Clinical Evaluation of a Multiplex PCR for the Detection of Salmonella enterica Serovars Typhi and Paratyphi A from Blood Specimens in a High-Endemic Setting.

Clinical Evaluation of a Multiplex PCR for the Detection of Salmonella enterica Serovars Typhi and Paratyphi A from Blood Specimens in a High-Endemic Setting. Am J Trop Med Hyg. 2019 Jul 08;: Authors: Pouzol S, Tanmoy AM, Ahmed D, Khanam F, Brooks WA, Bhuyan GS, Fabre L, Bryant JE, Gustin MP, Vanhems P, Carman B, Weill FX, Qadri F, Saha S, Endtz H Abstract Enteric fever is a major public health concern in endemic areas, particularly in infrastructure-limited countries where Salmonella Paratyphi A has emerged in increasing proportion of cases. We aimed to evaluate a method to detect Salmonella Typhi (S. Typhi) and Salmonella Paratyphi A (S. Paratyphi) in febrile patients in Bangladesh. We conducted a prospective study enrolling patients with fever> 38°C admitted to two large urban hospitals and two outpatient clinics located in Dhaka, Bangladesh. We developed and evaluated a method combining short culture with a new molecular assay to simultaneously detect and differentiate S. Typhi and S. Paratyphi A from other Salmonella directly from 2 to 4 mL of whole blood in febrile patients (n = 680). A total of 680 cases were enrolled from the four participating sites. An increase in the detection rate (+38.8%) in S. Typhi and S. Paratyphi A was observed with a multiplex polymerase chain reaction (PCR) assay, and absence of non-typhoidal Salmonella detection was reported. All 45 healthy controls were culture and PCR negative, generating an estimated 92.9% o...
Source: The American Journal of Tropical Medicine and Hygiene - Category: Tropical Medicine Authors: Tags: Am J Trop Med Hyg Source Type: research

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Abstract In February 2018, a typhoid fever outbreak caused by Salmonella enterica serotype Typhi (Typhi), resistant to chloramphenicol, ampicillin, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporins, was reported in Pakistan. During November 2016-September 2017, 339 cases of this extensively drug-resistant (XDR) Typhi strain were reported in Pakistan, mostly in Karachi and Hyderabad; one travel-associated case was also reported from the United Kingdom (1). More cases have been detected in Karachi and Hyderabad as surveillance efforts have been strengthened, with recent reports inc...
Source: MMWR Morb Mortal Wkl... - Category: Epidemiology Authors: Tags: MMWR Morb Mortal Wkly Rep Source Type: research
Abstract With prequalification of a typhoid conjugate vaccine by the World Health Organization, countries are deciding whether and at what geographic scale to provide the vaccine. Optimal local data to clarify typhoid risk are expensive and often unavailable. To determine whether quantitative real-time PCR can be used as a tool to detect typhoidal Salmonella DNA in the environment and approximate the burden of enteric fever, we tested water samples from urban Dhaka, where enteric fever burden is high, and rural Mirzapur, where enteric fever burden is low and sporadic. Sixty-six percent (38/59) of the water sources...
Source: Am J Trop Med Hyg - Category: Infectious Diseases Authors: Tags: Am J Trop Med Hyg Source Type: research
Conclusions: Typhoid fever was frequent among immigrants to endemic areas. Travelers returning from endemic areas with suspected typhoid fever should be treated empirically with third-generation cephalosporin after obtaining appropriate cultures. Moreover, preventive measurements such as education on food and water hygiene, and effective vaccination of travelers should be practiced widely among travelers to endemic areas to reduce morbidity and mortality. PMID: 30410688 [PubMed]
Source: Oman Medical Journal - Category: Middle East Health Tags: Oman Med J Source Type: research
ConclusionFrom these observations, it appears that AMR inS. Typhi will continue to emerge leading to treatment failure, changes in antimicrobial policy and further resistance developing inS. 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.
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research
This study describes enteric fever trends in Bangladesh along with these factors' progress between 1990 and 2014. Retrospective enteric fever data were collected from Dhaka Shishu (children) Hospital (DSH), Shishu Shasthya Foundation Hospital (SSFH), International Center for Diarrheal Disease Research, Bangladesh, and Popular Diagnostic Center (PDC). Contextual factors data were gathered from relevant organizations and their websites and plotted against time to see trends. During 2001-2014, data for a total of 131,449 blood cultures were available at DSH, SSFH, and PDC. Of those, 7,100 (isolation rate 5.4%) yielded either ...
Source: The American Journal of Tropical Medicine and Hygiene - Category: Tropical Medicine Authors: Tags: Am J Trop Med Hyg Source Type: research
CONCLUSIONS: The licensed Ty21a and Vi polysaccharide vaccines are efficacious in adults and children older than two years in endemic countries. The Vi-rEPA vaccine is just as efficacious, although data is only available for children. The new Vi-TT vaccine (PedaTyph) requires further evaluation to determine if it provides protection against typhoid fever. At the time of writing, there were only efficacy data from a human challenge setting in adults on the Vi-TT vaccine (Tybar), which clearly justify the ongoing field trials to evaluate vaccine efficacy. PMID: 29851031 [PubMed - as supplied by publisher]
Source: Cochrane Database of Systematic Reviews - Category: General Medicine Authors: Tags: Cochrane Database Syst Rev Source Type: research
Abstract Immune responses to poorly immunogenic antigens, such as polysaccharides, can be enhanced by conjugation to carriers. Our previous studies indicate that conjugation to Vi polysaccharide of Salmonella Typhi may also enhance immunogenicity of some protein carriers. We therefore explored the possibility of generating a bivalent vaccine against Plasmodium falciparum malaria and typhoid fever, which are co-endemic in many parts of the world, by conjugating Vi polysaccharide, an approved antigen in typhoid vaccine, to Pfs25, a malaria transmission blocking vaccine antigen in clinical trials. Vi-Pfs25 conjugates...
Source: Vaccine - Category: Allergy & Immunology Authors: Tags: Vaccine Source Type: research
Publication date: Available online 28 September 2017 Source:The Lancet Author(s): Celina Jin, Malick M Gibani, Maria Moore, Helene B Juel, Elizabeth Jones, James Meiring, Victoria Harris, Jonathan Gardner, Anna Nebykova, Simon A Kerridge, Jennifer Hill, Helena Thomaides-Brears, Christoph J Blohmke, Ly-Mee Yu, Brian Angus, Andrew J Pollard Background Salmonella enterica serovar Typhi (S Typhi) is responsible for an estimated 20 million infections and 200 000 deaths each year in resource poor regions of the world. Capsular Vi-polysaccharide-protein conjugate vaccines (Vi-conjugate vaccines) are immunogenic and can be used...
Source: The Lancet - Category: General Medicine Source Type: research
Publication date: Available online 23 May 2017 Source:Journal of Microbiological Methods Author(s): Solai Ramatchandirane Prabagaran, Vellingiri Kalaiselvi, Naganathan Chandramouleeswaran, Krishnan Nair Geetha Deepthi, Kootallur Narayanan Brahmadathan, Mariappa Mani A nested multiplex polymerase chain reaction (PCR) based diagnosis was developed for the detection of virulent Salmonella typhi in the blood specimens from patients suspected for typhoid fever. After the Widal test, two pairs of primers were used for the detection of flagellin gene (fliC) of S. typhi. Among them, those positive for fliC alone were subjected to...
Source: Journal of Microbiological Methods - Category: Microbiology Source Type: research
Cases of diarrhoeal disease number from 1.7 to 5 billion per year worldwide. One of the main causes of diarrhoeal disease is typhoid fever, which is a potentially life-threatening multi-systemic illness. According to the most recent estimates, a total of 26.9 million typhoid fever episodes occurred in 2010. The geographical distribution of the disease differs widely; in developed countries, the incidence rate per 100,000 per year varies from
Source: Journal of Preventive Medicine and Hygiene - Category: Global & Universal Source Type: research
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