Subgingival periodontal pathogens in Down syndrome children without periodontal breakdown. A case-control study on deciduous teeth

AIM

Down syndrome is the most common form of aneuploidia compatible with a long survival. The affected subjects are more susceptible to severe early-onset periodontal disease and show a lower risk to develop dental caries than the non-affected population. This study investigated the prevalence of periodontal pathogens in the subgingival plaque of deciduous teeth in children with Down syndrome without signs of periodontal breakdown.

METHODS

Thirty children suffering from Down syndrome and 46 matched healthy subjects were studied. A total of 228 subgingival plaque samples from deciduous teeth were separately collected and evaluated by polymerase chain reaction assays.

CONCLUSION

In absence of periodontal impairment, Down syndrome children display a clear presence of periodontal pathogens already in the deciduous dentition. The hypothesis of an intrinsic predisposing condition is here supported.

P–794 Prevalence of positivity for SARS-CoV–2 RNA in follicular fluid in infertile patients

Study question

Is Sars-Cov–2 present in the follicular fluid of infertile patients?

Summary answer

In the experience of the Infertility and IVF Unit, University Of Bologna, Italy, RNA of SARS-Cov–2 was not detected in the follicular fluid.

What is known already

Data on the risk of virus presence in reproductive cells and transmissibility in IVF procedures are very limited. In literature only one study reports the detection of SARS-Cov–2 viral RNA in oocytes of PCR positive women. Research of RNA in follicular fluid could be a marker able to indicate whether to continue IVF treatments in the case of swab-positive patients.

Study design, size, duration

Prospective study performed at Infertility and IVF Unit, Sant’Orsola University Hospital, University of Bologna, Italy, from March 2020 to January 2021. 451 IVF cycles were performed on 902 patients. In addition 59 cycles of oocyte cryopreservation were also performed to fertility preservation in oncological patients. In all positive swab patients was analyzed the follicular fluid for RNA virus detection.

Participants/materials, setting, methods

961 patients underwent telephone triage before going to the IVF Center to identify subjects with suspected or confirmed infection. Body temperature was measured on all patients before entering the IVF Center.

All patients were subjected to real-time analysis (RT PCR) of pharyngeal swab samples 48 hours before transvaginal ultrasound-guided oocyte retrieval.

In case of positive swab, PCR was performed on follicular fluid.

Main results and the role of chance

In our population of infertile patients the incidence of SARS COV–2 infection positivity was 0.4% (4/961).

No IVF treatments were suspended. The oocytes of the 4 women with positive swab were cryopreserved using closed devices stored in a special dedicated cryogenic container. No viral RNA was detected in the follicular fluid.

Limitations, reasons for caution

there are no limitations to the study.

Wider implications of the findings: The absence of SARS-COV–2 RNA in the follicular fluid is a reassuring result in the storage and future use of oocytes.

Trial registration number

Not applicable

Characterization of antibody response in neuroinvasive infection caused by Toscana virus

OBJECTIVES

Among sandfly-borne pathogens, Toscana virus (TOSV) is a prominent cause of summer meningitis in Mediterranean Europe. Here, we assessed the kinetics of anti-TOSV antibodies over time in 41 patients diagnosed with TOSV meningitis or meningoencephalitis in northeastern Italy.

METHODS

Acute and follow-up serum samples were collected up to 20 months after diagnosis of TOSV infection and tested for the presence of specific antibody using immunoenzymatic and indirect immunofluorescence assays. In addition, maturation of anti-TOSV IgG over time was evaluated as well as production of neutralizing antibodies.

RESULTS

Specific IgM and IgG response was present at diagnosis in 100% of patients; TOSV-specific IgM and IgG were detected in patients' sera up to 6 and 20 months after diagnosis, respectively. The avidity index (AI) increased over the first month after infection in 100% of patients and most cases exceeded 60% by Day 30 post infection. The AI subsequently plateaued then declined at 20 months after diagnosis. Finally, neutralization assay to TOSV was performed in 217 sera collected from 41 patients; 69.6% of tested samples resulted in reactive and moderate levels of neutralizing antibodies observed during all phases of infection despite high titres of total anti-TOSV IgG.

CONCLUSIONS

Specific antibody response develops rapidly and is long-lasting for neuroinvasive TOSV infection. Serodiagnosis of neuroinvasive TOSV requires simultaneous detection of specific IgM and IgG. Moderate levels of neutralizing antibodies were maintained over the study period, while the protective role of antibodies lacking neutralizing activity is unclear and requires further evaluation.

Comparative evaluation of the new xTAG GPP multiplex assay in the laboratory diagnosis of acute gastroenteritis. Clinical assessment and potential application from a multicentre Italian study

OBJECTIVE

Gastroenteritis caused by a single pathogen or multiple pathogens remains a major diagnostic challenge for the laboratory. The treatment of diarrhoea is based on microbiological results. Diagnosis is achieved using different laboratory techniques that have variable sensitivity and specificity. xTAG GPP is a new multiplex PCR assay that simultaneously detects 15 different pathogens responsible for diarrhoea. The results of the first multicentre study in Italy to evaluate the potential clinical application of the GPP assay in the laboratory diagnosis of diarrhoea are reported here.

METHODS

Faeces specimens (N=664) from hospitalized patients were tested with the GPP assay using a Luminex 200 instrument. All specimens were run using comparator methods following a routine algorithm: culture for bacteria, enzyme immunoassay and PCR for viruses, and microscopy for parasites.

RESULTS

Of the samples tested with the GPP, 53.61% (356/664) gave positive results, as compared to 45.33% by routine testing. Of the positive specimens, 34.55% showed the presence of genomic DNA from multiple pathogens. The Luminex method showed an increase in the percentage of positivity of 8.28%.

CONCLUSIONS

The GPP assay can be considered a helpful tool for the detection of gastrointestinal pathogens, with a hands-on time of 5h; it provides accurate data for the clinical management of hospitalized patients and for epidemiological surveillance.

Human and entomological surveillance of Toscana virus in the Emilia-Romagna region, Italy, 2010 to 2012

Toscana virus (TOSV), transmitted by phlebotomine sandflies, is recognised as one of the most important causes of viral meningitis in summer in Mediterranean countries. A surveillance plan based on both human and entomological surveys was started in 2010 in the Emilia-Romagna region, Italy. Clinical samples from patients with neurological manifestations were collected during 2010 to 2012. The surveillance protocol was improved during these years, allowing the detection of 65 human infections. Most of these infections were recorded in hilly areas, where sandflies reach the highest density. Entomological sampling around the homes of the patients resulted in a low number of captured sandflies, while later sampling in a hilly area with high number of human cases (n=21) resulted in a larger number of captured sandflies. Using this approach, 25,653 sandflies were sampled, of which there were 21,157 females, which were sorted into 287 pools. TOSV RNA was detected by real-time PCR in 33 of the pools. The results highlighted the role of Phlebotomus perfiliewi as the main vector of TOSV and a potential link between vector density and virus circulation. This integrated system shows that an interdisciplinary approach improves the sensitiveness and effectiveness of health surveillance.

The experience of West Nile virus integrated surveillance system in the Emilia-Romagna region: five years of implementation, Italy, 2009 to 2013

Predicting West Nile virus (WNV) circulation and the risk of WNV epidemics is difficult due to complex interactions of multiple factors involved. Surveillance systems that timely detect virus activity in targeted areas, and allow evidence-based risk assessments may therefore be necessary. Since 2009, a system integrating environmental (mosquitoes and birds) and human surveillance has been implemented and progressively improved in the Emilia-Romagna region, Italy. The objective is to increase knowledge of WNV circulation and to reduce the probability of virus transmission via blood, tissue and organ donation. As of 2013, the system has shown highly satisfactory results in terms of early detection capacity (the environmental surveillance component allowed detection of WNV circulation 3–4 weeks before human cases of West Nile neuroinvasive disease (WNND) occurred), sensitivity (capacity to detect virus circulation even at the enzootic level) and area specificity (capacity to indicate the spatial distribution of the risk for WNND). Strong correlations were observed between the vector index values and the number of human WNND cases registered at the province level. Taking into consideration two scenarios of surveillance, the first with environmental surveillance and the second without, the total costs for the period from 2009 to 2013 were reduced when environmental surveillance was considered (EUR 2.093 million for the first scenario vs EUR 2.560 million for the second). Environmental surveillance helped to reduce costs by enabling a more targeted blood unit testing strategy. The inclusion of environmental surveillance also increased the efficiency of detecting infected blood units and further allowed evidence-based adoption of preventative public health measures.

A model of laboratory surveillance for neuro-arbovirosis applied during 2012 in the Emilia-Romagna region, Italy

Arboviruses with neuroinvasive potential are gaining more attention due to the increased number of cases of autochthonous and imported infections in the human host. Diagnosis of infection caused by these viruses in patients with central nervous system (CNS) diseases is still underestimated and these infections represent an emerging threat to public health. We describe a model suitable for the laboratory surveillance of neuro-arbovirosis that was applied in the Emilia-Romagna region, north-eastern Italy, during the 2012 summer season. One hundred and twenty cases of suspected neuroinvasive infection were tested for arboviral agents on the basis of clinical and laboratory signs and epidemiological data. The most common virus detected was Toscana virus (TOSV): anti-TOSV specific antibodies or viral components were detected in 28.3% of the cases; 79.4% of the TOSV cases were in the acute phase of infection. No cases resulted in acute phase for West Nile (WNV), Usutu (USUV), Chikungunya (CHIKV) or Dengue (DENV) virus infection. Conversely, two patients with a history of staying in a tick-borne encephalitis virus (TBEV) endemic area showed a probable TBEV infection. These results emphasize the importance of a complete and 'ready to act' laboratory diagnostic system to be implemented within the larger frame of a regional integrated surveillance system.

West Nile virus in Europe: emergence, epidemiology, diagnosis, treatment, and prevention

West Nile virus (WNV), a mosquito-borne flavivirus in the Japanese encephalitis antigenic group, has caused sporadic outbreaks in humans, horses and birds throughout many of the warmer regions of Europe for at least 20 years. Occasional cases of West Nile encephalitis have also been associated with infected blood transfusions and organ donations. Currently, WNV appears to be expanding its geographical range in Europe and causing increasing numbers of epidemics/outbreaks associated with human morbidity and mortality. This brief review reports on the current epidemic situation regarding WNV in Europe, highlighting the clinical, diagnostic and preventive measures available for controlling this apparently emerging human pathogen.

Killing of Treponema denticola by mouse peritoneal macrophages

Treponema denticola has been identified as an important cause of periodontal disease and hypothesized to be involved in extra-oral infections. The objective of this study was to investigate the role of T. denticola cell length and motility during mouse peritoneal macrophages in vitro uptake. Macrophages, incubated under aerobic and anaerobic conditions, produced a similar amount of TNF-alpha when stimulated with Escherichia coli LPS. The uptake of FlgE- and CfpA-deficient mutants of T. denticola was significantly increased compared with the wild-type strain, due to cell size or lack of motility. Opsonization with specific antibodies considerably improved the treponemes' uptake. These results suggest that macrophages, in addition to other phagocytes, could play an important role in the control of T. denticola infection, and that the raising of specific antibodies could improve the efficacy of the immune response toward T. denticola, either at an oral site or during dissemination.