Population-based study of influenza and invasive meningococcal disease among Greek children during the COVID-19 pandemic.

BACKGROUND: Aiming to the containment of the coronavirus disease 2019 (COVID-19) pandemic, governments worldwide have implemented a series of non-pharmaceutical interventions. Many of them and especially school closures have impacted the circulation of multiple airborne pathogens among children and adolescents. This study investigates the incidence of influenza and invasive meningococcal disease among children aged 0-14 years in Greece during the COVID-19 pandemic. METHODS: Data regarding the number of influenza-like illness cases, influenza-related paediatric intensive care unit (PICU) admissions and invasive meningococcal disease cases among children 0-14 years old were obtained from the National Public Health Organization. The incidence of the two diseases during the COVID-19 pandemic period (2020/2021) was compared with that of the six preceding seasons (2014-2019). RESULTS: A notable decrease was observed in both influenza and invasive meningococcal disease cases during the period 2020/2021 compared with the years 2014-2019. The mean annual rate of influenza-like illness cases and influenza-related PICU admissions in children 0-14 years old has reduced by 66.9% and 100%, respectively, while the mean annual invasive meningococcal disease rate has declined by 70%. Both weekly influenza-like illness and monthly invasive meningococcal disease rates were significantly decreased. CONCLUSIONS: The activity of influenza and invasive meningococcal disease in the children and adolescents of Greece has decreased during the COVID-19 pandemic period. Reduced transmission is likely related to the public health measures that were implemented to control the pandemic. The value of these measures may have relevance to the future management of influenza or invasive meningococcal disease epidemics.

Impact of a Single-Tube PCR Assay for the Detection of Haemophilus influenzae Serotypes a, c, d, e and f on the Epidemiological Surveillance in Greece.

Background: The decrease in the rate of meningitis due to Haemophilus influenzae type b after vaccine introduction and a possible change in epidemiology of H. influenzae disease highlights the need for continuous serotype surveillance. Methods: A single-tube multiplex PCR assay for serotyping of H. influenzae was developed and deployed. Results: During 2003−2020, 108 meningitis cases due to H. influenzae were notified; 86 (80%) were confirmed and serotyped by molecular methods. The overall specificity and sensitivity of the assay were estimated (100% PPV and NPV respectively). The overall mean annual reported incidence for H. influenzae was 0.02, while for Hib and non-b meningitis equaled 0.02 and 0.03 per 100 000, respectively. Analysis by age group revealed that H. influenzae peaks in toddlers and children 0−4 years and in adults >45 years old. Among the serotyped cases, 39.8% were identified as Hib, 46.3% as NTHi, and 0.9% and 2.8% as serotypes a (Hia) and f (Hif)) respectively. Conclusions: Low incidence due to Hib was observed while non-typeable H. influenzae (NTHi) and serotypes Hia and Hif seem to emerge. The application of the current assay discloses the ongoing change of invasive H. influenzae disease trends during the Hib post-vaccine era.

Pneumococcal meningitis in Greece: A retrospective serotype surveillance study in the post-PCV13 era (2010-2020).

BACKGROUND: As Greece is a country which has introduced the 13-valent pneumococcal conjugate vaccine (PCV13) both in the infant and in the adult immunization programs, the aim of the study was to investigate age-specific and serotype-specific trends of pneumococcal meningitis over an 11-year period (2010-2020). MATERIALS AND METHODS: Data are reported from pneumococcal meningitis cases [notified to the National Public Health Organization (NPHO)], with clinical samples and bacterial isolates sent for pneumococcal identification and serotyping at the National Meningitis Reference Laboratory (NMRL). Pneumococcal identification was performed directly on clinical samples or bacterial isolates by multiplex PCR (mPCR) assay, while serotyping was carried out by application of the Capsular Sequence Typing (CST) method with the combination of single tube PCR assays. RESULTS: A total of 427 pneumococcal meningitis cases were notified to the NPHO between 2010 and 2020. Among those, 405 (94.8%) were microbiologically confirmed, while samples from 273 patients were sent to the NMRL for identification and/or further typing. The annual notification rate peaked at 0.47/100,000 in 2016 and since then has been decreasing. The incidence was highest in infants and in older adults. Pneumococcal serotypes were identified in 260/273 (95.2%) cases, where clinical samples were sent to the NMRL. The most prevalent serotypes (≥5%) were 3, 19A, 23B, 15B/C, 11A/D, 23A, 22F. During the study period there has been a decrease of PCV13 serotypes combined with an increase of non-PCV13 serotypes (p = 0.0045). CONCLUSIONS: This is the first study to report serotypes for pneumococcal meningitis across all ages in the post-PCV13 era in Greece. There is a need to enhance surveillance, by close monitoring of the emerging serotypes and the impact of vaccination programs. Higher-valency PCVs may help to improve the coverage of pneumococcal disease.

Adherence to Recommendations for Βacillus Calmette-Guérin Vaccination of High-risk Neonates in Greece.

In 2016 a Βacillus Calmette-Guérin vaccination policy targeting high-risk neonates for tuberculosis before discharge from maternity hospital was adopted in Greece. Vaccination rates were 38.2% in 2019 and 24.7% in 2020. Vaccination coverage varied by risk group (higher for neonates in close contact with an active noncompliant or multidrug-resistant tuberculosis case and lower for Roma and immigrant neonates).

Spatiotemporal Distribution and Genetic Characterization of Measles Strains Circulating in Greece during the 2017-2018 Outbreak.

Between May 2017 and November 2018, Greece has experienced a severe measles outbreak with a total of 3258 cases reported, after reaching its goal of eliminating measles since 2014-2015. In this study, we aimed to investigate the origin and the dispersal patterns of the measles strains that circulated in Greece during this outbreak and to identify possible transmission patterns of measles virus (MeV) in the country. Of the 832 measles suspect cases referred to the National Measles and Rubella Reference Laboratory for MeV RNA detection, 131 randomly selected positive samples, representative of the temporal and spatial distribution of the laboratory-confirmed measles cases in Greece, were processed for genotypic identification by an RT-PCR amplification of a 598 bp fragment containing the 450 bp hypervariable region of the measles virus N gene. Phylogenetic analysis was carried out by the approximate maximum likelihood method (ML) under the generalized time-reversible (GTR + cat) model. All samples analyzed were found to belong to genotype B3. Comparative analysis with other European and reference measles strains revealed three separate major clusters and other multiple viruses circulating simultaneously in Greece. They were all isolated from three main community groups, Greek-Roma children, non-minority Greek nationals and immigrants/refugees, a finding that is in accordance with what was also observed in the last two measles outbreaks in 2005-2006 and 2010-2011. Notably, for one of the three clusters, no similarity was detected with previously reported prototype strains. Our results indicate the need for a more intensive vaccination program against measles amongst minority populations and in refugee hot-spots as well as the importance of molecular surveillance as a tool for monitoring measles outbreaks.

Children and Adolescents With SARS-CoV-2 Infection: Epidemiology, Clinical Course and Viral Loads.

BACKGROUND: There is limited information on severe acute respiratory syndrome virus 2 (SARS-CoV-2) infection in children. METHODS: We retrieved data from the national database on SARS-CoV-2 infections. We studied in-family transmission. The level of viral load was categorized as high, moderate, or low based on the cycle threshold values. RESULTS: We studied 203 SARS-CoV-2-infected children (median age: 11 years; range: 6 days to 18.4 years); 111 (54.7%) had an asymptomatic infection. Among the 92 children (45.3%) with coronavirus disease 2019 (COVID-19), 24 (26.1%) were hospitalized. Infants <1 year were more likely to develop COVID-19 (19.5% of all COVID-19 cases) (P-value = 0.001). There was no significant difference between viral load and age, sex, underlying condition, fever and hospitalization, as well as between type of SARS-CoV-2 infection and age, sex, underlying condition and viral load. Transmission from a household member accounted for 132 of 178 (74.2%) children for whom the source of infection was identified. An adult member with COVID-19 was the first case in 125 (66.8%) family clusters. Child-to-adult transmission was found in one occasion only. CONCLUSIONS: SARS-CoV-2 infection is mainly asymptomatic or mild during childhood. Adults appear to play a key role in spread of the virus in families. Most children have moderate or high viral loads regardless of age, symptoms or severity of infection. Further studies are needed to elucidate the role of children in the ongoing pandemic and particularly in light of schools reopening and the need to prioritize groups for vaccination, when COVID-19 vaccines will be available.

First report of meningococcal ciprofloxacin resistance in Greece due to invasive isolates of the sequence type ST-3129.

A local outbreak caused by Neisseria meningitidis occurred in the migration camp in the Greek island of Lesbos during January-February 2020 (4 of 5 cases). In total, 5 samples positive for N. meningitidis were further investigated for sero-/genogroup, PorA, and WGS analysis. MenB was found among 3 cases, while in two cases, MenY was identified. WGS analysis and antibiotic susceptibility testing on the 2 culture positive MenB samples showed the new ST-3129, ciprofloxacin-resistant clone was circulating among the immigrants in the aforementioned camp. This is the first report of ciprofloxacin resistance in Greece.

Liver function tests in viremic and nonviremic chronic hepatitis B virus-infected pregnant women: importance of alanine aminotransferase/sodium ratio.

The major risk factor of perinatal transmission of Hepatitis B virus (HBV) infection is the level of maternal HBV-deoxyribonucleic acid (DNA) during the third trimester of pregnancy. The primary aim of this study was to evaluate the hematological and biochemical status in Hepatitis B e-antigen (HBeAg)-negative chronic HBV-infected pregnant women and to correlate the findings with the presence or absence of viremia. Ninety-five consecutive chronic HBV-infected pregnant women were evaluated between the 28th and 32nd week of gestation. Viral load was determined by using the COBAS TaqMan HBV test. Sixty-nine women were evaluated and 14 of them exhibited HBV-DNA levels higher than 2000 IU·ml. In this study, viremic women exhibited significantly higher alanine aminotransferase (ALT), creatinine, and uric acid values as well as significantly lower white blood cell count compared with nonviremic women. There was also a significant statistical difference concerning ALT/sodium ratio between viremic and nonviremic women (0.20 ± 0.22 vs. 0.10 ± 0.09, respectively, p= .024). The optimal cutoff points discriminating those women with a high probability to have detectable serum HBV-DNA were 0.092 for ALT/sodium ratio (sensitivity = 73.0%, specificity = 61.5%, area under the receiver operating characteristic curve [AUC] = 71.05%) and 12.8 IU/L for ALT (sensitivity = 73.0%, specificity = 63.0%, AUC = 72.2%). Chronic HBV-infected pregnant women with ALT/sodium ratio ≥ 0.11 had the higher probability of having serum HBV-DNA levels higher than 2000 IU/ml (sensitivity = 76.92%, specificity = 58%, AUC = 62.38%). Presence of HBV-DNA in maternal blood during the third trimester of pregnancy is significantly associated with maternal serum ALT levels in HBeAg-negative chronic HBV-infected pregnant women. Women with an ALT/sodium ratio greater than 0.092 have the higher probability of HBV-DNA presence in maternal blood whereas an ALT/sodium ratio greater than 0.11 could discriminate those women with HBV-DNA levels higher than 2000 IU/ml.

Evaluation of liver enzymes in asymptomatic chronic hepatitis B virus infected pregnant women.

BACKGROUND: The major risk factor for perinatal transmission of hepatitis B virus (HBV) infection and/or immunoprophylaxis failure is the level of maternal HBV-DNA. The aim of this study was to evaluate commonly used laboratory parameters in HBeAg-negative chronic HBV-infected pregnant women and to correlate the findings with the presence or absence of viremia. METHODS: 166 consecutive chronic HBV-infected pregnant women were hematologically, serologically and virologically evaluated between the 28th and 32nd week of gestation. 101 women were finally evaluated (66 HBV-DNA positive and 35 HBV-DNA negative). Twenty-one women exhibited HBV-DNA levels above 2000 IU/mL. RESULTS: Viremic women exhibit significantly higher ALT (25.43 IU/L vs. 15.50 IU/L, P=0.016) and GGT (17.47 IU/L vs. 10.22 IU/L, P=0.001) values as well as significantly lower white blood cell (10527 vs. 13793, P=0.008) and neutrophil count (7776 vs. 11088, P=0.001), compared to non-viremic women. The optimal cut-off points discriminating those women with a high probability to have detectable serum HBV-DNA were 7 IU/L for GGT (sensitivity = 81.6%, specificity = 69.6%, area under the ROC curve (AUC) = 75.3%) and 12 IU/L for ALT (sensitivity = 74.1%, specificity = 56.2%, AUC = 65.4%). The positive predictive value of detectable HBV-DNA in women with both serum parameters above the new limits proposed was 88.8% whereas the negative predictive value was 75%. CONCLUSION: Presence of HBV-DNA in maternal blood during the third trimester of pregnancy is significantly associated with maternal serum GGT levels. Women with GGT above 7 IU/L and ALT above 12 IU/L have a higher probability of HBV-DNA presence in maternal blood.

Serological and virological profile of chronic HBV infected women at reproductive age in Greece. A two-year single center study.

OBJECTIVE: Seroprevalence of HBsAg in 26,746 women at reproductive age in Greece and evaluation of HBeAg/anti-HBe serological status as well as serum HBV-DNA levels in a subgroup of HBsAg(+) women at labor. STUDY DESIGN: Serological markers were detected using enzyme immunoassays. Serum HBV-DNA was calculated using a sensitive quantitative PCR assay, with a lower limit of quantification of 200 copies/ml. RESULTS: Overall, 1.53% of women were HBsAg(+) and the majority of them (64.96%) were Albanian. Among Albanian women the mean prevalence of HBsAg was 4.9%, 5.57% among Asian women, and 1.29% among women from Eastern European countries. The prevalence of HBsAg among African (0.29%) and Greek women (0.57%) was very low and significantly lower in comparison with the mean value of the studied population. Only 2.67% of HBsAg(+) women were HBeAg(+). Of a subgroup of women in labor with available serum samples 28.6% had undetectable levels of viremia (<200 copies/ml) and 15.9% had extremely low levels of viral replication (<400 copies/ml). Only 12.7% of pregnant women evaluated at labor exhibited extremely high serum HBV-DNA levels (>10,000,000 copies/ml) whereas 42.8% of them exhibited HBV-DNA levels between 1500 and 40,000 copies/ml. CONCLUSIONS: The overall prevalence of HBsAg is relatively low among women at reproductive age in Greece but is higher among specific ethnic populations (Asian, Albanian). The HBeAg(-)/antiHBe(+) serological status is a finding observed in the vast majority of HBsAg(+) women of our study population, and a significant percentage of them (approximately 44.5%) exhibit extremely low or even undetectable levels of viral replication at labor, suggesting possibly that only a proportion of HBsAg(+) women in Greece exhibit an extremely high risk of vertical transmission of the infection.

HBeAg negative serological status and low viral replication levels characterize chronic hepatitis B virus-infected women at reproductive age in Greece: a one-year prospective single center study.

AIM: To evaluate the seroprevalence of hepatitis B surface antigen (HBsAg) in 13 581 women at reproductive age and the hepatitis B e antigen (HBeAg)/anti-HBe status as well as serum hepatitis B virus (HBV)-DNA levels in a subgroup of HBsAg(+) pregnant women at labor in Greece. METHODS: Serological markers were detected using enzyme immunoassays. Serum HBV-DNA was determined by a sensitive quantitative PCR assay. Statistical analysis of data was based on parametric methodology. RESULTS: Overall, 1.156% of women were HBsAg(+) and the majority of them (71.3%) were Albanian. The prevalence of HBsAg was 5.1% in Albanian women, 4.2% in Asian women and 1.14% in women from Eastern European countries. The prevalence of HBsAg in African (0.36%) and Greek women (0.29%) was very low. Only 4.45% of HBsAg(+) women were also HBeAg(+) whereas the vast majority of them were HBeAg(-)/anti-HBe(+). Undetectable levels of viremia (<200 copies/mL) were observed in 32.26% of pregnant women at labor and 29.03% exhibited extremely low levels of viral replication (<400 copies/mL). Only two pregnant women exhibited extremely high serum HBV-DNA levels (>10 000 000 copies/mL), whereas 32.26% exhibited HBV-DNA levels between 1 500 and 40 000 copies/mL. CONCLUSION: The overall prevalence of HBsAg is relatively low among women at reproductive age in Greece but is higher enough among specific populations. The HBeAg(-)/anti-HBe(+) serological status and the extremely low or even undetectable viral replicative status in the majority of HBsAg(+) women of our study population, suggest that only a small proportion of HBsAg(+) women in Greece exhibit a high risk for vertical transmission of the infection.