Evaluation of angiotensin converting enzyme 2 (ACE2), angiotensin II (Ang II), miR-141-3p, and miR-421 levels in SARS-CoV-2 patients: a case-control study.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly contagious virus that uses angiotensin converting enzyme 2 (ACE2), a pivotal member of the renin-angiotensin system (RAS), as its cell-entry receptor. Another member of the RAS, angiotensin II (Ang II), is the major biologically active component in this system. There is growing evidence suggesting that serum miRNAs could serve as prognostic biomarkers for SARS-CoV-2 infection and regulate ACE2 expression. Therefore, the aim of this study is to evaluate the changes in the serum levels of sACE2 and Ang II, as well as the expression level of miR-141-3p and miR-421 in SARS-CoV-2 positive and negative subjects. METHODS: In the present study, the serum levels of sACE2 and Ang II were measured in 94 SARS-CoV-2 positive patients and 94 SARS-CoV-2 negative subjects with some symptoms similar to those of SARS-CoV-2 positive patients using the ELISA method. In addition, the expression level of miR-141-3p and miR-421 as ACE2 regulators and biomarkers was evaluated using quantitative real-time PCR (qRT-PCR) method. RESULTS: The mean serum sACE2 concentration in the SARS-CoV-2-positive group was 3.268 ± 0.410 ng/ml, whereas in the SARS-CoV-2 negative group, it was 3.564 ± 0.437 ng/ml. Additionally, the mean serum Ang II level in the SARS-CoV-2 positive and negative groups were 60.67 ± 6.192 ng/L and 67.97 ± 6.837 ng/L, respectively. However, there was no significant difference in the serum levels of sACE2 (P value: 0.516) and Ang II (P value: 0.134) between the SARS-CoV-2 positive and negative groups. Meanwhile, our findings indicated that the expression levels of miR-141-3p and miR-421 in SARS-CoV-2 positive group were significantly lower and higher than SARS-CoV-2 negative group, respectively (P value < 0.001). CONCLUSIONS: Taken together, the results of this study showed that the serum levels of sACE2 and Ang II in SARS-CoV-2 positive and negative subjects were not significantly different, but the expression levels of miR-141-3p and miR-421 were altered in SARS-CoV-2 positive patients which need more investigation to be used as biomarkers for COVID-19 diagnosis.

Evaluation of the focus reduction neutralization and ELISA tests compared to the plaque reduction neutralization test for the detection of antibodies against measles virus.

Measles is an infectious febrile sickness caused by the measles virus (MeV). Despite an effective vaccine, regional elimination of measles remains a global priority and still faces challenges. To estimate community protection against measles, sensitive tests are needed to identify measles-specific antibodies. The enzyme-linked immunosorbent assay (ELISA) is the standard test for assessing immunity but may fail to detect weak antibody responses in vaccinated populations. The plaque reduction neutralization test (PRNT), is the gold standard test for the assessment of protective antibody levels, however, it is not suitable for routine use. This study validated the focus reduction neutralization test (FRNT) as an alternative. In eight assay runs, fifty serum samples were analyzed in triplicate using PRNT, FRNT, and ELISA. Data analysis revealed that 38 samples were positive by PRNT, 37 by FRNT, and 19 by ELISA. The results showed that ELISA was not sensitive enough to identify low levels of anti-measles antibodies and showed weak agreement with neutralization assays. In contrast, the two neutralization assays had a perfect correlation and similar sensitivity. FRNT appears to be a suitable alternative to PRNT for characterizing immunological responses and vaccination efficacy. Our results highlight the necessity of validating negative and equivocal ELISA results through neutralization methods, during the elimination phases.

Congenital cytomegalovirus infection in newborns suspected of congenital rubella syndrome in Iran: a cross-sectional study.

BACKGROUND: Following rubella virus control, the most important cause of congenital infections is human cytomegalovirus (HCMV). Congenital CMV (cCMV) may happen both in primary and non-primary maternal infections. The present study aimed to screen cCMV in symptomatic newborns suspected of congenital rubella syndrome (CRS) in Iran. METHODS: Out of 1629 collected infants' serum samples suspected of CRS but negative for rubella IgM, 524 samples were selected regarding cCMV complications. These samples were divided into two age groups: 1- one month and younger, 2- older than 1 month up to one year. Anti-HCMV IgM detection was performed on these serums. Then HCMV IgG avidity assay and HCMV DNA detection were carried out on all samples with positive and borderline results in IgM detection. RESULTS: Herein, 3.67% of symptomatic infants aged one month and younger had positive and borderline HCMV IgM, 12.5% of which had a low avidity index (AI). HCMV IgM detection rate among symptomatic infants older than one month to one year was 14.5%. Identified genotypes in this study were gB-1(63.63%), gB2 (18.18%), and gB3 (18.18%), respectively. CONCLUSIONS: This comprehensive study was performed on serum samples of symptomatic infants clinically suspected of cCMV from all over Iran. There was a good correlation between serology findings and PCR.

Impact of COVID-19 on the changing pattern of human orthopneumovirus (respiratory syncytial virus) infection in Iran.

BACKGROUND: Human orthopneumovirus (HOPV) or respiratory syncytial virus (RSV) is one of the important causes of acute respiratory infections (ARIs) during the cold months of the year worldwide. Many countries have reported an absence of ARIs due to HOPV during the winter of 2020-2021 associated with preventive measures to reduce the spread of SARS-CoV2. However, with the reduction of COVID-19 public health restrictions and the absence of immunity in the community due to the lack of exposure in the previous season, many countries had a delayed HOPV outbreak. Here we reported the impact of COVID-19 on the changing pattern of HOPV infection in Iran. METHODS: Throat and nasopharyngeal swab samples were collected from patients (children and adults) with ARIs and sent to the Iran National Influenza Center. After RNA extraction, Real time RT-PCR was performed for HOPV detection. RESULTS: In 260 samples collected from patients with ARIs in three different groups, which included children in March 2021, pilgrims in July 2022, and outpatients during November and December 2022, no HOPV was detected in any group. CONCLUSIONS: The lack of HOPV activity in Iran during the winter of 2020-2021 and then the resurgence in spring 2022 and again the absence of activity in summer and autumn 2022 was extraordinary in the HOPV epidemiology, and probably due to the implementation of public health non-pharmaceutical interventions to reduce the spread of SARS-CoV2. Although it is not possible to keep such restrictions, similar methods can be taken to control outbreaks caused by respiratory viruses.

Molecular detection and genotyping of Human Cytomegalovirus in kidney transplant recipients under ganciclovir prophylaxis in Iran.

INTRODUCTION: Human Cytomegalovirus (HCMV) infection is one of the most common viral complications in kidney transplant recipients. Although there are effective treatments strategies for the HCMV infection, this infection is still one of the causes of kidney transplant rejection. METHODS: A total of 246 kidney transplant recipients participated in this cross-sectional study. Viral DNA was extracted from these plasma samples and the presence of HCMV genome was determined by Semi-nested PCR with specific primers for HCMV B glycoprotein gene. Sanger sequencing analyses were carried out to determine HCMV genotypes and Mega x software was used for nucleotide alignment and construction of a phylogenetic tree. RESULTS: Human cytomegalovirus DNA was detected in 11 (4.47%) recipients. According to the phylogenetic analysis, HCMV gB3 was 50% among kidney transplant recipients, followed by gB4 30% and gB1 20% however, the gB2 genotype was not detected. CONCLUSIONS: This study demonstrated that the HCMV infection in our patients is relatively low because all transplant recipients received appropriate prophylaxis, thereby antiviral prophylaxis is recommended for all patients at risk of HCMV infection after kidney transplantation. Also, gB3 was the most predominant genotype among our kidney transplant recipients that was related to the higher rate of prevalence of severe HCMV infections. Moreover, elevated serum creatinine level was detected in patients at the time of detection of HCMV infection.

Usage of peptidases by SARS-CoV-2 and several human coronaviruses as receptors: A mysterious story.

Coronaviruses recognize a variety of host receptors to infect many humans and animals. Newly emerged severe acute respiratory syndrome coronavirus2 (SARS-CoV-2) recognizes angiotensin-converting enzyme 2 (ACE2) to gain entry into different cells. Interestingly, besides SARS-CoV2, four other human coronaviruses (HCoVs) use three different ectopeptidases (ACE2, dipeptidyl peptidase 4, and aminopeptidase N) as receptors independent of their common peptidase activity. This issue has led to the important question "why do several HCoVs rely on peptidases as their receptors?." In this paper, we discussed to answer this question. Mostly, it seems that the use of peptidases by HCoVs may be more related to their widespread presence on target cells and also viruses prefer to take advantage of molecules with relatively low affinity for their natural ligands through evolving a stronger binding affinity to the surface receptors for entry and endocytosis. Meanwhile evolutionary conservation of these receptors may allow HCoVs to switch between different host species. Finally, the choice of peptidases by HCoVs may reflect the "trial and error" nature of evolution. In conclusion, substantial efforts are needed to get a strong picture of this fascinating question and poorly explored area. Detailed understanding of the entry mechanisms offers opportunities for the development of refined strategies to stop viruses.

Molecular epidemiology of human adenoviruses in children with and without respiratory symptoms: Preliminary findings from a case-control study.

BACKGROUND: Human adenovirus (HAdV) is an important viral agent in children which can lead to severe acute respiratory infection (SARI). Reports on molecular epidemiology of HAdVs in Iran are limited. This case-control study is conducted to compare the HAdV infection rate and molecular epidemiology among two groups of children with and without respiratory symptoms in Tehran, Iran during 2018-2019. METHODS: Nested PCR was performed on 120 oropharyngeal swabs taken from children aged five and younger with SARI who were hospitalized as the case group, and 120 oropharyngeal swabs were collected from children of the same age without respiratory symptoms as the control group. For positive samples Sanger sequencing was done and a phylogenetic tree was drawn afterward. RESULTS: Out of 120 cases, 8 (6.6%) tested positive for eachHAdV types including 6 (75%) HAdV-B7, 1 (12.5%) HAdV-C2, and 1 (12.5%) HAdV-C6. Among the control group, out of 120 samples, 8 (6.6%) were positive comprising 5 (62.5%) HAdV-C5, 2 (25%) HAdV-F41, and 1 (12.5%) HAdV-C6. CONCLUSION: The present study indicated a different viewpoint of HAdV molecular epidemiology in which the genotypes were compared in children with and without respiratory symptoms. HAdV prevalence was equally common in cases and controls but different genotypes were detected in these two groups. HAdV-B7 was the main type among children with SARI, dissimilar to children with no respiratory symptoms where HAdV-C5 was the predominant type. Detecting HAdV-F in oropharyngeal swabs was a rare finding, which requires further investigation.

Lineage analysis of human papillomavirus types 31 and 45 in cervical samples of Iranian women.

Knowing the regional lineages/sublineages of human papillomavirus 31 (HPV 31) and 45 would be of great importance for further evolutionary, epidemiological, and biological analysis. In this regard, to characterize more common lineages and sublineages of HPV 31 and 45, the sequence variations of E6 gene were investigated in normal, premalignant, and malignant samples collected from the cervix in Iran. In total, 54 HPV 31- and 24 HPV 45-positive samples were analyzed by hemi-nested polymerase chain reaction (PCR) and nested-PCR, respectively. All PCR products were subjected to direct sequencing analysis. The results indicated that all three lineages A, B, and C were detected in HPV 31-positive samples; among which HPV 31 lineage A was dominant as it was found in 66.7% of all samples. HPV 31 lineages B and C were identified in 5.5% and 27.8% of samples, respectively. In HPV 45-infected samples, lineage B comprised of 62.5% of all samples and the remaining 37.5%  belonged to lineage A. In conclusion, our findings showed that lineage A of HPV 31 was predominant in Iran. Lineage B of HPV 45 was also dominant among Iranian women. However, further studies with larger sample size should be addressed to estimate the pathogenicity risk of HPV 31 or HPV 45 lineages/sublineages in the development of cervical cancer among Iranian women.

Molecular characterization of low pathogenic avian influenza H9N2 virus during co-circulation with newly-emerged highly pathogenic avian influenza H5N8 virus in Iran.

 Identification of molecular characteristics of low pathogenic avian influenza (LPAI) H9N2 virus provides insights into the evolution of this subtype due to the modulation of genomic characteristics in co-circulation with another subtype. The present study aimed to analyze the molecular and phylogenetic characteristics of the current LPAI H9N2 virus in characteristics of internal proteins are crucial for the adaptations of AIVs viruses to a new host. Since H9N2 is indigenous among poultry, continuous monitoring of viral genetic changes is needed for risk assessment of potential transmissibility to human population and emergence of new reassortant virus. domestic poultry during the emergence of new highly pathogenic avian influenza (HPAI) H5N8 virus in Iran. To this end, deep sequencing of LPAI H9N2 virus was performed on Illumina MiSeq sequencing platform and the complete sequences of avian influenza viruses were obtained from GISAID EpiFlu database. Phylogenetic analysis of the surface and internal gene segments showed that the H9N2 2018 virus was closely related to Pakistani H9N2 isolates. HA cleavage site motif sequence of the Iranian isolate was 317KSSR GLF323. The A/chicken/Iran/1/2018 H9N2 strain carried the amino acid substitution (Q216L), which is a mutation correlated with a shift in the affinity of the HA from avian type sialic receptors to human type. Besides surface glycoproteins, molecular. Keywords: A/H9N2; molecular characterization; A/H5N8; co-circulation; A/H5N1; Illumina MiSeq.

Prevalence of Human Metapneumovirus Infections in Iran: A Systematic Review and Meta-Analysis.

BackgroundWe sought to systematically review the literature and perform a meta-analysis by assessing the prevalence of human metapneumovirus (hMPV) infections from a number of studies conducted in Iran. Methods: Entire studies addressing epidemiology of hMPV in Iran using data from PubMed, Scopus, Science Direct, Web of science, Google Scholar, Embase, and national Persian databases up to June 2019 were included. Results: The estimated prevalence of hMPV was 8.9% (95% CI 5.4-14.2) in different regions in Iran. Compared to the global rate, in Iran hMPV infection presented an intermediate prevalence rate. The majority of hMPV positive patients were pediatric populations with pooled prevalence of 7.6% (I2 = 95%, 95% CI 3.5-15.6). Conclusion: This first comprehensive review covering researches over the last 11 years expanded our knowledge about hMPV circulating in Iran. Future large epidemiological studies are needed for the evaluation of hMPV prevalence and genotype distribution in different unanalyzed regions in Iran.

Seroepidemiology of dengue and chikungunya fever in patients with rash and fever in Iran, 2017.

After the mass campaign of Measles and Rubella vaccination in 2003 in Iran, the cases of measles and rubella infection decreased but still, the cases of rash and fever were reported. It is worth noting that some other viral infections show signs similar to measles and rubella such as some arboviruses. Considering the epidemic outbreak of arbovirus infections in countries neighbouring Iran, we performed this study to estimate the possibility of chikungunya and dengue fever among measles and rubella IgM negative patients presenting with rash and fever from December 2016 to November 2017 in the National Measles Laboratory at Tehran University of Medical Sciences. Serum samples were selected at random from patients from eight provinces. The presence of DENV IgM and CHIKV IgM was examined by enzyme-linked immunosorbent assay. Of the 1306 sera tested, 210 were CHIKV seropositive and 82 were dengue seropositive. Statistical analysis demonstrated a significant increase in the CHIKV IgM antibody seropositivity rate in Kerman (OR = 2.07, 95% CI: 1.10-3.92; P = 0.024) and Fars (OR = 1.77, 95% CI: 1.06-2.93; P = 0.027). The DENV and CHIKV seropositivity rate in summer is higher than in other seasons (P < 0.01). Our seropositive samples suggest possible CHIKV and DENV infection in Iran. It is likely that these viruses are circulating in Iran and there is a need to study vector carriage of these two viruses.

Molecular Detection of Adeno-Associated Virus DNA in Cases of Spontaneous and Therapeutic Abortion.

BACKGROUND: Adeno-associated viruses (AAVs) have been found in human blood cells, cervical biopsies, and epithelial cell brushings, endometrium, and abortion material, which suggest their possible roles in the induction of miscarriage. OBJECTIVE: In this case control study, the presence of AAV DNA in placental tissue of spontaneous and therapeutic abortions was compared. METHOD: Placenta samples were evaluated for AAV DNA by hemi-nested PCR in miscarriages occurring in the first 24 weeks of pregnancy from therapeutic and spontaneous abortions. RESULTS: Eighty-one therapeutic abortions (control group) and 83 spontaneous abortions (case group) were evaluated. Sixty-two (38.2%) of 164 abortions were AAV positive, including 35 (21.6%) spontaneous abortions and 27 (16.6%) therapeutic abortions. CONCLUSION: There was no statistically significant difference between the presence of the AAV genome in spontaneous and therapeutic abortions. This observation was consistent with other studies in this area.

Characterization of the DNA mismatch repair proteins MutS and MutL in a hypermutator Acinetobacter baumannii.

Mutations of mutS and mutL genes have been linked with the emergence of hypermutator (HPM) phenotype in several bacteria. Nevertheless, there is scarce evidence that these mutations occurred in HPM Acinetobacter baumannii, therefore, it remains unknown whether the mutations located in domains mediating the functions of MutS and MutL. To address this information gap, the nucleotide sequences of mutS and mutL were characterized and their mutations were identified. Additionally, we proposed in silico models of mutated proteins and analyzed the secondary and tertiary structures, and the interaction interfaces of MutL and MutS. The HPM A. baumannii and a wild-type strain were subjected to PCR amplification of full length mutS and mutL, cloning, and sequencing. Following several reads of both strands of each gene and sequence assembly, the mutations were identified. Thereafter, the three-dimensional (3-D) structure of A. baumannii ATCC 19606 was developed and utilized as a template for homology modeling of the mutated amino acid sequences using the Phyre2 and I-TASSER, VMD 1.9.3, LigPlus v.1.4.5, PyMOL v.0.99 software. Regardless of silent mutations (n = 43), 11 missense mutations were identified in the MutS domains of HPM strain such as A4T, T272S, D278N in N-terminus, connector, and core domains, respectively. Three mutations -I357T, A408S, N447S- and 16 silent mutations were observed in MutL. Secondary structure prediction of MutS revealed that the amount of alpha helices, beta sheets, and coils in HPM were 35, 29, and 63, respectively, while these values were 36, 28, and 63 for A. baumannii ATCC 19606 as non mutator. In the case of MutL, for both HPM and non-mutator, 20, 21, and 39 of complete protein were alpha helices, beta sheets, and coils, respectively. Superimposition of structures of MutS of HPM on non-mutator revealed that T272, D278, G457, S528, A533, Y715, and E747 are closely matched with S272, D278, A457, P528, V533, C715, and K747, respectively in non-mutator strain. When the structure of MutL model in HPM was superimposed on its counterpart in non-mutator, all but residues S447, S408, and T357 were identical. Many mutations along the mutS and mutL were noted, but most of the mutations were observed in the interaction interfaces of MutS and MutL. Other substitutions were predominantly detected in C-terminus of MutS that may lead to reduced ATP binding and hydrolysis. Three substitution mutations were adjacent to C-terminus of MutL and are raising the suggestion of reduction in MutL dimerization. It seems that a combination of these mutations is implicated in increased mutation frequency and accordingly emergence of HPM strain.

Type specific Real time PCR for detection of human herpes virus 6 in schizophrenia and bipolar patients: a case control study.

BACKGROUND: Schizophrenia (SC) and bipolar disorder (BD) are among the most devastating diseases worldwide. There are several lines of evidence suggesting that viruses may play significant roles in the etiology of these mental disorders. The aim of this study was the detection of HHV-6A/B in the peripheral blood mononuclear cells (PBMC) of SC and BD patients versus the healthy control (HC) subjects using a new method of type-specific Real time PCR analysis. METHODS: A type-specific Real time PCR was performed for simultaneous detection and typing of HHV-6A/B in the PBMCs of 120 SC and BD patients and 75 HCs. RESULTS: Only one case of HHV-6B out of 120 (0.8 %) SC and BD patients and two cases of HHV-6A (2.7 %) in 75 HCs were detected. CONCLUSIONS: The low levels of HHV-6 detection in PBMCs, severely limited the capacity of this study to investigate the association between the presence of HHV-6 and BD or SC in this population, thus no conclusions can be drawn in this regard. Meanwhile this study introduces a Real time PCR based method for type specific detection of HHV-6A/B in clinical samples.

The reproduction rate of severe acute respiratory syndrome coronavirus 2 different variants recently circulated in human: a narrative review.

SARS-COV-2 is responsible for the current worldwide pandemic, which started on December 2019 in Wuhan, China. On March 2020 World Health Organization announced COVID-19 as the new pandemic. Some SARS-COV-2 variants have increased transmissibility, cause more severe disease (e.g., increased hospitalizations or deaths), are resistant to antibodies produced by the previous infection or vaccination, and there is more difficulty in treatment and diagnosis of them. World Health Organization considered them as SARS-CoV-2 variants of concern. The introductory reproduction rate (R0) is an epidemiologic index of the transmissibility of the virus, defined as the average number of persons infected by the virus after known contact with an infectious person in a susceptible population. An R0 > 1 means that the virus is spreading exponentially, and R0 < 1, means that the outbreak is subsiding. In various studies, the estimated R and VOC growth rates were reported to be greater than the ancestral strains. However, it was also a low level of concordance between the estimated Rt of the same variant in different studies. It is because the R of a variant not only dependent on the biological and intrinsic factors of the virus but also several parameters can affect the R0, including the duration of contagiousness and the likelihood of infection per contact. Evaluation of changes in SARS-CoV-2 has shown that the rate of human-to-human transmission of this virus has increased. Like other viruses with non-human sources which succeeded in surviving in the human population, SARS-CoV-2 has gradually adapted to the human population, and its ability to transmit from human to human has increased. Of course, due to the continuous changes in this virus, it is crucial to survey the rate of transmission of the virus over time.

Comparison of clinical outcomes, demographic, and laboratory characteristics of hospitalized COVID-19 patients during major three waves driven by Alpha, Delta, and Omicron variants in Tehran, Iran.

Introduction: This study is the first study in which demographic, laboratory data, and outcomes of coronavirus disease-2019 (COVID-19) patients due to the circulating SARS-CoV-2 infections caused by different variants (Alpha, Delta, and Omicron) are compared in Iran. Methods: We conducted a retrospective study of confirmed hospitalized COVID-19 cases from April 9, 2021, to May 22, 2022. Demographic data and laboratory findings were extracted from patients' electronic medical records on the first day of admission to the hospital. All patients were followed up for outcomes related to COVID-19 including intensive care unit (ICU) admission and mortality rate. Results: Of 760 confirmed hospitalized COVID-19 cases, 362, 298, and 100 represented patients during waves 4-6, respectively. During the Omicron wave, hospitalized patients were older than the other two waves and had a lower median level of C-reactive protein (CRP), alanine transaminase (ALT), aspartate transaminase (AST), and erythrocyte sedimentation rate (ESR). The median length of hospital stay during waves 4-6 was 5 days (interquartile range [IQR]: 4.0-8.0), 7 days (IQR: 6.0-11), and 6 days (IQR: 5.0-9.0), respectively (p < 0.001). The rate of ICU admission during waves 4-6 significantly increased. Conclusions: Although the Omicron variant caused less severe disease, in older patients who were hospitalized due to Omicron infection, longer hospital and ICU stays were reported, which could be attributed to their old age. In particular, elderly patients are more vulnerable to severe COVID-19; otherwise, as expected, other laboratory parameters and clinical outcomes were in accordance with differences in pathogenicity and infectivity of these variants.

Plausible reasons for the resurgence of Mpox (formerly Monkeypox): an overview.

Poxviruses are large and diversified viruses that cause an emerging zoonotic disease known as monkeypox (mpox). In the past, mpox predominated primarily in the rural rainforests of Central and West Africa. Recently, the exportation of mpoxv from Africa to other continents has been progressively reported. However, the lack of travel history to Africa in most of the currently reported cases in 2022 promotes the sign of changing epidemiology of this disease. Concerns over the geographic distribution and continued resurgence of mpox is growing. In this review, we addressed the geographic distribution, transmission, reasons for the resurgence of mpox, and vaccination. Although the precise cause of the resurgence in mpox cases is mostly unknown, several suggested factors are believed to be waning immunity, accumulation of unvaccinated people, ecological conditions, risk behaviors of men who have sex with men, and genetic evolution.

SARS-CoV-2 in patient with protein C deficiency: A case report.

In SARS-CoV-2 pandemic different disorders in coagulation pathways in COVID-19 patients were reported. We described a 44-year-old female with COVID-19 and protein C deficiency history. She did not show any coagulation disorder during her disease course. Complete genome sequencing of SARS-CoV-2 was performed and some mutations identified and compared with Wuhan strain. Besides hospitalized patients, in COVID-19 outpatients with low concentration of protein C, early prescription of an anticoagulant such as heparin could be helpful in prevention of venous thromboembolism or pulmonary embolism.

Phylogenetic characterization of rhinovirus and adenovirus in hospitalized children aged ≤ 18 years with severe acute respiratory infection in Iran.

Background and Objectives: Human rhinoviruses (HRVs) and human adenoviruses (HAdVs) are among the most prevalent viruses in hospitalized patients with severe acute respiratory infection (SARI). This study aimed to evaluate the molecular characterization of HRV and HAdV in hospitalized patients with SARI, who aged ≤ 18 years in Tehran, Iran. Materials and Methods: To detect these two viruses, a conventional nested RT-PCR (Reverse transcription-polymerase chain reaction) assay was performed on 264 throat swabs collected from December 2018 to March 2019. The epidemiological data were analyzed and phylogenetic trees were constructed. Results: Of 264 cases with SARI, 36 (13.6%) and 28 (10.6%) were positive for HAdV and HRV respectively. Of 21 HRV sequenced samples, HRV-A (42.9%), HRV-B (9.5%) and HRV-C (47.6%) and of 36 HAdV sequenced samples, HAdV-C6 (38.9%), HAdV-B7 (22.2%), HAdV-B3 (11.1%), HAdV-B16 (5.6%), HAdV-C5 (13.9%), HAdV-C57 (5.6%), HAdV-E4 (2.8%); were detected in children with SARI. Some viral genotypes appeared to cause more severe disease, which may lead to hospitalization. Conclusion: Large-scale studies are recommended to investigate the epidemiology and molecular characterizations through surveillance networks to provide useful information on etiology, seasonality, and demographic associations in patients with SARI.

How to tackle single target gene positive results of SARS-CoV-2 real-time PCR: A cross-sectional study.

Background and Aims: Real-time reverse-transcriptase polymerase chain reaction (real-time RT-PCR) is the gold standard test for diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, when the test result is near the detection limit of the assay the possibility of getting false positive or negative results is high. In addition, it might result in single target gene positive (STGP) results which should be interpreted with caution. Methods: This study was performed on 29,962 nasal swabs from July 1 to August 31, 2020. Ct values less than 40 for each or both of N and RdRp genes were recommended to be selected as positive. Positive samples for one gene with the Cts more than 35 were rechecked by adding more templates. Results: The results showed that 1016 (3.39%) samples were positive just for one gene with high Ct values. The results of the second reactions showed that 325 (31.99%) samples were positive for both N and RdRp which were reported positive, 301 (29.65%) were positive only for one gene which were considered as suspicious cases and resampling was suggested for them. Finally, 390 (38.385%) samples were negative for both genes. Conclusion: In conclusion, tracking weak positive results of SARS-CoV-2 real-time RT-PCR revealed that most of the individuals who were STGP clean the infection completely in less than a week which showed they were in the convalescent phase of infection. However, some of them who were in the beginning of infection showed a decrease in Ct value during a week, so they could spread the virus in the society.