Role of serological rapid antibody test in the management of possible COVID-19 cases

Although the detection of viral particles by reverse transcription polymerase chain reaction(RT-PCR)is the gold standard diagnostic test for coronavirus disease 2019(COVID-19),the false-negative results constitute a big challenge.AIM To examine a group of patients diagnosed and treated as possible COVID-19 pneumonia whose multiple nasopharyngeal swab samples were negative for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)by RT-PCR but then serological immunoglobulin M/immunoglobulin G(IgM/IgG)antibody against SARS-CoV-2 were detected by rapid antibody test.METHODS Eighty possible COVID-19 patients who had at least two negative consecutive COVID-19 RT-PCR test and were subjected to serological rapid antibody test were evaluated in this study.RESULTS The specific serological total IgM/IgG antibody against SARS-CoV-2 was detected in twenty-two patients.The mean age of this patient group was 63.2±13.1-yearsold with a male/female ratio of 11/11.Cough was the most common symptom(90.9%).The most common presenting chest computed tomography findings were bilateral ground glass opacities(77.2%)and alveolar consolidations(50.1%).The mean duration of time from appearance of first symptoms to hospital admission,to hospital admission,to treatment duration and to serological positivity were 8.6 d,11.2 d,7.9 d,and 24 d,respectively.Compared with reference laboratory values,serologically positive patients have shown increased levels of acute phase reactants,such as C-reactive protein,ferritin,and procalcitonin and higher inflammatory markers,such as erythrocyte sedimentation rate,lactate dehydrogenase enzyme,and fibrin end-products,such as D-dimer.A left shift on white blood cell differential was observed with increased neutrophil counts and decreased lymphocytes.CONCLUSION Our study demonstrated the feasibility of a COVID-19 diagnosis based on rapid antibody test in the cases of patients whose RT-PCR samples were negative.Detection of antibodies against SARS-CoV-2 with rapid antibody test should be included in the diagnostic algorithm in patients with possible COVID-19 pneumonia.

Prevalence of HCV Antibody and its Associated Factors: A Study from Sentinel Hospitals in China

Objective The prevalence and related factors of serum anti-HCV in different regions and hospitals have not been studied extensively in China. We used routine screening data to determine the prevalence of HCV antibody in hospital patients, evaluate the epidemic trend of hepatitis C and formulate screening strategies.Methods Patient information and HCV antibody testing results were collected from January 2017 to December 2019 in 77 HCV sentinel hospitals in China. Univariate and multivariate logistic regression was used to determine the characteristics and associations.Results HCV antibody prevalence rates were distinct among patients in different departments, with a range of 0.33%–6.93%. Patients who were admitted to the liver disease-related departments(aOR =10.76;95% CI, 10.27–11.28), Internal Medicine(aOR = 2.87;95% CI, 2.75–3.00), and Department of Surgery(aOR = 1.95;95% CI, 1.87–2.04), were more likely to be tested for HCV antibody positive. HCV antibody prevalence was associated with patients aged 45 years and older(aOR = 2.74;95% CI,2.69–2.80), testing in infetious disease hospitals(aOR = 2.33;95% CI, 2.26–2.40) and secondary hospitals(aOR = 1.72;95% CI, 1.69–1.75). Patients in sentinel hospitals of the Northeast(aOR = 12.75;95% CI,12.40–13.11), the Central(aOR = 1.65;95% CI, 1.61–1.70), and the West(aOR = 1.78;95% CI, 1.73–1.83)China had higher HCV prevalence than those who were in the Eastern coastal area. Conclusion Those who were over 45 years old and saw doctors for liver diseases, and invasive diagnosis and treatment should be referred to HCV antibody testing.

Performance of Comparative Cervical Tuberculin Test and Serological Methods with Culturing of Nasal Swab in Diagnosis of Bovine Tuberculosis in Cross Breed Cattle Baghdad Iraq: A Comparative Evaluation

This study was designed to assess the diagnostic value of Rapid Antigen bovine TB antibody test kit (RAT) and any association with cervical comparative tuberculin test (CCTT), (iELISA) and nasal swabs culturing, among based detection of M. bovis infection. A herd of 21 animals aged 1 - 8 years cross bread cattle of college of veterinary medicine. 19 (90.47%) animals had good body condition scores, two bulls included, and 2 (9.52%) cows were fair. Serum samples were collected, analyzed for anti-bovine TB antibody using RAT and iELISA. Also the herd was screened by CCTT. The tests were carried out twice, more than ten month interval, and twelve nasal swabs were taken within second survey. The first survey results revealed prevalence rate: 4 (19.04%) animals considered positive results (one positive and 3 suspected results) for CCTT, while the prevalence rate according to RAT was 10 (47.61%). The difference between the two prevalence rate was significant (McNemar chi-statistic = 4.50, p-value = 0.03) Kappa = 0.215 95% confidence interval: from -0.128 to 0.558;the strength of agreement is considered to be “fair”. The study interprets: sensitivity 30%;specificity 99%. The second survey results revealed prevalence rate according to CCTT was 4 (36.36%), while prevalence rate according to RAT was 5 (45.45%). The difference between the two prevalence was not significant (McNemar chi-statistic = 0.33, p-value = 0.56). Kappa = 0.441 95% confidence interval: from -0.087 to 0.968;the strength of agreement is considered to be “moderate”;sensitivity: 60%;specificity: 83%. All serum samples and nasal swabs gave negative results for iELISA and culturing respectively. The study concluded that RAT was highly specific, easy, labor and time saving, suggesting its use as screening test in bovine tuberculosis, and CCTT could be used to confirm positive animals screened by RAT, while there was no association between RAT, CCTT with body condition scores, iELISA and nasal swabs culture results.

Tubal Infertility and Chlamydia Trachomatis in a Congolese Infertile Population

Infertility of tubal origin is the most frequent in sub-Saharan area. It is due to tuboperitoneal lesions mainly because of infection;especially sexually transmitted infection. Worldwide, Chlamydia trachomatis is the main pathogen. In our setting, some studies failed to establish the link between tubal infertility and chlamydia trachomatis. The current study aimed to determine the local data related to chlamydia trachomatis role in tubal infertility and the usefulness of Chlamydia trachomatis antibody titer test (CAT) in discrimination of the patients with and without tuboperitoneal lesions. Patients’ average age was 33.9 ± 4.8 years, average coitarche 19.4 ± 4.4 years and average number of partners: 3.1 ± 1.6. The level of CAT is correlated to the tuboperitoneal severity. CAT was more specific (93.3%;CI 95%: 81.7 - 98.6) than sensitive (72.7% CI 95%: 49.8 - 89.3) and discriminated correctly 89% (AUC = 0.89) of the patients with or without tuboperitoneal lesions. In conclusion, as it is stated worldwide, Chlamydia trachomatis is the most frequent sexually transmitted pathogen associated with tubal infertility. CAT has to be used as a tool to select patients to be submitted to invasive investigation, like laparoscopy.

Characterization of SARS-CoV-2-specific humoral immunity and its potential applications and therapeutic prospects

Coronavirus disease 2019(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),is an ongoing pandemic that poses a great threat to human health worldwide.As the humoral immune response plays essential roles in disease occurrence and development,understanding the dynamics and characteristics of virus-specific humoral immunity in SARS-CoV-2-infected patients is of great importance for controlling this disease.In this review,we summarize the characteristics of the humoral immune response after SARS-CoV-2 infection and further emphasize the potential applications and therapeutic prospects of SARSCoV-2-specific humoral immunity and the critical role of this immunity in vaccine development.Notably,serological antibody testing based on the humoral immune response can guide public health measures and control strategies;however,it is not recommended for population surveys in areas with very low prevalence.Existing evidence suggests that asymptomatic individuals have a weaker immune response to SARS-CoV-2 infection,whereas SARS-CoV-2-infected children have a more effective humoral immune response than adults.The correlations between antibody(especially neutralizing antibody)titers and protection against SARS-CoV-2 reinfection should be further examined.In addition,the emergence of cross-reactions among different coronavirus antigens in the development of screening technology and the risk of antibody-dependent enhancement related to SARS-CoV-2 vaccination should be given further attention.

Selecting accurate post-elimination monitoring tools to prevent reemergence of urogenital schistosomiasis in Morocco:a pilot study

Background:After alleged stop of transmission of schistosomiasis and further down the line in post elimination settings,sensitive tools are required to monitor infection status to prevent potential re-emergence.In Rahala,where transmission cycle of Schistosoma haematobium is interrupted since 2004 but where 30%of snails are still infected by S.bovis,potential human S.bovis infection can’t be excluded.As methods based on egg-counts do not provide the required sensitivity,antibody or antigen assays are envisaged as the most appropriate tools for this type of monitoring.Methods:In this pilot study,the performances of three assays were compared:two commercially available antibody tests(ELISA and haemagglutination format)indicating exposure,and an antigen test(lateral flow strip format)demonstrating active infection.All 37 recruited study participants resided in Rahala(Akka,province Tata,Morocco).Participants had been diagnosed and cured from schistosomiasis in the period between 1983 and 2003.In 2015 these asymptomatic participants provided fresh clinical samples(blood and urine)for analysis with the aforementioned diagnostics tests.Results:No eggs were identified in the urine of the 37 participants.The haemagglutination test indicated 6 antibody positives whereas the ELISA indicated 28 antibody positives,one indecisive and one false positive.ELISA and haemagglutination results matched for 18 individuals,amongst which 5 out of 6 haemagglutination positives.With the antigen test(performed on paired serum and urine samples),serum from two participants(cured 21 and 32 years ago)indicated the presence of low levels of the highly specific Schistosoma circulating anodic antigen(CAA),demonstrating low worm level infections(less than 5 pg/ml corresponding to probably single worm pair).One tested also CAA positive with urine.ELISA indicated the presence of human anti-Schistosoma antibodies in these two CAA positive cases,haemagglutination results were negative.Conclusions:To prevent reemergence of schistosomiasis in Morocco current monitoring programs require specific protocols that include testing of antibody positives for active infection by the UCP-LF CAA test,the appropriate diagnostic tool to identify Schistosoma low grade infections in travelers,immigrants and assumed cured cases.The test is genus specific will also identify infections related to S.bovis.

The positive influence the Onchocerciasis Elimination Program for the Americas has had on Africa programs

A recent article Is onchocerciasis elimination in Africa feasible by 2025:a perspective based on lessons learnt from the African control programmesH in Infectious Diseases of Poverty claimed that undue influence on African programs by concepts developed by the Onchocerciasis Elimination Program of the Americas(OEPA)is detrimental to stopping mass drug administration(MDA)in Africa.This claim is made despite a record year for MDA stoppage in four African countries of>3.5 million treatments in 2018,far exceeding any past OEPA or African Program for Onchocerciasis Control(APOC)stop MDA success.