Identifying and preventing human error in the sugar production process: A multi-stage approach using HTA, HEC and PHEA techniques

This article discusses the importance of identifying and preventing human error in industrial environments, specifically in the sugar production process. The article emphasizes the importance of choosing the right technique for risk assessment studies resulting from human errors. A cross-sectional study was conducted using a multi-stage approach - Hierarchical Task Analysis (HTA), Human Error Calculator (HEC), and Predictive Human Error Analysis (PHEA) - to identify potential human errors in the sugar production process. The HTA, HEC, and PHEA techniques were employed to evaluate each stage of the process for potential human errors. The results of the HTA technique identified 35 tasks and 83 sub-tasks in 14 units of the sugar production process. According to HEC technique 4 tasks with 80 % probability of human error and 2 tasks with 50 % probability of human error had the highest calculated error probabilities. The factors of individual skill, task repetition and importance were the most important factors of human error in the present study. The analysis of PHEA worksheets showed that the number of human errors identified in the tasks with highest probability were 8 errors, of which 50 % were action errors, 25 % checking errors, 13 % selection errors, and 12 % retrieval errors. To mitigate the consequences of human error, it was recommended training courses, raising operator awareness of error consequences, and installing instructions in the sugar production process. Based on the findings, the article concludes that the HEC and PHEA techniques are applicable and effective in identifying and analyzing human errors in process and food industries.

Exploring the Association Between Latent Toxoplasma gondii Infection and COVID-19 in Hospitalized Patients: First Registry-Based Study

Purpose

This study aimed to determine the possible association between Toxoplasma gondii infection and COVID-19 outcomes among 133 patients with an RT-PCR-positive test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), hospitalized at Imam Khomeini Hospital, Sari, Mazandaran Province, northern Iran, during August to November 2020.

Methods

A questionnaire was used to collect baseline data from the patients who were registered to the Iranian National Registry Center for Toxoplasmosis (INRCT). Also, blood samples were taken from each patient for detecting anti-T. gondii antibodies and T. gondii DNA using enzyme-linked immunosorbent assay (ELISA) and conventional-PCR methods, respectively. Variables related to the COVID-19 severity and outcomes were indicated based on multiple multinomial logistic regression models.

Results

Of 133 patients enrolled in the INRCT with COVID-19 through RT-PCR, 50 (37.59%), 52 (39.1%), and 31 (23%) suffered from mild, moderate, and severe COVID-19, respectively. 57.1% of the patients who died had severe COVID-19, while among those with other outcomes, only 18.60% had severe COVID-19 (P < 0.05). Anti-T. gondii IgG was detected in 109/133 (81.95%) patients, which was not statistically significant (P > 0.05). Among those with negative and positive anti-T. gondii IgG, 2 (8.30%) and 29 (26.60%) had severe COVID-19, respectively (P > 0.05). T. gondii DNA and anti-T. gondii IgM were not found in any of the patients. Moreover, all deaths occurred in those with moderate or severe COVID-19 and a positive anti-T. gondii IgG.

Conclusion

To our knowledge, this is the first registry-based study concerning T. gondii infection among patients with COVID-19. Our data show the high rate of latent T. gondii infection among COVID-19 with different severity. However, there is no significant relationship between latent T. gondii infection and COVID-19 severity and outcomes. Thus, conducting multicenter studies in different geographic regions of the world could offer a better understanding of this relationship.

Relationship between serum cystatin C and polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) causes an increased risk of metabolic cardiovascular syndrome. Also, cystatin C serum levels are associated with the risk of cardiovascular events in metabolic syndrome patients.

OBJECTIVE

To investigate the relationship between cystatin C in PCOS patients.

MATERIALS AND METHODS

35 women with PCOS were compared to 35 women with healthy matched age and body mass index. They all underwent tests to determine plasma levels of C-reactive protein (CRP), cystatin C, lipid profile and apo-lipoprotein. Blood pressure and demographic variables of each subject were obtained.

RESULTS

Systolic and diastolic blood pressure were higher in PCOS patients compared to control group. Triglyceride and low-density lipoprotein cholesterol levels were higher in PCOS; contrariwise, high-density lipoprotein was lower from that of healthy volunteers. Cystatin and CRP levels were significantly higher in patients with PCOS in comparison with healthy subjects (p<0.0001). Among measured determinants, only PCOS status was independently associated with cystatin C.

CONCLUSION

Cystatin C was positively correlated with PCOS status concentrations but not with systolic and diastolic blood pressure, or any of the lipid profile variables or demographic characteristics. Indeed, no correlation was found between cystatin C and CRP levels. Therefore, cystatin C might be related to PCOS beyond its use as a marker of the renal function.

Blood donation screening for hepatitis B virus markers in the era of nucleic acid testing: are all tests of value?

BACKGROUND

The American Red Cross implemented hepatitis B virus (HBV) minipool (MP)-nucleic acid testing (NAT) in June 2009, in addition to existing tests for hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B core antigen (anti-HBc). The value of all three tests was evaluated.

STUDY DESIGN AND METHODS

HBsAg, anti-HBc, and HBV DNA (Ultrio MP-NAT, Gen-Probe/Novartis) donation results were analyzed during a 12-month period (July 1, 2009-June 30, 2010). Additional testing by individual-donation (ID) polymerase chain reaction (PCR) to confirm donor infection was performed when any HBV screening test was reactive or positive, except in the case of HBsAg neutralization-positive, anti-HBc-reactive samples. Numbers of blood donations identified as reactive or positive versus nonreactive or negative were compared.

RESULTS

Of about 6.5 million donations, 699 were defined as from HBV-infected donors, of which 64% (444) were reactive for all three markers. More than 99% (697) had reactivity to one or both serologic tests with 68% (477) showing reactivity by MP-NAT. Only two donations were DNA-positive, seronegative NAT-yield donations (1 per 3.23 million), fewer than expected (p = 0.0075). Among MP-NAT-reactive donors, only small numbers represented early infection (2 or 0.4% with negative serology and 10 or 2.1% who were HBsAg confirmed positive, anti-HBc nonreactive). Of the 142 occult HBV-infected donors, 85% were MP-NAT nonreactive requiring ID-PCR for detection (121 or 54.5% of all MP-NAT nonreactives vs. 21 or 4.4% of all MP-NAT reactives).

CONCLUSIONS

The HBV DNA-positive yield rate from MP-NAT was lower than expected, likely representing the rarity of such findings even in very large studies. With the implementation of HBV MP-NAT, the value of maintaining anti-HBc for the detection of low-level HBV DNA-positive donors was confirmed; however, HBsAg screening showed no blood safety value.

Blood donation screening for hepatitis B virus markers in the era of nucleic acid testing: are all tests of value?

BACKGROUND

The American Red Cross implemented hepatitis B virus (HBV) minipool (MP)-nucleic acid testing (NAT) in June 2009, in addition to existing tests for hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B core antigen (anti-HBc). The value of all three tests was evaluated.

STUDY DESIGN AND METHODS

HBsAg, anti-HBc, and HBV DNA (Ultrio MP-NAT, Gen-Probe/Novartis) donation results were analyzed during a 12-month period (July 1, 2009-June 30, 2010). Additional testing by individual-donation (ID) polymerase chain reaction (PCR) to confirm donor infection was performed when any HBV screening test was reactive or positive, except in the case of HBsAg neutralization-positive, anti-HBc-reactive samples. Numbers of blood donations identified as reactive or positive versus nonreactive or negative were compared.

RESULTS

Of about 6.5 million donations, 699 were defined as from HBV-infected donors, of which 64% (444) were reactive for all three markers. More than 99% (697) had reactivity to one or both serologic tests with 68% (477) showing reactivity by MP-NAT. Only two donations were DNA-positive, seronegative NAT-yield donations (1 per 3.23 million), fewer than expected (p = 0.0075). Among MP-NAT-reactive donors, only small numbers represented early infection (2 or 0.4% with negative serology and 10 or 2.1% who were HBsAg confirmed positive, anti-HBc nonreactive). Of the 142 occult HBV-infected donors, 85% were MP-NAT nonreactive requiring ID-PCR for detection (121 or 54.5% of all MP-NAT nonreactives vs. 21 or 4.4% of all MP-NAT reactives).

CONCLUSIONS

The HBV DNA-positive yield rate from MP-NAT was lower than expected, likely representing the rarity of such findings even in very large studies. With the implementation of HBV MP-NAT, the value of maintaining anti-HBc for the detection of low-level HBV DNA-positive donors was confirmed; however, HBsAg screening showed no blood safety value.

Current incidence and residual risk of hepatitis B infection among blood donors in the United States

BACKGROUND

This study used two approaches to estimate the current incidence of hepatitis B virus (HBV) in a US donor population.

METHODS

HBV incidence was estimated through the hepatitis B surface antigen (HBsAg) yield approach and the seroconversion method. Residual risk was estimated by the incidence–window period model. HBsAg yield refers to an HBsAg confirmed-positive, antibody against hepatitis B core antigen (anti-HBc)–nonreactive donation, adjusted for false-positive neutralization results. The number of HBsAg-seroconverting repeat donors divided by total number of person-years of evaluation or the HBsAg yield rate divided by HBsAg yield window gave rise to incidence estimates.

RESULTS

The seroconversion and the yield approach, respectively, gave an incidence estimate of 3.41 or 3.43 per 105 person-years. Using a revised infectious window period of 38 or 30 days for current HBsAg assays, the current residual risk for HBV was respectively estimated for 2006 to 2008 at 1 in 282,000 or 1 in 357,000 donations from the seroconversion approach and 1 in 280,000 or 1 in 355,000 donations from the yield approach. With the same database and methods, this is a decrease from 1 in 86,000 to 1 in 110,000 observed in 1997 to 1999.

CONCLUSIONS

Current HBV incidence and residual risk are lower than earlier estimates, especially in the youngest donors, but remain higher in the absence of HBV nucleic acid test than those for human immunodeficiency virus or hepatitis C virus (HCV). In addition to the exclusion of HBsAg false-positive donors, the reduction could reflect shortened window periods and decreased incidence rates due to vaccination or other reasons.

Remifentanil versus Fentanyl for Assisted Reproductive Technologies: Effect on Hemodynamic Recovery from Anesthesia and Outcome of ART Cycles

BACKGROUND

We conducted this study to compare the outcome of assisted reproductive technology (ART) procedures and recovery from anesthesia in women who received opioid analgesia with remifentanil versus fentanyl.

MATERIALS AND METHODS

This double-blind, randomized clinical trial was carried out in the Yazd Research and Clinical Center for Infertility, Yazd, Iran. We studied 145 women who were participants in an ART program. During the first phase of the study, all patients underwent induction of anesthesia with thiopental and received analgesia with remifentanil or fentanyl. The primary endpoint was pregnancy rate per transfer. The numbers of oocytes collected, fertilized and cleaved were recorded, as was the number of oocytes transferred and recovery profile. In the second phase of the study, all patients were followed for outcome of ART cycle.

RESULTS

This study suggested that in women undergoing transvaginal ultrasound-guided oocyte retrieval procedures, the likelihood of a successful pregnancy was higher with a remifentanil-based monitored anesthesia care (MAC) technique than with a fentanyl-based MAC technique. The recovery from anesthesia was significantly better in the remifentanil group versus fentanyl group.

CONCLUSION

The results of this study suggest that remifentanil in clinical practice is superior to fentanyl (

REGISTRATION NUMBER

IRCT201009283468N3).

Prevalence, incidence, and residual risk of human immunodeficiency virus and hepatitis C virus infections among United States blood donors since the introduction of nucleic acid testing

BACKGROUND

Nucleic acid testing (NAT) for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) was introduced for blood donation screening in the United States in 1999. This study analyzes temporal trends of these two infections since NAT introduction.

STUDY DESIGN AND METHODS

Donation data from 1999 to 2008 were analyzed; each donation was tested for antibodies and viral RNA for HIV and HCV. Incidence for first-time (FT) donors was derived by multiplying that among repeat (RP) donors by the ratio of NAT yield rates between FT and RP donors. Incidence for all donors was the weighted mean based on percentage of FT and RP donors. Residual risk (RR) was determined using the window-period model.

RESULTS

During the 10-year period approximately 66 million donations were screened with 32 HIV (1:2 million) and 244 HCV (1:270,000) NAT yield donations identified. HCV prevalence among FT donors decreased by 53% for 2008 compared to 1999. HIV and HCV incidence among RP donors increased in 2007 through 2008 compared to 2005 through 2006. During 2007 through 2008, HIV incidence was 3.1 per 10(5) person-years (py), with an RR estimate of 0.68 per 10(6) (1:1,467,000) donations; HCV incidence was 5.1 per 10(5) py, with an RR estimate of 0.87 per 10(6) (1:1,149,000). The increase in HIV incidence was primarily among 16- to 19-year-old, male African American donors and that in HCV was primarily among Caucasian donors of 50 or more years. Donors from the Southern United States had higher incidence rates.

CONCLUSION

HCV prevalence decreased significantly since NAT introduction. The increase in HIV and HCV incidence in 2007 through 2008 warrants continued monitoring and investigation.

Changing age distribution of the blood donor population in the United States

BACKGROUND

The American Red Cross has been maintaining a research database of all blood donors. Such a database provides a unique opportunity for monitoring changes over time in donor and donation patterns.

STUDY DESIGN AND METHODS

Changes in age distribution among blood donors were analyzed through comparison of the volunteer donor population in 1996, 1999, 2002, and 2005, before and after adjustment for demographic changes of the general population in the United States.

RESULTS

Donations by repeat donors 50 years or older as a proportion of total donations increased from 22.1 percent in 1996 to 34.5 percent in 2005, or 1.4 percent per year, whereas donations from repeat donors of 25 to 49 years decreased from 49.1 percent in 1996 to 37.1 percent in 2005, or 1.3 percent per year. After adjusting for general population trends, the effective number of donors decreased by more than 10 percent in female and male repeat donors of age 20 to 49 years and male first-time donors of age 25 to 49 years from 1996 to 2005; female and male repeat donors of age 25 to 39 years decreased by greater than 40 percent. Prevalence rates of major infectious disease markers decreased by 3.3 percent or more per year for first-time donations and by 6.4 percent or more per year for repeat donations.

CONCLUSION

The aging patterns of blood donors suggest the need for improved recruitment and retention in the young adult and middle-aged groups. A severe shortage of blood and blood components may be forecast in the foreseeable future unless offset by significant increased supply or reduced usage of blood and blood components.

Limited effectiveness of donor deferral registries for transfusion-transmitted disease markers

BACKGROUND

Donor deferral registries (DDRs) detect repeat donations by previously deferred donors and prevent their release. The utility of DDRs has not been objectively demonstrated.

STUDY DESIGN AND METHODS

A total of 10.2 million first-time donors to the American Red Cross from 1995 through 2002 were reviewed to identify donors deferred by screening tests for human immunodeficiency virus (HIV; 0.19% of donors), hepatitis C virus (HCV; 0.55%), and hepatitis B virus (HBV; 0.13%). All repeat-reactive (RR) donors were deferred despite confirmatory testing. Donors were notified and counseled about their test results and deferral. Their subsequent donation behavior was assessed.

RESULTS

A total of 414 HIV-deferred donors (2.1%), 471 HCV-deferred donors (0.8%, p < 0.001 vs. HIV and HBV), and 222 HBV-deferred donors (1.6%, p < 0.01 vs. HIV) returned to donate despite their deferred status. For all three tests, confirmed-positive donors were less likely to return. Of donors originally confirmed positive, only 7 returning donors were negative by screening (thus the repeat donation interdicted from distribution by the DDR): 0 HIV RR donors, 2 of 36,092 HCV RR donors, and 5 of 8,404 HBV RR donors. Review of the laboratory results for the HCV donors and one HBV donor was consistent with originally false-positive confirmation tests. The four other HBV confirmed-positive donors were anti-hepatitis B core antigen-positive on their subsequent donation, which was discarded despite the DDR.

CONCLUSION

Of 10.2 million donors, the DDR did not prevent the release of any potentially dangerous blood component due to inappropriate return of donors deferred for HIV, HCV, and HBV tests. The effectiveness of DDRs should be evaluated for other deferrals.

Prevalence of selected viral infections among blood donors deferred for potential risk to blood safety

BACKGROUND

Health history questions identify blood donors believed to pose a higher risk of transmission of infectious diseases. This study assesses the current impact of some of these questions on blood safety as reflected by infectious disease markers.

STUDY DESIGN AND METHODS

Donors who were deferred from donating blood due to health history question(s) were recruited at four different regions of the American Red Cross Blood Services. A blood sample was tested for serologic markers of blood-borne infections as performed for accepted blood donors.

RESULTS

Of 497 deferred donors enrolled, 29 donors were deferred for having had "yellow jaundice, liver disease, or hepatitis since the age of 11" (Question 3), 1 of whom had hepatitis C virus antibodies (anti-HCV) and hepatitis B core antigen antibodies (anti-HBc), 2 had anti-HBc, and 1 had anti-HCV (p < 0.05 for both markers). Among 37 donors deferred for having "ever tested positive for hepatitis" (Question 4), 1 had hepatitis B surface antigen and anti-HBc and 3 had anti-HBc (p < 0.05 for both markers). Of 14 donors deferred for "having ever used a needle, even once, to take any illegal or nonprescription drug" (Question 12), 1 had anti-HCV, human T-lymphotropic virus-I antibodies and anti-HBc, 1 had anti-HCV and anti-HBc, and 2 had anti-HCV (p < 0.05 for all three markers).

CONCLUSIONS

Blood donors deferred for standard blood donor questions regarding risk of viral hepatitis as well as those with a history of intravenous drug use were more likely to have higher hepatitis marker rates than those who were not deferred. No significant findings were identified for other markers or questions.

Prevalence of selected viral infections among temporarily deferred donors who returned to donate blood: American Red Cross blood donor study

BACKGROUND

Health history questions are introduced into the predonation interview to identify blood donors believed to pose a higher risk of infectious diseases to recipients. This study assesses the current impact of some of those questions.

STUDY DESIGN AND METHODS

Donor deferral and donation data were extracted from a research database of the American Red Cross. The prevalence of hepatitis B surface antigen or antibodies to human immunodeficiency virus, hepatitis C virus, or human T-lymphotropic virus was obtained for different groups of donors who were temporarily deferred in 2000 through 2001 and later returned to donate blood in 2000 through 2003. The results were compared with either first-time or repeat donors in 2000 through 2003, while controlling for differences in sex, age, and year of donation.

RESULTS

Of donors temporarily deferred in 2000 through 2001 who had had no donation or deferral during the previous 2 years, only 22.08 percent subsequently returned to donate blood in 2000 through 2003. Donations from returning donors who had been deferred for potential infectious disease risk did not show a higher prevalence for any of the viral markers when those with no donation or deferral during the previous two years were compared with first-time donations, and those with prior donation were compared with repeat donations.

CONCLUSION

Blood donors temporarily deferred in 2000 through 2001 for potential risk of viral infection who later returned to donate blood did not appear to pose a higher risk compared to first-time or repeat donors. The effectiveness of some of the currently used deferral questions in reducing viral risks warrants further study.

Patterns of age- and sex-specific prevalence of major blood-borne infections in United States blood donors, 1995 to 2002: American Red Cross blood donor study

BACKGROUND

The American Red Cross has been maintaining a research database of all blood donations, including all testing results for infectious disease markers, since 1995. This study analyzes the temporal trends of major blood-borne infections among blood donors.

STUDY DESIGN AND METHODS

Temporal trends for age- and sex-specific prevalence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis infections in US blood donors were analyzed based on linear trend or time series model or other models as appropriate.

RESULTS

From 1995 to 2002, significant declines have been observed for infections that used to be at relatively higher levels. Declines in prevalence were slower among first-time donations than repeat donations. There was an increase in prevalence of anti-HCV among first-time male donors of 50 to 59 years of age. Anti-HIV prevalence appeared to have increased among first-time male donors of 30 to 39 years of age since 2000.

CONCLUSION

Different sex and age groups showed various patterns of decline and even signs of increase. The increasing prevalence among some age and sex groups may merit further investigation.

Current impact of the confidential unit exclusion option

BACKGROUND

In 1986, the FDA recommended using a confidential unit exclusion (CUE) option in blood centers; this was rescinded in 1992. The American Red Cross (ARC) has continued using the option. This study assessed its current impact.

STUDY DESIGN AND METHODS

Donor records from ARC for 1995 through 2001 were examined for CUE use in association with the prevalence and frequency of seroconversion of infectious disease markers. The likely yield of CUE was also estimated.

RESULTS

Donations with CUE use had a higher prevalence of HIV, HBV, HCV, and syphilis markers than those without CUE use, although both the sensitivity and positive predictive value (PPV) of CUE were low. Seroconverters had a higher frequency of using the CUE option than nonseroconverters. Similarly, the sensitivity and PPV of CUE were low. Based on analysis of infectious disease residual risk, the CUE option was estimated to have prevented the collection of 0.2 to 1.3 window-period units annually within the entire ARC system.

CONCLUSION

The CUE option had minimal effectiveness in further reducing the transmission of infectious diseases through window-period units. Further study of its current impact on reduction of units from risky but test-negative donors, as well as on loss of safe donors, may be warranted.