Rotavirus and adenovirus in children evaluated for viral gastroenteritis at a single healthcare center in the Eastern Province of Saudi Arabia: A perspective of two decades.

BACKGROUND: The aim of this study was to determine the distribution of rotavirus and adenovirus in pediatric patients evaluated for viral gastroenteritis in a hospital in the Eastern Province of Saudi Arabia for 22 years. MATERIALS AND METHODS: This was a retrospective study based in a secondary healthcare center in Saudi Arabia. Laboratory and demographic data were collected from hospital records for all pediatric patients (up to 14 years old) evaluated for viral gastroenteritis by rotavirus/adenovirus antigen detection kit from January 2000 to December 2022. Data were analyzed utilizing SPSS version 28.0. Categorical data were presented as frequency and percentages, whereas mean and standard deviations were computed for continuous variables. Chi-square test and t-test were used to determine statistical significance. RESULTS: The overall yields of antigen detection were 13.6% for rotavirus and 2.6% for adenovirus. Coinfection with both viruses was documented in 0.5% of the study population. Rotavirus was persistently detected in the past two decades with varying frequency, but the detection of adenovirus showed intervals of at least three consecutive years of zero confirmed cases. Before 2013, when the rotavirus vaccine was introduced in Saudi Arabia, rotavirus was much more prevalent than adenovirus (30% compared to 3.8% in 2010), but they became equally prevalent a decade after the introduction of the vaccine. Rotavirus gastroenteritis showed three different peaks in the year, in March, July, and December. Each peak was followed by a gradual decrease in prevalence before the next peak. Adenovirus, in contrast, was detected consistently around the year at rates between 2% and 5%. CONCLUSION: Rotavirus and adenovirus gastroenteritis have changed in prevalence in the past two decades. We found distinct seasonal patterns associated with rotavirus and adenovirus gastroenteritis. The utilization of virological testing for pediatric gastroenteritis with syndromic testing panels is to be encouraged to improve the knowledge of the true prevalence of enteric viruses.

Utility of the Xpert Xpress CoV-2/Flu/RSV Plus Kit: A Glance at RSV Infection in Adults and Coinfection Rate.

Background: Viral infection is responsible for the majority of respiratory tract infections (RTI). This retrospective study evaluates the advantages of using the multiplex Xpert Xpress CoV-2/Flu/RSV plus kit in laboratory diagnosis of RTI caused by the most related viruses. Materials and Methods: Data were obtained from medical records between November 2021 and May 2023 for any sample tested using either the Xpert Xpress Flu/RSV kit, Xpert Xpress Flu kit, Xpert Xpress SARS-CoV-2 kit, and Xpert Xpress CoV-2/Flu/RSV plus kit. Results: Influenza virus A was detected in 8.5% (55/649) of the samples using the Flu PCR kit and in 4.9% (123/2538) using CoV-2/Flu/RSV plus kit, while influenza virus B detection rates were 3.7% (24/649) using the Flu PCR kit and 1.7% (43/2538) using the CoV-2/Flu/RSV plus kit. However, the detection rates using the two kits were comparable when evaluated for the same time period of the year. SARS-CoV-2 infections were detected in 16.9% (1545/9153) and 10.5% (266/2538) of the cases using the SARS-CoV-2 kit and CoV-2/Flu/RSV plus kits, respectively. Respiratory syncytial virus (RSV) was identified in 17.7% (66/372) of children using Flu/RSV kit; this number dropped significantly when age-targeted testing of RSV was performed due to involvements of adults. With the CoV-2/Flu/RSV plus kit, about 34% (35/103) of RSV infections detected were in patients aged >20 years; these cases would have previously been overlooked because adults are not routinely tested for RSV using the Flu/RSV kit. All coinfection cases (n = 16) were only detected with the CoV-2/Flu/RSV plus kit. Conclusion: The use of Xpert Xpress CoV-2/Flu/RSV plus kit not only results in shorter turnaround times through accurate detection of all four viruses, but also provides information on RSV infection in adults and coinfection rates.

Diagnosis of group A streptococcal pharyngitis in the paediatric emergency department using a fluorescence-based RADT: predicted impact on antibiotic prescription.

Introduction. Using rapid antigen diagnostic tests (RADTs) in clinical practice has shown excellent specificity but often has diminished sensitivity.Gap Statement. Local data for evaluating the diagnostic performance of a new fluorescence-based RADT and its influence on the antibiotic prescription rate are not available.Aim. To evaluate the accuracy of fluorescent immunoassay (FIA)-RADTs for diagnosing group A streptococcal (GAS) pharyngitis among children and its estimated effect as a point of care test (POCT) on the antibiotic prescription rate at the paediatric emergency department.Methodology. A prospective study was conducted, comprising children 3 to 14 years old presenting with pharyngitis. Throat swab culture and FIA-RADTs were performed on all samples. Conventional PCR was performed on the discordant samples.Results. A total of 246 children were included in this study. The sensitivity, specificity, and positive and negative predictive values of the FIA-RADT, based on culture results and PCR detection combined, were 95.6, 96.8, 94.6 and 97.4 %, respectively. Antibiotics have been prescribed to 162 (65.9 %) children; however, if FIA-RADTs had been added in the clinical practice as a POCT, only 92 (37.4 %) children would have received antibiotics in total. Additionally, implementation of FIA-RADTs would significantly reduce the antibiotic prescription rate from 48.8 and 60.6 % to 9.5 and 31.9 % among patients with clinical scores of 2 and 3, respectively.Conclusion. The new FIA-RADT is simple, prompt and reliable. It is helpful in clinical settings and may be used to reduce antibiotic overprescription, especially for children who have a low risk for GAS pharyngitis, according to the clinical score.

Gut microbiota analyses of Saudi populations for type 2 diabetes-related phenotypes reveals significant association.

BACKGROUND: Large-scale gut microbiome sequencing has revealed key links between microbiome dysfunction and metabolic diseases such as type 2 diabetes (T2D). To date, these efforts have largely focused on Western populations, with few studies assessing T2D microbiota associations in Middle Eastern communities where T2D prevalence is now over 20%. We analyzed the composition of stool 16S rRNA from 461 T2D and 119 non-T2D participants from the Eastern Province of Saudi Arabia. We quantified the abundance of microbial communities to examine any significant differences between subpopulations of samples based on diabetes status and glucose level. RESULTS: In this study we performed the largest microbiome study ever conducted in Saudi Arabia, as well as the first-ever characterization of gut microbiota T2D versus non-T2D in this population. We observed overall positive enrichment within diabetics compared to healthy individuals and amongst diabetic participants; those with high glucose levels exhibited slightly more positive enrichment compared to those at lower risk of fasting hyperglycemia. In particular, the genus Firmicutes was upregulated in diabetic individuals compared to non-diabetic individuals, and T2D was associated with an elevated Firmicutes/Bacteroidetes ratio, consistent with previous findings. CONCLUSION: Based on diabetes status and glucose levels of Saudi participants, relatively stable differences in stool composition were perceived by differential abundance and alpha diversity measures. However, community level differences are evident in the Saudi population between T2D and non-T2D individuals, and diversity patterns appear to vary from well-characterized microbiota from Western cohorts. Comparing overlapping and varying patterns in gut microbiota with other studies is critical to assessing novel treatment options in light of a rapidly growing T2D health epidemic in the region. As a rapidly emerging chronic condition in Saudi Arabia and the Middle East, T2D burdens have grown more quickly and affect larger proportions of the population than any other global region, making a regional reference T2D-microbiome dataset critical to understanding the nuances of disease development on a global scale.

The Scope of Respiratory Syncytial Virus Infection in a Tertiary Hospital in the Eastern Province of Saudi Arabia and the Change in Seasonal Pattern during and after the COVID-19 Pandemic.

Background and Objectives: Respiratory syncytial virus (RSV) is a major cause of morbidity and hospital admission due to respiratory tract infection among infants and young children. The current study aims to describe the prevalence and the seasonal pattern of RSV during the previous seven years. Materials and Methods: Clinical data and RSV antigen and PCR test results were collected from patients' medical records at King Fahd Hospital of the University in the Eastern Province of Saudi Arabia between January 2015 and February 2022. Results: The overall percentage of RSV detection was 26.3% (336/1279) among the tested individuals. RSV infection was more common among children below five years and elderly above 60 years of age. Two-thirds of the cases required hospitalization. The average hospital stay due to RSV infection was 6.5 days (range 0−56 days). The rate of hospitalization was higher among infants and younger children and decreased with age (p-value < 0.001). RSV infection was more prevalent between August and February and decreased appreciably between March and July. The peak level of infection was during December and January. No RSV infections were reported during the COVID-19 pandemic and the following winter. The cases increased again in August 2021, with an unusual out-of-season peak. Conclusions: RSV infection is one of the important causes of morbidity and hospitalization among infants and young children in Saudi Arabia. The seasonal pattern of infection has changed after the COVID-19 pandemic, and the physicians should be aware that infection may happen currently at different times throughout the year.

Molecular characterization of Helicobacter pylori clinical isolates from Eastern Saudi Arabia.

OBJECTIVES: To describe the frequency of cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA) virulence genes and clarithromycin resistance-associated mutations among Helicobacter pylori (H. pylori) clinical isolates from Eastern Saudi Arabia. METHODS: A cross-sectional study was carried out between July 2020 and June 2021 in a tertiary hospital in AL-Khobar, Saudi Arabia. A total of 34 H. pylori isolates were obtained from gastric biopsies of patients with dyspepsia. The existence of the virulence genes was studied by polymerase chain reaction and the gene fragment of the 23s ribosomal subunit (23s rRNA) gene was sequenced. RESULTS: All isolates harbored the CagA gene. Approximately 97.1% (33/34) isolates were positive using the VacA M primer and 91.2% (31/34) isolates were positive using the VacA S primer. The most frequent allelic combination was S2/M2/cag (60%), followed by S1/M2/cag (26.7%), S1/M1/cag (10%), and S2/M1/cag (3.3%). Approximately 6.5% isolates harbored the A2142G mutation and 29% isolates harbored the A2143G mutation. One isolate contained the mutation T2182C. The phylogenetic analysis showed that 58% isolates clustered with the regional and global isolates while the remaining 42% isolates seemed to be specifically circulating in Saudi Arabia. Most of the patients (73.5%) had already underwent a previous H. pylori eradication therapy. CONCLUSION: We showed that there is a regional variation in the frequency of the virulence genes among H. pylori isolates. Additionally, we showed the frequency of 23s rRNA mutations related to clarithromycin resistance in Saudi Arabia.

Susceptibility to Rubella Infection and Incidence of Congenital Rubella Infection: 6 Years Retrospective Study.

Introduction: Rubella is considered one of the most serious and most common congenital infections. Despite global efforts for elimination, rubella cases are still being reported in many parts of the world. The purpose of this study is to determine the level of immunity to rubella in the community and most importantly among women at childbearing age in the eastern province of Saudi Arabia and compare it with the target set by the World Health Organization (WHO) along with the incidence of acute rubella infection and the associated congenital rubella infection and congenital rubella syndrome. Methods: This is a retrospective cross-sectional study over the six years period (Jan 2014-Jun 2020) on all individuals tested for rubella IgM and IgG in a university teaching hospital. Results: Nighty one percent (15,894/17,469) of the population tested showed evidence of rubella immunity with 8.8% (1546/17,469) being susceptible. Among women at childbearing age, susceptibility to rubella was higher with 9.2% (1220/13,278) of women showing no evidence of immunity. In addition, acute rubella infection was reported for 0.17% (29/17,469) of the population tested and 0.15% (20/13,278) in women at childbearing age. No cases of congenital rubella infection were reported in the study period. Discussion: The level of Rubella immunity in the population is 91% and is less than the WHO target for rubella control therefore, risk of resurge of cases is present, indicating the need for continued national surveillance and more efforts to improve vaccination coverage in the kingdom.

Low levels of soluble DPP4 among Saudis may have constituted a risk factor for MERS endemicity.

Most of the cases of Middle East respiratory syndrome coronavirus (MERS-CoV) were reported in Saudi Arabia. Dipeptidyl peptidase-4 (DPP4) was identified as the receptor for the virus. The level of soluble DPP4 (sDPP4) was found to be reduced in MERS-CoV infected patients while high levels of sDPP4 were suggested to be protective against MERS-CoV in animal models. We investigated whether the Saudi population has lower levels of sDPP4 which makes them more susceptible to MERS-CoV infection and, therefore, could explain the larger number of cases from the country. Blood samples were collected from 219 Saudi blood donors and 200 blood donors from other ethnic groups. The plasma level of sDPP4 was measured by ELISA and the following SNPs in the DPP4 gene; rs35128070, rs1861978, rs79700168, and rs17574, were genotyped by TaqMan SNP genotyping assay. The average level of plasma sDDP4 was significantly lower in Saudis than other Arabs and non-Arabs (P value 0.0003 and 0.012, respectively). The genotypes AG of rs35128070 and GT of rs1861978 were significantly associated with lower sDPP4 among Saudis (P value 0.002 for each). While both genotypes AA and AG of rs79700168 and rs17574 were associated with significantly lower average sDPP4 level in Saudis compared to other ethnic groups (P value 0.031 and 0.032, and 0.027 and 0.014, respectively). Herein, we report that the Saudi population has lower levels of plasma sDPP4 than other ethnic groups, which is associated with genetic variants in the DPP4 gene. This may have contributed to increase the susceptibility of the Saudi population to MERS-CoV infection and could be a factor in the long-lasting persistence of the virus in the country.

Assembly of infectious Kaposi's sarcoma-associated herpesvirus progeny requires formation of a pORF19 pentamer.

Herpesviruses cause severe diseases particularly in immunocompromised patients. Both genome packaging and release from the capsid require a unique portal channel occupying one of the 12 capsid vertices. Here, we report the 2.6 Å crystal structure of the pentameric pORF19 of the γ-herpesvirus Kaposi's sarcoma-associated herpesvirus (KSHV) resembling the portal cap that seals this portal channel. We also present the structure of its ß-herpesviral ortholog, revealing a striking structural similarity to its α- and γ-herpesviral counterparts despite apparent differences in capsid association. We demonstrate pORF19 pentamer formation in solution and provide insights into how pentamerization is triggered in infected cells. Mutagenesis in its lateral interfaces blocked pORF19 pentamerization and severely affected KSHV capsid assembly and production of infectious progeny. Our results pave the way to better understand the role of pORF19 in capsid assembly and identify a potential novel drug target for the treatment of herpesvirus-induced diseases.

Predictors of Illness Severity in COVID-19 Cases in Saudi Arabia.

PURPOSE: Multiple studies worldwide have reported the clinical and epidemiological features of coronavirus disease 2019 (COVID-19), with limited reports from the Middle East. This study describes the clinical and epidemiological features of COVID-19 cases in the Eastern Province of Saudi Arabia and identified factors associated with the severity of illness. PATIENTS AND METHODS: This was an observational study of 341 COVID-19 cases. These cases were reported in the first three months after the first case in the country was identified. Clinical and demographic data were analyzed and described to identify the effects of age, sex, and ethnicity on illness severity. In addition, the duration of viral shedding and cycle threshold (Ct) values of real-time PCR were evaluated as predictors of severity. RESULTS: The median age was 45 years. Males were twice as likely to be infected than females (p <0.0001). The duration of viral shedding ranged from 9 to 36 days. The most common clinical presentations include fever, shortness of breath, cough, myalgia, sore throat, vomiting, and headache. Critical cases were significantly higher in men (23% vs 8.7%), senior adults (>65 years), individuals of Bengali ethnicity, and in patients with comorbidities including diabetes, hypertension, and dyslipidemia (p =0.001). The case fatality rate was found to be 10%. The fatality was significantly higher in males than females (13.8% vs 2.6%), and in Asians (17.9%) than Arabs (6%) and Africans (0) (p =0.002). No association was found between viral load, represented by the RT-PCR cycle threshold (Ct) values, and severity of illness. CONCLUSION: Age, sex, and ethnicity are important predictors of COVID-19 severity. The cycle threshold (Ct) of the SARS-CoV-2 RT-PCR test cannot be used as a predictor of the criticality of illness.

Prevalence of Hepatitis E Virus Infection Among Blood Donors in the Eastern Province of Saudi Arabia.

PURPOSE: Hepatitis E virus (HEV) causes acute hepatitis in humans and constitutes a major problem for immunocompromised patients, patients with hematological diseases, and pregnant women. It is transmitted mainly through fecal oral route; however, transmission through blood and blood products is reported globally and becoming a health concern. We sought to determine the prevalence of HEV among blood donors in the Eastern Province of Saudi Arabia using molecular as well as serological assays to assess the safety of blood transfusion and the need for HEV screening among blood donors. PATIENTS AND METHODS: A total of 806 whole blood samples were collected from blood donors between May and November 2020 and tested for anti-HEV IgG and IgM antibodies by ELISA and for HEV RNA by RT-PCR. RESULTS: The overall seroprevalence of HEV IgG antibodies was 3.2% with no statistically significant difference between the non-Saudis (3.28%) and Saudis (3.17%) (p value 0.929) or between males (3.14%) and females (4.88%) (p value 0.527). None of the IgG positive individuals had IgM antibodies. HEV RNA was not detected in any of the blood donors. CONCLUSION: HEV seroprevalence is low among blood donors in the Eastern Province of Saudi Arabia and may constitute minimal risk for transfusion associated infections.

mCIM test as a reliable assay for the detection of CRE in the Gulf region.

Introduction. Carbapenem resistant Enterobacterales (CRE) are one of the leading causes of systemic and nosocomial infections and are multidrug-resistant organisms producing different carbapenemases. There are many genotypic and phenotypic methods for detecting the carbapenemases; however, there is a limitation for each. Modified carbapenem inactivation method (mCIM) assay is a recent phenotypic method which has been published by the Clinical and Laboratory Standards Institute.Hypothesis / Gap Statement. mCIM assay could provide a reliable method for the detection of carbapenemases in CRE.Aim. Evaluation of the mCIM assay performance for the detection of carbapenemases in Enterobacterales and the identification of the common carbapenemase genes at Eastern Province of Saudi Arabia and Kingdom of Bahrain.Methodology. A collection of 197 non-duplicate carbapenem resistant Enterobacterales clinical isolates, were evaluated with the mCIM test comparing its performance to multiplex PCR. The minimum inhibitory concentration susceptibility testing was done by the Etest method for imipenem, meropenem, and ertapenem.Results. The sensitivity of the mCIM assay was 94 % (95 % CI, (89.3-97.1)). In Saudi Arabia and Bahrain, OXA-48 was the most prevalent carbapenemase gene followed by NDM. Coexistence of multiple carbapenemase genes is reported in eleven cases.Conclusion. These findings indicate that the mCIM test is a reliable and simple assay for detecting the activity of carbapenemase in Enterobacterales, especially in resource-limited laboratories.

Laboratory tests for the detection of SARS-CoV-2 infection: basic principles and examples.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has circulated throughout the world causing the worst pandemic since 1918. All efforts have been marshalled towards testing different treatment approaches, obtaining clinical and epidemiological information, developing suitable diagnostic tests, and developing new vaccines. New ribonucleic acid (RNA)-based and viral vector-based vaccines have been developed and licensed under emergency use in many countries; however, there is a huge demand for vaccines, and it will take some time before a sufficient number of people are vaccinated to stop the circulation of the virus. Therefore, the proper diagnosis and identification of infected individuals are crucial for the isolation and treatment of these patients and tracing of their contacts. Many diagnostic tests and diag-nostic kits have been developed in a relatively short time. This review summarizes the principles of the available laboratory assays that are in use for the detection of SARS-CoV-2 RNA, antigens, or antibodies.

Development of multiplex real-time RT-PCR assay for the detection of SARS-CoV-2.

The outbreak of the new human coronavirus SARS-CoV-2 (also known as 2019-nCoV) continues to increase globally. The real-time reverse transcription polymerase chain reaction (rRT-PCR) is the most used technique in virus detection. However, possible false-negative and false-positive results produce misleading consequences, making it necessary to improve existing methods. Here, we developed a multiplex rRT-PCR diagnostic method, which targets two viral genes (RdRP and E) and one human gene (RP) simultaneously. The reaction was tested by using pseudoviral RNA and human target mRNA sequences as a template. Also, the protocol was validated by using 14 clinical SARS-CoV-2 positive samples. The results are in good agreement with the CDC authorized Cepheid`s Xpert® Xpress SARS-CoV-2 diagnostic system (100%). Unlike single gene targeting strategies, the current method provides the amplification of two viral regions in the same PCR reaction. Therefore, an accurate SARS-CoV-2 diagnostic assay was provided, which allows testing of 91 samples in 96-well plates in per run. Thanks to this strategy, fast, reliable, and easy-to-use rRT-PCR method is obtained to diagnose SARS-CoV-2.

Seropositivity of syphilis among individuals screened in a tertiary hospital in the Eastern Province of Saudi Arabia.

BACKGROUND: Sexually transmitted infections are a serious public health problem. Syphilis, a multistage, curable chronic disease caused by the spirochete Treponema pallidum, remains a major health problem worldwide. The disease re-emerged in the era of HIV in many countries despite the accessibility of curative therapy and continuing public health efforts to eliminate it. OBJECTIVE: Analyse the seropositivity for syphilis. DESIGN: Retrospective cross-sectional. SETTING: Tertiary hospital. PATIENTS AND METHODS: We retrospectively studied individuals who underwent screening tests for syphilis between January 2014 and December 2018. The samples that were positive by both screening and confirmatory tests were considered as confirmed positive for syphilis. MAIN OUTCOME MEASURES: Syphilis positivity identified by chemiluminescence immunoassay, the rapid plasma reagin test, and specific antibodies against Treponema pallidum. SAMPLE SIZE: 11 832. RESULTS: Of the 11 832, 54 (0.45%) were confirmed as seropositive for syphilis. Thirty-three (61.1%) were non-Saudi; 21 (38.9%) were Saudis. Thirty (55.6%) cases were males. Twenty-two (40.74%) were married and 29 (53.70%) were unmarried. Of the 54 diagnosed as syphilis positive, 28 (51.9%) were expatriate workers screened for pre-employment. The percentage of syphilis among Saudis was 0.36%. In an overall chi-square analysis, a P<.0001 indicated a difference among nationalities in the frequency of syphilis. A post-hoc analysis showed that Somalians (P=.004) and Sudanese (P=.005) differed significantly from other nationalities. CONCLUSION: The study showed that syphilis was low among the screened population. More than half of the syphilis positive cases in this study were household employees. Screening for syphilis assists in planning complementary services for target populations and improves syphilis control. LIMITATIONS: Retrospective design. Hospital-based findings may not be representative of the seroprevalence of syphilis in the general population. CONFLICT OF INTEREST: None.

Polymorphic Variants in 5'-UTR Regions of the RAD51 Gene are Associated With RAD51 Expression and Triple-Negative Breast Cancer (TNBC): A Case-Control Study.

Breast cancer is a heterogeneous disease at morphologic and molecular levels, which is considered the most commonly occurring cancer in women. RAD51, a DNA-repairing protein, involves homologous recombination and has a vital role in genome stability. Polymorphism of the RAD51 gene, and its overexpression, has been proposed to be associated with the development of breast cancer. Overexpression of RAD51 in many types of human cancer including metastatic breast cancer may signify its potential use as a biomarker. Considering the numerous reports on the role of the 5'-UTR-RAD51 polymorphism in breast cancer, this study aimed to investigate the utility of RAD51 gene expression and its variants G135C and G172T as a possible foretelling factor of breast cancer development. DNA sequencing and immunohistochemistry of RAD51 were conducted on 103 samples from patients diagnosed with sporadic breast cancer and 80 samples from a control group. The results demonstrated that the RAD51 variants, G135C and G172T, were significantly presented in the breast cancer tissue compared with the control group. RAD51 expression was mainly shown in the cytoplasm of malignant cells (56% of cases) and significantly correlated with p53 and G135C, C135C variants. Moreover, the occurrence of the G172T variant was significantly associated with the expression of estrogen receptor. Interestingly, 21/26 (81%) of the triple-negative breast cancer showed G135C and C135C genotypes that were significantly associated with the expression of RAD51 (73%). In conclusion, the G135C and C135C variants together with the cytoplasmic expression of RAD51 may have clinical potential as a prognostic predictor for breast cancer development and aggressiveness.

Pooled Specimen Testing Using Automated Cartridge-Based System for COVID-19: The Cost on Sensitivity.

BACKGROUND: Pooled specimen screening for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can improve laboratory testing capacity. This study assessed the impact of pooling and retesting individual swabs on the overall detection rate and reduction in the frequency of retesting. METHODS: One hundred respiratory swabs specimens were tested individually and in pools of three or five samples using the Cepheid's Xpert® Xpress SARS-CoV-2 test kit. The optimum number of samples per pool was calculated using the application 'A Shiny App for Pooled Testing'. RESULTS: Twenty-five pools were generated from 101 samples. Out of 13 pools that contained five samples each, three pools gave true positive results. While out of the 12 pools that contained three samples each, five pools gave true positive results. Four samples gave a false negative pool result. The overall sensitivity and specificity of the assay in the pools were 66.6% and 100%, respectively. The cycle threshold was reduced in most of the pools compared to individual sample tests. CONCLUSION: The overall pooled test had a remarkable impact on laboratory resources. Yet, caution is warranted when selecting the cases for pooled testing, since the reduction in sensitivity can significantly impact and increase the risk of exposure to infection.

Serological Evidence of West Nile Virus Infection Among Humans, Horses, and Pigeons in Saudi Arabia.

PURPOSE: This study was designed to investigate the seroprevalence of WNV antibodies in humans, horses, and pigeons in the Eastern Province of Saudi Arabia. MATERIALS AND METHODS: Blood samples were collected from 323 humans, 147 horses, and 282 pigeons from two regions, Al-Ahsa and Al-Qatif, in East of Saudi Arabia. Serum samples were tested for anti-WNV antibodies by ELISA. RESULTS: The percentage of anti-WNV antibodies in the human population was found to be 9.6% (3.1% in females and 6.5% in males). This percentage was much higher in horses, as 71.4% (105/147) of the horses had anti-WNV antibodies. However, no statistically significant difference in the anti-WNV antibody prevalence was found among horses from the two regions, Al-Ahsa (73.9%) and Al-Qatif (70.3%) (P value 0.665, 95% CI 0.37-1.82). No significant difference was found in the frequency of WNV antibodies among different age groups from humans or horses. Noticeably, 72.7% of the horses had detectable anti-WNV antibodies by the age of 1 year. In total, 53.19% (150/282) of the pigeons in the study had anti-WNV antibodies. CONCLUSION: Our study provided the first evidence for anti-WNV antibody detection in humans and pigeons. This study further ascertained the high seroprevalence of the virus in horses as reported previously by Hemida et al 2019. Overall data indicates that WNV is endemic in Saudi Arabia. These findings suggest that more attention should be given to the diagnosis and reporting of WNV infections in human and animals and monitoring of virus circulation in the environment.

Investigations of a Possible Role of SNPs in KAI1 Gene on Its Down-Regulation in Breast Cancer.

OBJECTIVE: KAI1 (CD82) is a metastasis suppressor gene known to be down-regulated in carcinomas of breast, prostate and many other organs. The mechanism of KAI1 down-regulation is complex and not well understood. Here, we investigate the role of 8 SNPs (not previously studied) in KAI1 gene that could influence its expression in tumor tissue samples of breast cancer patients from the Eastern province of Saudi Arabia. METHODS: Single nucleotide polymorphisms (SNPs) in KAI1 gene were selected from the NCBI website (dbSNP) and were then filtered for those SNPs causing stop codon mutations (rs139889503 and rs150533529) or nonsynonymous mutation in the 5'-UTR (rs11541048, rs77359459, rs115500759, rs182579675, rs200238062, and rs372733853). SNPs genotyping was performed using TaqMan SNP Genotyping Assay and the results were correlated with KAI1 protein expression profile by immunohistochemistry (IHC) on formalin-fixed paraffin-embedded (FFPE) samples of breast cancer and control none-neoplastic tissues. RESULTS: KAI1 expression by IHC was observed in all none-neoplastic breast tissue samples and only in 35% out of the 59 breast cancer tissue samples. None of the samples was homozygous for the stop codon allele A in the SNP rs139889503 or allele T in the SNP rs150533529. The SNPs in the 5-UTR, rs11541048, rs115500759, and rs182579675, were only present in the homozygous state for the G and C alleles respectively in both cancer and control samples. The other SNPs in the 5'-UTR (rs77359459, rs200238062, and rs372733853) had no significant difference in the allele distribution between KAI1 expressing or none-expressing tissue samples. CONCLUSION: Our findings showed no significant effect of the studied SNPs on down-regulation of KAI1 expression.
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