Search

Contains fulltext : 232443.pdf (Publisher’s version ) (Closed access) BACKGROUND: In the Netherlands, access to direct-acting antivirals (DAAs) against hepatitis C virus (HCV) has been unrestricted for chronic infection since 2015. We evaluated whether the nationwide incidence of HCV infections in individuals with HIV has changed since 2015. METHODS: In this retrospective cohort study, data from the ATHENA cohort of people with HIV aged 18 years or older attending any of the 24 HIV treatment centres in the Netherlands between 2000 and 2019 were assessed. We used parametric proportional hazards models with a piecewise exponential survival function to model HCV primary infection and reinfection incidence per 1000 person-years. FINDINGS: Of the 23 590 individuals without previous HCV infection, 1269 cases of HCV primary infection were documented (incidence 5·2 per 1000 person-years [95% CI 5·0-5·5]). The highest incidence was observed in men who have sex with men (MSM; 7·7 per 1000 person-years [7·3-8·2]) and was lower in people who inject drugs (PWID; 1·7 per 1000 person-years [0·7-4·1]) and other key populations (1·0 per 1000 person-years [0·8-1·2]). In MSM, incidence increased in 2007 to 14·3 per 1000 person-years and fluctuated between 8·7 and 13·0 per 1000 person-years from 2008 to 2015. In 2016, incidence declined to 6·1 cases per 1000 person-years and remained steady between 4·1 and 4·9 per 1000 person-years from 2017 to 2019. Of the 1866 individuals with a previous HCV infection, 274 reinfections were documented (incidence 26·9 per 1000 person-years [95% CI 23·9-30·3]). The highest incidence rate was observed in MSM (38·5 per 1000 person-years [33·9-43·7]) and was lower in PWID (10·9 per 1000 person-years [3·5-33·8]) and other key populations (8·9 per 1000 person-years [6·3-12·5]). In MSM, reinfection incidence fluctuated between 38·0 and 88·9 per 1000 person-years from 2006 to 2015, reaching 55·6 per 1000 person-years in 2015. In 2016, reinfection incidence declined to 41·4 per 1000 person-years, followed by further decreases to 24·4 per 1000 person-years in 2017 and 11·4 per 1000 person-years in 2019. INTERPRETATION: The sharp decline in HCV incidence in MSM with HIV shortly after restrictions on DAAs were lifted suggests a treatment-as-prevention effect. HCV incidence was already low in PWID and other groups before unrestricted access. Ongoing HCV transmission is occurring in MSM, as illustrated by a declining but high rate of reinfection, stressing the need for additional preventive measures. FUNDING: Dutch Ministry of Health, Welfare, and Sport.

PURPOSE: To evaluate the 'in vitro' bactericidal effect of the Nd:YAG laser (Genius, MØlsgaard Dental, Copenhagen, Denmark) on six periodontal pathogens.METHODS: Suspensions of six different periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum and Parvimonas micra) were prepared in small Eppendorff tubes, and exposed to a Nd:YAG laser for five different periods of time. Laser settings used: Power 6 Watt (on a scale of 1-12 W), Frequency 50 Hz, Pulse duration 250 mus. After exposure to the laser, aliquots of the suspensions were spread on blood agar plates for bacterial counting.RESULTS: After 5 s of laser exposure, there was a decrease in total colony forming units for all six selected microorganisms. After 15, 30 and 45 s, no viable bacterial cells could be retrieved.CONCLUSION: In this 'in vitro' model, 15 s of Nd:YAG laser use was found to be effective for total killing of the six tested periodontal pathogens.

Background and aims: Bacteria play an essential role in the pathogenesis of destructive periodontal disease. It has been suggested that not all bacteria associated with periodontitis may be normal inhabitants of a periodontally healthy dentition. In particular, Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans have been isolated infrequently from subjects without periodontitis. The aim of the present study was to compare prevalence and proportions of a number of periodontal bacteria in periodontitis patients and control subjects. Material and methods: In all, 116 consecutive subjects diagnosed with moderate to severe periodontitis (mean age 42.4) and 94 subjects without radiographic evidence of alveolar bone loss (mean age 40.4) were recruited for the study. The gingival condition in the control group varied between gingival health and various degrees of gingivitis. In patients, the deepest pocket in each quadrant was selected for microbiological sampling. In control subjects all mesial and distal sites of all first molars were selected for sampling. All paper points from a patient were pooled and processed for anaerobic cultivation within 6 h after sampling. Clinical variables of sampled sites included bleeding index, probing pocket depth and clinical attachment level. Results: A. actinomycetemcomitans, P. gingivalis, Prevotella intermedia, Bacteroides forsythus, Fusobacterium nucleatum and Peptostreptococcus micros were significantly more often prevalent in patients than in controls. The highest odds ratios were found for P. gingivalis and B. forsythus (12.3 and 10.4 resp.). Other odds ratios varied from 3.1 to 7.7 for A. actinomycetemcomitans and P. micros , respectively. Absolute numbers of target bacteria were all higher in patients, but only the mean percentage of B. forsythus was significantly higher in patients in comparison to controls (P

Background: The etiology of root caries is thought to be identical to coronal caries, though root caries seem to be more complicated because of the higher susceptibility of exposed roots (dentin) by periodontal therapy to demineralization than intact enamel. This implies that mutans streptococci are the most likely pathogens in the development of root caries. Although it is known that both the numbers of mutans streptococci and the frequency of isolation in root caries lesions are negatively correlated with the distance from the gingival margin, the subgingival sulcus has not been considered a possible habitat for mutans streptococci. However, subgingival occurence of mutans streptococci in both untreated and treated periodontal patients has not been documented well in the literature. Objective: To investigate the presence and levels of mutans streptococci in the subgingival plaque of patients (n=154) in different stages of periodontal therapy. The subgingival sulcus may be a possible habitat for mutans streptococci. This localisation of mutans streptococci may be of importance in the development of root caries after periodontal surgery. Materials and methods: In this cross-sectional study, subgingival plaque samples from 154 consecutive adult periodontitis patients were tested for presence and levels of mutans streptococci and putative periodontal pathogens by anaerobic cultures. These patients were divided into 3 groups based on their stage of periodontal treatment: (1) untreated patients; (2) patients after initial periodontal therapy only; (3) patients in the maintenance phase who not underwent periodontal surgery; (4) patients after periodontal surgery. Results: The prevalence of mutans streptococci in the 4 study groups varied from 82% in untreated patients to 94% in maintenance patients. The mean proportion of mutans streptococci was 6.65% in maintenance patients versus 1.86% in untreated patients (p=0.005) and 2.51% in patients after scaling and root planing (p=0.041). Conclusions: The subgingival area is a microbial habitat for mutans streptococci that may be of importance in the development of root caries in periodontitis patients.

Primary Sjogren’s syndrome (SS) is a systemic autoimmune disorder characterised by a chronic, progressive loss of salivary and lacrimal function resulting in symptoms of oral and ocular dryness. The involvement of exocrine glands is the result of a focal, periductal mononuclear cell infiltrate and the subsequent loss of secretory epithelial cells.1 As a consequence, major changes occur in both the salivary flow rate and salivary composition.2-9 In the case of secondary SS a second autoimmune disease is involved, mostly rheumatoid arthritis. The role of saliva in maintaining oral health and even quality of life is obvious in people who are lacking sufficient saliva.10-12 The effects of the reduced salivary flow rate (xerostomia) and changed salivary composition in SS are apparent (table 1): there are problems in eating, speaking, and swallowing12-15 and frequently disturbances in taste perception.16 In addition, reduced clearance of food, changes in microbial ecology and a reduced buffer capacity have their effects on oral health: an increased susceptibility to dental caries and oral infections are important clinical manifestations of the oral component of SS.17 18 When the systemic disease advances, salivary secretion declines further.7 View this table: Table 1 Consequences of xerostomia A reduction of the salivary flow rate below physiological values can be induced by several other causes as well.19 Dry mouth symptoms are known as a side effect of more than 400 drugs.20 21 In most of these cases the level of reduction of the salivary flow is slight and can be compensated for by mechanical or gustatory stimulation. Other common causes of prolonged hyposalivation include other autoimmune disorders such as systemic lupus erythematosus,22 23 uncontrolled diabetes mellitus24 25 and salivary gland injury as a result of radiotherapy in the head and neck region.26 This review describes the current …

Tobacco smoking has been identified as one major risk factor for destructive periodontal disease. Scaling and root planing have been shown to be less effective in smokers with periodontitis. The aim of the present study was to compare the subgingival microbial flora of treated and untreated smokers and non-smokers.Four independent adult patient groups with periodontitis were included in this investigation: 88 untreated smokers (U-S); 90 untreated non-smokers (U-NS); 119 treated non-smokers (T-NS); and 171 treated smokers (T-S). Clinical variables included cumulative plaque index (CPI), probing depth (PD), clinical attachment level (CAL), cumulative bleeding index (CBI), and cumulative suppuration index (CSI). Paper point samples from the deepest bleeding pocket in each quadrant of the dentition were analyzed for the presence and levels of 6 periodontal bacterial pathogens using anaerobic culture techniques.U-S showed a higher mean cumulative plaque index than U-NS (3.5 versus 2.7). Mean PD and mean CAL were higher in the T-S in comparison to the T-NS group (7.0 versus 6.6 mm and 5.6 versus 4.7 mm, respectively). Microbiological characteristics of U-S were a higher prevalence of Prevotella intermedia/nigrescens and higher mean levels of Peptostreptococcus micros (Pm) and Fusobacterium nucleatum (Fn). T-S patients were characterized by higher prevalence of Bacteroides forsythus (Bf), Pm, and Campylobacter rectus (Cr) and higher mean levels of Pm and Fn. The mean percentage of B. forsythus tended to be higher in the T-S group than in the T-NS group (6.9% versus 5.6%). The relative risk to be infected with Bf, Pm, and Cr was statistically higher in smokers (odds ratios: 1.9, 1.9, and 1.6, respectively). The chance to findor =10% of Bf, Pm, and/or Fn was 3.3 higher in smokers when A. actinomycetemcomitans and P gingivalis were absent. Detection ofor =20% Pm/Fn in treated patients was strongly associated with smoking (odds ratio 13.8, P= 0.002).Smoking is a determining factor for the composition of the subgingival microflora in adult patients with periodontitis and may select for a specific cluster of periodontal pathogens, notably Bf, Pm, Fn, and Cr. On the basis of these observations, smoking, among other criteria, may be one parameter to use in deciding to treat refractory periodontitis in smokers with a systemic antibiotic therapy directed against smoking-associated periodontal bacteria.