Virus IgM Antibodies Research Articles

Rapid Decline of Zika Virus IgM Antibodies against the NS1 Protein in Imported Israeli Cases.

Zika virus (ZIKV) infection during pregnancy may cause severe fetal abnormalities and therefore it is important to diagnose and distinguish between recent and past Zika infection. Serological diagnosis assays detect antibodies against the envelope protein, that suffer from high cross-reactivity. In addition, reports regarding long IgM persistence prevent its use in diagnosis of recent Zika infection. Following the Zika pandemic, a novel ELISA assay based on detection of antibodies against Zika nonstructural 1 (NS1) protein was developed (NS1-IgM). Here, NS1-IgM antibodies were assessed in Israeli travelers diagnosed with Zika. NS1-IgM and NS1-IgG antibodies from 36 travelers diagnosed with ZIKV infection were detected as early as 5 days after symptom onset. However, while IgG levels were maintained for several months, IgM levels in all samples declined rapidly and by 31 days after symptom onset, no IgM positive samples were detected. Interval-censored survival analysis demonstrated 25%, 50%, and 75% decline in NS1-IgM levels in 29 days (95% CI: 22-34), 34 days (95% CI: 29-44), and 44 days (95% CI: 34-65), respectively. Our results suggest that IgM antibodies against ZIKV NS1 are short lived and can be used as a reliable marker for diagnosis of recent ZIKV infection.

Seroprevalence and Potential Risk Factors of Hepatitis E Virus among Pregnant Women in Khartoum, Sudan

Although hepatitis E virus (HEV) infection has been widely understood as a public health concern in pregnant females, it is sometimes overlooked because of unusual observations of hepatitis E-induced complications during pregnancy. The objective of this descriptive cross-sectional study was to find out how frequent Hepatitis E virus infection is in pregnant women in Sudan. Blood samples were collected from pregnant women (n = 90) attending Khartoum North Hospital from February to December 2019. The specimens were investigated for Hepatitis E virus IgG and IgM antibodies using the commercial kits based on the enzyme immunosorbent assay (ELISA) technique. Out of ninety pregnant women, 36 (40%) were found positive for IgG antibodies, and 5 (6%) were tested positive for IgM antibodies. In addition, 13 (14.5%) of the positive cases are women in their third trimester. These data showed a significant association between previous Hepatitis E virus infection and miscarriage (p <0.001). This study did not find a significant association between maternal and gestation age, education, water sources, and hepatitis E virus infection. In conclusion, there was a high percentage of HEV infections among pregnant women attending Khartoum North Hospital. This study estimates the Hepatitis E virus burden in Khartoum state, but more extensive studies are required to confirm the burden in Sudan.

A COVID-19 Patient Discharged According to Strict Discharge Standards: Viral Negativity in Both Nasopharynx and Feces.

Severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) currently has spread all over the world. However, the dynamic characteristics of SARS-CoV-2 infections have not previously been described in detail. Here, we report a cured patient in West China Hospital, and describe the dynamic detection of SARS-CoV-2-RNA in different specimens and viral specific IgM and IgG antibodies in blood. The findings suggest that the fecal SARS-CoV-2-RNA negativity may be considered as a new standard for de isolation. Serum IgM and IgG antibodies detection were helpful for early diagnosis of SARS-CoV-2 infection and judgment of patients in recovery stage, respectively.

Determination of Dengue Virus IGM Seroprevalence, Malaria Parasitaemia and Some Haematological Parameters of HIV Infected Individuals in Awka, Nigeria

Dengue fever is regarded as an important neglected Arboviral disease worldwide. This study aimed at investigating the prevalence of dengue IgM seroprevalence, malaria parasitaemia and some haematological parameters of HIV infected individuals attending Chukwuemeka Odumegwu Ojukwu Teaching Hospital Amaku, Awka, Nigeria. A cross sectional study consisting of 188 participants was performed. The demographic data and possible risks factors of the subjects were obtained using well-structured questionnaire. Dengue virus IgM was analysed using Enzyme-linked immunosorbent assay (ELISA) techniques, Malaria parasitaemia was determined using microscopy technique while some haematological parameters were evaluated using heamatology auto analyser (PE-6800 fully auto heamatology analyser procan). Statistical analysis was performed using the statistical package for social (spss) version 25. The results of this study showed that the prevalence of Dengue virus was 20.2% while that of Malaria was 37.2%. The co-infection of Dengue virus IgM antibodies and Malaria parasitemia was 8.51%. Plasmodium falciparium was seen as the only specie of malaria parasite present in the study. The results of some haematogical parameters of the Dengue virus seropositive participants as compared with the Dengue virus seronegative participants were statistically significant with neutrophils (p = 0.035), mean cell hemoglobin concentration (MCHC = p<0.013), eosinophils (EOS = p<0.001) and mean corpuscular volume (MCV = p<0.001). This study suggests that Dengue maybe the emerging cause of fever of unknown origin among populations. This calls for urgent attention, adoption of immediate control measures and public health preventive actions against the disease so as to curb or mitigate the emergence as well as reduce the morbidity and mortality resulting from dengue burden especially in the immunocompromised individuals.

Current and Emerging Technologies for the Diagnosis of SARS-CoV-2

Currently, there are numerous under development or developed assays with various sensitivities and specificities for diagnosis of the Coronavirus Disease 2019 (COVID-19) caused by the SARS-CoV-2 virus. The World Health Organization (WHO) has approved several detection protocols based on real-time reverse transcription PCR (RT-qPCR) and the reliability of tests to detect the N, S, or RdRp/Hel genes of the SARS-Cov-2 virus has also investigated. Among these targets, COVID-19-RdRp/Hel targets represented the highest sensitivity. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) has also been developed to rapidly and efficiently amplify RNA under isothermal conditions. Other isothermal amplification approaches such as nucleic acid sequence-based amplification (NASBA), recombinase polymerase amplification (RPA), and rolling circle amplification (RCA) have also been reported for detecting coronaviruses but like LAMP assay. Different serological tests, including neutralization tests, immunofluorescent (IFA), enzyme-linked immunosorbent (ELISA), and western blotting assays, are available. Point-of-care tests (POCT) are emerging to detect the virus genome, IgG, or IgM antibodies against SARS-CoV-2. The advent of more sensitive, cheaper, and easier-to-perform diagnostic tests seems to be a fundamental prerequisite to improve the diagnosis of COVID-19 infection. Herein, we reviewed several commercially available diagnostic methods used in many clinical laboratories to detect COVID-19.

Seroprevalence of three emerging arboviral infections in Kuwaiti nationals

Diseases caused by dengue, sandfly fever and hanta viruses pose a major health risk in many countries. We determined the threat of these arboviral infections through a serologic using enzyme linked immunosorbent assay (ELISA) based tests. Hantavirus-specific antibodies were also detected using immunofluorescence. Of 499 samples tested for dengue virus IgG antibodies l4% were as positive for dengue positive by all the ELISA tests. Among the 42 showing strong IgG reactivity, only 1 was positive for dengue virus IgM antibodies. All samples tested for IgG antibodies to sandfly fever virus were negative. Hantavirus antibodies were detected in 11% of the 46 samples from high-risk individuals. The low prevalences suggest that at present these infections are not a serious problem in Kuwait.

Standardization and Evaluation of an Anti-ZIKV IgM ELISA Assay for the Serological Diagnosis of Zika Virus Infection.

ABSTRACT.Here, we describe the development of the in-house anti-Zika virus (ZIKV) IgM antibody capture ELISA (in-house ZIKV IgM ELISA) for the detection and diagnosis of acute ZIKV infections. We compared the in-house ZIKV IgM ELISA assay performance against two commercial kits, Euroimmun ZIKV IgM and InBios 2.0 ZIKV IgM ELISA. We tested the assays’ ability to detect anti-ZIKV IgM using a well-defined serum sample panel. This panel included 80 ZIKV negative samples (20 negative, 20 found to be primary dengue virus [DENV][ infections, 20 secondary DENV infections, and 20 Japanese encephalitis virus [JEV] infections) and 67 ZIKV reverse transcriptase–polymerase chain reaction–positive acute serum samples. The OD values were calculated to enzyme immunoassay (EIA) unts by comparing them to weak positive controls. The results demonstrated the high sensitivity (88.06%) and specificity (90.00%) of our in-house ZIKV IgM ELISA and its 89.12% overall percentage agreement. The kappa values were deemed to be within excellent range and comparable to the InBios ZIKV IgM ELISA. Some cross-reactivity was observed among secondary DENV and JEV samples, and to a much lower extent, among primary DENV samples. These data indicate that our in-house ZIKV IgM ELISA is a reliable assay for the detection of anti-ZIKV IgM antibodies in serum.

Seroprevalence Of Rubella Virus Antibodies Among Pregnant Women Attending Antenatal Clinic in Ekiti State

Rubella virus infection poses a great threat to the foetus whose mother acquires the infection. This study was therefore carried out to determine the seroprevalence of rubella virus IgM antibodies among the pregnant women attending Federal Teaching Hopsital, Ido Ekiti. One hundred and ninety two (192) sera were collected from pregnant women and screened for rubella virus IgM antibodies. A structured questionnaire was administered to subjects to obtain socio-demographic data. The sera samples were analysed using Enzymes Immunosorbent Assay (EIA) IgM rubella kit. Out of 192 pregnant women screened, 6(3.1%) subjects were sero-positive. Age group 31-35years recorded the highest prevalence 3(1.56%). Pregnant women with tertiary education had the highest prevalence of 4(2.08%) among different educational level; civil servants have a prevalence of 4(2.08%) compared with other occupational status. However, prenatal screening and post-partum is highly encouraged to detect congenital rubella syndrome. There is also a need to include rubella screening as part of the routine procedure for the expectant mother.

Seropositive coronavirus disease 2019 detection among apparently healthy voluntary blood donors

Background Despite the prevailing pandemic of coronavirus disease 2019, there are no recommendations available yet for serological screening of apparently healthy asymptomatic blood donors for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. Objective To explore the seropositivity for SARS-CoV-2 antibodies in serum samples of a group of randomly selected Egyptian voluntary blood donors who met the eligibility criteria for blood donation as a preliminary step to catch apparently healthy asymptomatic participants who constitute an important source of viral spread in the community. Patients and methods The first phase of our study design plan included 100 anonymous serum samples of a group of voluntary blood donors who donated blood at Ain-Shams University Hospitals’ blood bank during the period from the second week of September to the end of October 2020. After completion of the steps of donation, donors’ stored serum samples were screened for SARS-CoV-2-specific immunoglobulin (Ig)M and IgG antibodies. The next phase of our study design plan is intended to include larger samples of known apparently healthy asymptomatic blood donors in an attempt to reach seropositive patients to confirm the results by PCR and validate the testing. Results A total of 100 anonymous serum samples were included in the study. Eleven (11%) samples were reactive for viral specific IgM antibodies, and 38 (38%) samples were reactive for viral specific IgG antibodies. Conclusion As the ongoing pandemic of coronavirus disease 2019 is continuing to demand urgent attention, screening of all asymptomatic apparently healthy voluntary blood donors for SARS-CoV-2 antibodies followed by viral RNA detection by PCR in seropositive donors could abort viral spread to others in blood centers and eventually to the rest of the community.

Seroprevalence of hepatitis a virus antibody in 11-15 years old children in Vijayawada and age-related incidence of hepatitis a virus in GGH, Vijayawada

Background: To estimate seropositivity of hepatitis A virus Ig G antibody (HAV Ig G antibody) in 11 to 15 years aged children in Vijayawada.Methods: The study group includes 265 consecutive children aged 11 to 15 years attending GGH, Vijayawada and had a blood sample taken for any reason. The serum samples collected were screened for Anti HAV IgG antibody using commercially available Elisa kit (WANTAI). Information related to various socio demographic factors also were elicited by interview method. All the Anti-Hepatitis A virus IgM antibody positive individuals list are collected from 1stJuly 2015 to 1st august 2017 and were categorized based on age and analysed.Results: The total seropositivity against Hepatitis A virus is 71%. The number of children in the urban population showing IgG antibodies is lower compared to that of rural population (p value-0.028). The highest number of Hepatitis A virus infected population (positive IgM) is between 10-14 years (50), followed by 15-19 years (45) and 5-9 years (43). This shows that there is increased risk of infection in the older age group and there is a shift to 2nd and 3rd decade (p value – 0.045).Conclusions: The seropositivity of HAV IgG antibody in children aged 11-15 years is 71% in Vijayawada. Seroprevalence in the nearby area, Chennai, ten years back was found to be 95% by 12 years of age. This indicates there is a shift from high to intermediate endemicity in Vijayawada. There is need for vaccination in the susceptible individuals.

Persistence of IgM Antibodies after Vaccination with Live Attenuated Japanese Encephalitis Vaccine.

.Japanese encephalitis (JE) is a vaccine-preventable, mosquito-borne disease. Substantial progress with JE control in Asia has been made during the past decade, with most endemic countries now having JE vaccination programs, commonly using live attenuated SA14-14-2 JE vaccine (trade name CD-JEV). If a child develops encephalitis during the weeks to months following CD-JEV vaccination and anti-JE virus IgM (JE IgM) antibody is detected in serum, the question arises if this is JE virus infection indicating vaccine failure, or persistent JE IgM antibody postvaccination. To better understand JE IgM seropositivity following vaccination, sera from 268 children from a previous CD-JEV study were tested by two different JE IgM assays to determine JE IgM antibody frequency on days 28, 180, and 365 postvaccination. With the CDC JE IgM antibody capture ELISA (MAC-ELISA), 110 children (41%) had JE IgM positive or equivocal results on their day 28 sample, and eight (3%) and two (1%) had positive or equivocal results on day 180 and day 365 samples, respectively. With the InBios JE Detect™ MAC-ELISA (Seattle, WA), 118 (44%) children had positive or equivocal results on day 28 sample, and three (1%) and one (0.4%) had positive or equivocal results on day 180 and day 365 samples, respectively. Our results indicate that more than 40% children vaccinated with CD-JEV can have JE IgM antibodies in their serum at 1 month postvaccination but JE IgM antibody is rare by 6 months. These data will help healthcare workers assess the likelihood that JE IgM antibodies in the serum of a child with encephalitis after vaccination are vaccine related.

SARS-CoV-2 RapidPlex: A Graphene-Based Multiplexed Telemedicine Platform for Rapid and Low-Cost COVID-19 Diagnosis and Monitoring

The COVID-19 pandemic is an ongoing global challenge for public health systems. Ultrasensitive and early identification of infection is critical in preventing widespread COVID-19 infection by presymptomatic and asymptomatic individuals, especially in the community and in-home settings. We demonstrate a multiplexed, portable, wireless electrochemical platform for ultra-rapid detection of COVID-19: the SARS-CoV-2 RapidPlex. It detects viral antigen nucleocapsid protein, IgM and IgG antibodies, as well as the inflammatory biomarker C-reactive protein, based on our mass-producible laser-engraved graphene electrodes. We demonstrate ultrasensitive, highly selective, and rapid electrochemical detection in the physiologically relevant ranges. We successfully evaluated the applicability of our SARS-CoV-2 RapidPlex platform with COVID-19-positive and COVID-19-negative blood and saliva samples. Based on this pilot study, our multiplexed immunosensor platform may allow for high-frequency at-home testing for COVID-19 telemedicine diagnosis and monitoring.

S2737 When the Student Becomes the Patient: A Case of Epstein-Barr Virus-Induced Acute Liver Injury

INTRODUCTION: Viral hepatitis is a diagnosis that can lead to acute liver injury and commonly occurs following an acute Hepatitis A or B infection. Epstein-Barr virus (EBV) is a rare cause of acute viral hepatitis. We present a case of acute liver injury secondary to acute EBV infection. CASE DESCRIPTION/METHODS: A 25-year-old female medical student with no significant past medical history presented with five days of fever, sore throat, nausea, and left upper quadrant abdominal pain while on her Pediatric rotation. She was afebrile, tachycardic to 106 beats/min, and demonstrated tender cervical lymphadenopathy, exudative tonsillar enlargement, and splenomegaly on physical exam. Heterophile antibody was negative three days prior to presentation. Initial studies revealed a leukocytosis of 12,600/mm3 and elevated liver enzymes (AST 421 U/L, ALT 788 U/L, alkaline phosphatase 404 U/L, total bilirubin 1.4 mg/dL, and INR 1.3). CT abdomen revealed hepatosplenomegaly. Hepatic vasculature was patent on doppler ultrasound with an unremarkable gallbladder and biliary tree. Subsequent studies were pertinent for an undetectable serum acetaminophen level, negative Hepatitis A-C serologies, and negative cytomegalovirus PCR. EBV serologies were positive for acute infection including an elevated viral capsid antibody, IgM, IgG, and negative nuclear antigen antibody. The patient was discharged with supportive treatment and followed ten days later in clinic with liver enzymes improved to near normal levels. DISCUSSION: Infectious mononucleosis from EBV infection is associated with development of acute hepatitis in 80% of cases. Diagnosis may be delayed due to high rate of false negative heterophile antibodies early in the disease course. Most cases are subclinical with hepatomegaly occurring in only 14% of cases. The pattern of liver injury is typically hepatocellular. Serum aminotransferases exhibit a transitory rise to three-fold the upper limit of normal, peak in the second or third week of illness, and normalize within thirty days. Treatment is typically supportive, though steroids and antivirals have been used in severe cases. Viral hepatitis is a common cause of acute liver injury, second to drug-induced liver injury, and accounts for 10% of acute liver failure. This case highlights the importance of including uncommon causes of viral hepatitis in the differential for acute liver injury, particularly in patients without traditional risk factors for hepatitis.

WEST NILE ENCEPHALITIS: MISGIVINGS ABOUT LUMBAR PUNCTURE IN A PATIENT WITH ICU DELIRIUM ON DUAL ANTIPLATELET THERAPY

SESSION TITLE: Fellows Critical Care Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Delirium in the critically ill is common, reported in over 80% of ICU patients. When associated with fever, it warrants investigation. West Nile is an arbovirus that can cause neuroinvasive disease ranging from mild and self-limited to severe encephalitis with mortality rate of 10%. It is diagnosed with positive IgM antibody on cerebrospinal fluid (CSF), so lumbar puncture (LP) is important for this diagnosis. Traditionally, LP was thought to increase risk of serious bleeding complications such as spinal hematomas in patients on dual antiplatelet therapy (DAPT). We present a case of a patient with West Nile encephalitis whose symptoms were attributed to drug fever and ICU delirium after negative infectious workup and significant delay in LP due to DAPT. CASE PRESENTATION: A 59 year old male presented to the ER with chest pain. He was intubated on arrival and managed for acute myocardial infarction causing cardiogenic shock. He required percutaneous coronary intervention with drug-eluting stents and temporary mechanical circulatory support with Impella. Impella was removed 3 days later. He began to exhibit daily high-grade fevers. Antibiotics were started. He developed encephalopathy and could not be extubated, necessitating tracheostomy. Extensive infectious work-up including complete body imaging, blood, BAL, pleural fluid and urine cultures, respiratory viral panel, malaria, brucella, fungal tests were all negative. LP was considered but deferred as he was on DAPT after stent placement. Hyperthermic toxidromes were excluded. Drug fever in the setting of ICU delirium was considered and non-essential medications were eliminated. Fever persisted and LP was performed 3 weeks later. CSF studies were positive for West Nile Virus IgM antibody. Antibiotics were stopped. Supportive care was provided for West Nile encephalitis. The patient improved and was eventually discharged. DISCUSSION: Clinicians often lack crucial information needed to treat infections, with 30-60% of antibiotics prescribed in the ICU thought to be inappropriately broad or inappropriately narrow. Attributing an alarm symptom like fever to non-infectious causes in the setting of ICU delirium is a pitfall that can be avoided by completing infectious workup with LP. Recent studies do not show a significant increase in complications in patients who undergo LP while on antiplatelet therapy, with incidence of spinal hematomas ranging from 0-0.7%. CONCLUSIONS: While a risk benefit discussion is essential, our case underscores the importance of pursuing early microbiological diagnosis with LP in a patient with fever and encephalopathy, even when on DAPT. This allows de-escalation of antibiotics with their associated side effects, tailored therapy and data to inform prognosis. Reference #1: Lee, Paul W, and Michael Levy. "Risk of Hematoma From Aspirin or Clopidogrel Owing to Lumbar Puncture." Mayo Clinic Proceedings 94.8 (2019): 1552-555. DISCLOSURES: No relevant relationships by Abdul Khan, source=Web Response No relevant relationships by Sumit Patel, source=Web Response No relevant relationships by Nehan Sher, source=Web Response No relevant relationships by Tonya Whiting, source=Web Response

Low prevalence of antibodies against SARS-CoV-2 among voluntary blood donors in Guangzhou, China.

Since the first case of COVID‐19 reported in late December of 2019 in Wuhan, China, the SARS‐CoV‐2 virus has caused approximately 20 million infections and 732 thousand deaths around the world by 11 August 2020. Although the pathogen generally infects the respiratory system, whether it is present in the bloodstream and whether it poses a threat to the blood supply during the period of the outbreak is of serious public concern. In this study, we used enzyme‐linked immunosorbent assay (ELISA) to screen total antibodies against SARS‐CoV‐2 in 2199 blood donors, who had donated blood at the Guangzhou Blood Center during the epidemic. The Ig‐reactive samples were further characterized for IgA, IgG, and IgM subtypes by ELISA and viral nucleic acid by real‐time polymerase chain reaction. Among the 2199 plasma samples, seven were reactive under total antibodies' screening. Further testing revealed that none of them had detectable viral nucleic acid or IgM antibody, but two samples contained IgA and IgG. The IgG antibody titers of both positive samples were 1:16 and 1:4, respectively. Our results indicated a low prevalence of past SARS‐CoV‐2 infection in our blood donors, as none of the tests were positive for viral nucleic acid and only 2 out of 2199 (0.09%) of samples were positive for IgG and IgA. There would be a limited necessity for the implementation of such testing in blood screening in a COVID‐19 low‐risk area.

Neurological disease in adults with Zika and chikungunya virus infection in Northeast Brazil: a prospective observational study

BackgroundSince 2015, the arthropod-borne viruses (arboviruses) Zika and chikungunya have spread across the Americas causing outbreaks, accompanied by increases in immune-mediated and infectious neurological disease. The spectrum of neurological manifestations linked to these viruses, and the importance of dual infection, are not known fully. We aimed to investigate whether neurological presentations differed according to the infecting arbovirus, and whether patients with dual infection had a different disease spectrum or severity.MethodsWe report a prospective observational study done during epidemics of Zika and chikungunya viruses in Recife, Pernambuco, a dengue-endemic area of Brazil. We recruited adults aged 18 years or older referred to Hospital da Restauração, a secondary-level and tertiary-level hospital, with suspected acute neurological disease and a history of suspected arboviral infection. We looked for evidence of Zika, chikungunya, or dengue infection by viral RNA or specific IgM antibodies in serum or CSF. We grouped patients according to their arbovirus laboratory diagnosis and then compared demographic and clinical characteristics.FindingsBetween Dec 4, 2014, and Dec 4, 2016, 1410 patients were admitted to the hospital neurology service; 201 (14%) had symptoms consistent with arbovirus infection and sufficient samples for diagnostic testing and were included in the study. The median age was 48 years (IQR 34–60), and 106 (53%) were women. 148 (74%) of 201 patients had laboratory evidence of arboviral infection. 98 (49%) of them had a single viral infection (41 [20%] had Zika, 55 [27%] had chikungunya, and two [1%] had dengue infection), whereas 50 (25%) had evidence of dual infection, mostly with Zika and chikungunya viruses (46 [23%] patients). Patients positive for arbovirus infection presented with a broad range of CNS and peripheral nervous system (PNS) disease. Chikungunya infection was more often associated with CNS disease (26 [47%] of 55 patients with chikungunya infection vs six [15%] of 41 with Zika infection; p=0·0008), especially myelitis (12 [22%] patients). Zika infection was more often associated with PNS disease (26 [63%] of 41 patients with Zika infection vs nine [16%] of 55 with chikungunya infection; p≤0·0001), particularly Guillain-Barré syndrome (25 [61%] patients). Patients with Guillain-Barré syndrome who had Zika and chikungunya dual infection had more aggressive disease, requiring intensive care support and longer hospital stays, than those with mono-infection (median 24 days [IQR 20–30] vs 17 days [10–20]; p=0·0028). Eight (17%) of 46 patients with Zika and chikungunya dual infection had a stroke or transient ischaemic attack, compared with five (6%) of 96 patients with Zika or chikungunya mono-infection (p=0·047).InterpretationThere is a wide and overlapping spectrum of neurological manifestations caused by Zika or chikungunya mono-infection and by dual infections. The possible increased risk of acute cerebrovascular disease in patients with dual infection merits further investigation.FundingFundação do Amparo a Ciência e Tecnologia de Pernambuco (FACEPE), EU's Horizon 2020 research and innovation programme, National Institute for Health Research.TranslationsFor the Portuguese and Spanish translations of the abstract see Supplementary Materials section.

Absorbance Detection in Multireflection Microfluidic Channels Using a Commercial Microplate Reader System.

Absorbance detection is often prohibited in microfluidic channels due to the limited optical path length available in these systems. However, this optical distance may be significantly increased by guiding the probing light beam along the channel length via multiple reflections by patterned metallic surfaces. In this work, we demonstrate enhanced absorbance detection in glass microfluidic channels using a commercial microplate reader based on this principle, yielding detection limits comparable to that measured on standard microwell plates. This improvement in detectability was realized through careful optimization of the mirror lengths and locations combined with the appropriate design of a microchip holder to suitably position the microchannels in the microplate reader. Additionally, it was determined that the angle by which our device was tilted relative to the horizontal plane played an important role in this optimization. For an optimum choice of parameters accessible with our design, the sensitivity of our absorbance measurements in a 30 μm-deep channel was improved by as much as 52-fold, raising this quantity to about 84% of the corresponding value realized for 75 μL samples placed within 7 mm i.d. standard cylindrical microwells. Quantitative ELISAs employing the absorbance detection method were demonstrated on the noted multireflection microchip device for assessing West Nile viral IgM antibody levels in human serum samples yielding analyte detection limits comparable to that measured on standard microwell plates.

Single center experience from Egypt about fulminant hepatic failure in children

Aim: To assess fulminant hepatic failure (FHF) in children and its interrelating factors. Methods and materials: A retrospective review study of 24 patients less than 17 years old who presented to the National Liver Institute with FHF over a period of two years was done. FHF was defined as the presence of acute liver failure with or without encephalopathy without pre-existing liver disease, within 8 weeks of the onset of clinical liver disease. Hepatitis A virus (HAV) IgM antibodies, Hepatitis B virus surface antigen (HBsAg), IgM-anti Hepatitis B core antigen (HBc), Hepatitis E virus (HEV) IgM and Hepatitis C virus (HCV) RNA in nested PCR were done in all patients. Special investigations like alpha fetoprotein, serum copper, blood culture, drug levels and other metabolic studies were carried out whenever indicated. Detailed clinical evaluations and routine hepatic laboratory profile were done. Results: Acute hepatitis-A virus was the commonest cause. Severe coma was significantly present among non-survivals and no ascites. Patients who survived had got significantly lower level of prothrombin time, they also had significantly lower rate of descent of prothrombin time. Conclusion: Hepatitis A virus was the commonest etiology of FHF. The peak level of total serum bilirubin, the rate of change of the prothrombin time/day and ammonia level were significant predictors of mortality.

Serological immunochromatographic approach in diagnosis with SARS-CoV-2 infected COVID-19 patients

An outbreak of new coronavirus SARS-CoV-2 was occurred in Wuhan, China and rapidly spread to other cities and nations. The standard diagnostic approach that widely adopted in the clinic is nucleic acid detection by real-time RT-PCR. However, the false-negative rate of the technique is unneglectable and serological methods are urgently warranted. Here, we presented the colloidal gold-based immunochromatographic (ICG) strip targeting viral IgM or IgG antibody and compared it with real-time RT-PCR. The sensitivity of ICG assay with IgM and IgG combinatorial detection in nucleic acid confirmed cases were 11.1%, 92.9% and 96.8% at the early stage (1–7 days after onset), intermediate stage (8–14 days after onset), and late stage (more than 15 days), respectively. The ICG detection capacity in nucleic acid-negative suspected cases was 43.6%. In addition, the concordance of whole blood samples and plasma showed Cohen's kappa value of 0.93, which represented the almost perfect agreement between two types of samples. In conclusion, serological ICG strip assay in detecting SARS-CoV-2 infection is both sensitive and consistent, which is considered as an excellent supplementary approach in clinical application.

Upsurge of chikungunya cases in Uttar Pradesh, India.

Background & objectives:Chikungunya (CHIK) re-emerged in India in 2006 after a gap of three decades. In Uttar Pradesh (UP), <100 confirmed cases per million were reported during this outbreak. Based on an upsurge of CHIK cases at UP, this retrospective study was conducted to investigate clinical and serological profile of CHIK cases in UP.Methods:A retrospective study was done on all clinically suspected CHIK cases that had been tested by ELISA for anti-CHIK virus IgM antibodies from September 2012 to December 2017. Based on clinical features, a subset of patients had earlier been tested serologically for dengue and Japanese encephalitis (JE).Results:Of the 3240 cases enrolled, 771 (23.8%) were seropositive. Patients had a range of clinical manifestations with seropositivity highest in those exhibiting arthralgia with fever (40%), followed by fever of unknown origin (FUO) (22%), encephalitis (13%) and fever with rash (12%). Cases (total, seropositive) increased over 20-fold in 2016 (1389, 412) and 2017 (1619, 341), compared to 2012-2015. Nearly a third of dengue serology-positive cases and a fifth of JE serology-positive cases were co-positive for CHIKV.Interpretation & conclusions:Archival data from 2006-2011 and data from this study (2012-2017) indicated that UP experienced first CHIK outbreak in the decade in 2016, as part of a large-scale upsurge across northern India. CHIK should be considered as a differential diagnosis in patients presenting with fever of unknown origin or fever with rash or acute encephalitis, in addition to classical arthralgia.