First back-calculation and infection fatality multiplier estimate of the hidden prevalence of COVID-19 in Ireland.

BACKGROUND: To date computer models with multiple assumptions have focussed on predicting the incidence of symptomatic cases of COVID-19. Given emerging vaccines, the aim of this study was to provide simple methods for estimating the hidden prevalence of asymptomatic cases and levels of herd immunity to aid future immunization policy and planning. We applied the method in Ireland. METHODS: For large scale epidemics, indirect models for estimating prevalence have been developed. One such method is the benchmark multiplier method. A further method is back-calculation, which has been used successfully to produce estimates of the scale of a HIV infected population. The methods were applied from March to October 2020 and are applicable globally. RESULTS: Results demonstrated that the number of infected individuals was at least twice and possibly six times the number identified through testing. Our estimates ranged from ∼100 000 to 375 000 cases giving a ratio of 1-6 hidden cases for every known case within the study time frame. While both methods are subject to assumptions and limitations, it was interesting to observe that estimates corroborated government statements noting that 80% of people testing positive were asymptomatic. CONCLUSIONS: As Europe has now endured several epidemic waves with the emergence globally of new variants, it essential that both policy makers and the public are aware of the scale of the hidden epidemic that may surround them. The need for social distancing is as important as ever as we await global immunization rollout.

Prevalence and concordance of oral HPV infections with cervical HPV infections in women referred to colposcopy with abnormal cytology.

BACKGROUND: Considering the shared aetiology of Human Papillomavirus infections in oropharyngeal and cervical cancers and the possible role for sexual transmission, several key aspects of the relationship between cervical and oral infections merit investigation, including prevalence of concomitant oral HPV infection and type-specific concordance with concurrent cervical infections. METHODS: A cross-section study was performed on women referred to colposcopy clinics with cytological abnormalities and a cervical HPV infection. An oral rinse sample was taken from the participants at their baseline visit for HPV testing, and a demographic and risk factor questionnaire was also administered. HPV DNA testing was carried out on the Cobas 4800 platform and extended genotyping was carried out with the INNO-LiPA HPV Genotyping Extra II assay. HPV genotyping was also carried out on the concurrent cervical tissue samples on all women who had a positive oral HPV infection. RESULTS: The prevalence of oral HPV infections was 10.0% (95%CI:5.9-13.7) in the study population. HPV18 was the most frequent genotype (7.0%). Concordant oral and cervical HPV infections were detected in 28.6% of women. Age (p = 0.005) and level of education (p = 0.02) were significantly associated with a prevalent oral HPV infection. CONCLUSION: Concomitant oral HPV infections were present in 10.0% of women referred to colposcopy with a pre-existing cervical HPV infections and cytological abnormalities. Although mild type-specific concordance was observed between oral and cervical HPV infections, findings suggest that infections at these sites may not be independent of each other.

The second wave: estimating the hidden asymptomatic prevalence of COVID-19 in Ireland as we plan for imminent immunisation.

Since the first case of COVID-19 in Ireland was recorded policy makers have introduced mitigation measures to control the spread of infection. Infection is spread by both known cases and hidden, undetected asymptomatic cases.  Asymptomatic individuals are people who transmit the virus but display no clinical symptoms. Current evidence reveals that this population is a major contributing factor to the spread of the disease. There is little or no knowledge of the scale of the hidden prevalence of all infections both asymptomatic and symptomatic in Ireland. Furthermore, as governments plan for the roll out of imminent immunisation programmes, the need to know the scale of the hidden prevalence and hence knowledge of the level of immunisation required is essential. We describe and analyse the numbers of reported cases of COVID-19 in Ireland from the first case in February 2020 to mid-December 2020. Using the method of back-calculation we provide estimates of the asymptomatic prevalence of cases from June to December 2020. The descriptive analysis highlighted two epidemic waves of known cases in the time period. Wave two from June to December included twice as many cases as wave one and cases were significantly younger. The back-calculation estimates of asymptomatic prevalence during this time period revealed that for every case known there was an additional unknown case and total prevalence in wave two was estimated to be approximately 95,000 as opposed to the reported 48,390 cases. As prevalence in wave two is known to be spreading within and from younger age groups the role of mixing patterns on spread needs to be disseminated to the wider public to adequately inform them how personal modifications in behaviour can contribute to the control of the epidemic. While universally imposed lockdowns and mitigation measures may be essential, personal behavioural mixing choices are powerful protectors.

No time to delay reperfusion: A cross-sectional study of primary percutaneous coronary intervention times.

AIMS AND OBJECTIVES: To establish and report cross-sectional data of reperfusion times for emergency primary percutaneous coronary interventions (PPCI) and to examine factors associated with times to reperfusion. BACKGROUND: Rapid coronary reperfusion can salvage myocardial tissue, preserve left ventricular function and reduce mortality. PPCI is the gold standard of management. Researchers have reported on international median reperfusion times, but this is the first Irish study to do so. METHODS: This observational, prospective, cross-sectional study included patients diagnosed with ST-segment elevation myocardial infarction (STEMI) and admitted for emergency PPCI. Descriptive and inferential statistics were used. The study was ethically approved. We adopted the STROBE guidelines. RESULTS: All patients (N = 133) who met the inclusion criteria were included initially. Of these, 105 (79%) were diagnosed with STEMI and received emergency PPCI. The majority of STEMIs were diagnosed by paramedics and most (67%) were reperfused within 120 min, with a median time of 96 min. The results suggested that younger patients achieved timelier PPCI and source of referral was also significant in that more of those transferred directly to the coronary catheterisation laboratory achieved reperfusion within 120 min, compared with those who presented to the emergency department. CONCLUSION: A timely reperfusion service is achieved for the majority. Attention is needed in respect of the ageing and those admitted directly to the emergency departments with STEMI. RELEVANCE TO CLINICAL PRACTICE: Further international research is recommended to compare current reperfusion times against guidelines and to identify areas for improvement. Clinicians should be mindful of the importance of rapid reperfusion and the implications of its delay for patients with STEMI. Those presenting to emergency departments with chest pain should be prioritised.