Serological Diagnostic Tests Research Articles

Detection of Dirofilaria immitis via integrated serological and molecular analyses in coyotes from Texas, United States.

Wild canids serve as reservoir for various vector-borne pathogens of veterinary and medical importance, including the canine heartworm, Dirofilaria immitis. In North and Central America, coyotes (Canis latrans) may be a relevant reservoir host for heartworm transmission. The objective of this study was to determine the occurrence of D. immitis in coyotes across Texas using integrated antigen detection test and molecular assays. Matching whole blood and serum samples were collected from 122 coyotes from different locations across the state of Texas, United States, encompassing nine counties. Collections occurred from February to April 2016, and December 2016. Samples were assessed serologically using a commercial microtiter plate ELISA (DiroCHEK®), and molecularly by conventional PCR targeting the cytochrome oxidase c subunit 1 (cox1) and NADH dehydrogenase subunit 5 (nad5) of the mitochondrial DNA, and via a TaqMan© probe-based real-time PCR protocol, also targeting a fragment of the cox1 gene. Overall, 12 (9.83%) samples tested positive when serological and molecular results were combined. Seven of 122 samples (5.73%) were antigen-positive, 8 (6.55%) were qPCR-positive, and 4 (3.27%) were positive using conventional PCR. Of 12 positive samples, 4 tested antigen-positive by DiroCHEK® but were negative in all molecular tests, another 4 tested positive by at least one of the molecular assays but tested negative by DiroCHEK®, and 3 samples tested positive by both antigen test and at least one of the molecular assays. Two samples (16.67%) tested positive on both the antigen test and both conventional PCR and qPCR. Our study confirmed the presence of D. immitis infection in coyotes from southern and northern Texas. The combination of serologic and molecular diagnostic tests was proven synergistic for the identification of D. immitis infections, including occult dirofilariosis, and revealed a more accurate picture of heartworm occurrence in the sampled coyotes.

Meta-analysis of the robustness of COVID-19 diagnostic kit performance during the early pandemic

BackgroundAccurate detection of SARS-CoV-2 is necessary to mitigate the COVID-19 pandemic. However, the test reagents and assay platforms are varied and may not be sufficiently robust to diagnose COVID-19.MethodsWe reviewed...

Exploratory assessment of serological tests to determine antibody titer against SARS-CoV-2: Appropriateness and limits.

BackgroundSerological tests can be used to detect antibodies in the serum of subject's after SARS‐CoV‐2 infection and vaccination. Currently, variability in antibody titers and the availability of a multiplicity of serological tests have made it necessary to highlight their appropriateness and limitations in various diagnostic settings.MethodsThis study is part of Covidiagnostix, a multicenter project aimed at the assessment of the health technology used in SARS‐CoV‐2 serological tests. Based on data gained from the analysis of over 5000 subjects, a selected number of serum samples, representative of different diagnostic settings, were analyzed first by qualitative immunoassays (IgA, M, and G MILLIPLEX® SARS‐CoV‐2 tests based on Luminex®) to define the immunoglobulins serum composition and subsequently by four serological diagnostic tests (Elecsys Anti‐SARS‐CoV‐2 and Elecsys Anti‐SARS‐CoV‐2 S by Roche, SARS‐CoV‐2 IgG by Siemens Healthcare, and CHORUS SARS‐CoV‐2 “NEUTRALIZING” Ab by DIESSE). The first WHO International Standard for SARS‐CoV‐2 was also analyzed using the same methods.ResultsThis study evaluated the antibody content and titer of the WHO Standard and serum of subjects with/without previous infection and before/after vaccination for SARS‐CoV‐2.ConclusionThe definition of antibodies in the WHO standard and the analysis of serum samples allowed for the identification of the appropriateness of serological tests in each diagnostic setting, increasing the effectiveness of the resulting laboratory data. Furthermore, we found that it would be optimal to produce new international standards against the S1 domain and RBD of the SARS‐CoV‐2 spike protein for a more effective serological monitoring of vaccination.

A simple new screening tool for diagnosing imported schistosomiasis

ObjectivesWe sought to test the sensitivity and feasibility of a Schistosoma infection screening process consisting of a scored patient consultation questionnaire and a serological diagnostic test. Study designProspective cross-sectional study. MethodsWe collected from Schistosoma-exposed individuals a 14-point check list of clinical and laboratory data related to Schistosoma infection, alongside a serological test to detect Schistosoma spp infection. A check list score was created and compared with the risk of infection and clinical recovery through an agreement analysis. ResultsTwo-hundred and fifty individuals were enrolled, of whom 220 (88%) were male and 30 (12%) female. The median age was 39 (range 18–78). One hundred-fifty (60%, 95% CI 54.9%–65.1%) had a check-list score ≥2. Serology test results were positive for 142 (56.8%, 95% CI 51.6%–62%). Chronic complications compatible with long-term Schistosoma infection were detected in 29 out of these 142 (20.4%, 95% CI 13.8%–27%).,. The median score value was 3, the area under the receiver operating characteristic (ROC) curve against serology results was 0.85 and the estimated intercept check-list questionnaire score value was 1.72 (95%, CI: 1.3–2.2). Participants with a positive serological test had a substantially higher check-list score (Cohen's kappa coefficient: 0.62, 95% CI: 0.54–0.70). Ninety four percent patients empirically treated showed a subsequent improvement in clinical and laboratory parameters. ConclusionsA two-component process consisting of a scored patient consultation questionnaire followed by serological assay can be a suitable strategy for screening populations at high risk of schistosomiasis infection.

An Overview of Lassa fever, an Rising Old World Haemorrhagic Viral Disease

Lassa fever is an acute immunosuppressive illness of increasing public health concern causing severe morbidity and significant mortality especially in epidemic cases. Lassa fever is an acute viral zoonotic illness caused by Lassa virus, an arenavirus known to be responsible for a severe haemorrhagic fever characterised by fever, muscle aches, sore throat, nausea, vomiting, chest and abdominal pain. The virus exhibits persistent, asymptomatic infection with profuse urinary virus excretion in the ubiquitous rodent vector, Mastomys natalensis. Lassa fever is endemic in West Africa and has been reported from Sierra Leone, Guinea, Liberia, and Nigeria. The virus replicates through a strategy known as the Ambisense, where two RNA strands code for genes in both the sense and antisense direction that is rapid and demonstrate temporal control in replication. Different diagnostic tests for the virus are available, which range from viral culture to serological and molecular diagnostic tests. There is an urgent need to develop drugs and vaccines against the virus because the World Health Organization (WHO) has identified Lassa virus as one of the viruses that is likely to cause a future epidemic, although a research is ongoing to evaluate Lassa virus vaccine immunogenicity in the CBA/J-ML29 mouse model. This review gives an overview on the structure, replication cycle, pathogenesis and diagnosis of the virus. Keywords: Lassa fever, Lassa virus, Arenavirus, Replication, Pathogenesis, Diagnosis

Chagas Immunochromatographic Rapid Test in the Serological Diagnosis of Trypanosoma cruzi Infection in Wild and Domestic Canids.

Canis lupus familiaris (domestic dog) represents a reliable sentinel for the occurrence of a well-established transmission cycle of Trypanosoma cruzi among wild mammals in the surroundings and, consequently, where the risk of human infection exists. Serological diagnosis is the chosen method to identify T. cruzi infection in dogs that, in Brazil, rarely present positive parasitological tests. The use of recombinant chimeric parasitic antigens results in a sensitive and specific serological diagnostic test in contrast to the use of crude T. cruzi antigens. Our objective was to evaluate the Chagas/Bio-Manguinhos Lateral Flow Immunochromatographic Rapid Test (Chagas-LFRT) for the diagnosis of T. cruzi infection in domestic dogs and the potential of application of this diagnostic platform to wild canid species. Two recombinant proteins (IBMP-8.1 and IBMP-8.4) that displayed the best performance in the enzyme immunoassay (ELISA) in previous studies were tested in a platform with two diagnostic bands. A panel of 281 dog serum samples was evaluated: 133 positive for T. cruzi by serological diagnosis, including 20 samples with positive blood cultures belonging to different discrete typing units (DTUs); 129 negative samples; and 19 samples from dogs infected by other trypanosomatids: Leishmania infantum, Trypanosoma rangeli, Trypanosoma caninum and Crithidia mellificae, in addition to samples infected by Anaplasma platys, Dirofilaria immitis and Erlichia sp. that were employed to evaluate eventual cross-reactions. We also evaluated the Chagas-LFRT to detect T. cruzi infection in 9 serum samples from six wild canid species. We observed that the intensity pattern of the bands was directly proportional to the serological titer observed in IFAT. The sensitivity was 94%, the specificity was 91% according to the ROC curve, and the defined cutoff was an optical density of 4.8. The agreement obtained was considered substantial by the kappa analysis (84%). From T. cruzi positive hemoculture samples, 88.9% were positive by Chagas-LFRT. The test was efficient in recognizing infections by five of the six T. cruzi DTUs. Cross-reactions were not observed in infections by L. infantum, T. rangeli, T. caninum and D. immitis; however, they were observed in sera of dogs infected by Crithidia mellificae, Anaplasma sp. and Erlichia sp. A strong reaction was observed when serum samples from wild canids were submitted to the Protein A affinity test, confirming its applicability for these species. This test will allow rapid preventive actions in areas with high risk to the emergence of Chagas disease in a safer, reliable, low-cost and immediate manner, without the need for more complex laboratory tests.

Advances in the Rapid Diagnostic of Viral Respiratory Tract Infections.

Viral infections are a significant public health problem, primarily due to their high transmission rate, various pathological manifestations, ranging from mild to severe symptoms and subclinical onset. Laboratory diagnostic tests for infectious diseases, with a short enough turnaround time, are promising tools to improve patient care, antiviral therapeutic decisions, and infection prevention. Numerous microbiological molecular and serological diagnostic testing devices have been developed and authorised as benchtop systems, and only a few as rapid miniaturised, fully automated, portable digital platforms. Their successful implementation in virology relies on their performance and impact on patient management. This review describes the current progress and perspectives in developing micro- and nanotechnology-based solutions for rapidly detecting human viral respiratory infectious diseases. It provides a nonexhaustive overview of currently commercially available and under-study diagnostic testing methods and discusses the sampling and viral genetic trends as preanalytical components influencing the results. We describe the clinical performance of tests, focusing on alternatives such as microfluidics-, biosensors-, Internet-of-Things (IoT)-based devices for rapid and accurate viral loads and immunological responses detection. The conclusions highlight the potential impact of the newly developed devices on laboratory diagnostic and clinical outcomes.

Congenital Malaria in Newborns Delivered to Malaria-infected Mothers in the Hilly Region of Northern India: Is it Deadly?

Malaria is endemic in many states of India. Though there are reports of maternal and congenital malaria from endemic areas, however, there remains a paucity of data from hilly terrains. The present study evaluated the prevalence, clinical and microbiological spectrum of maternal and congenital malaria at a tertiary health care facility in Northern India over a period of 18 months. In this observational study, mothers along with their newborns were evaluated for malaria by maternal, placental, and cord blood smear examination and rapid point-of-care diagnostic serological tests. Positive cases were confirmed by polymerase chain reaction. Mother-newborn duos were followed up till discharge from the hospital. A total of 843 mothers delivered during the study period and were screened along with their newborns and placentae. A total of Ten (1.18%) mothers had evidence of malarial parasitemia (Plasmodium vivax, n=7 and Pl. falciparum, n=3), however, none of the placental and cord blood samples were positive for malaria. Overall, 127 (15.1%) neonates required admission in neonatal intensive care unit for various morbidities. Incidence of small for gestational age (SGA) was high (n=210; 24.9%). Multivariate logistic regression analysis demonstrated maternal malaria to be an independent contributor for SGA [Odds Ratio (95% Confidence Interval), 10.7 (2.06 - 49.72)]. However, only 2% variance of SGA could be explained by maternal malaria alone. We report an encouragingly lower incidence of maternal malaria in mothers attending for delivery and a 'Zero' incidence for placental and congenital malaria during the study period as compared to national data (upto 7.4% in non-immune mothers), although maternal malaria could be a causative factor for SGA.

Detection of Anti-SARS-CoV-2 Nucleocapsid and Spike Antibodies in Patients with Coronavirus Disease 2019 in Japan.

OBJECTIVESCoronavirus Disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Serological testing for anti-SARS-CoV-2 nucleocapsid (N) antibodies (Abs) and anti-SARS-CoV-2 spike (S) Abs is performed to detect prior COVID-19 infection. It is still controversial which antibodies are the most sensitive and specific, and which can be detected earliest after infection. Here, we evaluated the results of serological tests of anti-SARS-CoV-2 N and S Abs in Japan.METHODSSymptomatic COVID-19 patients (n = 84) and control patients with rheumatoid arthritis (n = 93) were recruited at Tokyo National Hospital. Anti-SARS-CoV-2 N and S Abs were measured by commercial electrochemiluminescence immunoassays.RESULTSThe fraction of patients positive for anti-SARS-CoV-2 N and S Abs was highest >14 days after symptom onset. The frequency of anti-SARS-CoV-2 S Ab positivity at this time (80.4%) tended to be slightly but not significantly lower than anti-SARS-CoV-2 N Ab positivity (84.8%). Optimized cut-off levels for anti-SARS-CoV-2 N and S Ab positivity were lower than the manufacturer's recommended cut-off levels. Using multiple linear regression analyzes with anti-SARS-CoV-2 N and S Abs, we created an Ab-index with high sensitivity.CONCLUSIONTo increase the sensitivity of serological diagnostic tests for COVID-19, it is suggested that both anti-SARS-CoV-2 N and S Abs should be measured and cut-off levels decreased.

Recent advances in methods for the diagnosis of Corona Virus Disease 2019.

Since the beginning of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic, it has been clear that effective methods for the diagnosis of Corona Virus Disease 2019 (COVID-19) are the key tools to control its epidemic. The current gold standard for diagnosing COVID-19 is the real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), which is a sensitive and specific method to detect SARS-CoV-2. Other RNA-based methods include RNA sequencing (RNA-seq), droplet digital reverse transcription-polymerase chain reaction (ddRT-PCR), reverse transcription loop-mediated isothermal amplification (RT-LAMP), and clustered regularly interspaced short palindromic repeats (CRISPR). The serological testing of antibodies (IgM and IgG), nanoparticle-based lateral-flow assay, and enzyme-linked immunosorbent assay (ELISA) can be used to enhance the detection sensitivity and accuracy. Because antibodies are usually detected a week after the onset of symptoms, these tests are used to assess the overall infection rate in the community. Sine the fact that healthcare varies from country to country across the world, different types of diagnosing COVID-19 imaging technologies including chest computed tomography (CT), chest radiography, and lung ultrasound are used in different degrees. Besides, the pooling test is an important public health tool to reduce cost and increase testing capacity in low-risk area, while artificial intelligence (AI) may aid to increase the diagnostic efficiency of imaging-based methods. Finally, depending on the type of samples and stages of the disease, a combination of information on patient demographics and histories, clinical symptoms, results of molecular and serological diagnostic tests, and imaging information is highly recommended to achieve adequate diagnosis of patients with COVID-19.

The Relationship Between Severity of Gastric Inflammation Due to Helicobacter pylori and Colorectal Malignancies

Objective: Several factors play role in colorectal carcinogenesis. Among these factors, helicobacter pylori infection is supposed to be one of the causative factors. Previous studies were focused on investigation of the relationship between helicobacter pylori existence and colon carcinomas by particular serological diagnostic tests. The aim of our study was to determine the effect of the helicobacter pylori infection and the severity of inflammation related to this infection on the colon carcinomas and non carcinoma colon mass lesions(tubular adenoma, tubulovillous adenoma, hyperplastic polyp). Method: A retrospective study was conducted at Kecioren Teaching - Research Hospital between 2010 to 2018. The files of 657 patients who underwent colonoscopy and were diagnosed as colon benign or malign mass lesions were examined retrospectively from the hospital database. Two hundred five patients who had undergone both upper gastrointestinal endoscopy and colonoscopies were included in the study. The presence and severity of inflammation due to helicobacter pylori were evaluated by histopathological examination of biopsies taken during upper gastrointestinal endoscopy. The severity of H. pylori inflammation was graded according to the Sydney classification Results: In the comparison of colon carcinoma with other colon mass lesions group, there was no statistical significance in terms of gender (P= 0.094) and H. pylori serology (P= 0.998). However, the degree of inflammation was significantly high in patients with colon carcinoma than other colon mass lesions (P< 0.001). Conclusions: The fact that the severity of helicobacter pylori inflammation is higher in patients with colon carcinoma than patients with non-carcinoma colonic mass lesions suggests that inflammation due to helicobacter pylori may be more important than the presence of helicobacter pylori in the carcinogenesis of colon cancer.

Sensitivity and specificity of a rapid diagnostic test for chronic Chagas disease at a referral center in Brazil - can it be included as a standard serological diagnostic test in the clinical practice of a referral center?

Introduction: Chagas disease (CD) is a neglected tropical disease. In the chronic phase of CD, the diagnosis is essentially serologic. Conventional reactions are currently in use. More recently, the use of rapid diagnostic testing (RDT) is indicated when conventional techniques are not available. Objective: To evaluate the sensitivity and specificity of RDTs for chronic CD diagnosis. Methodology: Individuals under suspicion of CD were evaluated using ELISA, Chemiluminescence (ChLIA) and RDT tests. Results: The RDT showed 95.1% sensitivity and 96.7% specificity, respectively. Conclusion: The findings of the present study showed that RDT used in the diagnosis of CD at a referral center in Brazil were not able to detect all CD cases when compared to Elisa and ChLIA.

Diagnostic Testing for Coronavirus Disease 2019: A Narrative Review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spread worldwide and infected multiple age groups. The best way to reduce the risk of spreading new coronavirus (coronavirus disease 19, COVID-19) is the rapid and accurate identification of carriers and infected patients in society. Although several diagnostic tests are available, reverse transcription-polymerase chain reaction (RT-PCR) testing is commonly used for this purpose. In this review, various methods were introduced for the identification of COVID-19 patients using clinical manifestations, gastrointestinal symptoms, and molecular and serological diagnostic techniques. Finally, the advantages and disadvantages of diagnostic tests, including molecular and serological tests, were evaluated to identify the novel coronavirus.

Seroprevalence and epidemiological characteristics of HDV infection among HBV patients in the Nile Delta, Egypt.

The epidemiology of HDV infection worldwide is obscure. Mapping the epidemiology of the infection is highly required, so, we aimed to estimate the prevalence of hepatitis D virus infection among chronic hepatitis B patients and the epidemiological characteristics in the Nile delta in Egypt. This was a prospective observational cross-sectional study including consecutive chronic hepatitis B patients in the out-patient clinics at the Egyptian Liver Research Institute and Hospital (ELRIAH) and its satellites in the Nile Delta from January 2016 until August 2018. They were recruited from patients enrolled in Educate, Test and Treat program, which was implemented in 73 Egyptian Villages. Subjects were tested by using HBsAg serological rapid diagnostic tests (RDTs), and then HBV DNA by PCR was done in HBsAg-positive cases. HDV IgG antibody testing and confirmatory HDV RNA PCR were done. Complete liver functions, abdominal ultrasonography and FibroScan were also performed. The prevalence of HDV was 3.4% using anti-delta antibody (22/631), and only 8 were positive for HDV RNA (8/22, 36.4%). Overall HDV prevalence using PCR was 8/631(1.27%). HDV-positive cases were mainly males (68.2%). Eight cases were cirrhotic (36.4%), 3 (13.6%) had HCC and 7 (31.8%) were HBeAg positive. HDV prevalence is low among chronic hepatitis B patients in the Nile delta, Egypt. Screening for HDV IgG is recommended in CHB patients who had cirrhosis, HCC or HBeAg positive.

A mini-review on diagnosis of contagious caprine pleuropneumonia

Diagnosis of contagious caprine pleuropneumonia is imperative for timely detection and devising interventions that prevent disease spread and loss to farmers. Diagnosis of contagious caprine pleuropneumonia involves clinical signs, gross morphological lesions on postmortem, histopathology, culture and isolation, hematological, biochemical, serological and molecular diagnostic tests. Culture and isolation confirms the disease however it has been costly, cumbersome and difficult owing to the requirements of specific media, slow and difficult growth of causative agent Mycoplasma capricolum subsp. capripneumoniae. With the recent developments, diagnosis has comparatively eased by novel readymade media, advanced serological latex agglutination test (LAT), competitive enzyme linked immunosorbent assay (cELISA) or gene-based amplification of DNA, viz. polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), hybridization and sequencing than the cumbersome and lengthy conventional tests; however they have financial implications and require sophisticated laboratory infrastructure and technical manpower. The latex agglutination test (LAT) is rapid, simple, and better test for field and real-time diagnosis applicable to whole blood or serum and is more sensitive than the compliment fixation test (CFT) and easier than the cELISA. PCR and monoclonal antibody based ELISA being specific aid to confirmation of CCPP. Future thrust is on developing rapid, sensitive, and specific tests that are cheap and convenient for field application.

Emergence and transboundary spread of lumpy skin disease in South Asia

Lumpy skin disease (LSD) is an OIE notifiable, transboundary pox viral disease of livestock. LSD is an emerging disease severely affecting livestock economics. The zoonotic potential of the LSD virus has not been extensively studied and reported. In approximately 90 years, the virus dispersed to numerous world locations after its first emergence in Zambia. LSD virus emergence in South Asia prevailed among livestock (cattle and water buffalo) owners due to economic/financial losses. The estimate of the economic impact of LSD in the southern, eastern and southeastern countries suggested direct losses of livestock and production of approximately USD 1.45 billion. In 2019, nearly the same time, the disease was reported for the first time from many bordering countries, such as India, Nepal, China, and Bangladesh. In 2020, the LSD was also recorded in Bhutan, Sri Lanka, Bangladesh, Vietnam and Southeast China. In 2021, it further spread to new countries such as Thailand, Malaysia and Cambodia. Cattle affected with LSD show a characteristic nodular lesion or skin lump over the whole body and may occasionally be associated with systemic signs. Hematophagous arthropod-borne mechanical transmission is considered primary and the most common route; however, other transmission routes related to illegal animal trade have played a role in the emergence of LSD in countries otherwise/earlier free from it. Among serological diagnostic tests, OIE recommends virus neutralization as the standard gold test. Diagnosis in LSD-free countries requires virus isolation and further sequencing of the isolate. Control of LSD is possible by most of the measures applied for rapidly transmitting viral infection, including vaccination. LSD virus-specific vaccines are considered suitable to confer protection to cattle and buffalo over heterologous vaccines. In countries such as India, the lack of a specific policy for LSD at the time of the first onset of this disease, the high density of susceptible unvaccinated populations, unawareness among farmers, veterinarians and prevailing laws of no slaughter of cattle created a favourable situation of its spread to many states. Amid COVID-19, the whole world is in turmoil; the emergence of diseases such as LSD is further lowering the economy, and hence must be reviewed to save and sustain the backbone of the developing country's economy in Southeast Asia.

Application of metagenomic next-generation sequencing in the diagnosis of severe pneumonia caused by Chlamydia psittaci

PurposePsittacosis is a zoonotic infectious disease caused by the transmission of the bacterium Chlamydia psittaci (C. psittaci) from birds to humans. Infections in humans mainly present as community-acquired pneumonia (CAP). However, most cases are treated without diagnostic testing, and the importance of Chlamydia psittaci infection as a cause of CAP is therefore unclear. Diagnostic tools, including culture, serologic test, and PCR-based methods, are available but prone to false negative results. Metagenomic next-generation sequencing (mNGS) has been increasingly used in the diagnosis of infectious diseases, particularly when conventional diagnostic approaches have limitation.Detection of nucleic acid sequence of C. psittaci in respiratory tract samples by metagenomic next-generation sequencing (mNGS) is effective for early diagnosis of severe C. psittaci pneumonia. Timely treatment based on tetracycline can reduce unnecessary use of antibiotics and improve prognosis of patients with severe C. psittaci pneumonia.MethodsClinical data of thirteen patients with severe C. psittaci pneumonia diagnosed by mNGS were collected. Clinical manifestations, treatment and prognosis of patients were summarized.ResultsThe typical symptoms of pneumonia caused by C. psittaci include fever, headache, myalgia, cough, and dyspnea. In the current study, all patients met the criteria for severe C. psittaci pneumonia and received mechanical ventilation, including noninvasive mechanical ventilation (five/thirteen) and invasive mechanical ventilation (eight/thirteen). The findings showed that patients with C. psittaci pneumonia presented with normal or slightly increased leucocytes and procalcitonin, and high C-reactive protein levels. Computed tomography manifestations included consolidation of lung parenchyma, with air bronchogram and pleural effusion in some patients. mNGS analysis results were obtained within 48–72 h. Eleven patients fully recovered after targeted treatment, however, two patients died from secondary multidrug-resistant Pseudomonas aeruginosa infection.ConclusionsThe findings of the current study show that mNGS is effective in diagnosis of C. psittaci pneumonia, and has significant diagnosis value in patients with severe infection. Patients responds well to the timely use of appropriate antibiotics.

Extensively Drug Resistant Salmonella Enterica Serovar Typhi Misdiagnosis In Pakistan: A Matter Of Serious Concern

There have been several outbreaks of antimicrobial resistant (AMR) strains of Salmonella enterica serovar Typhi that cause extensively drug resistant (XDR) typhoid fever in Pakistan. It has been observed that many clinicians use serological diagnostic tests such as Widal agglutination, and TyphiDOT that detects IgM and IgG antibodies against the outer membrane protein of S. Typhi. However, it has been confirmed by many scientists that these test may lead to misdiagnosis against XDR S. Typhi. Due to lack of implementation strategies health authorities are unable to hamper Widal or TyphiDOT tests which are still practiced in many rural and urban areas.

Evaluation of the performance of 25 SARS-CoV-2 serological rapid diagnostic tests using a reference panel of plasma specimens at the Uganda Virus Research Institute

IntroductionSerological testing is needed to better understand the epidemiology of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Rapid diagnostic tests (RDTs) have been developed to detect specific antibodies, IgM and IgG, to the virus. The performance of 25 of these RDTs was evaluated. MethodsA serological reference panel of 50 positive and 100 negative plasma specimens was developed from SARS-CoV-2 PCR and antibody positive patients and pre-pandemic SARS-CoV-2-negative specimens collected in 2016. Test performance of the 25 RDTs was evaluated against this panel. ResultsA total of 10 RDTs had a sensitivity ≥98%, while 13 RDTs had a specificity ≥98% to anti-SARS-CoV-2 IgG antibodies. Four RDTs (Boson, MultiG, Standard Q, and VivaDiag) had both sensitivity and specificity ≥98% to anti-SARS-CoV-2 IgG antibodies. Only three RDTs had a sensitivity ≥98%, while 10 RDTs had a specificity ≥98% to anti-SARS-CoV-2 IgM antibodies. Three RDTs (Autobio, MultiG, and Standard Q) had sensitivity and specificity ≥98% to combined IgG/IgM. The RDTs that performed well also had perfect or almost perfect inter-reader agreement. ConclusionsThis evaluation identified three RDTs with a sensitivity and specificity to IgM/IgG antibodies of ≥98% with the potential for widespread antibody testing in Uganda.

Single-reaction multi-antigen serological test for comprehensive evaluation of SARS-CoV-2 patients by flow cytometry.

Here, we describe a new, simple, highly multiplexed serological test that generates a more complete picture of seroconversion than single antigen‐based assays. Flow cytometry is used to detect multiple Ig isotypes binding to four SARS‐CoV‐2 antigens: the Spike glycoprotein, its RBD fragment (the main target for neutralizing antibodies), the nucleocapsid protein, and the main cysteine‐like protease in a single reaction. Until now, most diagnostic serological tests measured antibodies to only one antigen and in some laboratory‐confirmed patients no SARS‐CoV‐2‐specific antibodies could be detected. Our data reveal that while most patients respond against all the viral antigens tested, others show a marked bias to make antibodies against either proteins exposed on the viral particle or those released after cellular infection. With this assay, it was possible to discriminate between patients and healthy controls with 100% confidence. Analysing the response of multiple Ig isotypes to the four antigens in combination may also help to establish a correlation with the severity degree of disease. A more detailed description of the immune responses of different patients to SARS‐CoV‐2 virus might provide insight into the wide array of clinical presentations of COVID‐19.