scholarly journals Bacterial shedding and serologic responses following an outbreak of Salmonella Typhi in an endemic cohort

2021 ◽  
Author(s):  
Peter Johnston ◽  
Patrick Bogue ◽  
Angeziwa Chirambo ◽  
Maurice Mbewe ◽  
Reenesh Prakash ◽  
...  
Keyword(s):  
Capsular Polysaccharide ◽  
Pcr Amplification ◽  
Salmonella Typhi ◽  
World Health ◽  
Igg Antibody ◽  
Persistent Fever ◽  
Signed Rank ◽  
Antibody Titres ◽  
Vi Capsular Polysaccharide ◽  
Health Organization

Background: Salmonella enterica serovar Typhi (S. Typhi), the causative agent of Typhoid fever, is transmitted faecal-orally. Some typhoid sufferers shed S. Typhi beyond convalescence, but culturing stool following every case is impractical. Here we hypothesised that serology might direct testing and identify shedding after a typhoid outbreak. Methodology/Principle Findings: In 2016 there was a typhoid outbreak in a Nursing School in Malosa, Malawi. We collected serum three and six-months post-outbreak. We measured IgG antibody titres against Vi capsular polysaccharide (anti-Vi IgG) and IgM / IgG antibodies against H:d flagellin (anti-H:d). We screened faecal samples from participants with high and low anti-Vi IgG (measured at visit one) by culture and PCR. Participants reported whether they had persistent fever for ≥ three days (in keeping with World Health Organization definitions for typhoid) during the outbreak. We tested for environmental S. Typhi. 368 people provided serum at 3-months, of whom 320 provided serum at 6-months; 49 participants provided a faecal sample (25 from the highest and 24 from the lowest deciles for anti-Vi IgG titre). We did not grow S. Typhi from faeces, but one sample produced a positive PCR amplification for S. Typhi. Median anti-Vi IgG titre fell amongst participants with persistent fever (8.08 to 3.7 EU/ml, <0.000001, Wilcoxon signed rank). Median anti-H:d IgG titres fell in those with and without persistent fever (87.8 to 77.4 EU/, p = <0.000001 and 82.4 to 79.2 EU/ml, p = 0.0002, Wilcoxon signed rank, respectively). Anti-H:d IgM titres did not change significantly. Non-Typhoidal Salmonellae were identified in water sampled at source and a kitchen tap. Conclusions / Significance: We did not identify culture-confirmed shedding through sero-surveillance. Serologic trends signify a fall from an outbreak-associated peak. Despite effective vaccines, identifying ways to detect and treat shedding remain vital to break transmission and eliminate typhoid.

scholarly journals Immunogenicity and Induction of Functional Antibodies in Rabbits Immunized with a Trivalent Typhoid-Invasive Nontyphoidal Salmonella Glycoconjugate Formulation

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1749 ◽  
Author(s):  
Scott Baliban ◽  
Jessica Allen ◽  
Brittany Curtis ◽  
Mohammed Amin ◽  
Andrew Lees ◽  
...  
Keyword(s):  
Phase 1 ◽  
Treatment Options ◽  
Case Fatality ◽  
Salmonella Typhi ◽  
Sub Saharan Africa ◽  
World Health ◽  
Complication Rates ◽  
Igg Antibody ◽  
Health Organization

Typhoid fever due to Salmonella Typhi and invasive nontyphoidal Salmonella (iNTS) infections caused by serovars Enteritidis (SE) and Typhimurium (STm) are major pediatric health problems in sub-Saharan Africa. Typhoid has high complication rates, and iNTS infections have high case fatality rates; moreover, emerging antimicrobial resistance is diminishing treatment options. Vi capsule-based typhoid conjugate vaccine (Typbar-TCV™), licensed in India and pre-qualified by the World Health Organization, elicits durable immunity when administered to infants, but no iNTS vaccines are licensed or imminent. We have developed monovalent SE and STm glycoconjugate vaccines based on coupling lipopolysaccharide-derived core-O polysaccharide (COPS) to phase 1 flagellin protein (FliC) from the homologous serovar. Herein, we report the immunogenicity of multivalent formulations of iNTS COPS:FliC conjugates with Typbar-TCV™. Rabbits immunized with the trivalent typhoid-iNTS glycoconjugate vaccine generated high titers of serum IgG antibody to all three polysaccharide antigens for which anti-COPS IgG antibodies were directed primarily against serogroup-specific OPS epitopes. Responses to SE and STm FliC were lower relative to anti-COPS titers. Post-vaccination rabbit sera mediated bactericidal activity in-vitro, and protected mice after passive transfer against challenge with virulent SE or STm Malian blood isolates. These results support accelerated progression to clinical trials.

scholarly journals Persistent Detection and Infectious Potential of SARS-CoV-2 Virus in Clinical Specimens from COVID-19 Patients

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1384
Author(s):  
Michael Zapor
Keyword(s):  
Pcr Amplification ◽  
World Health ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Distinctive Features ◽  
Clinical Specimens ◽  
Polymerase Chain ◽  
Health Organization ◽  
Infectious Potential ◽  
Infective Potential

The Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) that emerged in December 2019 as the causative agent of Coronavirus 2019 (COVID-19) and was declared a pandemic by the World Health Organization in March 2020 has several distinctive features, including extensive multiorgan involvement with a robust systemic inflammatory response, significant associated morbidity and mortality, and prolonged persistence of viral RNA in the clinical specimens of infected individuals as detected by Reverse Transcription Polymerase Chain Reaction (RT-PCR) amplification. This review begins with an overview of SARS-CoV-2 morphology and replication and summarizes what is known to date about the detection of the virus in nasal, oropharyngeal, and fecal specimens of patients who have recovered from COVID-19, with a focus on the factors thought to contribute to prolonged detection. This review also provides a discussion on the infective potential of this material from asymptomatic, pre-symptomatic, and convalescing individuals, to include a discussion of the relative persistence and infectious potential of virus in clinical specimens recovered from pediatric COVID-19 patients.

Clinical and serological responses following primary and booster immunization with Salmonella typhi Vi capsular polysaccharide vaccines

Vaccine ◽  
1994 ◽  
Vol 12 (3) ◽  
pp. 195-199 ◽  
Author(s):  
Wendy A. Keitel ◽  
Nanette L. Bond ◽  
John M. Zahradnik ◽  
Tod A. Cramton ◽  
John B. Robbins
Keyword(s):  
Capsular Polysaccharide ◽  
Salmonella Typhi ◽  
Booster Immunization ◽  
Vi Capsular Polysaccharide

scholarly journals Development and Analytical Validation of an Immunoassay for Quantifying Serum Anti-Pertussis Toxin Antibodies Resulting from Bordetella pertussis Infection

2009 ◽  
Vol 16 (12) ◽  
pp. 1781-1788 ◽  
Author(s):  
Sandra L. Menzies ◽  
Vijay Kadwad ◽  
Lucia C. Pawloski ◽  
Tsai-Lien Lin ◽  
Andrew L. Baughman ◽  
...  
Keyword(s):  
Pertussis Toxin ◽  
Bordetella Pertussis ◽  
Collaborative Study ◽  
World Health ◽  
Enzyme Linked Immunosorbent Assay ◽  
Analytical Validation ◽  
Igg Antibody ◽  
Pertussis Infection ◽  
Validation Parameters ◽  
Health Organization

ABSTRACT Adequately sensitive and specific methods to diagnose pertussis in adolescents and adults are not widely available. Currently, no Food and Drug Administration-approved diagnostic assays are available for the serodiagnosis of Bordetella pertussis. Since concentrations of B. pertussis-specific antibodies tend to be high during the later phases of disease, a simple, rapid, easily transferable serodiagnostic test was developed. This article describes test development, initial evaluation of a prototype kit enzyme-linked immunosorbent assay (ELISA) in an interlaboratory collaborative study, and analytical validation. The data presented here demonstrate that the kit met all prespecified criteria for precision, linearity, and accuracy for samples with anti-pertussis toxin (PT) immunoglobulin G (IgG) antibody concentrations in the range of 50 to 150 ELISA units (EU)/ml, the range believed to be most relevant for serodiagnosis. The assay met the precision and linearity criteria for a wider range, namely, from 50 to 200 EU/ml; however, the accuracy criterion was not met at 200 EU/ml. When the newly adopted World Health Organization International Standard for pertussis antiserum (human) reference reagent was used to evaluate accuracy, the accuracy criteria were met from 50 to 200 international units/ml. In conclusion, the IgG anti-PT ELISA met all assay validation parameters within the range considered most relevant for serodiagnosis. This ELISA was developed and analytically validated as a user-friendly kit that can be used in both qualitative and quantitative formats. The technology for producing the kit is transferable to public health laboratories.

Serological response following re-vaccination with Salmonella typhi Vi-capsular polysaccharide vaccines in healthy adult travellers

Vaccine ◽  
2015 ◽  
Vol 33 (33) ◽  
pp. 4141-4145 ◽  
Author(s):  
Louise Roggelin ◽  
Christof D. Vinnemeier ◽  
Johanna Fischer-Herr ◽  
Brandi T. Johnson-Weaver ◽  
Thierry Rolling ◽  
...  
Keyword(s):  
Capsular Polysaccharide ◽  
Healthy Adult ◽  
Salmonella Typhi ◽  
Serological Response ◽  
Vi Capsular Polysaccharide

scholarly journals Karakteristik Penderita Demam Tifoid di RS. Ibnu Sina Kota Makassar Tahun 2016 - 2017

2020 ◽  
Vol 5 (1) ◽  
pp. 57-68
Author(s):  
Zaidan . . ◽  
Santriani Hadi ◽  
Ilma Khaerina Amaliyah B.
Keyword(s):  
World Health Organization ◽  
Salmonella Typhi ◽  
World Health ◽  
Health Organization

Latar Belakang: Demam Tifoid merupakan penyakit infeksi akut usus halus yang disebabkan oleh bakteri Salmonella typhi dan merupakan masalah utama kesehatan masyarakat Indonesia. Berdasarkan laporan World Health Organization (WHO) diperkirakan 11-20 juta orang di dunia terkena penyakit demam tifoid dan menyebabkan kematian sekitar 128.000 - 161.000 jiwa. Berdasarkan uraian di atas, maka penelitian ini dilakukan untuk melihat karakteristik penderita demam tifoid di rumah sakit Ibnu Sina kota makassar pada tahun 2016-2017. Metode: Penelitian ini bersifat deskriptif dengan metode total sampling menggunakan data sekunder dari rekam medik. Pada penelitian ini didapatkan jumlah penderita demam tifoid tahun 2016–2017 sebanyak 233 orang. Hasil: Kejadian demam tifoid tertinggi adalah tahun 2016 bulan April sebanyak 26 orang (14,8%) dengan kelompok usia terbanyak yaitu 21-30 sebanyak 80 orang (34,3%), jenis kelamin terbanyak perempuan sebanyak 124 orang (53,2%). Jenis pekerjaan penderita demam tifoid terbanyak yaitu kelompok mahasiswa sebanyak 62 orang (26,6%) dengan gejala subjektif demam sebanyak 233 orang (100%). Pada pemeriksaan lidah kotor positif sebanyak 80 orang (34,3%). Pemeriksaan penunjang diagnosis yaitu pemeriksaan darah rutin didapatkan yang mengalami anemia sebanyak 38 orang (12,5%). Kesimpulan: Gejala subjektif tertinggi yaitu demam dengan pemeriksaan fisis yaitu lidah kotor. Pemeriksaan penunjang diagnosis terbanyak adalah pemeriksaaan darah rutin dan pemeriksaan laboratorium yang sering dilakukan adalah tes widal.

scholarly journals Seroprevalence of polio antibodies in adult laboratory staff in South Africa, 2009 to 2013

2016 ◽  
Vol 31 (2) ◽  
pp. 57-60
Author(s):  
Shelina Moonsamy ◽  
Melinda Suchard
Keyword(s):  
South African ◽  
Communicable Diseases ◽  
World Health ◽  
Laboratory Staff ◽  
Population Immunity ◽  
Antibody Titres ◽  
Global Eradication ◽  
Health Organization ◽  
Type 3 ◽  
Health Programme

The global eradication of polio has been a World Health Organization goal since May 1988 with the current target for global eradication set at 2018. A keystone of the eradication initiative is achieving and maintaining high immunisation coverage, producing high population immunity. Assessing infant vaccination coverage does not give a reliable indication of adult immunity levels as antibody titres decline with age. A requirement of the occupational health programme at the National Institute for Communicable Diseases is to test newly appointed personnel for immunity to polio. During the period 2009 to 2013, 352 sera were collected and tested by means of antibody neutralisation assays to determine immunity to all three polio serotypes. The objective of this study was to assess immunity to polio in personnel employed at the National Institute for Communicable Diseases as a proxy for the general adult South African population. The seroprevalence to polio serotypes 1, 2 and 3 were 85.5, 90.0 and 74.0%, respectively. Of the 352 samples tested, 2.3% were sero-negative for all three serotypes and 36.0% were sero-negative to at least one of the serotypes. The seroprevalence to polio serotype 3 falls below the target of 80.0%, and could pose a potential risk following importation or development of vaccine derived poliovirus type 3.

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