Introduction:Chikungunya virus(CHIKV),an arthropod-borne alphavirus transmitted by Aedes aegypti and Aedes albopictus,causes fever,severe joint pain,and rash.By 2025,it has triggered outbreaks in 119 countries,endange...Introduction:Chikungunya virus(CHIKV),an arthropod-borne alphavirus transmitted by Aedes aegypti and Aedes albopictus,causes fever,severe joint pain,and rash.By 2025,it has triggered outbreaks in 119 countries,endangering 5.5 million people.Recent epidemics in Foshan,China,have strained healthcare systems,underscoring the need to characterize viral load dynamics across infection phases.Methods:We collected 1,156 clinical samples from four Foshan hospitals in July 2025,spanning 6 days before to 12 days after symptom onset.Specimens included serum(904 valid),saliva(22),urine(4),throat swabs(3),and stool(37).CHIKV RNA was quantified via qRT-PCR;timepoints and specimen types with insufficient samples were excluded.Results:Serum showed the highest positivity(90%),followed by saliva(68%),throat swabs(15%),and urine(11%);stool was negative(0%).Serum also had the highest viral loads,confirming its optimal utility.Viral RNA was detectable as early as 1 day presymptom onset(day-1).Days 0–7 post-onset marked explosive replication and elevated loads,representing the optimal sampling window.From Day 8 onward,loads declined,requiring IgG testing to avoid false negatives.Conclusions:Serum is the gold standard for acute CHIKV diagnosis,with superior positivity and viral loads.Pre-symptomatic viral shedding(day-1)supports enhanced port-of-entry screening to intercept imported cases.Days 0–7 post-onset is the optimal sampling window for acute infection.During clearance(day 8+),IgG testing complements molecular diagnostics to reduce gaps.These findings inform evidence-based diagnosis,outbreak control,and resource allocation.展开更多
A comparative study was performed to evaluate best practice culture media and enrichment broths for recovering Salmonella species from human stool samples. A total of 1297 human stools were collected and processed in ...A comparative study was performed to evaluate best practice culture media and enrichment broths for recovering Salmonella species from human stool samples. A total of 1297 human stools were collected and processed in this study. Evaluation of agar media was carried out by direct plating (DP), 1096 stool samples were inoculated on Modified Semisolid Rappaport-Vassiliadis (MSRV), Xylose-Lysine-Deoxycolate (XLD), MacConkey (MAC), and Hektoen Enteric (HE) agars. Evaluation of enrichment broths were carried out by enrichment all 1297 stool samples in Selenite broth (SB), Rappaport-Vassiliadis (RV) broth, and Buffered Peptone Water (BPW), followed by plating on MSRV, MAC, and HE agars. A total of 102 Salmonella-positive stools by DP, 85.3% (87/102) were recovered utilizing MSRV while recovery from XLD, MAC, and HE agars were 34.3% (35/102), 34.3% (35/102), and 29.4% (30/102) respectively. A total 299/1297 stools samples were Salmonella-positive on at least one plating medium after enrichment procedure were 77.3% (177/299) for SB, 86.0% (197/299) and 78.6% (180/299) for RV and BPW respectively. All Salmonella isolated in this study was nontyphi Salmonella. Presently, the data suggest that the use of MSRV over MAC, HE, and XLD agars for isolation nontyphi Salmonella species from human stools is more efficacious. Additionally, use of MSRV in combination with MAC and HE agars following enrichment in RV broth enhances recovery of nontyphi Salmonella species. However, RV broth is inhibitory to typhi Salmonella, thus use of MSRV medium in combination with MAC, HE or XLD agars in direct plating following enrichment in non-selective BPW is an alternate method for recovery of both typhi and nontyphi Salmonella species contaminated in human stool samples.展开更多
Campylobacter continues to be a major cause of bacteriamediated diarrheal diseases, both for Thai citizens and travelers to Thailand. For field epidemiological studies, appropriate methods for storage, intralaboratory...Campylobacter continues to be a major cause of bacteriamediated diarrheal diseases, both for Thai citizens and travelers to Thailand. For field epidemiological studies, appropriate methods for storage, intralaboratory transport of patients specimens and use of enrichment culture to isolate this organism is critical. Study A, represents patient stool specimens collected in Bangkok and processed for Campylobacter culture within three hours after collection. Study B, represents stool specimens collected from patients in northeast and Southern regions of Thailand in modified CaryBlair transport medium. These specimens were transported and processed for Campylobacter in Bangkok at varying intervals ranging from 1 to 7 days. Of 900 diarrheal samples examined in study A, a total of 158 were Campylobacter positive through culture. Of these, 145 and 141 isolates were cultured by direct plating and enrichment plating respectively (P = 0.5839). From 1,168 diarrheal stool samples examined in study B, 184 were positive for Campylobacter. Direct and enrichment plating resulted in 139 and 168 culture isolates;respectively (P = 0.0003). Samples from study B delayed in processing for 1 to 3 days, resulted in 46 and 50 isolated by direct and enrichment plating;respectively (P = 0.4545). However, among samples delayed in processing for 4 to 7 days, a total of 128 Campylobacter isolates were cultured, having cultured 93 and 118 isolates through direct and enrichment plating;respectively (P = 0.0003). At present these studies demonstrate that enrichment culture has no benefit when stool specimen collection and immediate processing occur and when there is a processing delay period of 1 - 3 days. However, enrichment culture was beneficial in instances where transport and processing was delayed 4 - 7 days.展开更多
基金Supported by the Guangdong Provincial Center for Disease Control and Prevention Supports Talent Projects(0720240122)the Guangdong Provincial Key Laboratory of Pathogen Detection for Emerging Infectious Disease Response(2023B1212010010).
文摘Introduction:Chikungunya virus(CHIKV),an arthropod-borne alphavirus transmitted by Aedes aegypti and Aedes albopictus,causes fever,severe joint pain,and rash.By 2025,it has triggered outbreaks in 119 countries,endangering 5.5 million people.Recent epidemics in Foshan,China,have strained healthcare systems,underscoring the need to characterize viral load dynamics across infection phases.Methods:We collected 1,156 clinical samples from four Foshan hospitals in July 2025,spanning 6 days before to 12 days after symptom onset.Specimens included serum(904 valid),saliva(22),urine(4),throat swabs(3),and stool(37).CHIKV RNA was quantified via qRT-PCR;timepoints and specimen types with insufficient samples were excluded.Results:Serum showed the highest positivity(90%),followed by saliva(68%),throat swabs(15%),and urine(11%);stool was negative(0%).Serum also had the highest viral loads,confirming its optimal utility.Viral RNA was detectable as early as 1 day presymptom onset(day-1).Days 0–7 post-onset marked explosive replication and elevated loads,representing the optimal sampling window.From Day 8 onward,loads declined,requiring IgG testing to avoid false negatives.Conclusions:Serum is the gold standard for acute CHIKV diagnosis,with superior positivity and viral loads.Pre-symptomatic viral shedding(day-1)supports enhanced port-of-entry screening to intercept imported cases.Days 0–7 post-onset is the optimal sampling window for acute infection.During clearance(day 8+),IgG testing complements molecular diagnostics to reduce gaps.These findings inform evidence-based diagnosis,outbreak control,and resource allocation.
文摘A comparative study was performed to evaluate best practice culture media and enrichment broths for recovering Salmonella species from human stool samples. A total of 1297 human stools were collected and processed in this study. Evaluation of agar media was carried out by direct plating (DP), 1096 stool samples were inoculated on Modified Semisolid Rappaport-Vassiliadis (MSRV), Xylose-Lysine-Deoxycolate (XLD), MacConkey (MAC), and Hektoen Enteric (HE) agars. Evaluation of enrichment broths were carried out by enrichment all 1297 stool samples in Selenite broth (SB), Rappaport-Vassiliadis (RV) broth, and Buffered Peptone Water (BPW), followed by plating on MSRV, MAC, and HE agars. A total of 102 Salmonella-positive stools by DP, 85.3% (87/102) were recovered utilizing MSRV while recovery from XLD, MAC, and HE agars were 34.3% (35/102), 34.3% (35/102), and 29.4% (30/102) respectively. A total 299/1297 stools samples were Salmonella-positive on at least one plating medium after enrichment procedure were 77.3% (177/299) for SB, 86.0% (197/299) and 78.6% (180/299) for RV and BPW respectively. All Salmonella isolated in this study was nontyphi Salmonella. Presently, the data suggest that the use of MSRV over MAC, HE, and XLD agars for isolation nontyphi Salmonella species from human stools is more efficacious. Additionally, use of MSRV in combination with MAC and HE agars following enrichment in RV broth enhances recovery of nontyphi Salmonella species. However, RV broth is inhibitory to typhi Salmonella, thus use of MSRV medium in combination with MAC, HE or XLD agars in direct plating following enrichment in non-selective BPW is an alternate method for recovery of both typhi and nontyphi Salmonella species contaminated in human stool samples.
文摘Campylobacter continues to be a major cause of bacteriamediated diarrheal diseases, both for Thai citizens and travelers to Thailand. For field epidemiological studies, appropriate methods for storage, intralaboratory transport of patients specimens and use of enrichment culture to isolate this organism is critical. Study A, represents patient stool specimens collected in Bangkok and processed for Campylobacter culture within three hours after collection. Study B, represents stool specimens collected from patients in northeast and Southern regions of Thailand in modified CaryBlair transport medium. These specimens were transported and processed for Campylobacter in Bangkok at varying intervals ranging from 1 to 7 days. Of 900 diarrheal samples examined in study A, a total of 158 were Campylobacter positive through culture. Of these, 145 and 141 isolates were cultured by direct plating and enrichment plating respectively (P = 0.5839). From 1,168 diarrheal stool samples examined in study B, 184 were positive for Campylobacter. Direct and enrichment plating resulted in 139 and 168 culture isolates;respectively (P = 0.0003). Samples from study B delayed in processing for 1 to 3 days, resulted in 46 and 50 isolated by direct and enrichment plating;respectively (P = 0.4545). However, among samples delayed in processing for 4 to 7 days, a total of 128 Campylobacter isolates were cultured, having cultured 93 and 118 isolates through direct and enrichment plating;respectively (P = 0.0003). At present these studies demonstrate that enrichment culture has no benefit when stool specimen collection and immediate processing occur and when there is a processing delay period of 1 - 3 days. However, enrichment culture was beneficial in instances where transport and processing was delayed 4 - 7 days.
