Test Conversion Rates Research Articles

Effectiveness of the antiviral medications azvudine and nirmatrelvir-ritonavir in treating COVID-19 in patients with hematological malignancies

BackgroundPatients with Hematological Malignancies (HM) are at a high risk of mortality from Coronavirus disease 2019 (COVID-19). The available antivirals were different between China and other countries. In China, azvudine was obtained for emergency use to treat adult COVID-19 patients with moderate symptoms in July 2022. While nirmatrelvir-ritonavir was well-known and used in many countries. The purpose of the present study was to assess whether there was any difference in the efficacy and safety of the two drugs. MethodsThis study was a prospective observational study of patients with HM who developed COVID-19. Patients were divided into three treatment groups: nirmatrelvir-ritonavir, azvudine, and observation. Treatment outcomes, first nucleic acid test negative time, hospitalization time, and the conversion rate of mild or moderate disease to severe disease were recorded. ResultsFirst nucleic acid test negative time (23.5 days vs. 34 days, p = 0.015), hospitalization time (p = 0.015), and conversion rate (31.8 % vs. 8 %, p = 0.046) were statistically different between the nirmatrelvir-ritonavir and observation groups. First nucleic acid test negative time (20 days vs. 34 days, p = 0.009) and hospitalization time (p = 0.026) were statistically different between the azvudine and observation groups. ECOG score and liver disease were significantly associated with the conversion rate from mild or moderate disease to severe disease using multivariate analysis (p < 0.05). ConclusionsThe authors found no significant differences existed in outcome measures between patients with HM and COVID-19 who were treated with nirmatrelvir-ritonavir or azvudine.

Impact of Different Traditional Chinese Medicine Constitutions on the Clinical Outcomes of COVID-19 Patients Infected with SARS-CoV-2 Omicron Variant: A Retrospective Observational Study.

Traditional Chinese Medicine (TCM) constitution and disease occurrence, development, and prognosis are interrelated. This study aimed to investigate the association between TCM constitution and the time to negative nucleic acid test results in patients with coronavirus disease 2019 (COVID-19) infected with the SARS-CoV-2 Omicron variant. We identified COVID-19 patients (≥18 years) infected with the SARS-CoV-2 Omicron variant and collected clinical data, including clinical symptoms, time to negative nucleic acid test results, and TCM constitution. Linear and logistic regression analyses explored the relationship between TCM constitution and the time to negative nucleic acid test results in patients with the COVID-19 Omicron variant. We included 486 patients with COVID-19, with a mean age of 40.2 years; 321 (66.0%) men and 165 (34.0%) women. Balanced constitution accounted for 43.8%, and unbalanced constitution accounted for 56.2%. Chi-square test showed that different TCM constitutions had significant differences in the influence of clinical symptoms of COVID-19 patients (P < 0.01). After controlling for various factors, multiple linear regression analysis revealed that an unbalanced constitution was significantly positively correlated with time to negative nucleic acid test results (P < 0.05). After controlling for various factors, logistic regression analysis revealed that an unbalanced constitution was closely related to the 7-day nucleic acid test conversion rate (odds ratio (OR): 0.53, 95% confidence interval (CI): 0.36-0.80, P < 0.05). After dividing the unbalanced constitution into deficiency constitution and non-deficiency constitution, the non-deficiency constitution was closely associated with the 7-day nucleic acid test conversion rate (OR = 0.45, 95% CI: 0.28-0.74, P < 0.05). Further analysis revealed that damp-heat constitution in the non-deficiency constitution was associated with the 7-day nucleic acid test conversion rate (OR = 0.33, 95% CI: 0.18-0.60, P < 0.05). In patients with COVID-19, an unbalanced constitution is associated with a longer time to negative nucleic acid test results and lower 7-day nucleic acid test conversion rates.

Nosocomial COVID-19 infection in women undergoing elective cesarean delivery: a prospective cohort study

BACKGROUNDThe COVID-19 pandemic placed obstetricians in a difficult position of continuing to perform elective cesarean delivery without the knowledge of the risk of the spread of nosocomial infection of the COVID-19 virus.OBJECTIVEThis study aimed to determine the nosocomial infection rate in women undergoing elective cesarean delivery at 2 academic institutions.STUDY DESIGNThis nonrandomized prospective cohort trial evaluated patients undergoing elective cesarean delivery during the reopening phase of the COVID-19 pandemic in the state of New York at 2 large volume labor and delivery units. Eligible patients with a negative preoperative reverse transcriptase-polymerase chain reaction test and immunoglobulin G antibody test for COVID-19 were retested 6 to 9 days after discharge. The primary objective was the COVID-19 test conversion rate defined as a positive polymerase chain reaction test for SARS-CoV-2 after discharge with a negative preoperative test. This was used as a proxy for the nosocomial infection rate.RESULTSA total of 136 patients were screened for participation. Of these patients, 2 tested positive for COVID-19 on preoperative testing, and 25 declined to participate. Overall, 111 patients consented to participate, and 96 patients underwent both preoperative and postoperative testing. No patient with a negative polymerase chain reaction test preoperatively, had a positive polymerase chain reaction test for the COVID-19 virus postoperatively.CONCLUSIONWith strict and methodical perioperative and postpartum protocols, we can limit nosocomial COVID-19 infection in women undergoing elective cesarean delivery.

Erratum to `Tuberculosis risk in the biologic era: tuberculin skin test conversion rates in children with rheumatologic diseases` [Turk J Pediatr 2021; 63: 978-985

This article is corrected. DOI: 10.24953/turkjped.2021.06.005.

Tuberculosis Exposure and Conversion Rates Can Guide Deimplementation of Annual Tuberculosis Screening

Background: The CDC recently updated recommendations on tuberculosis (TB) screening in healthcare facilities, suggesting the discontinuation of annual TB screening. However, hospitals may opt to continue based on their local TB epidemiology. We assessed TB infection control parameters in our facility to guide the implementation of the new CDC recommendations. Methods:We retrieved data for patients with an International Classification of Disease, Tenth Revision (ICD-10) code for TB treated at the University of Iowa Hospitals and Clinics during 2016–2019. We supplemented our search with microbiology data: culture or PCR for Mycobacterium tuberculosis. Based on manual chart review, we adjudicated each patient as active TB, latent TB, previously treated TB, unclear history, or no TB. We further labeled active TB cases based on their risk of transmission (pulmonary or extrapulmonary cases that underwent an aerosol generating procedure). We then calculated the number of exposure events associated with those patients and tuberculin skin test (TST) conversion rates among the exposed. Results: During 2016–2019, we identified 197 patients based on ICD-10 codes. In total, 10 additional patients were detected by microbiology data review. Of these 207 patients, 48 (23.2%) had active TB: lung, n = 24 (50%); lymph node, n = 9 (19%); bone or spine, n = 5 (10%); eye, n = 3 (6%); disseminated, n = 2 (4%); pleura, n = 2 (4%); skin abscess, n = 2 (4%); and meningitis, n = 1 (2%). Of the 24 pulmonary patients, 6 (25%) had either a positive smear or a cavity on imaging. In total, 159 patients were excluded: no TB, n = 22 (14%); latent TB, n = 27 (17%); old or treated TB, n = 93 (58%); and unclear history, n = 9 (6%). Of the 48 cases with active TB, 31 (65%) were deemed potentially infectious. Also, 10 cases (32%) led to the exposure of 204 healthcare workers (HCWs). Baseline and postexposure TST were available for 179 HCWs (88%); 72 (35%) followed up in the employee health clinic within the 8–12 weeks after exposure. Of 161 HCWs with a negative TST at baseline, no conversions occurred. Of 18 HCWs with positive TST at baseline, no HCW developed symptoms during the observation period. Conclusions: Nearly one-third of infectious TB cases led to HCW exposures in a low-incidence setting. However, no TST conversions or active TB infections were seen. Exposure and conversion rates are useful indicators of TB infection control in healthcare facilities and may help guide implementation of the new CDC TB control recommendations.Funding: NoneDisclosures: None

QuantiFERON TB‐gold conversion rate among psoriasis patients under biologics: a 9‐year retrospective study

Tuberculosis (TB) screening is mandatory for psoriasis biologic treatment. However, evidences regarding TB screening results during biologic treatment are conflicting. The aim of this study is to evaluate the rate of QuantiFERON TB Gold test (QFT) conversion in psoriasis patients during biologics over time. A 9-year single center retrospective study was performed in order to evaluate the rate of QFT conversion in patients affected by moderate-to-severe plaque psoriasis under available biological therapies (anti-TNF-α, IL-12/23, IL-17). For each patient, demographic data, age, gender, comorbidities, previous psoriasis therapy, as well as ongoing treatment type were registered. Five-hundred twenty-six patients (61.2% male, with a mean age of 52.6±13.9years) treated with biologics were enrolled. QFT conversion occurred in 6.5% of patients over a mean treatment duration of 3.2years. On average, QFT conversion occurred after 34.05months of treatment. Anti-TNF-α drugs, and among them, adalimumab above all (35.5% of all cases), were the most commonly involved treatment during QFT conversion, followed by anti-IL-12/23 (17.6%) and anti-IL-17 (14.7%). However, differences among biologics class or single biologics (adalimumab, etanercept, infliximab, golimumab, certolizumab, ustekinumab, ixekizumab, secukinumab) did not approach statistical significance. Annual TB screening is important in psoriasis patients under biologic treatment in order to avoid possible latent TB infection reactivation. Indeed, our data showed that even in a low TB prevalence country like Italy, QFT may convert over time in psoriasis patients under biologics in 6.5% of the cases.

P531 Tuberculin skin test conversion rate in inflammatory bowel disease patients receiving anti-TNFα agents

Anti-TNFα therapy increases the risk of tuberculosis (TB) (re)-activation in inflammatory bowel disease (IBD) patients. Purified protein derivative tuberculin skin test (PPD-TST) is considered a pre-requisite at baseline. However, few data exist regarding the kinetics of this test during therapy. Therefore, our study investigated the conversion rate of PPD-TST in IBD patients under anti-TNFα treatment. Anti-TNFα treated IBD patients followed up in our centre with a baseline PPD-TST underwent a sequential one during therapy. Those with a positive PPD-TST either at baseline or during therapy (d > 10 mm in naïve and d > 5 mm in those exposed to immunomodulators [IMS]) received 300 mg isoniazid orally for 9 months. Sixty-eight IBD patients have been enrolled so far (males: 51.47%, Crohn’s disease: 82.35%). Median age at IBD diagnosis was 33.1 years [IQR: 20.3, range: 16.7–66.7]. Median duration of IBD was 7.7 months [IQR: 9.8, range: 1.4–32.7]. Nine patients (13.23%) had a positive PPD-TST at baseline. Fifty-eight patients have undergone a second PPD-TST (median time between the first and second PPD-TST: 27.10 months [IQR: 41.22, range: 6.3–190.1]). Nineteen patients were under combination therapy with an IMS at the second PPD-TST. In seven patients with a positive baseline PPD-TST, this remained positive (in five patients the diameter was decreased and in two increased) and in one it turned negative. Out of the remaining 50 patients with a negative baseline PPD-TST, 10 (20%) exhibited a positive second PPD TST; three of them were receiving infliximab for less than 3 years and seven of them adalimumab (three for less and four for more than 3 years). Only 3 of 10 were under combination therapy. No case of active tuberculosis has been detected in this cohort so far. All patients with a PPD-TST conversion received anti-tuberculous treatment. A positive PPD-TST followed by anti-TB treatment before the initiation of anti-TNFα in IBD patients was not associated with an increased rate of TB infection during therapy. In one-fifth of the patients with a negative baseline PPD-TST the test exhibited conversion but without any undesirable consequence if so treated.

Effects of Appropriate Prolonged Sacral Neuromodulation Testing in Improving Implantation Rate of a Permanent Implantable Pulse Generator in Patients with Refractory Lower Urinary Tract Dysfunctions in Mainland China.

Background:Sacral neuromodulation (SNM) has become an effective method for treating lower urinary tract voiding dysfunction during the past 20 years. Because of the expensive cost, the number of implantable pulse generator (IPG) implantations per year in China is far lower than that in Western developed countries since 2012. This study was to summarize the effects of the appropriate prolonged SNM testing time in improving the implantation rate of a permanent IPG in patients with refractory lower urinary tract symptoms (LUTS) in mainland China.Methods:From January 2013 to June 2016, 51 patients with refractory LUTS received SNM therapy. In this study, we compared the conversion rate 2 weeks after the Stage I test and final actual conversion rate. We also observed the complications (such as pain, infection, and electrode displacement) and effectiveness. We tried to improve an appropriate prolonged test time which was favorable for improving the SNM conversion rate while ensuring safety and effectiveness.Results:Among 51 patients receiving SNM therapy, 19 patients (mean age 45.0 ± 16.9 years) had poor Stage I test results, and on an average, the electrode was removed 27.4 ± 9.6 days after the surgery. In one patient, the electrode was removed within 2 weeks; when the remaining 18 patients were questioned 2 weeks after testing, none of the patients wanted to terminate the test, and all the 18 patients desired to prolong the testing time to further observe the treatment effect. The remaining 32 patients (mean age 46.7 ± 15.3 years) received Stage II permanent implantation at 19.6 ± 10.4 days after the surgery. The overall Stage I–II conversion was 62.7% (32/51) in this study. Within 2 weeks after the surgery, only eight patients received Stage II permanent implantation, and the conversion rate was only 15.7% (8/51), which was much lower than the overall conversion rate of 62.7%. Nearly 84.4% (27/32) of the patients received Stage II implantation within 4 weeks. None of the patients had incision infections. In one patient, the entire system was removed 1 month after Stage II implantation due to pain in the implantation site.Conclusions:Appropriate extension of the Stage I testing time of an SNM-barbed electrode could significantly improve the Stage II permanent implantation rate in Chinese refractory LUTS patients; there were no wound infections, and the postoperative complication rate was low. This study recommended that Stage I period of SNM therapy should be 4 weeks according to safety and successful conversion rate.

LATENT TUBERCULOSIS AMONG PROFESSIONALS FROM A REFERRAL HOSPITAL IN ONCOLOGY

Introduction: Tuberculosis (TB) is an ancient contagious disease, and continues to be the leading cause of morbidity and mortality among infectious contagious diseases. It can be considered an occupational infectious disease when it happens in health professionals. These professionals are directly exposed to TB and are considered to be a high risk population for latent tuberculosis infection (LTBI) and active TB. The primary aim of this study was to estimate the prevalence of LTBI among the clinical and administrative staff of an oncology referral hospital in Rio Grande do Sul. The secondary aim of this study was evaluate tuberculin skin test (TST) conversion rate and the risk factors for TST positivity in this population. Methods : A cross-sectional study was carried out in a retrospective cohort with data collected in March 2013 and March 2014. Data of professionals from different hospital units were included. Those with induration ≥ 10 mm were considered as reactors, and conversion rate was assessed by an increase ≥ 10 mm in induration in the second TST compared with the first one. Results: Among the 225 professionals evaluated in 2013, 135 (60%) were reactors and 90 (40%) were non-reactors. The mean age was 32.9 (± 9.55), 176 (78.22%) were female, and most of the reactors worked in the hospital for 4 years or less. Non-reactors in 2013 were recommended to repeat the test in 2014, and the conversion rate was 9.37%. There was no significant difference in prevalence among the different professional categories, and the assessed risk factors were not associated with ILTB. Conclusions: The prevalence of LTBI in the study population was high, reinforcing the need to implement effective control measures to prevent LTBI in the hospital where the study was conducted. Keywords: Latent tuberculosis; occupational risk; tuberculin test; vulnerable populations

Institutional Tuberculosis Transmission. Controlled Trial of Upper Room Ultraviolet Air Disinfection: A Basis for New Dosing Guidelines.

Transmission is driving the global tuberculosis epidemic, especially in congregate settings. Worldwide, natural ventilation is the most common means of air disinfection, but it is inherently unreliable and of limited use in cold climates. Upper room germicidal ultraviolet (UV) air disinfection with air mixing has been shown to be highly effective, but improved evidence-based dosing guidelines are needed. To test the efficacy of upper room germicidal air disinfection with air mixing to reduce tuberculosis transmission under real hospital conditions, and to define the application parameters responsible as a basis for proposed new dosing guidelines. Over an exposure period of 7 months, 90 guinea pigs breathed only untreated exhaust ward air, and another 90 guinea pigs breathed only air from the same six-bed tuberculosis ward on alternate days when upper room germicidal air disinfection was turned on throughout the ward. The tuberculin skin test conversion rates (>6 mm) of the two chambers were compared. The hazard ratio for guinea pigs in the control chamber converting their skin test to positive was 4.9 (95% confidence interval, 2.8-8.6), with an efficacy of approximately 80%. Upper room germicidal UV air disinfection with air mixing was highly effective in reducing tuberculosis transmission under hospital conditions. These data support using either a total fixture output (rather than electrical or UV lamp wattage) of 15-20 mW/m(3) total room volume, or an average whole-room UV irradiance (fluence rate) of 5-7 μW/cm(2), calculated by a lighting computer-assisted design program modified for UV use.

PD27-10 IMPACT OF NUMBER OF ACTIVE ELECTRODES AT TIME OF SACRAL TINED LEAD PLACEMENT ON VOLTAGE THRESHOLDS AND CLINICAL OUTCOMES

INTRODUCTION AND OBJECTIVES: Sacral neuromodulation (SNM) is an effective treatment for medically refractory overactive bladder (OAB). The procedure is performed as a 2-stage technique with first stage tined placement (FSTLP) followed by second stage stimulator 4 weeks later. The most significant morbidity for the procedure is infection, reported in up to 12%. We assessed the infection rates in patients who were implanted within a dedicated SNM theatre environment and compared them to those in patients who underwent SNM on mixed operating lists. METHODS: We reviewed the complications in all patients having SNM surgery over a 12 month period within either a dedicated SNM operating theatre, with the same surgeon, advanced nurse practitioner, anaesthetist and radiological team, or on the mixed urological lists. In the mixed theatre lists SNM cases were performed amongst other urological cases by varying theatre teams. Infection rates (requiring lead or device explantation) were recorded, and results compared using Student T-tests. RESULTS: Between Sept 2013-2014, 118 consecutive patients had 2-stage implants performed by each of the two theatre processes (59 in each group). There was no difference in test conversion rates between theatres, but a significant difference in infection rate was observed (p<0.01)(Table 1). The single infection on the dedicated theatre team occurred when the advanced nurse practitioner was absent. CONCLUSIONS: In our centre a dedicated SNM theatre results in significant reduction in infection rates. We recommend grouping all SNM cases in dedicated theatre lists to reduce substantial patient morbidity and health care costs of implant infections.

PD27-09 DOES THE USE OF A DEDICATED OPERATING SPACE AND SURGICAL TEAM REDUCE INFECTION RATES FOR FIRST STAGE SACRAL NEUROMODULATION?

INTRODUCTION AND OBJECTIVES: Sacral neuromodulation (SNM) is an effective treatment for medically refractory overactive bladder (OAB). The procedure is performed as a 2-stage technique with first stage tined placement (FSTLP) followed by second stage stimulator 4 weeks later. The most significant morbidity for the procedure is infection, reported in up to 12%. We assessed the infection rates in patients who were implanted within a dedicated SNM theatre environment and compared them to those in patients who underwent SNM on mixed operating lists. METHODS: We reviewed the complications in all patients having SNM surgery over a 12 month period within either a dedicated SNM operating theatre, with the same surgeon, advanced nurse practitioner, anaesthetist and radiological team, or on the mixed urological lists. In the mixed theatre lists SNM cases were performed amongst other urological cases by varying theatre teams. Infection rates (requiring lead or device explantation) were recorded, and results compared using Student T-tests. RESULTS: Between Sept 2013-2014, 118 consecutive patients had 2-stage implants performed by each of the two theatre processes (59 in each group). There was no difference in test conversion rates between theatres, but a significant difference in infection rate was observed (p<0.01)(Table 1). The single infection on the dedicated theatre team occurred when the advanced nurse practitioner was absent. CONCLUSIONS: In our centre a dedicated SNM theatre results in significant reduction in infection rates. We recommend grouping all SNM cases in dedicated theatre lists to reduce substantial patient morbidity and health care costs of implant infections.

169 Occupational factors associated with latent tuberculosis infection and conversion in health care workers in a high tuberculosis/HIV prevalence setting

ObjectiveSouth African health care workers are at growing risk of tuberculosis (TB). This study sought occupational risk factors for latent TB infection (LTBI).MethodsA sample of public sector facility staff in...

Tuberculin skin test conversion rate among short-term health care workers returning from Gaborone, Botswana

Our objective was to determine tuberculin skin test conversion rate of health care workers traveling to Botswana. The rate of tuberculin skin test conversion was 4.2% for the entire group studied or 6.87 per 1000 person weeks (95% CI, 1.87-17.60). International travel by health care workers traveling from low incidence countries to areas of the world where tuberculosis is highly endemic places the health care worker at an increased risk of acquiring tuberculosis. To determine the tuberculin skin test conversion rate of health care workers living in the United States with previously negative tuberculin skin test results working for less than 1 year in a hospital in Botswana where tuberculosis is highly endemic. We performed a cross-sectional survey among health care workers affiliated with the University of Pennsylvania School of Medicine who participated in patient care in Botswana between July 1st 2004 and June 30th 2009. We recruited health care workers after returning from Botswana who had a documented negative tuberculin skin test in the year prior to travel, who spent at least 2 weeks but not more than 1 year and who had a documented tuberculin skin test 2-3 months post travel. The main study outcome was a positive tuberculin skin test 6-12 weeks after returning from Botswana, defined by an area of at least 10mm induration 48-72h after placement of the tuberculin skin test. 95 Subjects participated in the study and there were 4 tuberculin skin test conversions. The rate of tuberculin skin test conversion in our study population was 4.2% for the entire group studied or 6.87 per 1000 person weeks (95% CI, 1.87-17.60). The tuberculin skin test conversion rate was higher than the reported conversion rates for those not working in a health care setting.

AB0363 Rate of tuberculin skin test or interferon gamma release assay conversion during anti-tumor necrosis factor therapy in rheumatic patients

BackgroundDespite negative baseline testing for tuberculosis (TB) with traditional (tuberculin skin test/TST, chest X-ray/CXR) or newer (interferon-gamma release assays/IGRAs) screening methods, a small number of patients receiving anti-tumor necrosis factor...

Prevalence and Incidence of Latent Tuberculosis Infection in Georgian Healthcare Workers

BackgroundTuberculosis is a major occupational hazard in low and middle-income countries. Limited data exist on serial testing of healthcare workers (HCWs) with interferon-γ release assays (IGRAs) for latent tuberculosis infection (LTBI), especially in low and middle-income countries. We sought to evaluate the rates of and risk factors for LTBI prevalence and LTBI test conversion among HCWs using the tuberculin skin test (TST) and QuantiFERON-TB Gold In-tube assay (QFT-GIT).MethodsA prospective longitudinal study was conducted among HCWs in the country of Georgia. Subjects completed a questionnaire, and TST and QFT-GIT tests were performed. LTBI testing was repeated 6-26 months after baseline testing.ResultsAmong 319 HCWs enrolled, 89% reported prior BCG vaccination, and 60% worked in TB healthcare facilities (HCFs). HCWs from TB HCFs had higher prevalence of positive QFT-GIT and TST than those from non-TB HCFs: 107/194 (55%) vs. 30/125 (31%) QFT-GIT positive (p<0.0001) and 128/189 (69%) vs. 64/119 (54%) TST positive (p = 0.01). There was fair agreement between TST and QFT-GIT (kappa = 0.42, 95% CI 0.31–0.52). In multivariate analysis, frequent contact with TB patients was associated with increased risk of positive QFT-GIT (aOR 3.04, 95% CI 1.79–5.14) but not positive TST. Increasing age was associated with increased risk of positive QFT-GIT (aOR 1.05, 95% CI 1.01–1.09) and TST (aOR 1.05, 95% CI 1.01–1.10). High rates of HCW conversion were seen: the QFT-GIT conversion rate was 22.8/100 person-years, and TST conversion rate was 17.1/100 person-years. In multivariate analysis, female HCWs had decreased risk of TST conversion (aOR 0.05, 95% CI 0.01–0.43), and older HCWs had increased risk of QFT-GIT conversion (aOR 1.07 per year, 95% CI 1.01–1.13).ConclusionLTBI prevalence and LTBI test conversion rates were high among Georgian HCWs, especially among those working at TB HCFs. These data highlight the need for increased implementation of TB infection control measures.

Occupational Infections among Health Care Workers in a Secondary Care Hospital Saudi Arabia

Introduction: Healthcare workers (HCWs) are frequently exposed to various infectious agents while performing their duties and many accidental exposures to blood borne and air borne pathogens are preventable if health care workers comply with appropriate precautions. Objectives: Assessment of some occupational exposure among health care workers in a secondary care hospital- Najran province- Saudi Arabia during the period (2009-2012). Subjects and methods: Retrospective review of health care workers’ (HCWs) records from staff health clinic to determine the distribution of occupational infections among different job categories which was confirmed by clinical manifestations, laboratory investigations and reports of needle stick incidents to which HCWs were exposed during period of data collection. Results: The most common occupational infection among healthcare workers was chicken pox. There was low Tuberculin skin test (TST) conversion rate among different professional categories and nurses were the most affected occupational category during the study period as regard exposure to sharp injuries and air borne infections. Conclusions: Management policy and procedures should be directed and implemented to minimize and prevent occupational infections with emphasis on nurses as being the highly affected risk group.

Comparative evaluation of phenol and thimerosal as preservatives for a candidate vaccine against American cutaneous leishmaniasis

For decades thimerosal has been used as a preservative in the candidate vaccine for cutaneous leishmaniasis, which was developed by Mayrink et al. The use of thimerosal in humans has been banned due to its mercury content. This study addresses the standardization of phenol as a new candidate vaccine preservative. We have found that the proteolytic activity was abolished when the test was conducted using the candidate vaccine added to merthiolate (MtVac) as well as to phenol (PhVac). The Montenegro's skin test conversion rates induced by MtVac and by PhVac was 68.06% and 85.9%, respectively, and these values were statistically significant (p < 0.05). The proliferative response of peripheral mononuclear blood cells shows that the stimulation index of mice immunized with both candidate vaccines was higher than the one in control animals (p < 0.05). The ability of the candidate vaccines to induce protection in C57BL/10 mice against a challenge with infective Leishmania amazonensis promastigotes was tested and the mice immunized with PhVac developed smaller lesions than the mice immunized with MtVac. Electrophoresis of phenol-preserved antigen revealed a number of proteins, which were better preserved in PhVac. These results do in fact encourage the use of phenol for preserving the immunogenic and biochemical properties of the candidate vaccine for cutaneous leishmaniasis.

Protecting health care workers from tuberculosis: A 10-year experience

Cook County Hospital (CCH) is an inner-city, large public hospital. Twenty-five percent of Chicago's tuberculosis (TB) cases are diagnosed at CCH. We wanted to review and analyze interventions implemented over a 10-year period at CCH to prevent TB infection in health care workers. We performed a retrospective review of interventions to prevent health care-associated tuberculosis. We collated and analyzed tuberculin skin test conversions in our employees for the same time period. From 1990 to 2002, we cared for over 1800 in-patients with tuberculosis. During 1992-1997, multiple interventions to eliminate health care-associated spread of tuberculosis were implemented. Tuberculin skin test conversions in our employees decreased markedly from January 1994 through December 2002. Two drops in tuberculin skin test conversion rates occurred: one after introduction of basic administrative and engineering controls and a second after we experienced a decrease in missed TB cases and the introduction of N-95 personal respirators with 1-time qualitative fit testing. Our annual health care worker skin test conversion rate fell significantly when our primary interventions were relatively simple administrative and engineering controls. Educating health care workers to promptly recognize patients with TB and placing exhaust fans to create negative-pressure respiratory isolation rooms were probably our 2 most potent infection control measures.

Differences in Tuberculin Reactivity as Determined in a Veterans Administration Employee Health Screening Program

In response to a difference in pricing, the San Diego Veterans Administration Medical Center changed its tuberculin preparation from Tubersol to Aplisol in the fall of 2006. Following the change, an increased number of employee skin test conversions was noted. Employee tuberculin skin test converters from 2006 were screened with the QuantiFERON Gold (QFT-G) gamma interferon release assay. Those employees who tested negative by QFT-G were asked to repeat their skin test with both Tubersol and Aplisol tuberculin preparations. Of the new purified protein derivative converters, 12 of 14 returned for repeat testing with QFT-G, and the assay was negative for 83% (10/12), positive for 8% (1/12), and indeterminate for 8% (1/12) of the individuals. Nine of the individuals who were QFT-G negative agreed to repeat skin testing with both tuberculin preparations, and 7/8 (87.5%) demonstrated reactivity with the Aplisol preparation, while 0/8 (0%) reacted to the Tubersol preparation. A change from Tubersol to Aplisol resulted in elevated tuberculin skin test conversion rates that may be due to false-positive reactions. The differences in skin test reactivity between preparations support CDC guidelines that recommend that institutions should not change tuberculin preparations, as doing so may falsely increase the number of positive reactions.