Low Risk of Serological Cross-Reactivity between the Dengue Virus and SARS-CoV-2-IgG Antibodies Using Advanced Detection Assays.

Several studies have reported serological cross-reactivity of the immune responses between SARS-CoV-2 and DENV. Most of the available studies are based on the point-of-care rapid testing kits. However, some rapid test kits have low specificity and can generate false positives. Hence, we aimed to investigate the potential serological cross-reactivity between SARS-CoV-2 and DENV-IgG antibodies using advanced assays including chemiluminescence immunoassay (CLIA) and enzyme-linked immunosorbent assay (ELISA) test. A total of 90 DENV-IgG-ELISA-positive and 90 DENV-IgG-ELISA-negative prepandemic sera were tested for anti-SARS-CoV-2-IgG using the automated CL-900i CLIA assay. Furthermore, a total of 91 SARS-CoV-2-IgG-CLIA-positive and 91 SARS-CoV-2-IgG-CLIA-negative postpandemic sera were tested for anti-DENV-IgG using the NovaLisa ELISA kit. The DENV-IgG-positive sera resulted in five positives and 85 negatives for SARS-CoV-2-IgG. Similarly, the DENV-IgG-negative sera also resulted in 5 positives and 85 negatives for SARS-CoV-2-IgG. No statistically significant difference in specificity between the DENV-IgG-positive and DENV-IgG-negative sera was found (p value = 1.00). The SARS-CoV-2-IgG-positive sera displayed 43 positives, 47 negatives, and 1 equivocal for DENV-IgG, whereas the SARS-CoV-2-IgG-negative sera resulted in 50 positives, 40 negatives, and 1 equivocal for DENV-IgG. No statistically significant difference in the proportion that is DENV-IgG positive between the SARS-CoV-2-IgG-positive and SARS-CoV-2-IgG-negative sera (p value = 0.58). In conclusion, there is a low risk of serological cross-reactivity between the DENV and SARS-CoV-2-IgG antibodies when using advanced detection assays.

Effect of Water-Pipe Smoking on the Normal Development of Zebrafish.

BACKGROUND: Among all types of tobacco consumption, Water-Pipe Smoking (WPS) is the most widely used in the Middle East and second-most in several other countries. The effect of WPS on normal development is not yet fully understood, thus the aim of this study is to explore the acute toxicity effects of WPS extract on zebrafish larvae. METHODS: In this study, we compared the effects of WPS smoke condensates at concentrations varying from 50 to 200 µg/mL on developmental, cardiac, and behavioural (neurotoxicity) functions. Gene expression patterns of cardiac biomarkers were also evaluated by RT-qPCR. RESULTS: Exposing zebrafish embryos to 50, 100, 150 and 200 µg/mL WPS for three days did not affect the normal morphology of Zebrafish embryos, as the tail flicking, behavioural and locomotion assays did not show any change. However, WPS deregulated cardiac markers including atrial natriuretic peptide (ANP/NPPA) and brain natriuretic peptide (BNP/NPPB). Furthermore, it induced apoptosis in a dose-dependent manner. CONCLUSION: Our data demonstrate that WPS can significantly affect specific cardiac parameters during the normal development of zebrafish. Further investigations are necessary to elucidate the pathogenic outcome of WPS on different aspects of human life, including pregnancy.

The prevalence of HEV among non-A-C hepatitis in Qatar and efficiency of serological markers for the diagnosis of hepatitis E.

BACKGROUND: The rapid growth of Qatar in the last two decades has attracted a large influx of immigrant workers who mostly come from HEV-hyperendemic countries. Thus, we aim to investigate the prevalence of HEV among acute non-A-C hepatitis patients in Qatar; and to evaluate the performance of four dominant commercial serological assays for HEV diagnosis. METHODS: 259 patients with non-A-C hepatitis were tested using the Wantai HEV-IgM, HEV-IgG, HEV-Ag ELISA kits, and the MP Biomedical HEV-Total Ab ELISA kit. ALT levels were tested and HEV RNA (viral loads) was performed using Taqman AmpliCube HEV RT-PCR kit (Mikrogen, Neuried, Germany). The performance of each kit was assessed according to the RT-PCR results. RESULTS: HEV-RNA was detected in 23.1% of the samples. Most of these HEV-RNA-positive cases belonged to non-Qatari residents from the Indian subcontinent; India, Pakistan, etc. HEV-Ag, HEV-IgM, HEV-IgG, HEV-Total Ab were detected in 5.56%, 8.65%, 32.1%, and 34.2% of all tested samples, respectively. Elevated ALT levels were highly correlated with the HEV-Ag, HEV-IgM, HEV-RNA but not with the HEV-IgG and HEV-Total Ab. Although HEV-Ag was very specific (100%), yet its sensitivity was poor (36.7%). HEV-IgM demonstrated the best second marker for diagnosis of acute HEV after RT-PCR as jugged by the overall performance parameters: specificity (96.2%), sensitivity (71.4%), PPV (83.3%), NPP (92.7%), agreement with RT-PCR (91.0%), and Kappa-value (0.71). CONCLUSION: Our study demonstrated a high prevalence of HEV virus in Qatar, mostly among immigrants from the Indian subcontinent. The HEV-IgM represents the best marker for detecting the acute HEV infection, where RT-PCR cannot be performed.

Prevalence and Phylogenetic Analysis of Parvovirus (B19V) among Blood Donors with Different Nationalities Residing in Qatar.

Human parvovirus (B19V) is the causative agent of erythema infectiosum in children and is linked to a wide range of clinical manifestations. Studies related to B19V prevalence in the Middle East and North Africa (MENA) region and other parts of Asia are very scarce. The objectives of this study were to estimate the seroprevalence (anti-B19V IgM and IgG), the viremia rate (B19V DNA), and the circulating genotypes of B19V among blood donors in Qatar. METHODS: Donors' blood samples (n = 5026) from different nationalities, mainly from the MENA region and South East Asia, were collected from 2014-2016. Samples were tested for the B19V DNA using RT-PCR. Furthermore, 1000 selected samples were tested to determine the seroprevalence of B19V antibodies using enzyme-linked immunosorbent assay (ELISA). Genotyping was performed on 65 DNA positive samples by sequencing of nested PCR fragments (NS1-VP1u region, 927 nt). RESULTS: Only 1.4% (70/5026) of the samples had detectible B19V DNA in their blood. B19V DNA prevalence statistically decreased with age (p = 0.03). Anti-B19V IgG was detected in 60.3% (561/930) of the tested samples, while only 2.1% (20/930) were IgM-positive and 1.2% (11/930) were both IgM- and IgG-positive. B19V genotyping showed a predominance of Genotype 1 (100%). Sequence analysis of the NS1-VP1u region revealed 139 mutation sites, some of which were amino acid substitutions. CONCLUSION: Our results indicated a relatively high seroprevalence of B19V in Qatar. Most importantly, B19 DNA was detected among Qatari and non-Qatari blood donors. Therefore, blood banks in Qatar might need to consider screening for B19V, especially when transfusion is intended for high-risk populations, including immunocompromised patients.

Cardiac function and blood flow hemodynamics assessment of zebrafish (Danio rerio) using high-speed video microscopy.

BACKGROUND: In the last few decades, zebrafish (Danio rerio) were introduced as a model organism to investigate human diseases including cardiovascular and neuronal disorders. In most zebrafish investigations, cardiac function and blood flow hemodynamics need to be assessed to study the effects of the interference on the cardiovascular system. For heart function assessment, most important parameters include heart rate, cardiac output, ejection fraction, fractional area change, and fractional shortening. METHODS: A 10 s high-speed video of beating heart and flowing blood within major vessels of zebrafish that are less than 5 days post fertilization (dpf) were recorded via a stereo microscope equipped with a high speed camera. The videos were analyzed using MicroZebraLab and image J software for the assessment of cardiac function. RESULTS: Using the technique described here, we were able to simply yet effectively assess cardiac function and blood flow dynamics of normal zebrafish embryos. We believe that the practical method presented here will help cardiac researchers using the zebrafish as a model to examine cardiac function by using tools that could be available in their laboratory.

Dengue and chikungunya seroprevalence among Qatari nationals and immigrants residing in Qatar.

The objective of this study is to characterize the seroprevalence of anti-dengue (DENV) and anti-chikungunya (CHIKV) antibodies among blood donors residing in Qatar who are Middle East and North Africa (MENA) nationals and non-nationals. Sera were collected from adult blood donors in Qatar from 2013 to 2016 and tested for anti-DENV and anti-CHIKV IgG using commercial microplate enzyme-linked immunosorbent assays. Age-specific seroprevalence was summarized by region/nationality: Asia (India, Philippines), Middle East (Iran, Jordan, Lebanon, Pakistan, Palestine, Syria, Yemen), North Africa (Egypt, Sudan), Qatar. The adjusted odds of anti-DENV and anti-CHIKV IgG seropositivity was estimated by logistic regression. Among 1,992 serum samples tested, Asian nationals had higher adjusted odds of being seropositive for anti-DENV antibodies compared to nationals of the Middle East (aOR 0.05, 95% CI 0.04-0.07), North Africa (aOR 0.14, 95% CI 0.10-0.20), and Qatar (aOR 0.01, 95% CI 0.01-0.03). Asian nationals also had higher adjusted odds of being seropositive for anti-CHIKV antibodies compared to those from the Middle East (aOR 0.14, 95% CI 0.07-0.27), North Africa (aOR 0.50, 95% CI 0.26-0.96), and Qatar (aOR 0.38, 95% CI 0.15-0.96). The adjusted odds of being anti-DENV seropositive was higher among anti-CHIKV seropositive adults, and vice versa (aOR 1.94, 95% CI 1.09-3.44), suggesting co-circulation of these viruses. DENV and CHIKV exposure is lower in Qatar and MENA nationals compared to Asian nationals suggesting a lower burden of DENV and CHIKV disease in the MENA. Antibodies to both viruses were detected in nationals from most MENA countries, supporting the need to better understand the regional epidemiology of these viruses.

Performance evaluation of five commercial assays in assessing seroprevalence of HEV antibodies among blood donors.

INTRODUCTION: Although hepatitis E virus (HEV) is mainly transmitted via the faecal-oral route, the rate of HEV transmission via blood donation is on the rise. However, the seroprevalence of HEV among blood donors is not well established and is thought to be affected by the type of diagnostic assay used. We aimed to evaluate performance and correlation among widely used commercial diagnostic assays for the seroprevalence assessment of HEV-IgM/IgG among blood donors. METHODOLOGY: A total of 1049 blood donor samples were tested for HEV IgG and IgM using different enzyme immunoassays (Wantai, Eruoimmune, MP diagnostics, Mikrogen immunoblot, HEV-IgM rapid test). The performance of each assay was evaluated according to our established silver standard value based on three or more IgG concordant assay results. RESULTS: HEV seroprevalence varied considerably using these assays, ranging from 10.1 % (Euroimmune-ELISA) to 18.0 % (Wanti-ELISA) for HEV-IgG, and from 0.2 % (Wanti-ELISA) to 2.6 % (MP Rapid test) for HEV-IgM. A total of 155 of 216 (71.6%) samples tested positive for HEV-IgG by three or more concordant assays. On the other hand, IgM assays showed poor agreement as only 7.6 % (4/52) of the specimens were positive according to three or more concordant assay test results. All HEV-IgG assays revealed high sensitivity and specificity (ranging 96.5-100 %),and excellent Kappa concordance (0.88-0.95), except for Euroimmun ELISA (sensitivity=61.5 %, kappa=0.63). MP ELISA showed the highest levels of sensitivity (100 %) and specificity (98.5 %). CONCLUSIONS: Due to discrepancies in the performance of various IgG and IgM assays, seroprevalence studies should be based on furher confirmatory testing for decisive conclusions to be reached.

Performance evaluation of four type-specific commercial assays for detection of herpes simplex virus type 1 antibodies in a Middle East and North Africa population.

BACKGROUND: The number of diagnostic assays for the detection of herpes simplex virus type 1 (HSV-1) antibodies has increased over the years. However, their performance characteristics could vary among global populations. OBJECTIVE: To investigate performance of two commercial ELISA kits, HerpeSelect® 1 ELISA and Euroimmun Anti-HSV-1 (gC1) ELISA (IgG); and two commercial immunoblot (IB)/Western blot (WB) assays, HerpeSelect® 1 and 2 Immunoblot IgG, and Euroimmun Anti-HSV-1/HSV-2 gG2 Euroline-WB (IgG/IgM); in detecting HSV-1 antibodies in a Middle East and North Africa (MENA) population. STUDY DESIGN: Blood specimens were collected from blood donors in Doha, Qatar, June 2013-2016. Twenty specimens were randomly selected from 10 MENA nationalities (Egypt, Iran, Jordan, Lebanon, Pakistan, Palestine, Qatar, Sudan, Syria, and Yemen; total = 200), and tested for HSV-1 antibodies. RESULTS: Across all six comparisons between assays, positive percent agreement ranged between 95.7% (95% CI: 91.4-98.3%) and 100.0% (95% CI: 97.8-100.0%). Negative percent agreement ranged between 86.2% (95% CI: 68.3-96.1%) and 96.2% (95% CI: 80.4-99.9%). Overall percent agreement ranged between 95.7% (95% CI: 91.7-97.8%) and 99.4% (95% CI: 96.7-99.9%). Cohen's kappa statistic ranged between 0.84 (95% CI: 0.73-0.95) and 0.98 (95% CI: 0.93-1.00). Compared against IB/WB, HerpeSelect® and Euroimmun had sensitivities and specificities >96% and >86%, respectively. Positive and negative predictive values were >97% and >83%, respectively. CONCLUSION: The assays showed excellent concordance with one another, and with a high kappa statistic. The ELISA kits demonstrated robust diagnostic performance compared to the IB/WB assays. These findings support the assays' utility in clinical diagnosis and research in MENA populations.

Herpes Simplex Virus Type 2 Seroprevalence Among Different National Populations of Middle East and North African Men.

BACKGROUND: There are limited data on herpes simplex virus type 2 (HSV-2) seroprevalence in the Middle East and North Africa (MENA). We examined country- and age-specific HSV-2 seroprevalence among select MENA populations residing in Qatar. METHODS: Sera were collected from male blood donors attending Hamad Medical Corporation between June 2013 and June 2016. Specimens were screened for anti-HSV-2 IgG antibodies following a 2-test algorithm: HerpeSelect 2 ELISA was used to identify HSV-2-positive specimens, and Euroline-WB was used to confirm positive and equivocal specimens for final HSV-2 status. Trends and associations with HSV-2 seropositivity were assessed. RESULTS: Of the 2077 tested sera, 61 were found and confirmed positive. The proportion of those confirmed positive increased steadily with HerpeSelect 2 ELISA index value, ranging from 16.3% for index values of 1.101 to 1.999 to 92.9% for index values of 4 or greater. Nationality-specific seroprevalence was 6.0% (95% confidence interval [CI], 4.1%-8.8%) in Qataris, 5.3% (95% CI, 2.5%-11.1%) in Iranians, 4.2% (95% CI, 1.8%-9.5%) in Lebanese, 3.1% (95% CI, 1.2%-7.7%) in Sudanese, 3.0% (95% CI, 1.4%-6.4%) in Palestinians, 2.2% (95% CI, 1.1%-4.3%) in Egyptians, 2.0% (95% CI, 1.0%-5.0%) in Syrians, 1.0% (95% CI, 0.3%-3.6%) in Jordanians, 0.7% (95% CI, 0.1%-3.7%) in Yemenis, and 0.5% (95% CI, 0.1%-2.8%) in Pakistanis. There was evidence for higher seroprevalence in older age groups. CONCLUSIONS: The seroprevalence of HSV-2 was in the range of few percentage points. There were no major differences in seroprevalence by nationality. These findings add to our understanding of HSV-2 epidemiology in MENA and indicate unmet needs for sexual health and control of sexually transmitted infections.

Seroprevalence of hepatitis E virus among blood donors in Qatar (2013-2016).

BACKGROUND: Hepatitis E virus (HEV) is an RNA virus transmitted mainly through zoonotic transmission or fecal-oral route. More than 80% of Qatar's population are expatriates, including many coming from hyperendemic countries; thus, it is important to estimate the seroprevalence and to compare between different nationalities. The results can be useful in alerting blood banks to the importance of HEV screening. STUDY DESIGN AND METHODS: Samples from 5854 blood donations provided by Hamad Medical Corporation were tested in the period between June 2013 to June 2016. Samples were tested for the presence of anti-HEV immunoglobulin (Ig)G and IgM antibodies and viral RNA using real-time polymerase chain reaction (PCR). Descriptive statistics, bivariate analysis, and multivariate logistic regression were used. RESULTS: Anti-HEV seroprevalence was 20.7%. A total of 1198 and 38 donations tested positive for IgG and IgM antibodies, respectively. Of the IgM-positive donations four tested positive by PCR. A significant association was detected between HEV seroprevalence with age and nationality. CONCLUSION: The seroprevalence of anti-HEV was high in Qatar. Since HEV IgM and RNA were detected, this suggests the possibility of HEV transmission by transfusion. Blood banks in Qatar and the region should consider screening for HEV, especially when transfusion is intended to pregnant women or immunocompromised patients.

Detection and phylogenetic analysis of human pegivirus (GBV-C) among blood donors and patients infected with hepatitis B virus (HBV) in Qatar.

Human Pegivirus (HPgV), formerly GB virus-C/Hepatitis G virus (GBV-C/HGV), collectively known as GBV-C, is widely spread and has been reported to be associated with non-A-E hepatitis. To our knowledge, no previous study was conducted about HPgV in Qatar. Thus, the objectives of this study were as follows: (i) to determine the rates of HPgV infection in Qatar among healthy blood donors and HBV-infected patients, and (ii) to determine the most predominant HPgV genotype in Qatar. A total of 714 blood plasma samples from healthy donors (612) and HBV-infected patients (102) were collected. RNA was extracted, reversed transcribed, and then subjected for HPgV detection by two round-nested PCR using primers amplifying a 208 bp of 5'-UTR of the HPgV. For genotyping, the 5'-UTR PCR products (from 25 randomly picked samples) were cloned and sequenced. The overall infection rate of HPgV in Qatar was 13.3%. There was no significant difference (P = 0.41) in the infection rates between healthy donor (13.7%) and in HBV-infected patients (10.7%). Moreover, we did not find any significant association between HPgV infection rates and nationality, sex, or age (P > 0.05). Sequence analysis of 40 5'-UTR PCR amplicons yielded the European genotype 2 as most predominant in Qatar, although other genotypes (5 and 7) were also present. Our results indicate that there is no strong correlation between HPgV infection rate, condition, nationality, age, and sex, and genotype 2 is most predominant in Qatar.