What risk factors affect hospitalisation for confirmed pertussis cases among infants in the Czech Republic?

BACKGROUND: We estimated what risk factors affect hospitalisation for confirmed pertussis cases among infants (child up to 1 year) in the Czech Republic based on data from the questionnaire-based enhanced surveillance system (ESS) in years 2015, 2017 and 2019. METHODS: Retrospective cohort study was conducted in which we assessed demographic, clinical data, vaccination status and risk/protective factors. Vaccination status was extracted from the electronic nationwide notification system (NNS). We performed descriptive, univariable and multivariable analysis using risk ratio (RR) and logistic regression with odds ratio (OR). RESULTS: A total of 104 confirmed cases (27, 13, 64) were reported in the ESS during 2015, 2017 and 2019. Most cases were in age group 1 month (24), more males (57). Fifteen cases were vaccinated and 89 unvaccinated. Of 88 hospitalised cases, 31 cases reported stay in Intensive Care Unit (ICU). The median length of hospitalisation was 8 days. Although the variable vaccinated in infants was statistically significant in a univariable analysis for outcome hospitalisation, RR 0.76 (95% CI 0.53-1.10), it was not in multivariable. Hospitalisation was strongly associated with the younger age group of 0-3 months adjusted by a smoking family member in a household (OR = 9.72; 95% CI: 2.97-31.81). Stay in ICU was strongly correlated with the younger age group of 0-3 months (OR = 5.07; 95% CI: 1.44-17.87) and with a contact with confirmed or probable pertussis (OR = 7.05; 95% CI: 1.36-36.52). CONCLUSIONS: Our study demonstrated younger age and contact with other pertussis case as risk factors for hospitalisation of infants with pertussis. It is necessary to consider adolescent and adult boosters, including vaccination during pregnancy. We suggest integrating the variables from the enhanced surveillance system into the nationwide notification system, in order to simplify the data reporting and evaluation. Further studies are needed to evaluate the ESS and to monitor the vaccination of pregnant women against pertussis.

First evaluation of completeness and sensitivity of the measles surveillance system in the Czech Republic, January 1, 2018 until June 30, 2019.

AIM: The aim of study was to evaluate completeness and estimate sensitivity of the measles surveillance using the new electronic version of the national notification system of infectious diseases (ISIN) in order to assess its performance. MATERIAL AND METHODS: The completeness of measles reporting in the ISIN for demographic characteristics (week and region of reporting, age and gender), date of onset, complications, hospitalisations, vaccination status, used laboratory methods and country of import from January 2018 to June 2019 was assessed. The register from National Reference Laboratory (NRL) and the ISIN were compared using the capture-recapture method (CRM). Cases were matched using unique personal identifier. The total number of measles cases in the population was assessed using the Chapmans formula. Sensitivity of reporting was calculated by dividing the number of reported cases by the CRM estimated true number of cases. RESULTS: In the ISIN, 765 measles cases were registered within specified time period. For many variables 100% completeness was found. The data were missing mainly for vaccination status (20%), serology results (55%) and used laboratory methods (8%). The NRL confirmed 653 patient samples in respected period. Within both registries (ISIN and NRL) the total 612 cases were matched. Estimated real number of measles cases using the CRM was 816 (95% CI: 809-823) compared to 806 reported cases. The estimated surveillance system sensitivity was 98.8%. Five percent (n = 41) of cases tested positively in the NRL were not reported to the ISIN. CONCLUSIONS: We found high level of reported measles data completeness in the ISIN for most variables. Estimated real and reported number of cases was in a good correlation and calculated sensitivity of the ISIN was on very high level. Though, the data sources used in the study were not independent on each other, therefore results may not be fully accurate. The technical changes (more mandatory fields and more logical syntax to check data) in the ISIN to improve data completeness are being recommended. Data providers should report all measles cases to the ISIN with maximum precision in entering individual variables and investigating laboratories should send samples for confirmation to the NRL in required cases.

Measles outbreaks in 2017-2019 - molecular surveillance started in the Czech Republic.

OBJECTIVE: Between 2017 and 2019, measles virus spread globally, causing a large measles epidemic that suddenly ended in 2020. Measles outbreaks also occurred in the Czech Republic (CR) as part of the global public health problem. In the recent alarming epidemiological situation, molecular surveillance is becoming increasingly important as it plays a vital role in the identification of imported cases and in the monitoring of virus transmission. Molecular surveillance makes it possible to obtain evidence of the discontinuation of the endemic spread and is indispensable for the verification of measles elimination. The study aim is to find out whether any of measles virus genotypes circulated in the CR for more than 12 months in order to either confirm or refute the endemic spread of measles virus in the country in relation to the recent loss of the measles elimination status. Another aim is to assess the current laboratory diagnosis from the perspective of recent measles outbreaks and the obligation to refer samples for confirmation and genotyping. MATERIAL AND METHODS: In total, 243 positive nasopharyngeal swabs collected from outbreak patients from all over the CR in 2018 and 2019 were analysed by molecular methods. The most variable part of the measles virus genome, the nucleoprotein gene (N-450), was sequenced according to the WHO protocol. The sequence analysis was performed by Sanger method using the Applied Biosystems 3 500 sequencer, and sequence data were analysed by the bioinformatics programe Geneious. RESULTS: In the CR, only two genotypes were found in measles outbreaks in 2018-2019, eight variants of the dominant D8 and six B3 variants, while genotype A was detected in eight samples. The dominant genotype of 2017 (D8, 4283) was identified for the first time in the CR in January 2018. Four months later, it was replaced by genotype D8, 4683, occurring in the CR from March 2018 to June 2019. This genotype was identified in 170 of 243 samples (70%). There was a 3-month window between the first and the second detection of this genotype, which does not imply that in the meantime the virus did not circulate in the population. The analysis of seven samples from 2017 conducted by the collaborating Regional Reference Laboratory at the Robert Koch Institute (RRL RKI) in Berlin assigned five samples from Ostrava to genotype B3 and detected two variants of genotype D8 (Praha, Liberec). Laboratory diagnosis was facilitated by a higher proportion of clinical specimens available for direct detection of the virus, which increased from 18% in 2017 to 43% in 2019. Samples were referred to the National Reference Laboratory (NRL) in Prague for sequencing in accordance with the set legal rules. Between 2018 - 2019, laboratories sent 424 samples. Two hundred and forty-three samples (60%) were successfully sequenced, while the sequencing of the remaining samples failed due to low viral load. CONCLUSIONS: Measles virus sequencing was introduced in the Czech Republic as a necessary part of molecular surveillance, and almost 60% of positive samples were analysed. The sequencing analysis confirmed the endemic spread of measles virus, with genotype D8, 4683 MVs/GirSomnath.IND/42.16 found to circulate in the CR for 16 months between 2018 and 2019. Laboratory diagnosis is recently focusing more on direct detection of the virus, which along with genotyping extended to include another part of the genome will improve molecular surveillance.

Questionnaire-based epidemiological analysis of acute gastroenteritis outbreak among employees of two neighbouring institutions sharing canteen in Prague 2019.

OBJECTIVES: On 17th Dec 2019 gastroenteritis outbreak occurred in two Pragues neighbouring institutions. Investigation aimed to describe outbreak, identify etiological agent, vehicle and propose control measures. METHODS: Routine outbreak investigation and retrospective cohort study was done. Data collected via online questionnaire were analysed using descriptive, univariate and stratified analysis. RESULTS: Of 960 employees, 276 responded (29%). We identified 39 (14%) cases, one tested norovirus positive. Canteen staff didnt report illness. No food item or environmental sample was tested. Sichuan pork served for lunch on 17th Dec was the most likely vehicle of outbreak (odds ratio (OR) 5.02, 95% confidence interval (CI) 1.98-12.64). Eating Sichuan pork and Chinese soup showed OR 31.5, 95% CI 5.0-320.7. Twenty-two (56%) cases can be explained by consumption of these food items. CONCLUSIONS: Epidemiological analytical method provided evidence of likely vehicle. We did not find the source. Control measures were early ensured and outbreak ceased. We emphasise full outbreak investigation using analytical epidemiology, environmental screening and microbiological testing of cases and possibly all kitchen staff.

COVID-19 reinfections.

Reports of SARS-CoV-2 reinfections are on the rise. This study focused on reinfections in patients with confirmed COVID-19 in the Czech Republic. Between 1 March 2020 and 9 November 2020, 362 084 cases with the onset of symptoms before 31 October 2020 were reported. Overall, 28 cases of symptomatic SARS-CoV-2 reinfections were identified, 11 in males and 17 in females, age range 25-80 years, median age 46 years. The interval between the first and second episodes of the disease ranged from 101 to 231 days, and the median interval was 201.5 days. During both symptomatic episodes, all patients have been tested by RT-PCR. Altogether 26 patients (92.9%) have been tested negative after recovery from the first episode of COVID-19. Symptomatic reinfections occurred in nearly 0.2% of all patients at risk. Most patients with reinfection had mild symptoms in both episodes, and only three episodes were moderate to severe. Thus, reinfections may have been underdiagnosed. In summary, COVID-19 reinfections are possible and not exceptional.