HAT-field: a very cheap, robust and quantitative point-of-care serological test for Covid-19.

We have recently described a very simple and cheap serological test called HAT to detect antibodies directed against the RBD of the SARS-Cov-2 virus. HAT is based on hemagglutination, triggered by a single reagent (IH4-RBD) comprised of the viral RBD domain fused to a nanobody specific for glycophorin, which is expressed at very high levels at the surface of human red blood cells (RBCs). One of the main initial goals of this study was to devise a test protocol that would be sensitive and reliable, yet require no specialized laboratory equipment such as adjustable pipets, so that it could be performed in the most remote corners of the world by people with minimal levels of training. Because antibody levels against the viral RBD have been found to correlate closely with sero-neutralisation titers, and thus with protection against reinfection, it has become obvious during the course of this study that making this test reliably quantitative would be a further significant advantage. We have found that, in PBN, a buffer which contains BSA and sodium azide, IH4-RBD is stable for over 6 months at room temperature, and that PBN also improves HAT performance compared to using straight PBS. We also show that performing HAT at either 4°C, room temperature or 37°C has minimal influence on the results, and that quantitative evaluation of the levels of antibodies directed against the SARS-CoV-2 RBD can be achieved in a single step using titration of the IH4-RBD reagent. The HAT-field protocol described here requires only very simple disposable equipment and a few microliters of whole blood, such as can be obtained by finger prick. Because it is based on a single soluble reagent, the test can be adapted very simply and rapidly to detect antibodies against variants of the SARS-CoV-2, or conceivably against different pathogens. HAT-field appears well suited to provide quantitative assessments of the serological protection of populations as well as individuals, and given its very low cost, the stability of the IH4-RBD reagent in the adapted buffer, and the simplicity of the procedure, could be deployed pretty much anywhere, including in the poorest countries and the most remote corners of the globe.

Epidemiology of SARS-CoV-2 infection in Italy using real-world data: methodology and cohort description of the second phase of web-based EPICOVID19 study.

Digital technologies have been extensively employed in response to the SARS-CoV-2 pandemic worldwide. This study describes the methodology of the two-phase internet-based EPICOVID19 survey, and the characteristics of the adult volunteers respondents who lived in Italy during the first (April - May 2020) and the second wave (January - February 2021) of the epidemic. Validated scales and ad-hoc questionnaires were used to collect socio-demographic, medical and behavioural characteristics, as well as information on COVID-19. Among those who provided email addresses during phase I (105,355), 41,473 participated in phase II (mean age 50.7 years +/- 13.5 SD, 60.6% females). After a median follow-up of ten months, 52.8% had undergone naso-pharyngeal swab (NPS) testing and 13.2% had positive result. More than 40% had undergone serological test (ST) and 11.9% were positive. Out of the 2,073 participants with at least one positive ST, 72.8% had only negative results from NPS or never performed it. These results indicate that a large fraction of individuals remained undiagnosed, possibly contributing to the spread of the virus in the community. Participatory online surveys offer a unique opportunity to collect relevant data at individual level from large samples during confinement.

COVID-19 Serology Control Panel Using the Dried-Tube Specimen Method

The dried-tube specimen (DTS) procedure was used to develop the COVID-19 serology control panel (CSCP). The DTS offers the benefit of shipping materials without a cold chain, allowing for greater access without deterioration of material integrity. Samples in the panel were sourced from COVID-19 convalescent persons from March to May 2020. The immunoglobulin subtypes (total Ig, IgM, and IgG) and their respective reactivity to severe acute respiratory syndrome coronavirus 2 nucleocapsid, spike, and receptor-binding domain antigens of the samples were delineated and compared with the WHO International Standard to elucidate the exact binding antibody units of each CSCP sample and ensure the CSCP provides adequate reactivity for different types of serological test platforms. We distribute the CSCP as a kit with five coded tubes to laboratories around the world to be used to compare test kits for external quality assurance, for harmonizing laboratory testing, and for use as training materials for laboratory workers.

Waning of SARS-CoV-2 Antibody levels response to inactivated cellular vaccine over 6 months among healthcare workers

Background Health Care workers (HCW) are an important group affected by this pandemic and COVID-19 has presented substantial challenges for health professionals and health systems in many countries. The Brazilian vaccination plan implemented in October, so that third dose for HCW. However, the persistence of CoronaVac vaccine-induced immunity is unknown, and immunogenicity according to age cohorts may differ among individuals. Objective Evaluate the post vaccination immune humoral response and the relationship between post-vaccination seropositivity rates and demographic data among Healthcare Workers over 6 months after CoronaVac immunization. Methods A cross section study including Healthcare professionals vaccinated with CoronaVac for 6 months or more. The study was carried with the analysis of post-vaccination serological test to assess the levels of humoral response after vaccination. Results 329 participants were included. Among them, 76% were female. Overall, 18.5% were positive quantitative titles (IQR 42.87-125.5) and the negative group was 80%, quantitative titles (IQR 5.50-13.92). Conclusion It was possible to identify a group with positive quantitative titles in serological test for IgG antibody against the SARS-CoV-2. Further investigation is required to determine the durability of post-vaccination antibodies and how serological tests can be determine the ideal timing of vaccine booster doses.

Prevalence of Helicobacter Pylori Infection Among Patients with Dyspepsia by Stool Antigen and Serology Tests

Background: Helicobacter pylori is the most common chronic bacterial infection globally and is the underlying cause of many disorders, including dyspepsia. Also, the prevalence of gastric cancer in Zanjan city is high. Therefore, this study investigates the prevalence of H. pylori infection in patients with dyspepsia by the H. pylori stool antigen (HpSA) test. Materials and Methods: This cross-sectional study was performed on patients over 18 years of age who were referred to Shafieieh Special Clinic in Zanjan with dyspepsia during 2019-2020. First, the HpSA test was examined for H. pylori infection. Since the results of two separate tests are needed to prove that H. pylori infection is negative, the serological test was used in the patients with HpSA negative results. Results: Based on the demographic information of the present study, most patients (70.1%) were under 40 years old, and most (55.1%) were women. Smoking, alcohol, drug, and non-steroidal anti-inflammatory drugs (NSAIDs) use in patients were 16.5%, 6.3%, 7.9%, and 39.4%, respectively. The highest and lowest symptoms were abdominal pain (44.9%) and burp (22%), respectively. Except for the relationship between positive serological results and age (P˂0.001), no significant relationship was found between other variables (P≥0.05). Based on the HpSA test, H. pylori infection was seen in 56.7% of patients. By the serological test, another 29 patients had H. pylori infection. Therefore, the total number of patients was 101, and the overall prevalence of H. pylori increased to 79.5%. Conclusion: The results of the present study showed that the overall prevalence of H. pylori infection was high compared to previous studies. Also, above the age of 40 years, female gender in HpSA test and male gender in serology test, higher education level, and the presence of risk factors (smoking, alcohol, and NSAIDs) have a higher positive test for H. pylori.

Prevalence of Hepatitis B viral infection amongst pregnant women in rural community in Southern Nigeria

Background: Hepatitis B Viral (HBV) infection is a potentially fatal infection of public health importance globally. Pregnant women and their unborn children are at risk of this infection due to its mode of transmission especially when in contact with infected body fluids and from mother to child transmission respectively. The prevalence of HBV infection in Nigeria is 13.6%. Aim: To determine the prevalence of HBV infection amongst pregnant women in rural community in southern Nigeria. Methods: This was a retrospective cross sectional study of pregnant women at Ogoni Primary Health Centers and General Hospitals in Southern Nigeria carried over a 4-month period. Serological test results for Hepatitis B surface antigen (HBsAg) of subjects were retrieved from the laboratories. Permission was gotten from Director of Public Health Rivers State Ministry of Health. The information gotten was analyzed using independent t test, chi square and fisher exact tests. Significance level was set at 0.05. Result: One hundred and eighty-five pregnant women were recruited for the study. The mean age of the antenatal clinic attendees was 28 ± 2 years, the mean gestational age at booking was 25 weeks and the mean parity was 2. Majority had secondary level of education represented by 122 (66%). Fifteen (8.1%) of the pregnant women were positive for Hepatitis B surface antigen. Conclusion: The prevalence of HBV infection was 8.1% in Ogoni southern Nigeria. This is worisome, hence preventive measures including HBV vaccines should be made available to the populace.

Added value of 3D-DRIVE and SWI Magnetic Resonance Imaging Sequences in Intraventricular Neurocysticercosis (IVNCC): An Institutional Experience from Northeast India

Background: Prompt diagnosis and early treatment institution are important in intraventricular neurocysticercosis(IVNCC) as compared to the parenchymal or racemose form because it is associated with a poorer patient prognosis. Intraventricular neurocysticercosis is often missed on CT scan or conventional cranial magnetic resonance imaging because of similar density or signal intensity of cysticercus lesion with cerebrospinal fluid. Thestudy aims to evaluate the added value of 3D-DRIVE and SWI MRI sequences in isolated intraventricular cysticercosis with acute neurological presentation.Methods and Materials: This retrospective study was carried out on diagnosed 10patients with isolated intraventricular neurocysticercosis(IVNCC) presented to a tertiary care hospital with an acute onset of symptoms or acute neurological deficit between June 2019 to May 2021. Relevant neurological examination, CSF analysis, a serological test of neurocysticercosis and MRI scan of the brain were performed.Result: Tenpatients of isolated intraventricular neurocysticercosis (3 males and 7 females) having 3 pediatric and7 adults were included in this study sample.The common neurological complications of the isolated intraventricular neurocysticercosis in this study are observed as obstructive hydrocephalus in 8(80%) patients and ependymitis in 7(70%) patients.IVNCC with distinctly visualized scolex (visibility score 2) identified in 2(20%) patients in T2WI, 8 (80%)patients in 3D-DRIVE and 3(30%) patients in SWI sequences. The cyst wall of IVNCC was distinctly visualized (visibility score 2) in 1(10%) patient in T2WI, 8(80%) patientsin 3D-DRIVE and 6(60%) patients in SWI sequence.Conclusion: Heavily T2-weighted steady-state and SWI sequences should be added to routine MRI sequences that helps to identify IVNCC and should be used in patients with unexplained hydrocephalus, especially in endemic regions of Neurocysticercosis.

Clinical and epidemiological characterization in the follow-up of newborns with COVID-19: a descriptive study

Introduction COVID-19 disease affects newborns, but its middle and long-term effects are still unclear. Objective To describe the clinical and epidemiological characteristics and follow-up of newborns infected with SARS-CoV-2. Methods An observational and descriptive study. We included newborns with SARS-CoV-2 positive RT-PCR born from SARS-CoV-2 seropositive mothers. Delivery and newborn care were provided at the 'Instituto Nacional Materno Perinatal' from Peru between June 1 and September 30, 2020. Perinatal information was collected from medical records. Remote follow-up and face-to-face evaluations gathered epidemiological and clinical information, in addition to serological and RT-PCR tests for SARS-CoV-2. Descriptive statistics were used for analysis. Results During the study period, 4733 neonates were born at the institution. We found that 1488 (31.4%) were born from seropositive for SARS-CoV-2 mothers. Finally, we included the 34 (2.3%) newborns with positive RT-PCR for SARS-CoV-2. Regarding the included newborns, 29.4% were delivered by cesarean section, 26.5% had low birth weight, 11.8% were preterm, 26.5% were hospitalized, and one died. Twenty-eight had a remote follow-up, and 18 also had a face-to-face follow-up. A total of 64.3% were exclusively breastfed, 28.6% were mixed breastfed, and 7.1% used a substitute formula. The face-to-face evaluation was performed between one and four months of chronological age. We found that 100% had negative control RT-PCR test for COVID-19, 38.9% had a negative serological test (IgM, IgG), and 61.1% positive IgG. Conclusions Neonatal SARS-CoV-2 infection is rare, and most infected infants are asymptomatic. Vaginal delivery, breastfeeding, and joint isolation did not related with complications during hospital care. Infants under remote and in-person follow-up showed favorable clinical evolution during the study period.

To Determine the Clinical Profile and Manifestations of Scrub Typhus among People

Introduction: In developing countries acute febrile illness (AFI) is the most common presenting complaint in emergency and outpatients department. Usually in the rainy season and post rainy season Outbreaks of AFI occur in India. Outbreaks like Dengue, Malaria, Typhoid, Scrub typhus and several viral infections have been classically responsible. Orientia tsutsugamushi is an obligate intracellular gram negative bacteria which cause Scrub typhus. Scrub typhus is the infection caused by the bite of infected chiggers. The clinical manifestation is characterised by the presence of fever, body pain, headache and rarely can cause rashes. Scrub typhus is mite borne rickettsiosis and is an endaemic infection in area unique to Asia, with an estimated one billion people. In recent years, many parts of India scrub typhus have rapidly remerged to become the major cause of AFI during monsoon seasons. In India, of the 29 states, 23 have reported the presence of scrub typhus. Aim: The main aim of this study is to determine the clinical profile and manifestation of scrub typhus infection among people. Material and method: Total 72 patients with conform cases of scrub typhus fever were included in this study. The evaluation of fevers were undergone clinically initially serological test and Weil–Felix test followed by immunoglobulin M (IgM) scrub typhus and positive cases were included in this study. Consideration was taken of their clinical appearance and investigations. Results: Total 72 positive cases were included in this study. Among the total IgM positive for scrub typhus were analyzed with their age and sex variation. From each and every patient different clinical manifestations and complications were analyzed and recorded. The common symptoms were fever; myalgia, breathlessness, rash, and abdominal pain were recorded as 100%, 66.7%, 8.3%, 13.9% and 36.1% respectively. Renal failure was the most common complications followed by pneumonia as 19.4% and 9.7% respectively. In laboratory findings high C-reacting protein and leukocytosis are also found in 81.9% and 33.3% respectively. Conclusion: Scrub typhus is a widespread tropical infection and often occurs as pyrexia of unknown origin. However sometime it is under diagnosed due to low indication of suspicion and due to non-specific clinical manifestation and also in most of clinical settings due to lack of diagnostic procedures. If there was early diagnosed then treatment will be easy and cost effective due to good response of antibiotics.

COVID-19: The Pediatric Perspective

Since the appearance of the novel corona virus disease 19 (COVID-19) from Wuhan in China, there have been a lot of researches to uncover the hidden clues that may help in eliminating the outbreak. In a short period of time, the disease has infected millions of people around the globe and was declared as a pandemic by the world health organization (WHO). Different subgroups of the community have been studied and reports have described the course of the disease among pregnant ladies, elders, immunodeficient patients and patients with chronic diseases. However, this review aimed at describing the novel COVID-19 among children and adolescents. The review discusses the prevalence, symptoms, diagnostic investigations, management, and the role of pharmacotherapy of COVID-19. In general, children have a milder course of diseases compared to adults. The symptoms include fever, diarrhea, abdominal pain, cough, fatigue, and other non-specific symptoms. The diagnosis is usually made with a serological test of a body fluid sample from saliva or nose. The role of radiography in the forms of chest X-ray and computed tomography (CT) is not of great benefit to the children. For mild presentations of the disease among children, the management is mainly supportive and there is no indication for antiviral therapy or specific pharmacotherapy except for fever lowering agents like Paracetamol. In terms of prevention, children aged 12 or more can be vaccinated for the objective of preventing the spread of infection, inducing antibody release, and shortening the recovery period.