Hemodynamic effects of the human aorta arch with different inflow rate waveforms from the ascending aorta inlet: A numerical study.

BACKGROUND: Heart failure (HF) is a common disease globally. Ventricular assist devices (VADs) are widely used to treat HF. In contrast to the natural heart, different VADs generate different blood flow waves in the aorta. OBJECTIVE: To explore whether the different inflow rate waveforms from the ascending aorta generate far-reaching hemodynamic influences on the human aortic arch. METHODS: An aortic geometric model was reconstructed based on computed tomography data of a patient with HF. A total of five numerical simulations were conducted, including a case with the inflow rate waveforms from the ascending aorta with normal physiological conditions, two HF, and two with typical VAD support. The hemodynamic parameters, wall shear stress (WSS), oscillatory shear index (OSI), relative residence time (RRT), and the strength of the helical flow, were calculated. RESULTS: In contrast to the natural heart, numerical simulations showed that HF decreased WSS and induced higher OSI and RRT. Moreover, HF weakened helical flow strength. Pulsatile flow VADs that elevated the WSS, induced some helical flow, while continuous flow VADs could not. CONCLUSIONS: HF leads to an adverse hemodynamic environment by decreasing WSS and reducing the helical flow strength. Based upon hemodynamic effects, pulsatile flow VADs may be more advantageous than continuous flow VADs. Thus, pulsatile flow VADs may be a better option for patients with HF.

Effects of reverse deployment of cone-shaped vena cava filter on improvements in hemodynamic performance in vena cava.

BACKGROUND: Cone-shaped vena cava filters (VCFs) are widely used to treat venous thromboembolism. However, in the long term, the problem of occlusion persists even after the filter is deployed. A previous study hypothesized that the reverse deployment of a cone-shaped VCFs may prevent filter blockage. METHODS: To explore this hypothesis, a comparative study of the traditional and reverse deployments of VCFs was conducted using a computational fluid dynamics approach. The distribution of wall shear stress (WSS) and shear stress-related parameters were calculated to evaluate the differences in hemodynamic effects between both conditions. In the animal experiment, we reversely deployed a filter in the vena cava of a goat and analyzed the blood clot distribution in the filter. RESULTS: The numerical simulation showed that the reverse deployment of a VCF resulted in a slightly higher shear rate on the thrombus, and no reductions in the oscillating shear index (OSI) and relative residence time (RRT) on the vessel wall. Comparing the traditional method with the reversely deployed cases, the shear rate values is 16.49 and 16.48 1/s, respectively; the minimal OSI values are 0.01 and 0.04, respectively; in the vicinity of the VCF, the RRT values are both approximately 5 1/Pa; and the WSS is approximately 0.3 Pa for both cases. Therefore, the reverse deployment of cone-shaped filters is not advantageous when compared with the traditional method in terms of local hemodynamics. However, it is effective in capturing thrombi in the short term, as demonstrated via animal experiments. The reversely deployed cone-shaped filter captured the thrombi at its center in the experiments. CONCLUSIONS: Thus, the reverse deployment of cone-shaped filters is not advantageous when compared with the traditional method in terms of local hemodynamics. Therefore, we would not suggest the reverse deployment of the cone-shaped filter in the vena cava to prevent a potentially fatal pulmonary embolism.

Investigation and control of an outbreak of urinary tract infections caused by Burkholderia cepacian-contaminated anesthetic gel.

BACKGROUND: This report describes an outbreak of 71 patients developed B. cepacia urinary tract infection (UTI) by contaminated single-use anesthetic gel. METHODS: Epidemiological investigation of patients with B. cepacia-positive urine or blood samples between March 19, 2018 and Novemeber 15, 2018 was conducted to identify the source of infection. Microbiological samples from hospital surfaces, endoscopes, disposable items, and the hands of staff were tested for B. cepacia contamination. Pulsed-field gel electrophoresis (PFGE) was used to compare homology in B. cepacia isolates. RESULTS: During the outbreak, nosocomial B. cepacia UTI was confirmed in 71 patients. Epidemiological investigation showed that 66 patients underwent invasive urological diagnosis and treatment, while the remaining five patients underwent bedside indwelling catheterization, with all patients exposed to single-use anesthetic gel. All batches of anesthetic gel were recalled and the outbreak abated. Overall, 155 samples were collected from environmental surfaces and disposable items, and B. cepacia contamination was confirmed in samples from one used cystoscope and three anesthetic gels from the same batch. PFGE showed homology between 17 out of 20 B. cepacia isolates from patients and three isolates from the contaminated anesthetic gel. All patients achieved cure. CONCLUSION: Contaminated single-use anesthetic gel was confirmed as the source of the B. cepacia outbreak, with infection occurring during invasive urological diagnostic and treatments. Thus, investigations of nosocomial outbreaks of B. cepacia infection should consider contamination of diagnostic and treatment items used in infected patients.

The Minimum Data Set and Quality Indicators for National Healthcare-Associated Infection Surveillance in Mainland China: Towards Precision Management.

The magnitude and scope of the healthcare-associated infections (HCAIs) burden are underestimated worldwide, and have raised public concerns for their adverse effect on patient safety. In China, HCAIs still present an unneglected challenge and economic burden in recent decades. With the purpose of reducing the HCAI prevalence and enhancing precision management, China's National Nosocomial Infection Management and Quality Control Center (NNIMQCC) had developed a Minimum Data Set (MDS) and corresponding Quality Indicators (QIs) for establishing national HCAI surveillance system, the data elements of which were repeatedly discussed, investigated, and confirmed by consensus of the expert team. The total number of data elements in MDS and QIs were 70 and 64, and they were both classified into seven categorical items. The NNIMQCC also had started two pilot projects to inspect the applicability, feasibility, and reliability of MDS. After years of hard work, more than 400 health facilities in 14 provinces have realized the importance of HCAI surveillance and contributed to developing an ability of exporting automatically standardized data to meet the requirement of MDS and participate in the regional surveillance system. Generally, the emergence of MDS and QIs in China indicates the beginning of the national HCAI surveillance based on information technology and computerized process data. The establishment of MDS aimed to use electronic health process data to ensure the data accuracy and comparability and to provide instructive and ongoing QIs to estimate and monitor the burden of HCAIs, and to evaluate the effects of interventions and direct health policy decision-making.

Multicenter surveillance study of surgical site infection and its risk factors in radical resection of colon or rectal carcinoma.

BACKGROUND: Colorectal surgery is associated with high rates of surgical site infection (SSI). We investigated SSI in radical resection of colon or rectal carcinoma and its epidemiological distribution in 26 hospitals in China. METHODS: We conducted prospective surveillance of patients who underwent radical resection of colon or rectal carcinoma in 26 selected hospitals from January 2015 to June 2016.An information system monitored all of the surgical inpatients. Infection control professionals observed the inpatients with suspected SSI who had been screened by the system at the bedside. The infection status of the incisions was followed up by telephone 1 month after the operation. RESULTS: In total, 5729 patients were enrolled for the two operations; SSIs occurred in 206 patients, and the infection rate was 3.60%. The incidence of SSI after radical resection of rectal carcinoma (5.12%; 119/2323) was 2.1 times higher than that after radical resection of colon carcinoma (2.55%; 87/3406) (P < 0.0001). Additionally, in the colon versus rectal groups, the rate of superficial incisional SSI was 0.94% versus 2.28% (P < 0.0001), the rate of deep incisional SSI was 0.56% versus 1.11% (P = 0.018), and the rate of organ space SSI was 1.06% versus 1.72% (P = 0.031), respectively. The most common pathogens causing SSIs after radical resection of colon carcinoma were Escherichia coli (21/38) and Pseudomonas aeruginosa (5/38). Escherichia coli (24/65) and Enterococcus spp. (14/65) were the two most common pathogens in the rectal group. The multivariate logistic regression analysis showed that only the operating time and number of hospital beds were common independent risk factors for SSIs after the two types of surgery. CONCLUSION: This multicenter study showed that there were significant differences in the incidence of SSIs, three types of SSIs, and some risk factors between radical resection of colon carcinoma and rectal carcinoma.

Study of helical flow inducers with different thread pitches and diameters in vena cava.

Pulmonary embolism is a severe, potentially life-threatening condition. Inferior vena cava filters have been used to prevent recurrent pulmonary embolisms. However, the build-up of thrombosis in vena cava filters after deployment presents a severe problem to patients. Previous studies proposed that filters with helical flow are beneficial and capable of alleviating this problem. In this study, the hemodynamic performances of four typical helical flow inducers in the vena cava are determined using computational fluid dynamics simulations (steady-state and pulsatile flow) and compared. Pilot in vitro experiments were also conducted. The simulation results demonstrate that large-diameter inducers produce helical flow. Among inducers with identical diameter, those with a smaller thread pitch are more likely to induce increased helical flow. We also observed that the small thread pitch inducers can yield higher shear rates. Furthermore, a large diameter, small thread pitch helical flow inducer increases the time-averaged wall shear stress and reduces the oscillating shear index and relative residence time on the vessel wall in the vicinity of the helical flow inducer. In vitro experiments also verify that large diameter inducers generate a helical flow. A notable observation of this study is that the diameter is the key parameter that affects the induction of a helical flow. This study will likely provide important guidance for the design of interventional treatments and the deployment of filters associated with helical flow in the vena cava.

A real-time surgical site infections surveillance mode to monitor surgery classification-specific, hospital-wide surgical site infections in a Chinese tertiary hospital.

We introduced a real-time surgical site infections surveillance mode (SSISM) to monitor hospital-wide surgical site infections (SSIs) based on the ICD-9-CM Volume 3 operational codes and the ICD-10 disease codes. Compared with the gold standard, the SSISM confirmed 71.9% (82/114) of SSIs from 3,048 operations with a 60-fold time-savings. The SSISM could obtain the SSI rates for each type of surgery or disease among hospital-wide inpatients in a tertiary hospital with 3,800 beds.

Improvement of hemodynamic performance using novel helical flow vena cava filter design.

We propose a vena cava filter in which helical flow is created in the filter's working zone to minimize filter blockage by trapped clots and facilitate the lysis of trapped clots. To validate this new design, we compared five helical flow inducers with different thread pitches in terms of blood flow patterns in the filter. The vena cava was reconstructed based on computed tomography images. Both the numerical simulation and in vitro experiment revealed that the helical flow inducer can effectively create a helical flow in the vessel, thereby subduing the filter structure's adverse disruption to blood flow, and increasing flow-induced shear stress in the filter center. In addition, the smaller thread pitch helical flow inducer reduced the oscillating shear index and relative residence time on the vessel wall. Moreover, we observed that the helical flow inducer in the vena cava could induce flow rotation both in clockwise and counterclockwise directions. In conclusion, the new design of the filter with the smaller thread pitch inducer is advantageous over the traditional filter in terms of improving local hemodynamics, which may reduce thrombosis build-up after deployment.

Post-ERCP infection and its epidemiological and clinical characteristics in a large Chinese tertiary hospital: a 4-year surveillance study.

Background: Endoscopic retrograde cholangiopancreatography (ERCP) is widely performed as a treatment for biliary and pancreatic illness in China; however, there are few data available regarding post-ERCP infections. This study aimed to describe the overall incidence of post-ERCP infections and the epidemiological characteristics of infected patients in a large tertiary-care hospital in China. Methods: Real-time surveillance was performed from 2012 through 2015 to identify all healthcare-associated infections (HAIs) that occurred after ERCP, using an automatic system. All HAIs (e.g., cholangtitis, bacteremia) were identified by infection control practitioners and doctors. Inpatient data were automatically collected by the surveillance system. Results: A total of 1743 ERCP operations were included in the study, among these, 132 (7.57%) HAIs were identified. ERCP postoperative infections occurred following different surgical procedures, with infection rates ranging from 3.58 to 13.51%. The most prevalent HAI was biliary tract infection (4.02%), followed by transient bacteremia (1.14%). Overall, 62 cases of bacteremia occurred following ERCP surgery and 34 (54.84%) cases occurred on the day of the operation or 1-day post-surgery. The most prevalent isolates detected during bacteremia were Enterococcus faecium (12/58) and Escherichia coli (11/58). A large proportion (72.73%) of the E. coli isolates and all of the E. faecium isolates were resistant to ciprofloxacin. In addition, only 37.50% of the E. coli isolates were susceptible to ceftriaxone. Conclusions: The high incidence of post-ERCP infection and the prevalence of drug resistance suggests that employing second generation cephalosporin or ceftriaxone as the antibiotic of choice for prophylaxis before ERCP, as recommended by the Chinese clinical application of antibacterial drugs guidelines, may not be effective.

Surveillance of Dihydropteroate Synthase Genes in Stenotrophomonas maltophilia by LAMP: Implications for Infection Control and Initial Therapy.

Stenotrophomonas maltophilia is a common nosocomial pathogen that causes high morbidity and mortality. Because of its inherent extended antibiotic resistance, therapeutic options for S. maltophilia are limited, and sulfamethoxazole/trimethoprim (SXT) is the only first-line antimicrobial recommended. However, with the spread of dihydropteroate synthase (sul1 and sul2) genes, global emergence of SXT resistance has been reported. There is an urgent need to develop a rapid and sensitive but cost-efficient method to monitor the dissemination of sul genes. In this study, we developed loop-mediated isothermal amplification (LAMP) assays for sul1 and sul2 using real-time turbidity and hydroxy naphthol blue coloration methods. The assays could quickly detect sul genes with high sensitivity and specificity. The LAMP detection limit was 0.74 pg/reaction of extracted genomic DNA for sul1 and 2.6 pg/reaction for sul2, which were both 10-fold more sensitive than the corresponding traditional PCR assays. Additionally, the LAMP assays could positively amplify DNA from sul1-producing strains, but not from the negative controls. We then used the LAMP assays to investigate the dissemination of sul genes among S. maltophilia isolates from patients in three hospitals in Beijing, China. Among 450 non-duplicated samples collected during 2012-2014, 56 (12.4%) strains were SXT-resistant. All these SXT-resistant strains were positive for sul genes, with 35 (62.5%) carrying sul1, 17 (30.4%) carrying sul2, and 4 (7.1%) carrying both sul1 and sul2, which indicated that sul genes were the predominant resistance mechanism. Of 394 SXT-susceptible strains, 16 were also sul-positive. To provide epidemiological data for the appropriate choice of antimicrobials for treatment of sul-positive S. maltophilia, we further tested the susceptibility to 18 antimicrobials. Among these, sul-positive strains showed the highest susceptibility to tetracycline derivatives, especially minocycline (MIC50/MIC90, 0.5/4; susceptibility rate, 95.4%). Ticarcillin-clavulanate and new fluoroquinolones (moxifloxacin and levofloxacin) also showed some in vitro activity. Apart from these three kinds of antimicrobials, other agents showed poor activity against sul-positive strains.

Association of Single Nucleotide Polymorphisms in Toll-like Receptors with Acinetobacter baumanii Infectionin a Chinese Population.

BACKGROUND: During recent years, infection of Acinetobacter baumanii showed a rapid growth in hospitals and community. Toll-like receptors (TLRs) are the most important pattern recognition receptors, which play a critical role during recognizing invading pathogens by the natural immune system. Our objective was to determine the associations of TLRs polymorphisms with the susceptibility to A. baumanii infection in a Chinese population. METHODS: We carried out a case-control study, genotyping 13 polymorphisms of TLR-2, TLR-4, TLR-5 and TLR-9 genes on 423 A. baumanii-infected patients and 385 exposed controls. Thirteen SNPs at the TLR-2 (rs3804099, rs7656411 and rs76112010), TLR-4 (rs1927914, rs10759932 and rs11536889), TLR-5 (rs1341987, rs1640827, rs1861172, rs2241097, rs5744174 and rs17163737) and TLR9 (rs187084) genes were analyzed. SNP genotyping was performed using an improved multiplex ligation detection reaction (iMLDR) technique. RESULTS: The SNP of TLR-9, rs187084, was related to A. baumanii-infection significantly under recessive model (G/G, to A/A + G/A, P = 0.0064, OR = 0.59, 95% CI = 0.40-0.86) after adjustment with age. Besides, the haplotype GCG of TLR-4 was significantly associated with A. baumanii infection (P = 0.027). CONCLUSION: TLR-4 and TLR-9 may be related to the susceptibility to A. baumanii infection in a Chinese population.

Nosocomial infection in adult admissions with hematological malignancies originating from different lineages: a prospective observational study.

BACKGROUND: Nosocomial infection (NI) causes prolonged hospital stays, increased healthcare costs, and higher mortality among patients with hematological malignancies (HM). However, few studies have compared the incidence of NI according to the HM lineage. OBJECTIVE: To compare the incidence of NI according to the type of HM lineage, and identify the risk factors for NI. METHODS: This prospective observational study monitored adult patients with HM admitted for >48 hours to the General Hospital of the People's Liberation Army during 2010-2013. Attack rates and incidences of NI were compared, and multivariable logistic regression was used to control for confounding effects. RESULTS: This study included 6,613 admissions from 1,922 patients. During these admissions, 1,023 acquired 1,136 NI episodes, with an attack rate of 15.47% and incidence of 9.6‰ (95% CI: 9.1-10.2). Higher rates and densities of NIs were observed among myeloid neoplasm (MN) admissions, compared to lymphoid neoplasm (LN) admissions (28.42% vs. 11.00%, P<0.001 and 11.4% vs. 8.4‰, P<0.001). NI attack rates in acute myeloid leukemia (AML) and myelodysplastic/myeloproliferative neoplasm (MDS/MPN) were higher than those in MDS (30.69% vs. 20.19%, P<0.001; 38.89% vs. 20.19%, P = 0.003). Attack rates in T/NK-cell neoplasm and B-cell neoplasm were higher than those in Hodgkin lymphoma (15.04% vs. 3.65%; 10.94% vs. 3.65%, P<0.001). Multivariable regression analysis indicated prolonged hospitalization, presence of central venous catheterization, neutropenia, current stem cell transplant, infection on admission, and old age were independently associated with higher NI incidence. After adjusting for these factors, MN admissions still had a higher risk of infection (odds ratio 1.34, 95% CI: 1.13-1.59, P<0.001). CONCLUSION: Different NI attack rates were observed for HM from different lineages, with MN lineages having a higher attack rate and incidence than LN lineages. Special attention should be paid to MN admissions, especially AML and MDS/MPN admissions, to control NI incidence.

Report of recombinant norovirus GII.g/GII.12 in Beijing, China.

BACKGROUND: Norovirus (NoV) has been recognized as the most important cause of nonbacterial acute gastroenteritis affecting all age group people in the world. Genetic recombination is a common occurance in RNA viruses and many recombinant NoV strains have been described since it was first reported in 1997. However, the knowledge of recombinant NoV in China is extremely limited. METHODS: A total of 685 stool specimens were tested for NoV infection from the acute gastroenteritis patients who visited one general hospital in Beijing from April 2009 to November 2011. The virus recombination was identified by constructing phylogenetic trees of two genes, further SimPlot and the maximum chi-square analysis. RESULTS: The overall positive rate was 9.6% (66/685). GII.4 New Orleans 2009 and GII.4 2006b variants were the dominant genotype. Four GII.g/GII.12 and one GII.12/GII.3 recombinant strains were confirmed, and all derived from adult outpatients. The predictive recombination point occurred at the open reading frame (ORF)1/ORF2 overlap. CONCLUSIONS: The GII.g ORF1/GII.12ORF2 recombinant has been reported in several countries and it was the first report of this recombinant in China.

Real-time automatic hospital-wide surveillance of nosocomial infections and outbreaks in a large Chinese tertiary hospital.

BACKGROUND: We aimed to develop a real-time nosocomial infection surveillance system (RT-NISS) to monitor all nosocomial infections (NIs) and outbreaks in a Chinese comprehensive hospital to better prevent and control NIs. METHODS: The screening algorithm used in RT-NISS included microbiological reports, antibiotic usage, serological and molecular testing, imaging reports, and fever history. The system could, in real-time, identify new NIs, record data, and produce time-series reports to align NI cases. RESULTS: Compared with a manual survey of NIs (the gold standard), the sensitivity and specificity of RT-NISS was 98.8% (84/85) and 93.0% (827/889), with time-saving efficiencies of about 200 times. RT-NISS obtained the highest hospital-wide monthly NI rate of 2.62%, while physician and medical record reviews reported rates of 1.52% and 2.35% respectively. It took about two hours for one infection control practitioner (ICP) to deal with 70 new suspicious NI cases; there were 3,500 inpatients each day in the study hospital. The system could also provide various updated data (i.e. the daily NI rate, surgical site infection (SSI) rate) for each ward, or the entire hospital. Within 3 years of implementing RT-NISS, the ICPs monitored and successfully controlled about 30 NI clusters and 4 outbreaks at the study hospital. CONCLUSIONS: Just like the "ICPs' eyes", RT-NISS was an essential and efficient tool for the day-to-day monitoring of all NIs and outbreak within the hospital; a task that would not have been accomplished through manual process.

Penetration of erythromycin through Staphylococcus epidermidis biofilm.

BACKGROUND: The catheter related infection caused by Staphylococcus epidermidis biofilm is increasing and difficult to treat by antimicrobial chemotherapy. The properties of biofilms that give rise to antibiotic resistance are only partially understood. This study aimed to elucidate the penetration of erythromycin through Staphylococcus epidermidis biofilm. METHODS: The penetration ratio of erythromycin through Staphylococcus epidermidis biofilms of 1457, 1457-msrA, and wild isolate S68 was detected by biofilm penetration model at different time points according to the standard regression curve. The RNA/DNA ratio and the cell density within the biofilms were observed by confocal laser microscope and transmission electromicroscope, respectively. RESULTS: The penetration ratios of erythromycin through the biofilms of 1457, 1457-msrA, and S68 after cultivation for 36 hours were 0.93, 0.55 and 0.4, respectively. The erythromycin penetration ratio through 1457 biofilm (0.58 after 8 hours) was higher than that through the other two (0.499 and 0.31 after 24 hours). Lower growth rate of the cells in biofilm was shown, with reduction of RNA/DNA proportion observed by confocal laser microscope through acridine orange stain. Compared with the control group observed by transmission electrmicroscope, the cell density of biofilm air face was lower than that of agar face, with more cell debris. CONCLUSIONS: Erythromycin could penetrate to the Staphylococcus epidermidis biofilm, but could not kill the cells thoroughly. The lower growth rate of the cells within biofilm could help decreasing the erythromycin susceptibility.

[Study on the molecular epidemiological characteristics of norovirus in acute gastroenteritis of Beijing].

OBJECTIVE: To study the prevalence, genotypes and molecular characteristics of norovirus (NoV) in acute gastroenteritis. METHODS: RT-PCR was used to determine the molecular epidemiology of NoV. RESULTS: Out of 685 samples, 66 positive specimens were identified and the prevalence was 9.6% (66/685), 9.9% in males and 9.4% in females, respectively, with no significant difference. The prevalence rates showed no differences between age groups or between inpatients and outpatients. NoV gastroenteritis did not present any seasonal distribution. 43 out of the 66 specimens were classified, with 10 (22.7%) belonged to GI including 2 GI.3, 1 GI.4, 4 GI.5 and 3 GI.7. Other 33 (77.3%) belonged to GII genogroup, including GII.4 accounted for 60.6% (20/33) and followed by 7 GII.12, 2 GII.6, 1 GII.2, 1 GII.3, 1 GII.5. Six specimens mixed with GI and GII and 3 specimens were classified as GI.3/GII.7, GI.5/GII.5 and GI.4/GII.4. CONCLUSION: The main symptoms of acute gastroenteritis were abdominal pain, nausea, vomit and fever. There were many genotypes identified in our study and the main genotypes were GII.4/2006a and 2006b. GI and GII could be coinfected with each other.

Consistency of the key genotypes of Orientia tsutsugamushi in scrub typhus patients, rodents, and chiggers from a new endemic focus of northern China.

Scrub typhus is one of the most common infectious diseases of rural south and southeastern Asia and the western Pacific. It emerged in Shandong Province in northern China from autumn to winter of 1986. Since then, the "autumn-winter type scrub typhus" has been found in many areas of northern China. However, the principle genotypes of Orientia tsutsugamushi still remain unknown. This study was undertaken to identify the genotypes of O. tsutsugamushi obtained from scrub typhus patients, chigger mites and rodents from the focal point of the problem in Shandong Province. Forty-four isolates from patients, rodents, and chiggers, 47 blood clots from patients during the acute phase, 10 eschars from patients during the convalescence phase and 16 pools of larval chiggers were tested for the scrub typhus antigen 56-kD protein (Sta56) gene by nested PCR methodology and additional sequence analysis including DNA sequence alignment and phylogenetic analysis. Based on nested PCR, ninety-five initial PCR-positive samples produced amplicons using Kawasaki strain-specific primers, while the other two (the FXS4 and LHGM2 strains) produced amplicons using Karp strain-specific primers. The partial Sta56 gene sequence analysis indicated that the sequence homologies of 3 selected isolates (the B16, FXS2, and XDM2 strains) and 7 eschars out of the 95 samples, which were nested PCR-positive using Kawasaki strain-specific primers, were 94-98% to that of Kawasaki strain. The sequence homology of the FXS4 and LHGM2 strains to that of the Karp strain was respectively 83 and 96%. These findings implied that the key genotypes of O. tsutsugamushi in patients, rodents, and chiggers in Shandong Province were identical and similar to Kawasaki strains.

Clinical application of RT-nested PCR integrated with RFLP in Hantavirus detection and genotyping: a prospective study in Shandong Province, PR China.

The aim of the present study was to evaluate the clinical usefulness of applying RT-nested PCR along with RFLP as a method for diagnosis and genotypic differentiation of Hantavirus in the acute-stage sera of HFRS patients as compared to the ELISA technique. A prospective study of patients with suspected HFRS patients was carried out. Sera were collected for serological evaluation by ELISA and RT-nested PCR testing. Primers were selected from the published sequence of the S segment of HTNV strain 76-118 and SEOV strain SR-11, which made it possible to obtain an amplicon of 403 bp by RT-nested PCR. The genotypic differentiations of the RT-nested PCR amplicons were carried out by RFLP. Sequence analyses of the amplicons were used to confirm the accuracy of the results obtained by RFLP. Of the 48 acute-stage sera from suspected HFRS patients, 35 were ELISA-positive while 41 were positive by RT-nested PCR. With Hind III and Hinf I, RFLP profiles of the RT-nested PCR amplicons of the 41 positive sera exhibited two patterns. 33 had RFLP profiles similar to the reference strain R22, and thus belonged to the SEOV type. The other 8 samples which were collected during October-December had RFLP profiles similar to the reference strain 76-118, and thus belonged to the HTNV type. Sequence phylogenetic analysis of RT-nested PCR amplicons revealed sdp1, sdp2 YXL-2008, and sdp3 as close relatives of HTNV strain 76-118, while sdp22 and sdp37 as close relatives of SEOV strain Z37 and strain R22 located in two separate clusters in the phylogenetic tree. These results were identical to those acquired by RFLP. RT-nested PCR integrated with RFLP was a rapid, simple, accurate method for detecting and differentiating the genotypes of Hantavirus in the acute-stage sera of suspected HFRS patients. In Shandong province, the main genotypes of Hantavirus belonged to the SEOV types, while the HTNV types were observed during the autumn-winter season.

The cross-transmission of 2009 pandemic influenza A (H1N1) infections among healthcare workers and inpatients in a chinese tertiary hospital.

We reported 2009 H1N1 influenza infections among healthcare workers (HCWs) and inpatients and the prevention measures instituted in a large Chinese hospital. In total, 171 HCWs and 89 inpatients tested positive for H1N1. Sixteen HCWs had known hospital exposure, among whom only 7 had working-contact exposure. There was no influenza outbreak.

Perinatal outcomes and congenital abnormalities in the newborns of women affected by the 2009 pandemic influenza A (H1N1) in Beijing, China.

OBJECTIVE: To investigate the pregnancy complications, perinatal outcomes, and congenital abnormalities (CAs) that occurred in Beijing, China, when pregnant women became infected with the 2009 pandemic influenza A (H1N1) (H1N1 pdm). METHODS: Pregnancy complications, perinatal outcomes, and CAs were compared among 3 groups of pregnant women. The 23 women in group 1 were confirmed to harbor viral RNA; the 23 in group 2 had serum levels of virus-specific antibodies against H1N1 pdm, meaning that they were suspected of being infected with the virus; and the 93 in group 3 had no detectable virus-specific antibodies. RESULTS: Perinatal outcomes and pregnancy complications were not significantly different in groups 1 and 3. Higher percentages of stillbirths (12.0%) and placental disorders (13.0%) were observed in group 2 than in group 3. Many women in group 2 (62.5%) experienced symptoms of having a cold during pregnancy and most took no medication. Two cases of CA occurred in group 1, in the offspring of women infected in the second trimester. CONCLUSION: When left untreated, infection with the 2009 H1N1 pdm virus during pregnancy appears to have increased fetal mortality and morbidity. Because CAs are traumatic for all concerned, their possible association with the virus should be further evaluated.