Diagnosing COVID-19; towards a feasible COVID-19 rule-out protocol.

INTRODUCTION: We present the results of the COVID-19 rule-out protocol at Ghent University Hospital, a step-wise testing approach which included repeat NFS SARS-CoV-2 rRT-PCR, respiratory multiplex RT-PCR, low-dose chest CT and bronchoscopy with BAL to confirm or rule-out SARS-CoV-2 infection in patients admitted with symptoms suggestive of COVID-19. RESULTS: Between 19 March 2020 and 30 April 2020, 455 non-critically ill patients with symptoms suspect for COVID-19 were admitted. The initial NFS for SARS-CoV-2 rRT-PCR yielded 66.9%, the second NFS 25.4% and bronchoscopy with BAL 5.9% of total COVID-19 diagnoses. In the BAL fluid, other respiratory pathogens were detected in 65% (13/20) of the COVID-19 negative patients and only in 1/7 COVID-19 positive patients. Retrospective antibody testing at the time around BAL sampling showed a positive IgA or IgG in 42.9 % of the COVID-19 positive and 10.5% of the COVID-19 negative group. Follow-up serology showed 100% COVID-19 positivity in the COVID-19 positive group and 100% IgG negativity in the COVID-19 negative group. CONCLUSION: In our experience, bronchoscopy with BAL can have an added value to rule-in or rule-out COVID-19 in patients with clinical and radiographical high-likelihood of COVID-19 and repeated negative NFS testing. Furthermore, culture and respiratory multiplex PCR on BAL fluid can aid to identify alternative microbial etiological agents in this group. Retrospective analysis of antibody development in this selected group of patients suggests that the implementation of serological assays in the routine testing protocol will decrease the need for invasive procedures like bronchoscopy.

Identifying a consensus sample type to test for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis and human papillomavirus.

OBJECTIVES: Sexually transmitted infections (STIs) are a global cause of acute illness. Early detection plays a crucial role in interrupting transmission and preventing complications. However, the accessibility of STI testing is curbed by the lack of an overall preferred sample type. By means of a prospective study in female sex workers (FSW), we compared the sensitivity of samples from different anatomical sites in detecting Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma genitalium and human papillomavirus. Besides, we documented the prevalence of each STI in this high-risk population. METHODS: We selected 303 FSW and tested them for each STI by nucleic acid amplification testing on two vaginal and cervical swabs from different manufacturers, cervical smear and first-void urine. The sensitivity of each sample type was compared for each infectious agent in order to identify a consensus sample type. RESULTS: Vaginal swabs were superior to all other sample types, with an overall sensitivity of 86%. The sensitivity was the lowest for first-void urine, detecting only 63% of positive cases. The prevalence was 3.3% (10/299) for Neisseria gonorrhoeae; 9.0% (27/299) for Chlamydia trachomatis; 7.4% (22/298) for Trichomonas vaginalis; 10.8% (32/296) for Mycoplasma genitalium and 55.6% (158/284) for human papillomavirus. CONCLUSIONS: When testing for STIs, vaginal swabs are the sample of choice and first-void urine should be avoided. Designating (self-sampled) vaginal swabs as a consensus sample type enables harmonization of STI testing and extension of testing to large numbers of unscreened females.

Evaluation of different confirmatory algorithms using seven treponemal tests on Architect Syphilis TP-positive/RPR-negative sera.

The Architect Syphilis TP is considered to be a suitable screening test due to its high sensitivity and full automation. According to the International Union against Sexually Transmitted Infections (IUSTI) 2014 guidelines, however, positive screening tests need confirmation with Treponema pallidum particle agglutination (TP.PA). Among Architect-positive results, samples with a negative non-treponemal test present the major diagnostic challenge. In this multicenter study, we investigated if other, preferable less labor-intensive treponemal tests could replace TP.PA. A total of 178 rapid plasma reagin (RPR)-negative sera with an Architect value between 1 and 15 S/CO were prospectively selected in three centers. These sera were analyzed with TP.PA and six alternative treponemal tests: three immunoblots and three tests on random-access analyzers. The diagnostic performance of the treponemal tests differed substantially, with the overall agreement between the six alternative tests ranging from 44.6 to 82.0%. Based on TP.PA as the gold standard, the INNO-LIA IgG blot, the BioPlex 2200 IgG, and the Syphilis TPA showed a high sensitivity, while the EUROLINE-WB IgG blot, recomLine Treponema IgG blot, and the Chorus Syphilis screen showed a high specificity. However, an Architect cut-off of 5.6 S/CO can serve as an alternative for these confirmatory treponemal tests in case of an RPR-negative result. Treponemal tests show poor agreement in this challenging group of Architect-positive/RPR-negative sera. The most optimal algorithm is obtained by assigning sera with an Architect value >5.6 S/CO as true-positives and sera with a value between 1 and 5.6 S/CO as undetermined, requiring further testing with TP.PA.

Evaluation of Copan FLOQSwab for the molecular detection of Chlamydia trachomatis by Abbott RealTime CT PCR.

OBJECTIVES: We evaluated Copan FLOQSwabs next to Abbott swabs for the detection of Chlamydia trachomatis (CT) by Abbott RealTime PCR. METHODS: We collected 1062 paired swabs from female sex workers. The study was divided in two arms, according to the order of swab collection. RESULTS: If the Abbott swab was collected first, 501 couples were concordant and two discordant (Abbott negative and Copan positive). If the Copan swab was collected first, 537 couples were concordant and 10 discordant (eight Abbott negative and Copan positive and two Abbott positive and Copan negative). All discordant samples contained low levels of C. trachomatis. Technical issues lead to retesting of 64 Copan and 21 Abbott swabs. CONCLUSION: Our results show that Copan FLOQSwabs can be used interchangeably with Abbott swabs. While appearing to have an advantage in detecting more positive samples, the use of Copan swabs led to a higher retesting rate due to technical errors.

Let's not forget herpes simplex virus in case of fulminant hepatic failure.

Fulminant herpes simplex virus (HSV) hepatitis is a rare condition, which is usually identified only after orthotopic liver transplantation (OLT) or at autopsy. The most commonly affected individuals are immunosuppressed patients, although HSV hepatitis can occur in immunocompetent patients as well. A high degree of suspicion combined with early diagnostic modalities may improve survival. We present a case report of fulminant herpetic hepatitis, requiring OLT. In addition, a review of the literature was performed.

Epstein-Barr virus serology and PCR: conflicting results in an immunocompetent host. A case report and review of literature.

We present the case of a 27-year-old immunocompetent man who progressively developed a generalized lymphadenopathy and B symptoms. Results of Epstein-Barr virus (EBV) serology were suggestive for a past infection, but the EBV viral load in whole blood was high. Also, core needle biopsy of the largest lymph node showed an image which could fit an EBV-driven reactive lymphoproliferation. Despite the absence of an immune disorder, all medical evidence points to an EBV-driven lymphoproliferative proces. In immunocompetent patients, it seems extremely uncommon to detect a high EBV viral load in the absence of serological evidence of an acute EBV infection or reactivation. We reviewed literature on this topic and on the selection of the appropriate sample type for EBV PCR, as this is known to be a critical point. Serological testing for the diagnosis of EBV infection is the gold standard in immunocompetent patients. Measuring EBV viral load is only recommended when dealing with immunocompromised patients. Although extremely rare, this case report shows that there is a place for EBV PCR in certain situations in immunocompetent patients. Besides, there is still no consensus regarding the specimen of choice for the determination of the EBV viral load. The preferred specimen type seems to depend on the patient's underlying condition.

Low yield by molecular detection of Chlamydophila pneumoniae in respiratory samples in Belgium questioning its etiological role in respiratory tract infections.

The actual burden of respiratory infections due to Chlamydophila pneumoniae is difficult to assess due to the major differences in positivity rates between PCR- and serology-based methods. The aim of the current study was to objectively analyse the yield of PCRs for the detection of C. pneumoniae in respiratory samples and to evaluate the additional value of performing laboratory diagnosis for C. pneumoniae in a setting of respiratory infection. The data based on routine analysis of respiratory samples with request for C. pneumoniae detection were collected from 4 large Belgian hospitals during 2 consecutive years. In total 3560 respiratory samples have been analysed and overall only 7 samples (0.2%) were found positive. Based on these observations, the critical evaluation of the actual role of C. pneumoniae in the etiology of lower respiratory infections and consequently of the extensive use of diagnostic tools for the detection of C. pneumoniae is needed.

Etiological diagnosis in the hearing impaired newborn: proposal of a flow chart.

OBJECTIVE: Most industrialized countries have introduced some form of universal newborn hearing screening program. Both identification and rehabilitation of hearing loss in newborns have evolved to an acceptable standard and the need for a standardized etiological protocol is emerging. METHODS: Extensive literature search to determine which investigations can help identifying the cause of congenital hearing loss and how to limit extensive testing in these children by taking into account the most prevalent causes. FINDINGS: A stepwise approach to detect the cause of hearing loss in children with congenital sensorineural hearing loss was developed. CONCLUSION: In general it is advised to first rule out Cx26/Cx30 and infectious causes (cytomegalovirus and, if indicated, toxoplasmosis and rubella), and to preserve more extensive investigations for those children in whom these causes do not explain the hearing loss.

Synthesis, antiretroviral and antioxidant evaluation of a series of new benzo[b]furan derivatives.

The antiretroviral and anti-oxidant profile of a series of new C-2 and C-7 substituted benzo[b]furans was explored by employing well established antiviral and antioxidant protocols. The most potent antioxidant compound tested was analog 7, which bears an OH at C-7 and a benzoyl group at C-2. In the influenza A type H3N2 virus screens analog 8a was almost five-fold more active than its counterparts and equipotent to rimantadine and amantadine. In the influenza B screening all of the new compounds tested were at least ten-fold more active than the control drug amantadine. The anti-HIV screening, using acutely infected MT-4 cells, showed that compound 8f (n = 4), was fifteen-fold more active than its monomer congeners, 8a and 8c, d and almost five-fold more potent than monomer 8b and dimer 8f (n = 3).

Synthesis, antiviral and cytostatic activities of carbocyclic nucleosides incorporating a modified cyclopentane ring. Part 2: Adenosine and uridine analogues.

Six new carbocyclic nucleosides were prepared by mounting a purine (compounds 5-7), 8-azapurine (compounds 9 and 10) or pyrimidine (compound 13) base on the amino group of (1R,cis)-3-(aminomethyl)-1,2,2-trimethylcyclopentylmethanol (2). The antiviral activity of compounds 5-7, 10 and 13, and their cytostatic activity, were evaluated. At subtoxic concentrations, the compounds showed no or marginal antiviral activity. Compound 5 showed moderate inhibition on tumor cell proliferation.

New neplanocin analogues. VIII. Synthesis and biological activity of 6'-C-ethyl, -ethenyl, and -ethynyl derivatives of neplanocin A.

This report describes the synthesis and antiviral effects of (6'R)-6'-C-ethynyl, -ethenyl, and -ethyl derivatives of neplanocin A (7a, 8a, and 9a, respectively) and the corresponding 6'S-diastereomers (7b, 8b, and 9b, respectively), as examples of 6'-C-substituted analogues of neplanocin A. Grignard reaction of the 6'-formyl derivative 4, which was readily prepared from neplanocin A, with ethynylmagnesium bromide gave a diastereomeric mixture of the corresponding 1,2-addition products 5a and 5b. After removal of the protecting groups, (6'R)- and (6'S)-6'-C-ethynylneplanocin A's (7a, 7b) were separated. The corresponding ethenyl derivatives 8a and 8b and ethyl derivatives 9a and 9b were prepared by catalytic hydrogenation of 7a and 7b, respectively. As compared to neplanocin A, the new neplanocin A derivatives were much weaker inhibitors of S-adenosyl-L-homocysteine hydrolase, the R-diastereomers being more inhibitory than the S-diastereomers. The decreasing order of activity was 7a > 8a > 7b > 9a > 8b > 9b. The cytotoxicity (for CEM cells) followed exactly the same order. Of these compounds, (6'R)-6'-C-ethynylneplanocin A (7a, RENPA) showed an antiviral activity spectrum that was comparable to, and an antiviral specificity that was higher than, that of neplanocin A. RENPA was particularly active against those viruses (i.e. vaccinia virus, vesicular stomatitis virus) that are known to be highly sensitive to AdoHcy hydrolase inhibitors.

Synthesis and antiviral activity evaluation of some new aminoadamantane derivatives. 2.

The synthesis of some new aminoadamantane derivatives is described. The new compounds were evaluated against a wide range of viruses [influenza A H1N1, influenza A H2N2, influenza A H3N2, influenza B, parainfluenza 3, herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), thymidine kinase-deficient (TK-) HSV-1, vaccinia, vesicular stomatitis, polio 1, Coxsackie B4, Sindbis, Semliki forest, Reo 1, varicella-zoster virus (VZV), TK- VZV, human cytomegalovirus (HCMV), and human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2)]. Some of them proved markedly active against the influenza A H2N2 (compounds 4a,b, 5a, 6a, and 7a), H3N2 (compounds 5a, 6a, and 7a), and H1N1 (compounds 4b,c and 6d). Since compounds 5a, 6a, and 7a, amantadine, and rimantadine showed the same comparative pattern of potency against influenza strains H2N2, H3N2, and B, it may postulated that they act according to a similar mechanism, with regard to their "amine" effect, on the M2 ion channel of influenza A (H1N1, H2N2, or H3N2). In general, no significant activity was noted with any of the new compounds against any of the other viruses tested, making their activity against influenza virus more specific and striking. Borderline activity was noted with some of the compounds (4b,c, 5a-c, and 8a) against HIV-1.