounter with Serovar Hvittingfoss Causing Acute Gastroenteritis in India: A Case Report.
Infect Dis Rep
December 2024
Department of Microbiology, JSS Medical College and Hospital, JSS Academy of Higher Education and Research, Mysuru 570015, India.
serovar Hvittingfoss, a member of the non-typhoidal group, is an important foodborne serovar most frequently identified in regions (Australia, Belgium, and the United States) with active surveillance systems. This serovar has been implicated in outbreaks of foodborne illness. Soft cheese, crab cocktail, beef, and rock melon are commonly involved in these outbreaks.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!