#Epidemiology and #antimicrobial #resistance of invasive non-typhoidal #Salmonellosis in rural #Thailand from 2006-2014 (PLoS Negl Trop Dis., abstract)

[Source: PLoS Neglected Tropical Diseases, full page: (LINK). Abstract, edited.]


Epidemiology and antimicrobial resistance of invasive non-typhoidal Salmonellosis in rural Thailand from 2006-2014

Toni Whistler , Patranuch Sapchookul, David W. McCormick, Ornuma Sangwichian, Possawat Jorakate, Sirirat Makprasert, Anchalee Jatapai, Sathapana Naorat, Uraiwan Surin, Surathinee Koosakunwat, Surachai Supcharassaeng, Barameht Piralam, Mathew Mikoleit,  [ … ], Christopher J. Gregory

Published: August 6, 2018 / DOI: https://doi.org/10.1371/journal.pntd.0006718 / This is an uncorrected proof.




Invasive salmonellosis is a common cause of bloodstream infection in Southeast Asia. Limited epidemiologic and antimicrobial resistance data are available from the region.


Blood cultures performed in all 20 hospitals in the northeastern province of Nakhon Phanom (NP) and eastern province of Sa Kaeo (SK), Thailand were captured in a bloodstream infection surveillance system. Cultures were performed as clinically indicated in hospitalized patients; patients with multiple positive cultures had only the first included. Bottles were incubated using the BacT/Alert system (bioMérieux, Thailand) and isolates were identified using standard microbiological techniques; all Salmonella isolates were classified to at least the serogroup level. Antimicrobial resistance was assessed using disk diffusion.


Salmonella was the fifth most common pathogen identified in 147,535 cultures with 525 cases (211 in Nakhon Phanom (NP) and 314 in Sa Kaeo (SK)). The overall adjusted iNTS incidence rate in NP was 4.0 cases/100,000 person-years (95% CI 3.5–4.5) and in SK 6.4 cases/100,000 person-years (95% CI 5.7–7.1; p = 0.001). The most common serogroups were C (39.4%), D (35.0%) and B (9.9%). Serogroup D predominated in NP (103/211) with 59.2% of this serogroup being Salmonella serovar Enteritidis. Serogroup C predominated in SK (166/314) with 84.3% of this serogroup being Salmonella serovar Choleraesuis. Antibiotic resistance was 68.2% (343/503) for ampicillin, 1.2% (6/482) for ciprofloxacin (or 58.1% (280/482) if both intermediate and resistant phenotypes are considered), 17.0% (87/512) for trimethoprim-sulfamethoxazole, and 12.2% (59/484) for third-generation cephalosporins (cefotaxime or ceftazidime). Multidrug resistance was seen in 99/516 isolates (19.2%).


The NTS isolates causing bloodstream infections in rural Thailand are commonly resistant to ampicillin, cefotaxime, and TMP-SMX. Observed differences between NP and SK indicate that serogroup distribution and antibiotic resistance may substantially differ throughout Thailand and the region.


Author summary

Invasive strains of non-typhoidal salmonella (iNTS) are a common cause of bloodstream infection in Southeast Asia, however limited epidemiologic and antimicrobial resistance data are available and no population-based studies have been published from the region. We use nine years of bloodstream infections data from surveillance conducted in two Thai border provinces to report on the incidence, serotype distribution and antimicrobial resistance patterns. Incidence of iNTS was 5.1 cases/100,000 population (95% CI 4.7–5.6), likely an under estimate of the true burden of disease as we only used hospitalized cases and less sensitive blood culture for bacterial isolation. Levels of drug non-susceptibility were high among isolates, especially for fluoroquinolones such as ciprofloxacin (~60%) and third-generation cephalosporins such as cefotaxime or ceftazidime (~15%) that are commonly prescribed to provide empirical coverage against these pathogens. Multidrug resistance was widespread at 20% of isolates. Our data emphasizes the need for increased microbiological surveillance, and support the need for rational antibiotic therapy and the development of treatment guidelines.


Citation: Whistler T, Sapchookul P, McCormick DW, Sangwichian O, Jorakate P, Makprasert S, et al. (2018) Epidemiology and antimicrobial resistance of invasive non-typhoidal Salmonellosis in rural Thailand from 2006-2014. PLoS Negl Trop Dis 12(8): e0006718. https://doi.org/10.1371/journal.pntd.0006718

Editor: Thomas C. Darton, Oxford University Clinical Research Unit Vietnam, VIET NAM

Received: May 18, 2018; Accepted: July 25, 2018; Published: August 6, 2018

This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Data Availability: Data sets belong to the Thai Ministry of Health and access is restricted but available on request with an accompanying explanation as to what the data will be used for. Please contact Dr. John MacArthur (zae5@cdc.gov) to request the relevant data used for this manuscript. He can direct your query to appropriate contacts within the Thai MOPH.

Funding: Support for this project was provided by the Global Disease Detection program of the U.S. Centers for Disease Control and Prevention, and the Pneumococcal Vaccines Accelerated Development and Introduction Plan (PneumoADIP) (www.preventpneumo.org) funded by the GAVI Alliance (www.gavi.org) based at the Johns Hopkins Bloomberg School of Public Health. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: Antibiotics; Drugs Resistance; Salmonella spp.; Thailand.


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Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.