Blood defense system - Proposal for a new concept of an immune system against blood borne pathogens comprising the liver, spleen and bone marrow.

Blood-borne pathogen (BBP) infections can rapidly progress to life-threatening sepsis and must therefore be promptly eliminated by the host's immune system. Intravascular macrophages of the liver sinusoid, splenic marginal zone and red pulp and perisinusoidal macrophage protrusions in the bone marrow (BM) directly phagocytose BBPs in the blood as an innate immune response. The liver, spleen and BM thereby work together as the blood defence system (BDS) in response to BBPs by exerting their different immunological roles. The liver removes the vast majority of these invading organisms via innate immunity, but their complete elimination is not possible without the actions of antibodies. Splenic marginal zone B cells promptly produce IgM and IgG antibodies against BBPs. The splenic marginal zone transports antigenic information from the innate to the adaptive immune systems. The white pulp of the spleen functions as adaptive immune tissue and produces specific and high-affinity antibodies with an immune memory against BBPs. The BM works to maintain immune memory by supporting the survival of memory B cells, memory T cells and long-lived plasma cells (LLPCs), all of which have dedicated niches. Furthermore, BM perisinusoidal naïve follicular B cells promptly produce IgM antibodies against BBPs in the BM sinusoid and the IgG memory B cells residing in the BM rapidly transform to plasma cells which produce high-affinity IgG antibodies upon reinfection. This review describes the complete immune defence characteristics of the BDS against BBPs through the collaboration of the liver, spleen and BM with combined different immunological roles.

[Analysis of the reentry status of blood donors with reactive bloodborne pathogen screening markers in Hangzhou City].

Objective: To explore the reentry rate of reactive blood donors in the bloodborne pathogen infection screening in Hangzhou City, and analyze the donation behavior of those who successfully returned. Methods: A retrospective analysis of the return data of blood donors with reactive bloodborne pathogen screening markers was conducted at Zhejiang Provincial Blood Center from June 2017 to May 2022. The reentry process for blood donors with reactive bloodborne pathogen screening markers in Hangzhou City is as follows: after the initial screening period of 6 months, donors can voluntarily apply for return to the blood center. Samples are collected and subjected to routine enzyme-linked immunosorbent assay (ELISA) screening for HBsAg, anti-HCV, HIV Ab/Ag, and anti-TP, as well as a single nucleic acid (HIV/HCV/HBV) test. For samples that show non-reactivity in both ELISA and nucleic acid tests, serum biomarker testing for the reasons of exclusion is performed using chemiluminescence immunoassay (CLIA), and those with non-reactivity are allowed to return. Results: A total of 4 583 reactive blood donors who met the criteria for re-entry applied for reentry, out of which 475 applications were received from donors in the Hangzhou area. Among these, 279 donors were successfully readmitted, resulting in a success rate of 58.74% (279/475). By the end of December 2021, out of the 174 donors who successfully returned, 114 donors chose to donate again. They collectively donated 39 530 ml of whole blood and 1 147.2 therapeutic doses of platelets. Among these, 21 donors once again showed reactivity for pathogen infection biomarkers, accounting for 18.42% (21/114). Conclusion: The reentry strategy has somewhat mitigated the attrition of blood donors. Nevertheless, there are instances where donors who were successfully readmitted show reactivity once more in the screening for pathogen infection biomarkers.

Management of Occupational Bloodborne Pathogen Exposure among Medical Personnel: a 4-Year Prospective Study.

This study examined the management of occupational bloodborne pathogen exposure at a tertiary hospital in China. This prospective study was conducted at the Zhejiang Hospital of Traditional Chinese Medicine between January 2016 and December 2019. Data on bloodborne occupational exposure management were collected. In total, 460 exposures were reported. The majority of exposures (40.2 %) were from hepatitis B virus (HBV)-positive index patients. Of the 460 cases, 453 (98.5%) exposures were reported timeously, and 371 (80.7%) cases received emergency treatment response and management. Sixty-eight personnel (93.2%) received timely prophylaxis treatment. Only 82/113 (72.6%) personnel completed the recommended follow-up period. Outsourced personnel(P = 0.002) and interns (P = 0.011) were independent follow-up factors. Although adequate compliance was achieved with timely reporting and prophylactic medication, there is room for improvement in terms of emergency treatment response and follow-up compliance. Furthermore, HBV vaccination and improved follow-up with outsourced personnel are recommended.

Epidemiology of occupational exposure to blood-borne viruses, postexposure prophylaxis and seroconversion over 10 years among healthcare workers.

BACKGROUND: Healthcare workers (HCWs) are at increased risk of infection with blood-borne pathogens due to occupational blood exposures (OBEs). Early reporting, detection and postexposure prophylaxis (PEP) help to prevent infections. AIM: To investigate the incidence of OBEs, related epidemiological characteristics, PEP completion rate, time and reason for PEP discontinuation, and seroconversion rate reported over 10 years. METHODS: This retrospective study analysed 1086 cases of OBE and PEP management from January 2012 to December 2021 among staff in a South Korean tertiary hospital. FINDINGS: The mean incidence of OBE was 7.82 per 100 beds and 3.0 per 100 HCWs. Of 1086 cases of OBE, 633 (58.3%) HCWs required PEP and 453 (41.7%) did not. After OBE, 70.1% (444/633) of HCWs subject to PEP completed tracking, and 29.9% (189/633) stopped PEP tracking (P<0.001). The PEP completion rate showed a significant difference by gender (P=0.024), occupation (P<0.001) and exposure frequency (P<0.001). None of the 444 HCWs who completed PEP seroconverted to hepatitis B virus, hepatitis C virus, human immunodeficiency virus or Treponema pallidum (syphilis). CONCLUSION: The study findings demonstrate the need to improve follow-up care among HCWs following OBE. There is a need for education in healthcare facilities; moreover, establishing a national surveillance system is necessary to ensure that HCWs undergo PEP proactively and complete their follow-up visits.

Surgical Glove Perforation and Percutaneous Injury during Intermaxillary Fixation with 0.5 Mm Stainless Steel Wire.

INTRODUCTION: The risk of exposure of either the patient or the surgeon to pathogens when the surgical glove is perforated is significant. This is particularly so in jaw fractures when intermaxillary fixation is done with the stainless-steel wire as many perforations also result in percutaneous injury. MATERIAL AND METHOD: This study was carried out in two tertiary Hospitals in Abuja, Nigeria. Adult patients for intermaxillary fixation as a result of jaw fractures were consecutively recruited into the study. Similarly, surgeons and their trainees (assistants) were also recruited. Factors investigated included the method of gloving used by surgeons and trainees (single versus double gloving), glove perforations and percutaneous injury rates, years of operator's experience, among others. During surgical operations, percutaneous injuries were recorded and obviously perforated or torn gloves were labelled and changed. At the end of every surgical procedure, gloves used were investigated for perforation. RESULTS: A total of 564 gloves were investigated (Surgeons-337; Trainees-227) after use for wire intermaxillary fixation procedures. The frequency of glove perforations for the surgeons was 72 (21.4%). Forefinger perforations were most frequent; 40 (55.6%) cases. Assistants, had 35 (15.4%) cases of glove perforations. Percutaneous injury occurred in 9.7% (7/72) and 5.7% (2/35 cases) of cases for surgeons and assistants, respectively. CONCLUSION: The study revealed high risk for wire-based IMF procedures. Single gloving was more frequently associated with percutaneous injuries although double gloving was more associated with perforations with higher surgeon infection risk. Double gloving reduces the risk of percutaneous injuries and, therefore, the likelihood of exposure to blood-borne pathogens.

INTRODUCTION: Le risque d'exposition du patient ou du chirurgien à des agents pathogènes lorsque le gant chirurgical est perforé est important. Cela est particulièrement le cas dans les fractures de la mâchoire lorsque la fixation intermaxillaire est effectuée avec le fil en acier inoxydable, car de nombreuses perforations entraînent également des lésions percutanées. MATÉRIEL ET MÉTHODE: Cette étude a été réalisée dans deux hôpitaux tertiaires à Abuja, au Nigeria. Des patients adultes pour une fixation intermaxillaire à la suite de fractures de la mâchoire ont été recrutés consécutivement dans l'étude. De même, des chirurgiens et leurs stagiaires (assistants) ont également été recrutés. Les facteurs étudiés comprenaient la méthode de gloving utilisée par les chirurgiens et les stagiaires (simple versus double gloving), les perforations de gants et les taux de blessures percutanées, les années d'expérience de l'opérateur, entre autres. Au cours des opérations chirurgicales, des blessures percutanées ont été enregistrées et des gants manifestement perforés ou déchirés ont été étiquetés et changés. À la fin de chaque intervention chirurgicale, les gants utilisés ont été étudiés pour la perforation. RÉSULTATS: Au total, 895 gants ont fait l'objet d'une enquête (Surgeons-337; Stagiaires-227) après utilisation pour les procédures de fixation intermaxillaire du fil. La fréquence des perforations de gants chez les chirurgiens était de 72 (21,4 %). Les perforations de l'index étaient les plus fréquentes, 40 (55,6 %) cas. Assistant, avait 35 (15,4%) cas de perforations de gants. Des lésions percutanées sont survenues dans 9,7 % (7/72) et 5,7 % (2/35 cas) des cas chez les chirurgiens et les assistants respectivement. CONCLUSION: L'étude a révélé un risque élevé pour les procédures filaires du FMI. Le gloving simple était plus fréquemment associé à des blessures percutanées, bien que le double gloving soit plus associé à des perforations avec un risque d'infection plus élevé chez le chirurgien. Le double gloving réduit le risque de blessures percutanées et, par conséquent, la probabilité d'exposition à des agents pathogènes transmissibles par le sang. MOTS CLÉS: Fixation intermaxillaire, gants, Chirurgien, Lésion percutanée.

[Risk factors analysis and intervention of blood-borne occupational exposure in medical staff].

Objective: To analyze the risk factors of blood-borne occupational exposure among medical staff and explore the relevant intervention measures. Methods: In June 2020, the data of blood-borne occupational exposure and related factors reported by medical staff in a grade Ⅲ, Grade A general hospital from 2011 to 2019 were analyzed by retrospective investigation. Results: Among 431 cases of blood-borne occupational exposure, 69.37% were nurses. It mainly occurred in medical staff with 0-4 years of service, accounting for 63.57%; The main place of occupational exposure was in the ward 47.56%; Sharp instrument injury was the main occupational exposure route 91.65%. Occupational exposure department was mainly surgery department 17.87%; The main source of exposure was hepatitis B virus (HBV) 37.12%, followed by treponema pallidum 20.19%. Statistical analysis results show that: Exposure sites (χ(2)=43.585, P<0.01) , exposure sources (χ(2)=22.693, P<0.01) , treatment methods after exposure (χ(2)=18.866, P<0.01) , Flushing (χ(2)=31.963, P<0.01) and disinfection (χ(2)=14.216, P<0.01) were significantly different. Conclusion: The effective measures to reduce blood-borne occupational exposure are to strengthen occupational protection training of medical staff, standardize operation procedures, strengthen supervision of key groups and departments, improve reporting, monitoring and follow-up systems to realize informatization, and do a good job in risk control.

Investigation of the occupational exposure to blood-borne pathogens of staff at a third-class specialist hospital in 2015-2018: a retrospective study.

To understand the current situation of occupational exposure to blood-borne pathogens in a women's and children's hospital and analyze the causes to provide a scientific basis for improving occupational exposure prevention and control measures. We analyzed occupational exposure to blood-borne pathogens in a third-class women's and children's hospital from 2015 to 2018, considering the workers' occupational categories and length of service; the sites, types, and causes of exposure; and the pathogens of the source patients. From 2015 to 2018, there were 146 cases of occupational exposure to blood-borne pathogens, mainly from sharp-instrument injuries (81.5%; 119/146). Trainees represented the highest proportion of occupational exposure (30.1%; 44/146), followed by nurses (29.5%; 43/146). Occupational exposure among staff with less than one year of service accounted for 43.2% (63/146) of cases. Fisher's exact test showed that different occupational groups had different types of occupational exposure, and among the occupationally exposed populations, the proportion of sharp injuries is higher than that of blood and body fluid exposure, and the difference is statistically significant (χ2 = 12.937, P = 0.008). Different occupational groups faced exposure to different types of pathogens: medical staff were more likely than workmen to be exposed to hepatitis B, while workmen were more likely than medical staff to be exposed to unknown pathogens; these differences were statistically significant (χ2 = 55.344, P < 0.001). Health records were established for all cases of occupational exposure to blood-borne pathogens, and no staff members contracted a blood-borne disease due to occupational exposure. In order to reduce occupational exposure, regular training in occupational protection for junior medical staff and workers should be strengthened, the monitoring and protection system of occupational exposure to blood-borne pathogens improved, standard prevention measures strengthened, operations standardized, safe injection equipment provided, and comprehensive measures taken.

Multiplex detection of blood-borne pathogens on a self-driven microfluidic chip using loop-mediated isothermal amplification.

Detection of blood-borne pathogens such as hepatitis C virus (HCV), hepatitis B virus (HBV) and human immunodeficiency virus (HIV) is essential to ensure the safety of blood transfusion. However, traditional PCR-based pathogen nucleic acid detection methods require relatively high experimental facilities and are difficult to apply in areas with limited resources. In this study, a self-driven microfluidic chip was designed to carry out multiplex detection of HBV, HCV and HIV by using loop-mediated isothermal amplification (LAMP). Benefitting from the air permeability of the polydimethylsiloxane material, the chip could accomplish sample loading within 12 min driven by the pressure difference between the reaction chambers and vacuum chambers in the chip without using pumps or any injection devices. Multiplex detection is achieved by presetting LAMP primers specific to different targets in different reaction chambers. Calcein was used as an indicator to indicate the positive amplification reaction, and the result can be recorded by a smartphone camera. After 50 min of isothermal amplification at 63 °C, 2 copies/µL of HBV, HCV and HIV target nucleic acids could be detected. The results of HBV detection of 20 clinical plasma samples by using the chip are consistent with that of the qPCR-based kit, indicating that the LAMP-based self-driven chip has the clinical application potential for blood-borne pathogen detection, especially in resource-limited areas.

Occupational Exposure to Blood-Borne Pathogens among Healthcare Workers in a Tertiary Care Center in Lebanon.

OBJECTIVES: Despite numerous initiatives, occupational exposure to blood-borne pathogens (BBP) caused by percutaneous injuries or mucosal contamination remain common among healthcare workers (HCWs). These exposures were decreasing at the American University of Beirut Medical Center (AUBMC) in the previous decades. Recently, the medical center activity has been increasing with higher number of interventions performed and shorter hospital stay. Our aim was to determine the trend of incidents resulting from BBP exposures at AUBMC from 2014 till 2018 and identify whether the increase in hospital activity affected the rate of these exposures. We also aimed to assess the risk factors associated with needle stick injuries (NSIs). METHODS: A retrospective observational descriptive study of all exposures to BBPs among HCWs reported to the Environmental Health, Safety, and Risk Management department at the AUBMC between 2014 and 2018 was performed. RESULTS: There were 967 exposures reported among which 84% were due to needlesticks. Residents (40%), followed by nurses (30%), and then by attending physicians (16%) were the top three most exposed occupational groups. Half of the participants injured themselves using either a syringe or a suture needle; and mostly during or after use. Occupation and incident location were associated with NSIs. The mean BBP exposure incidence rate was 5.4 per 100 full-time employees, 65.6 per 100 bed-years, and 0.48 admission-years. The BBP exposure rate per 100 occupied beds per year decreased between 2014 and 2017 then increased in 2018 (P < 0.001). The number of BBP exposures showed a strong, though non-significant negative correlation with the average length of hospital stay (Spearman correlation coefficient = -0.9, P = 0.083). CONCLUSIONS: BBP exposure remains a serious occupational hazard. Our study shows that the BBP exposure rate per 100 occupied beds per year started decreasing during the study period before increasing again in 2018. Only the nursing department showed a consistent decrease of exposures. The occupation and incident location were found to be risk factors associated with NSIs. In addition to providing education and training, additional steps such as providing safety equipment and future interventions directed towards adjusting to higher workload should be all considered.

Fatal sepsis associated with a storage container leak permitting platelet contamination with environmental bacteria after pathogen reduction.

BACKGROUND: Pathogen reduction technology and enhanced bacterial culture screening promise to significantly reduce the risk of transfusion-associated septic reactions due to contaminated platelets. Recent reports suggest that these interventions lack efficacy for post-collection and processing contamination with environmental organisms if the storage bag integrity is compromised. CASE REPORT: We report a fatal septic transfusion reaction in a 63-year-old patient with chronic kidney and liver disease who received a pathogen reduced platelet transfusion in anticipation of surgery. METHODS: The residual platelet concentrate was cultured, with the detected microorganisms undergoing 16S genotype sequencing. Separate pathogen reduction studies were performed on the recovered bacteria, including assessment for amotosalen photoproducts. The storage container was subjected to pressure testing and microscopic examination. Environmental culture screening was performed at the hospital. RESULTS: Gram negative rods were detected in the platelet unit and cultures of both platelet component and the patient's blood grew Acinetobacter baumannii complex, Leclercia adecarboxylata and Staphylococcus saprophyticus. These strains were effectively inactivated with >7.2, 7.7, and >7.1 log10 kill, respectively. The platelet storage container revealed a leak visible only on pressure testing. Hospital environmental cultures were negative and the contamination source is unknown. A. baumannii complex and S. saprophyticus 16S genotyping sequences were identical to those implicated in a previously reported septic reaction. CONCLUSION: Findings are compatible with post-processing environmental contamination of a pathogen reduced platelet concentrate via a non-visible, acquired storage container leak. Efforts are warranted to actively prevent damage to, and detect defects in, platelet storage containers, and to store and transport components in clean environments.

Occupational exposures to bloodborne pathogens and its underreporting in dental teaching environment in an Indian dental school.

INTRODUCTION: The aims of this study were 1) to find out the prevalence of occupational exposures to contaminated biological material among undergraduate students and interns; 2) to find out how many cases of occupational exposures to bloodborne pathogens are reported; and 3) to know the reasons for non-reporting of occupational exposures. MATERIALS AND METHODS: The study was conducted in a Dental School in Navi-Mumbai, India. An anonymous self-administered questionnaire was formulated. 210 dental students were given a questionnaire out of which 150 students attending clinical postings in their third year, final year, and internship responded. Approval was obtained from the Institutional Ethical Committee. RESULTS: The study revealed a very high prevalence (66.7%) of exposures among the students. Only 12% of the students reported the exposures to the staff. Students from III year and final year BDS (Bachelor of Dental Surgery) had mean exposure of 2.40 as compared to 1.94 among interns. 46% of the students stated that they did not report about the exposure because they thought that injury was of minor nature. CONCLUSION: There is a very high prevalence of occupational exposures among students which are not reported. There is a need for the development of a post exposure protocol which has to be strictly implemented. The principle of infection control has to be emphasised to the students periodically and they should be encouraged to report incidences of exposures to biological material.

The Prevalence of Blood-Borne Pathogens in Maxillofacial Trauma Patients.

BACKGROUND: Blood-borne pathogen infections (BPIs), caused by the human immunodeficiency virus, hepatitis C and hepatitis B viruses pose an occupational hazard to healthcare workers. Facial trauma reconstruction surgeons may be at elevated risk because of routine use of sharps, and a higher than average incidence of BPIs in the trauma patient population. METHODS: The authors retrospectively reviewed health records of patients admitted to a level 1 trauma center with a facial fracture between January 2010 and December 2015. Patient demographics, medical history, mechanism of injury, type of fracture, and procedures performed were documented. The authors detemined the frequency of human immunodeficiency virus, hepatitis B, and hepatitis C diagnosis and utilized univariable/multivariable analyses to identify risk factors associated with infection in this population. RESULTS: In total, 4608 consecutive patients were included. Infections were found in 4.8% (n = 219) of patients (human immunodeficiency virus 1.6%, hepatitis C 3.3%, hepatitis B 0.8%). 76.3% of BPI patients in this cohort were identified by medical history, while 23.7% were diagnosed by serology following initiation of care. 39.0% of all patients received surgical treatment during initial hospitalization, of whom 4.3% had a diagnosed BPI. History of intravenous drug use (odds ratio [OR] 6.79, P < 0.001), assault-related injury (OR 1.61, P = 0.003), positive toxicology screen (OR 1.56, P = 0.004), and male gender (OR 1.53, P = 0.037) were significantly associated with a BPI diagnosis. CONCLUSION: Patients presenting with facial fractures commonly harbor a BPI. The benefit of early diagnosis and risk to surgical staff may justify routine screening for BPI in high risk facial trauma patients (male, assault-related injury, and history of intravenous drug use).

The effect of pathogen inactivation on cryoprecipitate: a functional and quantitative evaluation.

BACKGROUND: As a pooled donor blood product, cryoprecipitate (cryo) carries risks of pathogen transmission. Pathogen inactivation (PI) improves the safety of cryoprecipitate, but its effects on haemostatic properties remain unclear. This study investigated protein expression in samples of pathogen inactivated cryoprecipitate (PI-cryo) using non-targeted quantitative proteomics and in vitro haemostatic capacity of PI-cryo. MATERIALS AND METHODS: Whole blood (WB)- and apheresis (APH)-derived plasma was subject to PI with INTERCEPT® Blood System (Cerus Corporation, Concord, CA, USA) and cryo was prepared from treated plasma. Protein levels in PI-cryo and paired controls were quantified using liquid chromatography-tandem mass spectrometry. Functional haemostatic properties of PI-cryo were assessed using a microparticle (MP) prothrombinase assay, thrombin generation assay, and an in vitro coagulopathy model subjected to thromboelastometry. RESULTS: Over 300 proteins were quantified across paired PI-cryo and controls. PI did not alter the expression of coagulation factors, but levels of platelet-derived proteins and platelet-derived MPs were markedly lower in the WB PI-cryo group. Compared to controls, WB (but not APH) cryo samples demonstrated significantly lower MP prothrombinase activity, prolonged clotting time, and lower clot firmness on thromboelastometry after PI. However, PI did not affect overall thrombin generation variables in either group. DISCUSSION: Data from this study suggest that PI via INTERCEPT® Blood System does not significantly impact the coagulation factor content or function of cryo but reduces the higher MP content in WB-derived cryo. PI-cryo products may confer benefits in reducing pathogen transmission without affecting haemostatic function, but further in vivo assessment is warranted.

Occupational exposure to blood and body fluids among primary healthcare workers in Johannesburg health district: High rate of underreporting.

BACKGROUND: Healthcare workers (HCWs) are at risk of bloodborne infections from sharp instrument injuries and skin and mucous membrane exposures to contaminated blood and body fluids (BBF). While these have clinical and occupational health implications, little is known about BBF exposure and its reporting pattern in South African primary healthcare (PHC). The aim of this study was to determine the rate of BBF exposure, the extent of reporting and the reasons for not reporting among HCWs in PHC facilities in Johannesburg, South Africa. METHODS: In a cross-sectional study involving 444 participants, an 18-item, self-administered questionnaire was used to collect information on socio-demographic characteristics, HCWs' exposures to BBF in the last year, whether the exposure was reported and the reasons for not reporting. Analysis included descriptive statistics and chi-square test. RESULTS: Most participants were nurses (87.4%) and female (88.1%). About a quarter of participants (112) reported having at least one BBF exposure in the last year. Overall, there were 355 exposures, resulting in 0.8 BBF exposure per HCW per year. Of these exposures, 291 (82.0%) were not reported. Common reasons for not reporting include lack of time (42.72%), perception that the source patient was at low risk for human immunodeficiency virus (24.7%) and concerns about confidentiality (22.5%). Blood and body fluids exposures involving nurses (p 0.001), sharp instrument (p 0.001) and HCWs aged 50 years (p = 0.02) were significantly more likely to be reported. CONCLUSION: This study found a high rate of underreporting of BBF exposures among HCWs in PHC facilities in Johannesburg, suggesting an urgent need for interventions to improve reporting.

[Investigation of 603 medical staff occupational exposure with blood-borne pathogens].

Objective: To investigate the occupational exposure with blood-borne pathogens of medical staff, and explore the protective strategy. Methods: Using cluster sampling method, 603 medical staff with occupational exposure with blood-borne pathogens were analyzed, from July 2014 to July 2018 in a tertiary hospital. Results: In total of 603 occupational exposure incidents, 70.98% (428/603) were freshmen younger than 30 years old. 48.92% (295/603) nurses. The most cases of occupational exposure were in surgery (35.16%, 212/603) . Sharp injury was the major contact manner (86.90%, 524/603) . Hands were the main contact parts (90.38%, 545/603) . Ward (53.57%, 323/603) and the operating room (22.72%, 137/603) were the high-risk place. The most dangerous actions were needle injection (34.83%, 210/603) , surgery (20.89%, 126/603) and finishing/cleaning items (19.73%, 119/603) . The main items lead to injuries were scalp needles (34.73%, 182/524) . The most exposure source was hepatitis B virus (HBV) which occupied 39.30% (237/603) . Exposure source mainly comes from medical devices containing blood (81.92%, 494/603) . To compared the groups (χ(2)=19.940, P<0.01) and titer (t=-8.592, P<0.01) of hepatitis B surface antibody (HBsAb) before and after used prophylactics, the differences were statistically significant. Conclusion: Comprehensive strategies of occupational exposure protection education, operation norms and monitoring management were effective methods to reduce the occupational exposure in the medical staff with blood-borne pathogens.

The human spleen as the center of the blood defense system.

Blood-borne infections can develop into sepsis and are therefore a major human health risk. The responsible pathogens thus need to be eliminated rapidly. Intravascular macrophages in the liver and bone marrow (BM) sinuses, and in the red pulp and marginal zone of the spleen, remove the majority of these microorganisms via innate immunity. However, specific antibodies are essential for their complete elimination. Splenic marginal zone B cells simultaneously produce many of the IgM and IgG2 antibodies that target blood-borne pathogens within a few days of infection. Subsequently, follicular B cells of the white pulp of the spleen produce specific IgG antibodies against the invading pathogens, known as adaptive immunity. Although the liver, BM, and spleen work together to activate the defense response to blood-borne pathogens through innate and adaptive immunity, the spleen acts as the center of the blood defense system (BDS). The structure of the spleen is introduced in this review in relation to its function in the BDS as part of the response of the immune system and of functioning organs to blood-borne pathogens. The concept of a BDS is also important for hematological disorders, such as lymphomas and; therefore, may be useful to hematologists and pathologists.

Systematic Review of Blood-Borne Pathogen Exposure Rates Among Medical Students.

BACKGROUND: Blood-borne pathogen exposures (BBPEs) pose a risk to health care workers (HCWs). Needlestick injuries (NSIs) have declined overall, but not for surgical HCWs. There are limited data regarding BBPEs among medical students (MSs) in their clinical years. We aimed to quantify this risk for third- and fourth-year MSs. METHODS: A literature review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The PUBMED database was searched to identify studies of third- and fourth-year MSs using the terms BBPE, NSI, and MS. Studies of other HCWs were excluded if MS data were not extractable. Additional studies were identified from references. Descriptive analysis was performed. RESULTS: Seven of 171 articles published from 2002 to 2018 met study criteria. All used self-reported data from surveys/questionnaires. One-third of MSs reported BBPEs (n = 194/600, 32.3%) with a mean of 1 in 3.09 and a median of 1 in 3.53 (range: 1 in 1.9-8.3 students). Most events were NSIs (144/194, 74%) with a mean of 1 NSI per 4.05 MSs and median of 1 in 4.625 (range: 1 in 2.47-10.71). The remaining BBPEs reported included blood and bodily fluid splashes (n = 37, 19%), other mucocutaneous exposures (n = 7, 3.6%), and uncategorized injuries (n = 2, 1%). CONCLUSIONS: One-third of senior MSs reported BBPEs during clinical rotations. Most BBPEs were NSIs. Quantifying this risk allows for anticipatory education and protocol development to protect students and other new HCWs. Educational efforts focused on NSI prevention before and during clinical rotations may help reduce BBPEs.

Conhecimento e adesão como fatores associados a acidentes com agulhas contaminadas com material biológico: Brasil e Colômbia / Knowledge and compliance as factors associated with needlestick injuries contaminated with biological material: Brazil and Colombia / Conocimiento y adhesión como factores asociados a los accidentes con agujas contaminadas con material biológico: Brasil y Colombia

Resumo Fizemos estudo transversal para iniciar coorte em dois Hospitais Universitários de dois países - Brasil e Colômbia - para avaliar a prevalência de acidentes com material biológico (AT-MB), o nível de adesão às Precauções Padrão (PP) e o conhecimento sobre patógenos transmissíveis pelo sangue e fatores associados entre trabalhadores e estudantes da saúde, no marco da implementação da norma NR-32. Criamos escalas para estimar conhecimento e adesão baseadas em 12 e 11 perguntas respectivamente. Utilizamos Regressão de Poisson-Tweedie para avaliar a associação do conhecimento e da adesão às PP com sofrer AT-MB. Avaliamos 965 indivíduos (348 estudantes e 617 profissionais). O conhecimento teve média de 10,98 com mediana de 11 (10, 12) e α-Cr de 0,625. A média de adesão foi de 30,74 com mediana de 31 (28, 34) e α-Cr de 0,745, associando-se a País, grupo (estudantes) e percepção de risco. Entre os fatores associadas ao relato de AT-MB encontraram-se o conhecimento, a adesão às PP, País de origem e ter tomado o esquema completo de vacinação contra Hepatites B. Concluímos que o nível de conhecimento e adesão foram adequados, ainda melhores entre os participantes do Brasil e associaram-se ao relato AT-MB.

Abstract This was a cross-sectional study to start a cohort in two University Hospitals of two countries - Brazil and Colombia - for assessing the prevalence of needlestick and sharps injuries (NSI), the level of compliance with standard precautions (SPs), and knowledge on blood borne pathogens and associated factors among health students and professionals, within the framework of the implementation of the NR-32 standard. We created compliance scales based on 12 and 10 questions, for assessing knowledge. We used the Multinomial Poisson-Tweedie Regression to evaluate the relationship between knowledge and compliance with SPs within NSI. We evaluated 965 individuals (348 students and 614 professionals). The mean score points for level of knowledge was 10.98, with a median of 11 (10; 12) and α-Cr of 0,625. Compliance with SP had a mean of 30.74 and median of 31 (28; 34), with a α-Cr coefficient of 0.745, associated with country, group (student) and risk perception. Among the factors associated with the report of NSI, we singled out knowledge and compliance, country of origin, and full vaccination scheme against the Hepatitis B virus. We concluded that the level of knowledge and compliance were adequate among participants, but better among Brazilian participants, and it was associated with NSI reporting.

Resumen Hicimos estudio transversal como punto de partida de estudio de cohorte en dos Hospitales Universitarios en dos países - Brasil y Colombia - para evaluar la prevalencia de accidentes con material biológico (AT-MB), el nivel de adhesión a las Precauciones Estándares (PUs) y el conocimiento sobre patógenos transmisibles y factores asociados entre trabajadores y estudiantes de la Salud en el marco de la implementación de la norma NR-32. Creamos escalas para evaluar el conocimiento y la adhesión con base en 12 e 11 preguntas respectivamente. Utilizamos Regresión de Poisson-Tweedie para evaluar asociación entre el conocimiento y la adhesión a las PUs con sufrir AT-MB. Evaluamos 965 individuos (348 estudiantes e 617 profesionales). El puntaje medio de conocimiento fue 10,98 con mediana de 11 (10, 12) y α-Cr de 0,625. La media de adhesión fue de 30,74 con mediana de 31 (28, 34) e α-Cr de 0,745, asociándose a país, grupo (estudiantes) e percepción de riesgo. Entre los factores asociados al relato de AT-MB encontramos conocimiento, adhesión a las PUs, país de origen y tener el esquema completo de vacunación contra Virus da Hepatitis B. Concluimos que el nivel de conocimiento y adhesión fueron adecuados, aunque mejores entre los participantes del Brasil y se asociaron a los AT-MB.

Preclinical safety assessment of pathogen reduced red blood cells treated with amustaline and glutathione.

BACKGROUND: The nucleic acid targeted pathogen reduction (PR) system utilizing amustaline (S-303) and glutathione (GSH) is designed to inactivate blood-borne pathogens and leukocytes in red blood cell concentrates (PR-RBCC). Inactivation is attained after amustaline intercalates and forms covalent nucleic acid adducts preventing replication, transcription, and translation. After pathogen inactivation, amustaline spontaneously hydrolyzes to S-300, the primary negatively charged reaction product; amustaline is below quantifiable levels in PR-RBCC. GSH quenches free unreacted amustaline. STUDY DESIGN AND METHODS: The genotoxic and carcinogenic potential of PR-RBCC, the reaction by-products, and S-300 were assessed in accordance with the International Conference on Harmonization (ICH) guidelines and performed in compliance with the Food and Drug Administration (FDA) good laboratory practice standards, 21 CFR Part 58. in vitro bacterial reverse mutagenicity and chromosomal aberration assays were performed with and without exogenous S9 metabolic activation, and in in vivo clastogenicity and carcinogenic assays using validated murine models. RESULTS: PR-RBCCs were not genotoxic in vitro and in vivo and were non-carcinogenic in p53+/- transgenic mice transfused over 26 weeks. Estimated safety margins for human exposure ranged from >90 to >36 fold for 2 to 5 PR-RBCCs per day, respectively. PR-RBCCs and S-300 did not induce chromosome aberration in the in vivo murine bone marrow micronucleus assay at systemically toxic doses. CONCLUSIONS: PR-RBCCs did not demonstrate genotoxicity in vitro or in vivo and were not carcinogenic in vivo. These studies support the safety of PR-RBCCs and suggest that there is no measurable genotoxic hazard associated with transfusion of PR-RBCCs.