Rapid Antibody Test Research Articles

Maternal Deaths caused by COVID-19 Infection in the First Year of the Pandemic Wave

Highlights: These cases of maternal deaths caused by COVID-19 infections illustrated the significant risk factors for maternal mortality during the early phases of the pandemic, while studies had not extensively reported this. COVID-19 infections increase the risk of maternal and neonatal mortality, with infants having a lower chance of survival even if they are delivered. Respiratory support, antiviral medications, antibiotics, anticoagulants, and supportive care are the primary treatments for severe COVID-19 in pregnancy. AbstractThis article presents seven cases of maternal deaths attributed to COVID-19 during the first year of the pandemic wave. These cases provide insights into the natural progression of COVID-19 in pregnant women who were not vaccinated. This study showed that COVID-19 significantly increased maternal and neonatal mortality and morbidity. All of the patients exhibited symptoms of fever, cough, and dyspnea upon admission to the hospital. They were admitted with elevated respiratory rates (26–32 times/minute) and low oxygen saturation (<95%). Four patients had obesity, while one patient had pregestational diabetes. The COVID-19 diagnosis was established using a rapid antibody or antigen test and chest X-ray, which indicated pneumonia. Medical interventions administered to the patients included antiviral therapy (5 patients), antibiotics (6 patients), and anticoagulants (4 patients). From a total of five babies delivered, four babies were delivered via cesarean section. Two babies were not delivered due to previability and maternal deaths before delivery. The patients passed away within 3–10 days of hospital admission. In conclusion, adequate and early intervention and management of pregnant women infected with COVID-19 are crucial in preventing maternal and neonatal deaths, especially in unvaccinated women.

Pediatric Respiratory Syncytial Virus Diagnostic Testing Performance: A Systematic Review and Meta-analysis.

Adding additional specimen types (eg, serology or sputum) to nasopharyngeal swab (NPS) reverse transcription polymerase chain reaction (RT-PCR) increases respiratory syncytial virus (RSV) detection among adults. We assessed if a similar increase occurs in children and quantified underascertainment associated with diagnostic testing. We searched databases for studies involving RSV detection in persons <18 years using ≥2 specimen types or tests. We assessed study quality using a validated checklist. We pooled detection rates by specimen and diagnostic tests and quantified performance. We included 157 studies. Added testing of additional specimens to NP aspirate (NPA), NPS, and/or nasal swab (NS) RT-PCR resulted in statistically nonsignificant increases in RSV detection. Adding paired serology testing increased RSV detection by 10%, NS by 8%, oropharyngeal swabs by 5%, and NPS by 1%. Compared to RT-PCR, direct fluorescence antibody tests, viral culture, and rapid antigen tests were 87%, 76%, and 74% sensitive, respectively (pooled specificities all ≥98%). Pooled sensitivity of multiplex versus singleplex RT-PCR was 96%. RT-PCR was the most sensitive pediatric RSV diagnostic test. Adding multiple specimens did not substantially increase RSV detection, but even small proportional increases could result in meaningful changes in burden estimates. The synergistic effect of adding multiple specimens should be evaluated.

Hepatitis C virus screening in community pharmacies: results on feasibility from a Swiss pilot

BackgroundHepatitis C virus (HCV) infections are a public health burden worldwide and often go undetected until sequelae develop. Offering HCV screening for the different vulnerable populations in community pharmacies could help prevent further undetected HCV infections. This pilot aimed to assess the feasibility and pharmacist acceptance of HCV rapid antibody saliva testing in community pharmacies.MethodsA structured pharmaceutical care intervention was developed that included addressing, informing, and screening clients, as well as referral and reporting to subsequent health care providers. Participating pharmacies from French-, German- and Italian-speaking parts of Switzerland were trained to provide this service to local vulnerable populations. Information on client recruitment, feasibility, and acceptability of HCV screening was collected.ResultsOf 36 pharmacies initially recruited, 25 started the pilot and approached 435 clients, 145 of whom (33%) were interested in screening. Eight of these rapid antibody tests returned positive (prevalence rate: 5.5%). Facilitators were being able to offer a free rapid test (73%), followed by having training prior to the project (67%) and having a new service to offer (67%). The possibility of clients reacting dismissively (53%) and of unsettling clients (47%) were reported to be the main barriers.ConclusionsThis pilot demonstrated the general feasibility of an HCV screening service with rapid antibody saliva testing in Swiss community pharmacies, which achieved a higher prevalence rate than national estimates. With appropriate communication training and remuneration, Swiss community pharmacies could be an important partner in implementing HCV elimination strategies.

Robust Combination Testing: Methods and Application to COVID-19 Detection

Simple and affordable testing tools are often not accurate enough to be operationally relevant. For coronavirus disease 2019 (COVID-19) detection, rapid point-of-care tests are cheap and provide results in minutes, but they largely fail policy makers’ accuracy requirements. We propose an analytical methodology, based on robust optimization, that identifies optimal combinations of results from cheap tests for increased predictive accuracy. This methodological tool allows policy makers to credibly quantify the benefits from combination testing and thus, break the trade-off between cost and accuracy. Our methodology is robust to noisy and partially missing input data and incorporates operational constraints—relevant considerations in practice. We apply our methodology to two data sets containing individual-level results of multiple COVID-19 rapid antibody and antigen tests, respectively, to generate Pareto-dominating receiver operating characteristic curves. We find that combining only three rapid tests increases out-of-sample area under the curve by 4% (6%) compared with the best-performing individual test for antibody (antigen) detection. We also find that a policy maker who requires a specificity of at least 0.95 can improve sensitivity by 8% and 2% for antibody and antigen testing, respectively, relative to available combination testing heuristics. Our numerical analysis demonstrates that robust optimization is a powerful tool to avoid overfitting, accommodate missing data, and improve out-of-sample performance. Based on our analytical and empirical results, policy makers should consider approving and deploying a curated combination of cheap point-of-care tests in settings where “gold standard” tests are too expensive or too slow. This paper was accepted by Stefan Scholtes, healthcare management. Supplemental Material: The data files and electronic companion are available at https://doi.org/10.1287/mnsc.2023.4826 .

COMPARISON OF ANTIBODY DETECTION BY RAPID DIAGNOSTIC KIT AND ELISA TEST FOR DIAGNOSIS OF HEPATITIS C VIRUS INFECTION

Background: Hepatitis C virus (HCV) infection is a major cause of healthcare problem along with burden of health management care cost of international concern. Hepatitis C is a serious threat with long term complication. The present study is undertaken to compare rapid card test based on Immunochromatography principle with ELISA test for detection of anti HCV antibodies. In the absence of vaccine, primary prevention of Hepatitis C should be targeted to reduce transmission of virus. High risk people should be provided with education, counselling and screening. A cross-sectional study was done at Dept. of Microbiology, M.G.M.M.C, Indore Method: for one year comprising of 500 samples after getting Institutional Scientic Research and Ethics Committee approval. Rapid card and ELISA tests were performed in the samples received for detection of Anti-HCV ab. Out of 500 blood samples test Result: ed on Rapid card 22 were positive while 478 were negative. Further testing on same 500 samples with ELISA test 22 were positive and 478 were negative. Discussion: Present study ndings suggest that for screening of anti HCV antibody ELISA and Rapid card tests both can be used as diagnostic tool depending upon facilities available in the laboratory. Rapid card Conclusion: tests were found to be equally diagnostic as compared to ELISA test and hence can be recommended in screening of HCV

Mortality Predictors of Pre-variant SARS-CoV-2 Infected ARDS Patients Receiving Favipiravir and Tocilizumab

Objective: In this study, we investigated the risk factors affecting mortality of critically ill COVID-19-related acute respiratory distress syndrome (ARDS) patients who were followed up in the intensive care unit (ICU) and received tocilizumab and favipiravir treatments together before vaccination. Materials and Methods: The data of patients who were followed up and treated between 1, July 2020 and 5, October 2020 were retrospectively analyzed. Demographic data of the patients (age, gender), acute physiology and chronic health evaluation score II (APACHE II), sequential organ failure assessment (SOFA) score, RT-PCR of oro-nasopharyngeal swabs, the severity of ARDS on the day of tocilizumab admission, time from RT-PCR positivity to tocilizumab administration, respiratory support treatments, all other medical treatments, and ICU outcomes were recorded. Risk factors affecting mortality were evaluated with multiple regression analysis. Results: A total of 60 patients with a median age of 69.8 (24-87) years, 25 females and 35 males were included in the study. The mean APACHE II score was 18.9 ± 8.0, and the SOFA score was 4.5 ± 2.0. Fifty-two (86.7%) patients had positive oro-nasopharyngeal swabs for SARS-CoV-2 by RT-PCR; (13,3%) patients had positive IgM/Ig G rapid antibody tests for SARS-CoV-2. Tocilizumab was given on an average of 2.5th days (± 2.0 days). On the day of tocilizumab administration, 1 (1.7%) patient had mild ARDS, 30 (50.0%) had moderate ARDS, and 29 (48.3%) had severe ARDS. The PaO2/FIO2 ratio of the study group on the day of tocilizumab administration was 96.7 ± 36.6 mmHg. Thirty-four (56.7%) patients were intubated during follow-up. Forty (66.7%) patients died, while 20 (33.3%) patients were transferred to the ward. The mean length of stay in the ICU was 11.4 ± 5.5 days. Advanced age (Hazard ratio (HR) 1.8; 95% confidence interval (CI) 0.88-0.93; p &lt; 0.001), higher APACHE II score (HR 0.81, 95% CI 0.74-0.98; p = 0.001), higher SOFA score on the day of tocilizumab administration (HR 1.47, 95% CI 0.39-0.79; p = 0.001), and lower PaO2/FIO2 ratio (HR 2.54, 95% CI 2.33-3.79; p &lt; 0.001) were determined as independent risk factors for mortality. Conclusion: Patients administered tocilizumab and favipiravir in our ICU were mostly patients with moderate-severe ARDS and had higher inflammatory markers. The reason for the high mortality in this study was attributed to the fact that all of the patients had moderate-severe COVID-19-related ARDS, rather than severe COVID-19.

Perceptions in Trimester III About Covid-19 Scrining Using Rapid Test Antibody

Rapid antibody test is one method of screening for Covid-19 in third trimester pregnant women during the pandemic. The low participation of pregnant women in the third trimester in the implementation of Covid-19 screening can be seen from the delay in pregnant women carrying out rapid antibody tests. The purpose of the study was to find out the Perception of Pregnant Women in the Third Trimester Regarding Screening for Covid-19 Using Antibody Rapid Tests. The research design used a descriptive method. The variable is the perception of pregnant women in the third trimester regarding Covid-19 screening using a rapid antibody test. The population is 40 people and the number of samples is 29 respondents who are taken by purposive sampling. The research was carried out on April 20 - May 22, 2021 at the Kusuma Pertiwi Clinic, Kepung Village, Kepung District, Kediri Regency. The results showed that the perception of pregnant women in the third trimester about screening for Covid-19 using a rapid antibody test was mostly negative. 17 pregnant women in the third trimester (52%), the negative perception was almost entirely influenced by the education of 18 respondents (62%). The negative perception of pregnant women in the third trimester about screening for Covid-19 using rapid antibody tests is influenced by negative information for pregnant women about rapid antibody tests, causing negative perceptions about the process of implementing the Covid-19 screening, pregnant women's trust in hoax news caused by the information provided to them. less than optimal pregnant women.

Incidence and clinical characteristic of ocular surface manifestation: an evaluation of conjunctival swab results in Corona Virus 2019 (COVID-19) patients in Jakarta, Indonesia

ObjectivesThis study aimed to investigate the spectrum of ocular characteristics and viral presence in the conjunctival swab of patients with COVID-19.MethodsIn this cross-sectional study, fifty-three patients were recruited from two COVID-19 referral hospitals in Jakarta (Cipto Mangunkusumo Hospital and Persahabatan Hospital) from July 2020 to March 2021. The inclusion criteria were patients who were suspected of or confirmed cases of COVID-19 with or without ocular symptoms. Demographic data, history of COVID-19 exposure, underlying medical condition, systemic symptoms, ocular symptoms, supporting laboratory results, reverse-transcriptase polymerase chain reaction (RT-PCR) of naso-oropharyngeal (NOP) swab and conjunctival swab were collected.ResultsFifty-three patients who were suspected, probable or confirmed cases of Covid-19 were included. Forty-six out of 53 patients (86.79%) tested positive for either Covid-19 antibody rapid test or naso-oropharyngeal (NOP) swab. Forty-two patients tested positive for NOP swab. Fourteen out of 42 patients (33.33%) experienced symptoms of ocular infection including red eye, epiphora, itchy eyes, and eye discharge. None of these patients were tested positive for conjunctival swab. Two out of 42 patients (4.76%), who were tested positive for conjunctival swab, did not experience any ocular symptoms.ConclusionsEstablishing the relationship between Covid-19 infection, ocular symptoms, and presence of SARS-CoV-2 virus on the ocular surface proves to be challenging. In Covid-19 patients, ocular symptoms did not warrant a positive conjunctival swab result. On the contrary, a patient without ocular symptoms can also have detectable presence of SARS-CoV-2 virus on the ocular surface.

Performance evaluation of newly developed surrogate virus neutralization tests for detecting neutralizing antibodies against SARS-CoV-2

We evaluated newly developed surrogate virus neutralization tests (sVNT) for detecting neutralizing antibodies (NAbs) against the receptor binding domain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). VERI-Q SARS-CoV-2 Neutralizing Antibody Detection ELISA Kit (MiCo BioMed, Gyeonggi-do, Republic of Korea, hereafter, “eCoV-CN”) is an enzyme-linked immunosorbent assay-based sVNT, and VERI-Q SARS-CoV-2 Neutralizing Antibody Rapid Test Kit (MiCo BioMed, hereafter, “rCoV-RN”) is a point-of-care lateral-flow immunochromatography test with auto-scanner. A total of 411 serum samples were evaluated. Both evaluations used a 50% plaque reduction neutralization test (PRNT50) as the gold standard. Compared with PRNT50, the eCoV-CN showed 98.7% positive percent agreement (PPA), 96.8% negative percent agreement (NPA), 97.4% total percent agreement (TPA), with kappa values of 0.942. The rCoV-RN showed 98.7% PPA, 97.4% NPA, 97.8% TPA, and kappa values of 0.951, comparing to PRNT50. Neither assay indicated cross-reactivity for other pathogens, and the signal indexes were statistically significantly correlated to the PRNT50 titer. The two evaluated sVNTs show comparable performances to the PRNT50 with the advantages of technical simplicity, speed, and do not require cell culture facilities.

Diagnostic accuracy of the NOVA Tuberculosis Total Antibody Rapid test for detection of pulmonary tuberculosis and infection with Mycobacterium tuberculosis

BackgroundThe NOVA Tuberculosis Total Antibody Rapid Test is a commercially available lateral flow serological assay that is intended to be used as an aid in the diagnosis of tuberculosis. We conducted a study to estimate diagnostic accuracy of this assay for diagnosis of active pulmonary tuberculosis disease and for detection of M. tuberculosis infection. MethodsThis study used existing frozen plasma specimens that had been obtained previously from consenting HIV-negative adults in Cambodia, South Africa, and Vietnam whose tuberculosis status was rigorously characterized using sputum mycobacterial cultures and blood interferon gamma release assay. The investigational assay was performed in a single laboratory by laboratory staff specifically trained to conduct the assays according to the manufacturer’s procedures. In addition, intensity of the test band was subjectively assessed. ResultsPlasma specimens from 150 participants were tested. All testing attempts yielded a determinate result of either positive or negative. For diagnosis of active pulmonary tuberculosis disease, test sensitivity and specificity were 40.0 % (20/50, 95 % confidence interval [CI] 27.6 % to 53.8 %) and 85.0 % (95 % CI 76.7 % to 90.7 %), respectively. For detection of M. tuberculosis infection, test sensitivity and specificity were 28.0 % (95 % CI 20.5 % to 37.2 %) and 86.0 % (95 % CI 73.8 % to 93.0 %), respectively. Among the 35 positive tests, no statistically significant band intensity trend was found across participant groups (p = 0.17). ConclusionStudy findings do not support a role for the NOVA Tuberculosis Test in current tuberculosis diagnostic algorithms.

Severe acute respiratory syndrome coronavirus-2 detection in domestic animals as a reservoir for the virus transmission to humans in Yogyakarta, Indonesia.

The coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that attacks the respiratory and digestive tract. The SARS-CoV-2 showed systemic characteristics with various clinical symptoms from subclinical to fatal (causing death). Transmission of SARS-CoV-2 has been reported to occur from humans to pets (cats, dogs, tigers, ferrets, and poultry). Knowledge about the role of domestic animals in the transmission of SARS-CoV-2 to humans, and as reservoirs of this virus needs to be investigated further. This study aimed to detect the presence of SARS-CoV-2 in domestic animals such as dogs, cats, pigs, cows, birds, and bats that are often in contact with humans. A total of 157 samples, which included nasopharyngeal and oropharyngeal swabs, along with sera samples from domestic animals such as cats, pigs, cows, birds, and bats, were taken from Veterinary Hospitals, Veterinary Clinics, and farms around the Yogyakarta region. Detection of the virus was done using rapid detection of viral antigens, antibodies, and reverse transcriptase-polymerase chain reaction (RT-PCR) technique. The results showed that 5/157 (3.1%) samples found positive against the COVID-19 virus using a rapid antibody test; however, the results were negative on the rapid antigen and RT-PCR tests. Antibody-positive samples came from animals that had a history of household COVID-19 human infection. Thus, findings of the present study conclude that there is a potential for transmission of the COVID-19 virus between animals and humans.

Prevalence of and risk factors for Human Immunodeficiency Virus (HIV) infection in entrants and residents of an Ethiopian prison.

Prisoners generally have a higher prevalence of HIV infection compared to the general population from which they come. Whether this higher prevalence reflects a higher HIV prevalence in those entering prisons or intramural transmission of HIV within prisons or both is unclear. Any of these possibilities would increase the prevalence found in resident prisoners above that in the general population. Moreover, comparisons of HIV prevalence in entrants and residents and in men and women in African prisons are not well documented. The purpose of this study was to estimate and compare the prevalence and risk factors for HIV infection amongst both male as well as female and entrant and resident prisoners in a large Ethiopian Federal Prison. We studied consenting prisoners cross-sectionally from August 2014 through November 2016. Prison entrants were screened continuously for HIV infection and its associated risk factors and residents were screened in two waves one year apart. HIV was diagnosed at the prison hospital laboratory based on the Ethiopian national HIV rapid antibody testing protocol. An external, internationally-accredited reference laboratory confirmed results. Agreement of results between the laboratories were assessed. A total of 10,778 participants were screened for HIV. Most participants were young (median age of 26 years, IQR: 21-33), male (84%), single (61%), literate (89%), and urban residents (91%) without prior incarceration (96%). Prevalence of HIV was 3.4% overall. Rates of HIV (p = 0.80) were similar in residents and entrants in wave 1 and in entrants in both waves, but were 1.9-fold higher (5.4% vs 2.8%) in residents than entrants in wave 2 (both p<0.001). At entrance to the prison women were more likely to be HIV+ than men (5.5% in women vs 2.5% in men, p< 0.001). In contrast resident women were less likely to be HIV+, but this difference was not statistically significant (3.2% in women vs 4.3% in men, p = 0.125). Other risk factors associated with HIV infection were increasing age (p<0.001), female gender (p<0.001), marital status (never vs other categories, p = 0.016), smaller number of rooms in their houses pre-imprisonment (p = 0.031), TB diagnosis ever (p<0.001), number of lifetime sex partners (especially having 2-10, p<0.001), and genital ulcer (p = 0.037). Prevalence of HIV in the residents at this large, central Ethiopian prison was higher than that estimated for the general population and lower than in many other studies from other smaller Ethiopian prisons. A higher prevalence in residents than in entrants were found only in our second wave of screening after one year of continuous screening and treatment, possibly representing increased willingness of residents at increased risk of HIV to participate in the second wave. Thus, this findings did not clearly support intramural transmission of HIV or the effectiveness of screening to reduce prevalence. Finally, the higher HIV prevalence in women than men requires that they be similarly screened and treated for HIV infection.

Low detection rate of RT-PCR-confirmed COVID-19 using IgM/IgG rapid antibody tests in a large community sample in Lima, Peru

BackgroundRapid IgM/IgG antibody tests were largely used in lieu of RT-PCR tests as part of COVID-19 public health response activities in Lima, Peru. To assess their utility, we explored the relationship between the time since onset of several COVID-19-related symptoms and the sensitivity of a rapid combined IgM/IgG antibody test.MethodsWe collected data from a community sample of individuals (n = 492) who received concurrent RT-PCR and rapid IgM/IgG antibody testing between May 2020 and March 2021. We estimated the sensitivity of the antibody test, against the RT-PCR test, by weeks since symptom onset via segmented regression analysis.ResultsThe overall sensitivity of the rapid IgM/IgG antibody test was 46.7% (95% CI, 42.4–51.2%). Among 372 (75.6%) participants who reported COVID-19-related symptoms, sensitivity increased from 30.4% (95% CI, 24.7–36.6%) in week 1 after symptom onset to 83.3% (95% CI, 41.6–98.4%) in week 4. The test sensitivity increased by 31.9% (95% CI, 24.8–39.0%) per week until week 2 to 3, then decreased by − 6.0% (95% CI, − 25.7–13.7%) per week thereafter.ConclusionRapid antibody tests are a poor substitute for RT-PCR testing, regardless of presenting symptoms. This highlights the need for future pandemic planning to include timely and equitable access to gold-standard diagnostics, treatment, and vaccination.

Reliability of antibody tests for COVID-19 diagnosis

Objective: The reverse transcription–polymerase chain reaction test (RT-PCR) is the gold standard for the diagnosis of coronavirus&#x0D; disease 2019 (COVID-19), and antibody tests are useful as supplemental tools for diagnosis, for measuring the population’s immunity&#x0D; levels, and for checking infection in asymptomatic contacts. This study aimed to evaluate the reliability of five commercial antibody&#x0D; detection test kits.&#x0D; Materials and Methods: The reliability of the Colloidal Gold COVID-19 IgG/IgM Rapid Test Kit, Antibody Rapid Test Hotgen,&#x0D; Beijing Hotgen Biotech Co., Ltd., China), Abbott Chemiluminescent Microparticle Immunoassay (Illinois, USA), Roche&#x0D; Electrochemiluminescence Immunoassay (Roche Diagnostics, Switzerland), Siemens Chemiluminescence (Munich, Germany), and&#x0D; Euroimmun ELISA (Lübeck, Germany) for COVID-19 diagnosis was studied. The antibody-negative group included 50 sera from&#x0D; 2018, and the antibody-positive group included 98 patients with positive RT-PCR results from whom blood samples had been collected&#x0D; 3–9 weeks after hospital discharge. Statistical analysis was performed using SPSS version 23.0 (IBM Corporation, Armonk, NY, USA).&#x0D; The antibody tests’ validity and intra-assay reproducibility were examined, and the Cohen’s kappa coefficients were obtained. The&#x0D; disease prevalence was pegged at 10%.&#x0D; Results: The antibody tests’ sensitivity (69.12–72.46%) and positive predictive values (42.44–100.0%) were low, and their specificity&#x0D; (89.58–100%) and negative predictive values (96.31–97.03%) were high. Their accuracy rates varied from 87.54% to 97.25%, and their&#x0D; intra-assay coefficients of variation varied from 1% to 10%.&#x0D; Conclusion: The agreement between the results of the antibody detection test kits was higher when the kits were classified according to&#x0D; the targeted antigens. The time of blood sample collection, targeted antigens, and antibody types affected the results. Serological tests&#x0D; were found to be useful, and the commercial kits were found to be largely reliable, although, some parameters need to be improved.

Seroprevalence of SARS-CoV2 Infections in Health Care Personnel in a Long-Term Care Institution After the First Wave of the Pandemic: A Cross-Sectional Study.

At the time of our study, occupational health evidence specific for long-term care employees was mostly lacking. The purpose of this study was to determine the proportion of positive cases in employees after the first COVID-19 wave in May 2020. We also determined the prevalence of asymptomatic cases. The study population included all health care workers (HCW) employed at one mid-size long-term hospital in Spain (May 2020). A cross-sectional study design included an interviewer-administered self-reported questionnaire (including sociodemographic questions, risk factors for COVID-19 complications such as hypertension or diabetes, and previous polymerase chain reaction [PCR] results) and antibody determination (Biozek rapid test). Data were analyzed using Student's t, Fisher, and chi-square tests. Two multivariate logistic models were created to evaluate exposure factors and symptoms separately on the outcome of having had COVID-19. Of the 97% of workers who participated (580/596), 300 (51.7%) suffered symptoms of COVID-19, 161 (27.8%) of the rapid antibody tests were positive for IgM and/or IgG, 160 (27.6%) workers had at least one risk factor, and 32 (19.0%) of the 168 SARS-CoV-2-positive cases were asymptomatic. The proportion of negative or unavailable PCRs, with positive antibody, was 11.7% (56/477). Casual contact without protection (odds ratio [OR]: 1.9, 95% confidence interval [CI]: 1.1-3.4), doctor occupation (OR 3.3, 95% CI: 1.1-10.2), and nursing assistant occupation (OR 2.5, 95% CI: 1.2-5.8) were independently associated with SARS-CoV-2 infection. Physicians and nursing assistants in a long-term care setting were at a higher risk of SARS-COV-2 infection over other occupations in the first wave of the pandemic, especially when in contact with patients without protection. Almost one-fifth of the workers with a positive PCR test for SARS-COV-2 were asymptomatic and seroprevalence (27.8%) was well below the approximated herd immunity cutoff (60-70%). Essential workers in long-term care must be monitored frequently by Employee Health Service and should be required to wear personal protective equipment including a fit-tested N-95 while in close contact with patients and coworkers.

An investigative study on the zoonotic potential of Helicobacter pylori

BackgroundHelicobacter pylori is one of the most common bacterial infections and is widespread globally. It causes a variety of gastrointestinal disorders, though a great proportion of infections are asymptomatic. A total of 143 fresh stool samples were collected from apparently healthy farm and pet animals (43 cattle, 50 buffaloes, 50 sheep, 50 dogs, and 50 cats), in addition to 768 human stool samples. The samples were examined using stool antigen and rapid antibody tests, and further confirmation of glmM “human antigen-positive samples and animal milk samples” was conducted by polymerase chain reaction (PCR).ResultsThe prevalence rates of H. pylori infection in animals were 22.2% and 16% in antibody and stool antigen tests, respectively. The detection rates were 28%, 24%, 12%, 10%, and 4.7% in cats, dogs, buffaloes, sheep, and cattle, respectively. On the other hand, the prevalence rate of H. pylori infection in human stool samples was 74.8%, and a statistically significant association was observed between prevalence and several factors, such as sex, age, and locality. PCR was performed to detect the glmM gene of H. pylori, and this gene was found in 21 of 27 human antigen-positive samples and 5 of 13 animal milk samples.ConclusionsH. pylori was detected in both human and animal samples. Furthermore, glmM was found in milk and human samples. Our findings suggest that pet and farm animals could transmit H. pylori infection to humans.

Performance of the SureScreen Diagnostics COVID-19 antibody rapid test in comparison with three automated immunoassays

Lateral flow immunoassays (LFIA) for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies are used for population surveillance and potentially individual risk assessment. The performance of the SureScreen Diagnostics LFIA targeting the spike protein was evaluated in comparison with 3 automated assays (Abbott Alinity-i SARS-CoV-2 IgG, DiaSorin Liaison® SARS-CoV-2 S1/S2 IgG, Wantai SARS-CoV-2 Ab ELISA). We assessed sensitivity using 110 serum samples from PCR confirmed COVID-19 infected patients. Specificity was evaluated using 120 prepandemic samples, including potential cross-reactive antibodies samples. Sensitivity ranged between 93.3% and 98.7% on samples collected >14 days postsymptom onset. All assays achieved a specificity >98%. Moreover, its performance seems not to be affected by Alpha, Beta or Delta variants over a wide range of antibody titers. The latter showed a very good agreement with the Wantai and the Abbott assays and a substantial agreement with the DiaSorin assay. Our data demonstrate the good clinical performance of the SureScreen Diagnostics LFIA for SARS-CoV-2 seroprevalence screening.

Hepatitis C virus prevalence, determinants, and cascade of care among people who inject drugs in Iran

BackgroundPeople who inject drugs (PWID) continue to experience the highest burden of hepatitis C virus (HCV). We aimed to characterize HCV antibody prevalence, determinants of infection, and the cascade of engagement in HCV care among PWID in Iran. MethodsParticipants were recruited in 11 cities of Iran using respondent-driven sampling. PWID underwent a structured interview capturing measures on socio-demographics, behaviors, and the HCV cascade of care. HCV and HIV were tested using antibody rapid tests. Multivariable logistic regression models identified characteristics associated with HCV seropositivity. ResultsHCV antibody prevalence was 26.0% among 2684 PWID enrolled. Of 699 participants who were HCV antibody positive, 88 (12.6%) were aware of past infections. HCV antibody prevalence was associated with older age (adjusted odds ratio [aOR] 2.09; 95% CI 1.18, 3.71), lower education (aOR 1.31; 95% CI 1.02, 1.69), >10 years of injecting (aOR 6.03; 95% CI 4.10, 8.85), methamphetamine injection (aOR 1.46; 95% CI 1.07, 1.99), daily injection drug use (aOR 1.26; 95% CI 1.01, 1.58), needle/syringe sharing (aOR 2.04; 95% CI 1.24, 3.34), recent incarceration (aOR 1.74; 95% CI 1.30, 2.32), and HIV seropositivity (aOR 7.93; 95% CI 4.12, 15.24). Additionally, 12.0% had ever tested for HCV, 4.0% had previously tested reactive for HCV antibody, and 3.7% had received an HCV diagnosis. Of diagnosed cases, 44.4% were linked to care, 15.2% initiated treatment, and 3.0% achieved sustained virologic response. ConclusionOur data show a high prevalence of HCV antibody and low engagement in HCV care, underscoring an unmet need for HCV prevention, screening, and treatment among PWID in Iran. HCV prevention and treatment programs tailored for PWID are needed to enhance harm reduction efforts and access to HCV care in Iran.

Clinical Application of SARS-CoV-2 IgM and IgG Antibody Detection Using the Colloidal Gold Immunochromatography Assay

Objective: The COVID-19 pandemic, which was caused by SARS-CoV-2, has had a significant effect on global public health, economies, and societies worldwide. Serum antibody testing is a critical method for the diagnosis of COVID-19 and can complement RT-PCR in the diagnosis of COVID-19 patients; however, the performance of rapid antibody assays in the clinical setting has not been established. Methods: Rapid antibody assays were evaluated by investigating 296 COVID-19-positive individuals and 542 negative individuals confirmed by clinical diagnosis. The clinical diagnostic results were used as controls to evaluate the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), kappa, and 95% confidence interval (CI) of the rapid tests. Result: IgM-positivity had a sensitivity of 86.1% and specificity of 99.1%. IgG-positivity had a sensitivity of 86.5% and specificity of 98.7%. The sensitivity of combined IgM- and IgG-positivity in clinically confirmed patients was 73.1% in the early stage (1-7 days after symptom onset) and reached 99% 15 days after symptom onset. The concordance between rapid antibody-positive tests and clinical diagnosis-positivity had a kappa value of 0.93. In addition, the false-positive rate of IgM and IgG combined nucleic acid detection was 30% in the early stage. Conclusion: The combined use of IgM and IgG could serve as a more suitable alternative detection method for patients with COVID-19. The rapid antibody test can be considered as an excellent supplementary approach for detecting SARS-CoV-2 in clinical application.

A retrospective study of SARS-CoV-2 antibodies in children with allergies.

The dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children are continually changing. We conducted a survey of pediatric allergy patients attending our department to determine the prevalence of antibodies against SARS-CoV-2 in children. A retrospective study was performed among children aged <11 years, referred to a pediatric allergy department between February 2020 and January 2022 with a chief complaint of allergy. The data of children with blood examination findings were retrospectively studied. Qualitative testing for anti-SARS-CoV-2 IgG and IgM antibodies was performed using a SARS-CoV-2 rapid antibody test. Participants were retested 1 year later to evaluate changes in antibody levels. In total, 310 patients with a median age of 26 months (interquartile range: 11.6-58.4 months) and male/female ratio of 1.31 were included. A total of 32 patients tested positive for anti-SARS-CoV-2 IgG or IgM antibodies. No differences were observed in the severity of allergic disease. The prevalence of antibodies was higher among children enrolled in preschool or school (odds ratio: 13.19, 95% confidence interval; 2.30-249.7). A total of 66.7% of patients underwent follow-up testing. The antibody positivity rate increased between the first and second testing, but this was not related to the number of medical visits or the severity of allergic disease. Antibody prevalence in children was low but increased during the study period. The majority of children who tested positive for SARS-CoV-2 antibodies did not have a history of coronavirus disease 2019, suggesting that most infections were subclinical.