Spectrum Analysis of Inherited Metabolic Disorders for Expanded Newborn Screening in a Central Chinese Population

Neonatal inherited metabolic disorders (IMDs) are closely associated with early neonatal death and abnormal growth and development. Increasing attention has been paid to IMDs because of their high incidence and diversity. However, there are no reports about the incidence of IMDs in Changsha, China. Therefore, we retrospectively analyzed the screening results of neonates to evaluate the characteristics of IMDs in the area. From January 2016 to December 2020, 300,849 neonates were enrolled for expanded newborn screening by tandem mass spectrometry in the Neonatal Disease Screening Center of the Changsha Hospital for Maternal & Child Health Care. Newborns with mild initial results were recalled for repeated tests; if the second test was still positive, the patient was referred for confirmatory tests. A total of 71 confirmed cases were identified in our study, with an incidence rate of 1:4,237. There were 28 cases of amino acid metabolic disorders, representing 39.44% of the IMDs diagnosed, with an incidence rate of 1:10,745. Twelve newborns were diagnosed with organic acid metabolic disorders, accounting for 16.66% of IMDs, with an incidence rate of 1:25,071. There were 31 cases of fatty acid oxidation disorders, representing 43.05% of IMDs, with an incidence rate of 1:9,705. Overall, 14 types of IMDs were found in Changsha. The most common disorders in the region were primary carnitine deficiency, hyperphenylalaninemia and short-chain acyl-CoA dehydrogenase deficiency. Their incidence rate is respectively 1:13,675, 1:16,714 and 1:42,978. The mutations in PAH, SLC22A5, and ACADS are the leading causes of IMDs in this area. This study demonstrates the importance of utilizing MS/MS in IMD screening for early diagnosis and treatment. This strategy may be used for prenatal genetic counseling to avoid irreversible growth and intellectual development disorders in children.

COVID-19 AND THE HUMAN EYE – CONJUNCTIVITIS A LONE COVID-19 FINDING - A case-control study

Background: The worldwide sudden appearance and drastic increase in the number of infected cases with the severe acute respiratory syndrome-Coronavirus 2 (SARS-CoV-2) determined the World Health Organization to declare it as a pandemic situation. The ‘Corona Virus Disease 2019’ (COVID-19) has varied clinical manifestations, from asymptomatic to severe cases, and conjunctivitis, seems not only to be one of them, but sometimes found to be lone initial symptom present. Aim and method: The aim was to identify the prevalence of conjunctivitis as the first symptom in COVID-19 patients, in a primary healthcare unit. A retrospective study was conducted analyzing the presenting complains/symptoms and results of COVID-19 confirmatory tests. Results: Out of the 672 cases that were sent for RT-PCR testing only 121 (18%) were found to be positive. Among this 2.67% of patients who had both conjunctivitis and COVID-19, 77.77% of patients had unilateral eye affected while 22.22% had bilateral conjunctivitis of varying degrees. 15 patients diagnosed to have both acute conjunctivitis and COVID-19, presented other symptoms associated with COVID-19 infection. While 3 patients had only acute conjunctivitis during their entire course of COVID-19. Conclusions: Conjunctivitis is a symptom of COVID-19 and maybe the first sign of the infection, until the onset of the classical manifestations, the patient serves to be a viral reservoir. The physicians should not miss unilateral conjunctivitis, as it can be the only presenting complain of the COVID-19 disease at the initial phase, which might worsen if underwent undetected and can aid in the spread of the contagion.

Validation and deployment of a direct saliva real-time RT-PCR test on pooled samples for COVID-19 surveillance testing

A direct, real-time reverse transcriptase PCR test on pooled saliva was validated in 2,786 participants against oropharyngeal swabs. Among asymptomatic/pre-symptomatic participants, the test was found to be in 99.21% agreement and 45% more sensitive than contemporaneous oropharyngeal swabs. The test was then used for surveillance testing on 44,242 saliva samples from asymptomatic participants. Those whose saliva showed evidence of SARS-CoV-2 within 50 cycles of amplification were referred for confirmatory testing, with 87% of those tested by nasal swab within 72 hours receiving a positive diagnostic result on Abbott ID NOW or real-time PCR platforms. Median Ct values on the saliva PCR for those with a positive and negative confirmatory tests was 30.67 and 35.92 respectively, however, binary logistic regression analysis of the saliva Ct values indicates that Ct thresholds as high as 47 may be useful in a surveillance setting. Overall, data indicate that direct RT-PCR testing of pooled saliva samples is an effective method of SARS-CoV-2 surveillance.

A novel electrochemical synthesis of graphene oxide: Converting waste product to utility

We comprehensively report here a green route for synthesizing graphene oxide from waste batteries. The satisfactory yield, formulated wholly through basic medium, is validated through confirmatory tests via X-ray Diffraction analysis, FTIR, UV-Vis and Raman Spectroscopy. The overall scheme turns out to be engaging less reactants as well as facile; thus converting a waste material to a useful product.

Evaluation of the Diagnostic Values and Utility of Helicobacter Pylori Stool Antigen Lateral Immunochromatography Assay

Helicobacter pylori is the most common human gastric infection. H. pylori stool antigen lateral flow immunochromatography assay (HpSA-LFIA) is considered one of the most cost-effective and rapid non-invasive assays (active tests). The evaluation of this test is crucial for accuracy and utility assurance. This study aimed to evaluate the polyclonal antibody-based HpSA-LFIA in comparison to a monoclonal antibody-based ELISA kit. Methodology: Stool samples were collected from 200 gastric patients for HpSA-LFIA and semi-quantitative HpSA-ELISA. Statistical analysis of the diagnostic values was performed using MedCalc software. Chi-square tests were used to determine the effects of gender and age. Results: The obtained results found that HpSA-LFIA achieved promising sensitivity (93.75%) and NPV (98.00%). However, it had poor specificity, PPV, and accuracy, respectively, 59.76%, 31.25%, and 65.31%. LR+ & LR- were 2.33% & 0.1%, respectively. Gender had no significance on the di-agnostic parameters of HpSA-LFIA. Age groups had irrelevant sensitivity; however, specificity was significantly higher in patients over 45 years. Conclusion: It was concluded that HpSA-LFIA was not accurate enough to be the sole test for di-agnosis and needs other confirmatory tests in case of positive conditions

845. Impact of the COVID-19 Pandemic on Routine HIV Screening in an Emergency Department

Background The Emergency Department (ED) at Memorial Hermann Hospital (MHH) - Texas Medical Center (TMC), Houston, Texas has a long established screening program targeted at detection of HIV infections. The impact of the COVID-19 pandemic on this screening program is unknown. Methods The Routine HIV screening program includes opt-out testing of all adults 18 years and older with Glasgow score > 9. HIV 4th generation Ag/Ab screening, with reflex to Gennius confirmatory tests are used. Pre-pandemic (March 2019 to February 2020) to Pandemic period (March 2020 to February 2021) intervals were compared. Results 72,929 patients visited MHH_ED during the pre-pandemic period and 57,128 in the pandemic period, a 22% decline. The number of patients tested for HIV pre-pandemic was 9433 and 6718 pandemic, a 29% decline. When the pandemic year was parsed into first and last 6 months interval and compared to similar intervals in the year pre pandemic, 39% followed by 16% declines in HIV testing were found. In total, 354 patients were HIV positives, 209, (59%) in the pre-pandemic and 145 (41%) in the pandemic period.The reduction in new HIV infections found was directly proportional to the decline in patients visiting the MHH-ED where the percent of patients HIV positive was constant across intervals (2.21% vs 2.26%). Demographic and outcome characteristics were constant across the compared intervals. Conclusion The COVID -19 pandemic reduced detection of new HIV infections by screening in direct proportion to the reduction in MHH-ED patient visits. The impact of COVID-19 pandemic decreased with duration of the pandemic. Disclosures All Authors: No reported disclosures

A novel high performing multiplex immunoassay Multi-HTLV for serological confirmation and typing of HTLV infections

Background Human T-Cell Lymphotropic Viruses (HTLV) type 1 and type 2 account for an estimated 5 to 10 million infections worldwide and are transmitted through breast feeding, sexual contacts and contaminated cellular blood components. HTLV-associated syndromes are considered as neglected diseases for which there are no vaccines or therapies available, making it particularly important to ensure the best possible diagnosis to enable proper counselling of infected persons and avoid secondary transmission. Although high quality antibody screening assays are available, currently available confirmatory tests are costly and have variable performance, with high rates of indeterminate and non-typable results reported in many regions of the world. The objective of this project was to develop and validate a new high-performance multiplex immunoassay for confirmation and discrimination of HTLV-1 and HTLV-2 strains. Methodology/Principal findings The multiplex platform was used first as a tool to identify suitable antigens and in a second step for assay development. With data generated on over 400 HTLV-positive blood donors sourced from USA and French blood banks, we developed and validated a high-precision interpretation algorithm. The Multi-HTLV assay demonstrated very high performance for confirmation and strain discrimination with 100% sensitivity, 98.1% specificity and 100% of typing accuracy in validation samples. The assay can be interpreted either visually or automatically with a colorimetric image reader and custom algorithm, providing highly reliable results. Conclusions/Significance The newly developed Multi-HTLV is very competitive with currently used confirmatory assays and reduces considerably the number of indeterminate results. The multiparametric nature of the assay opens new avenues to study specific serological signatures of each patient, follow the evolution of infection, and explore utility for HTLV disease prognosis. Improving HTLV diagnostic testing will be critical to reduce transmission and to improve monitoring of seropositive patients.

Genomic Epidemiology of Colistin-resistant Enterobacterales from Dutch Patients: A Prospective Matched Case-control Study

Colistin is a last-resort treatment option for infections with multidrug-resistant Gram-negative bacteria. However, colistin resistance is increasing. A six-month prospective matched case-control study was performed in which 22 Dutch laboratories with 32 associated hospitals participated. Laboratories were invited to send a maximum of five colistin-resistant Escherichia coli or Klebsiella pneumoniae (COLR-EK) isolates and five colistin-susceptible isolates (COLS-EK), matched on patient location, material of origin and bacterial species. After confirmatory tests, 72 COLR-EK/COLS-EK pairs (75% E. coli and 25% K. pneumoniae) were included. Twenty-one percent of COLR-EK patients had received colistin, in contrast to 3% of COLS-EK patients (OR>2.9). Of COLR-EK isolates, five contained mcr-1 and two mcr-9. One isolate lost mcr-9 after repeated sub-culturing, but retained colistin resistance. Among 46 sequenced COLR-EK isolates, genetic diversity was large and 19 (41.3%) isolates had chromosomal mutations potentially associated with colistin resistance. In conclusion, colistin resistance is not rare in the Netherlands and caused by the mcr gene in a minority of COLR-EK isolates.

Epidemiological Analysis of COVID-19 Cases in Native Amazonian Communities from Peru

Despite early control measures, SARS-CoV-2 reached all regions of Peru during the first wave of the pandemic, including native communities of the Peruvian Amazon. Here, we aimed to describe the epidemiological situation of COVID-19 in the Amazonas region of Peru using an open database of 11,124 COVID-19 cases reported from 19 March to 29 July 2020, including 3278 cases from native communities. A high-incidence area in northern Amazonas (Condorcanqui) reported a cumulative incidence of 63.84/1000 inhabitants with a much lower death rate (0.95%) than the national average. Our results showed at least eight significant factors for mortality, and the Native Amazonian ethnicity as a protective factor. Molecular confirmatory tests are necessary to better explain the high incidence of antibody response reported in these communities.

Investigation on the Compressive Strength and Time of Setting of Low-Calcium Fly Ash Geopolymer Paste Using Response Surface Methodology

Approximately 2.78 Mt of coal fly ash is produced in the Philippines, with a low utilization rate. Using fly ash-based geopolymer for construction will lessen the load sent to landfills and will result in lower GHG emissions compared to OPC. It is necessary to characterize the fly ash and optimize the geopolymer components to determine if it can replace OPC for in situ applications. The activator-to-precursor ratio, the water-to-solids ratio, and the sodium hydroxide-to-sodium silicate ratio were optimized using a randomized I-optimal design from the experimental results of 21 runs with five replicates, for a total of 105 specimens of 50 mm × 50 mm × 50 mm paste cubes. The engineering properties chosen as the optimization responses were the unconfined compressive strength (UCS), the initial setting time, and the final setting time. The samples were also ambient-cured with the outdoor temperature ranging from 30 °C to 35 °C and relative humidity of 50% ± 10% to simulate the on-site environment. Runs with high unconfined compressive strength (UCS) and short setting times were observed to have a low water-to-solids (W/S) ratio. All runs with a UCS greater than 20 MPa had a W/S ratio of 0.2, and the runs with the lowest UCS had a W/S of 0.4. The initial setting time for design mixes with a W/S ratio of 0.2 ranged from 8 to 105 min. Meanwhile, five out of seven design mixes with a W/S ratio of 0.4 took longer than 1440 min to set. Specimens with an alkali activator ratio (NaOH/WG) of 0.5 (1:2) and 0.4 (1:2.5) also had significantly lower setting times than those with an alkali activator ratio of 1. The RSM model was verified through confirmatory tests. The results of the confirmatory tests are agreeable, with deviations from the expected UCS ranging from 0 to 38.12%. The generated model is a reliable reference to estimate the UCS and setting time of low-calcium FA geopolymer paste for in situ applications.