Challenges and experiences of the SARS-CoV-2 pandemic in molecular diagnostics / A SARS-CoV-2-járvány kihívásai és tapasztalatai a molekuláris diagnosztikában

Összefoglaló. Bár a SARS-CoV-2-pandémia próbára tette a diagnosztikus kapacitásokat, számos hasznos tapasztalattal is szolgált, melyek alacsonyabb mintaszám mellett nem lettek volna levonhatók. Míg korábban a PCR-vizsgálatok jellemzoen diagnosztikus, illetve kvantitatív követési célokat szolgáltak, a járvány során többségbe kerültek a szuro- és (kezdetben) a felszabadító vizsgálatok. Jól követheto volt, hogy a tesztek piacra juttatásának eroltetett üteme sokszor nem tette lehetové a teljesen kiforrott koncepciók létrehozását. Tekintettel arra, hogy a molekuláris diagnosztika során nem teljes vírusgenomokat, hanem célszakaszokat mutatunk ki, amelyek aránya a fertozés egyes szakaszaiban nem feltétlenül állandó, egyre valószínubb, hogy nem azonos célgének a legmegfelelobbek diagnosztikus, szuro- és felszabadító vizsgálatokhoz. A nagy mennyiségu, aspecifikusan végzett vizsgálat még kiváló fajlagosság mellett is a pozitív prediktív érték csökkenéséhez vezethet, amennyiben a fertozés tényleges prevalenciája a vizsgálati csoportban alacsony. Munkánkban megkíséreljük irodalmi és saját adatok felhasználásával összefoglalni az elmúlt két év fontosabb diagnosztikus tapasztalatait a teljesség igénye nélkül. Orv Hetil. 2021; 162(52): 2071-2078. Summary. Although the SARS-CoV-2 pandemic has been a great challenge for the diagnostic capacities, it also proved to be a unique source of experience. While previously PCR tests had overwhelmingly been used for targeted diagnostic and quantitative follow-up testing, screening and (initially) release tests became far more prevalent during the pandemic. It was well to be seen that the forced pace of bringing tests to market often gave way to not fully mature concepts. The PCR method is based on the detection of sequences, the proportions of which are likely to alter throughout the course of the disease. It is becoming increasingly clear that different target genes might be the best suitable for diagnostic, screening and release testing. Even with specific assays, an unprecedentedly high number of tests might result in the inflation of the positive predictive value, when the true prevalence of the infection remains very low among the tested individuals. Here we try to summarize some of the potentially most relevant diagnostic conclusions of the pandemic so far according to our own data and the literature. Orv Hetil. 2021; 162(52): 2071-2078.

HCV prevalence and risk behaviours among injectors of new psychoactive substances in a risk environment in Hungary-An expanding public health burden.

BACKGROUND: In Hungary a large increase in injecting new psychoactive substances (NPS) coincided with decreasing harm reduction efforts and rising HCV infection. We describe these, and assess changes in HCV prevalence and risk behaviours, 2011-2014, among NPS injectors, using 2011-2015 syringe exchange programme (SEP) data as a key contextual ('risk environment') variable. METHODS: We conducted repeated national sero-behavioural surveys in people who inject drugs (PWID) injecting in the last month and attending SEPs or drug treatment centres (n=399, 2011; 384, 2014), using face-to-face interviews and dried blood-spot samples. Prevalence of injected drugs and SEP coverage (2011-2015) were assessed through our national SEP monitoring system and using population size estimates. RESULTS: NPS injecting tripled among PWID attending SEPs in Hungary (2011: 26%; 2015: 80%). Among NPS injectors, HCV prevalence, sharing syringes and sharing any injecting equipment (last month), doubled (2011-2014: 37%-74%, 20%-48%, 42%-71%, respectively), significantly exceeding prevalence in other PWID groups. Among young NPS injectors (aged<25), HCV prevalence increased 7-fold (12%-76%), among new injectors (injecting<2years) 4-fold (13%-42%), coupled with high levels of equipment sharing (79% and 72% respectively). Not using a condom at last intercourse (79%), ever-imprisonment (65%) and last-year homelessness (57%) were highly prevalent among NPS injectors (2014). The number of syringes distributed per estimated PWID nationally fell from 114 to 81 (2011-2014) and dropped to 28 in 2015. CONCLUSION: NPS injectors in Hungary are at severe risk of blood-borne infections due to high levels of injecting and sexual risk behaviours within a high-risk environment, including continuously low SEP provision, imprisonment and homelessness. An HIV outbreak cannot be excluded. Stronger investment in evidence-based prevention measures, with special focus on young and new injectors, and expansion of hepatitis C treatment are urgently needed.

Phylogenetic analysis of a transfusion-transmitted hepatitis A outbreak.

A transfusion-associated hepatitis A outbreak was found in the first time in Hungary. The outbreak involved five cases. Parenteral transmission of hepatitis A is rare, but may occur during viraemia. Direct sequencing of nested PCR products was performed, and all the examined samples were identical in the VP1/2A region of the hepatitis A virus genome. HAV sequences found in recent years were compared and phylogenetic analysis showed that the strain which caused these cases is the same as that had spread in Hungary recently causing several hepatitis A outbreaks throughout the country.

Emerging Risks Due to New Injecting Patterns in Hungary During Austerity Times.

As a consequence of the massive restructuring of drug availability, heroin injection in Hungary was largely replaced by the injecting of new psychoactive substances (NPS) starting in 2010. In the following years in our sero-prevalence studies we documented higher levels of injecting paraphernalia sharing, daily injection-times, syringe reuse, and HCV prevalence among stimulant injectors, especially among NPS injectors. Despite the increasing demand, in 2012 the number of syringes distributed dropped by 35% due to austerity measures. Effects of drug market changes and the economic recession may have future epidemiological consequences. Study limitations are noted and future needed research is suggested.

Prevalence and correlates of HCV, HVB, and HIV infection among prison inmates and staff, Hungary.

The aim of this national, multicenter, cross-sectional study was to assess the prevalence of hepatitis B (HBV), hepatitis C (HCV), and human immunodeficiency viruses (HIV) among prisoners, and to identify related risk behaviors including injection drug use. Overall, 4,894 inmates from 20 prisons were enrolled. To have a comparison group, prison staff were also asked to take part. Altogether, 1,553 of the 4,894 inmates from seven prisons completed a questionnaire on risk behaviors. According to the survey, 1.5%, 4.9%, and 0.04% of the prisoners were tested positive for HBsAg, anti-HCV and anti-HIV, respectively. These prevalence data are among the lowest reported from prisons worldwide, although comparable to the Central European data. The prevalence of HBV, HCV, and HIV in the Hungarian prison staff was low (0.38%, 0.47%, and 0%, respectively). The rate of HCV infection was significantly higher among inmates who have ever injected drugs (22.5%) than among inmates who reported they had never injected drugs (1.1%). This first prevalence study of illegal drug injection-related viral infections among Hungarian prisoners points out that ever injecting drugs is the main reason for HCV infection among inmates. The opportunity to reach drug users infected with HCV for treatment underlines the importance of screening programs for blood-borne viruses in prisons.

Adaptation of Saffold virus 2 for high-titer growth in mammalian cells.

Saffold viruses (SAFV) are a recently discovered group of human Cardioviruses closely related to Theiler's murine encephalomyelitis viruses (TMEV). Unlike TMEV and encephalomyocarditis virus, each of which is monotypic, SAFV are genetically diverse and include at least eight genotypes. To date, only Saffold virus 3 (SAFV-3) has been grown efficiently in mammalian cells in vitro. Here, we report the successful adaptation of SAFV-2 for efficient growth in HeLa cells after 13 passages in the alpha/beta interferon-deficient human glial cell line U118 MG. Nine amino acid changes were found in the adapted virus, with single mutations in VP2, VP3, and 2B, while 6 mutations arose in VP1. Most capsid mutations were in surface loops. Analysis of SAFV-2 revealed virus growth and cytopathic effect only in human cell lines, with large plaques forming in HeLa cells, with minimal cell association, and without using sialic acid to enter cells. Despite the limited growth of SAFV-2 in rodent cells in vitro, BALB/c mice inoculated with SAFV-2 showed antibody titers of >1:10(6), and fluorescence-activated cell sorting (FACS) analysis revealed only minimal cross-reactivity with SFV-3. Intracerebral inoculation of 6-week-old FVB/n mice produced paralysis and acute neuropathological changes, including meningeal infiltrates, encephalitis, particularly of the limbic system, and spinal cord white matter inflammation.

Expression of bacterial genes and induction of INF-gamma in human myeloid dendritic cells during persistent infection with Chlamydophila pneumoniae.

The interactions between human monocyte-derived dendritic cells (DCs) and Chlamydophila pneumoniae (Cpn) infection were investigated. Cpn infection induced the maturation and functional activation of DCs, and Cpn antigens were present in all of the subpopulations during the maturation process. Chlamydial antigens were detected in DCs during an observation period of 28 days. The exponential production of infectious elementary bodies was not observed. Chlamydial transcripts of the 16S rRNA gene, groEL-1 and omcB genes were expressed, as determined by a quantitative real-time PCR, but the expression of the ftsK gene was limited. DC cultures produced IFN-gamma, but the presence of IFN-gamma in the culture medium was not the major factor that decreased the growth of Cpn, as was shown by neutralization of the IFN-gamma. A cell population identified as producing IFN-gamma had no markers for T, B, natural killer, monocyte cells or macrophages but displayed DC morphology and the expression of specific DC markers, such as CD11c and HLA-DR. These results reveal a persistent infection of DCs with the expression of some, but not cell division-related genes and the production of IFN-gamma that may contribute to the pathomechanism of chronic inflammatory diseases associated with persistent Cpn infection.

Chronic infections and genetic factors in the development of ischemic stroke.

The aim of this study was to examine whether chronic infections and genetic factors of the host play roles in the pathophysiology of acute noncardioembolic ischemic stroke. Blood samples from 59 subjects with ischemic stroke and 52 control patients were investigated by nested PCR for the presence of C. pneumoniae DNA, HCMV DNA and enterovirus RNA, by ELISA for the levels of antibodies to C. pneumoniae, HCMV, HSV, HHV-6, EBV and the inflammatory chemokine IL-8, and by PCR for promoter polymorphism of the IL-8 and CD14 host genes. Associations of stroke with the HCMV IgG and HSV-1 IgA antibody levels were observed. No association of stroke was detected with the presence of C. pneumoniae, HCMV or enterovirus nucleic acids in the peripheral blood, C. pneumoniae IgM, IgG and IgA, the HSV IgG, the EBV IgG, or HHV-6 IgG antibody levels, the pathogen burden, the IL-8 or CD14 promoter polymorphisms, or with the serum levels of IL-8 in the overall study population. These results are consistent with the hypothesis that certain pathogens are involved in the development of ischemic stroke.