Eurosurveillance - Volume 29, Issue 28, 11 July 2024

By mid-September 2023, several event notifications related to cryptosporidiosis had been identified from different regions in Spain. Therefore, a request for urgent notification of cryptosporidiosis cases to the National Surveillance Network was launched.

We aimed at assessing the extent of the increase in cases, the epidemiological characteristics and the transmission modes and compared to previous years.

We analysed data on case notifications, outbreak reports and genotypes focusing on June–October 2023 and compared the results to 2016–2022.

In 2023, 4,061 cryptosporidiosis cases were notified in Spain, which is an increase compared to 2016–2022. The cumulative incidence was 8.3 cases per 100,000 inhabitants in 2023, sixfold higher than the median of 1.4 cases per 100,000 inhabitants 2016–2022. Almost 80% of the cases were notified between June and October. The largest outbreaks were related to contaminated drinking water or swimming pools. Cryptosporidium hominis was the most common species in the characterised samples (115/122), and the C. hominis IfA12G1R5 subtype, previously unusual in Spain, was detected from 76 (62.3%) of the 122 characterised samples.

A substantial increase in cryptosporidiosis cases was observed in 2023. Strengthening surveillance of Cryptosporidium is essential for prevention of cases, to better understand trends and subtypes circulating and the impact of adverse meteorological events.

Wastewater surveillance is an effective approach to monitor population health, as exemplified by its role throughout the COVID-19 pandemic.

This study explores the possibility of extending wastewater surveillance to the Paris 2024 Olympic and Paralympic Games, focusing on identifying priority pathogen targets that are relevant and feasible to monitor in wastewater for these events.

A list of 60 pathogens of interest for general public health surveillance for the Games was compiled. Each pathogen was evaluated against three inclusion criteria: (A) analytical feasibility; (B) relevance, i.e. with regards to the specificities of the event and the characteristics of the pathogen; and (C) added value to inform public health decision-making. Analytical feasibility was assessed through evidence from peer-reviewed publications demonstrating the detectability of pathogens in sewage, refining the initial list to 25 pathogens. Criteria B and C were evaluated via expert opinion using the Delphi method. The panel consisting of some 30 experts proposed five additional pathogens meeting criterion A, totalling 30 pathogens assessed throughout the three-round iterative questionnaire. Pathogens failing to reach 70% group consensus threshold underwent further deliberation by a subgroup of experts.

Six priority targets suitable for wastewater surveillance during the Games were successfully identified: poliovirus, influenza A virus, influenza B virus, mpox virus, SARS-CoV-2 and measles virus.

This study introduced a model framework for identifying context-specific wastewater surveillance targets for a mass gathering. Successful implementation of a wastewater surveillance plan for Paris 2024 could incentivise similar monitoring efforts for other mass gatherings globally.

As Ireland prepared for an autumn 2023 COVID-19 vaccination booster campaign, there was concern that vaccine fatigue would affect uptake, which has been abating.

This study aimed to quantify the direct impact of the COVID-19 vaccination programme in Ireland on averted COVID-19-related outcomes including symptomatic presentations to primary care/community testing centres, emergency department (ED) presentations, hospitalisations, intensive care unit (ICU) admissions and deaths, in individuals aged ≥ 50 years, during Omicron dominance.

We conducted a retrospective observational COVID-19 vaccine impact study in December 2021–March 2023 in Ireland. We used national data on notified outcomes and vaccine coverage, as well as vaccine effectiveness (VE) estimates, sourced from the World Health Organization’s live systematic review of VE, to estimate the count and prevented fraction of outcomes in ≥ 50-year-olds averted by the COVID-19 vaccination programme in this age group.

The COVID-19 vaccination programme averted 48,551 symptomatic COVID-19 presentations to primary care/community testing centres (36% of cases expected in the absence of vaccination), 9,517 ED presentations (53% of expected), 102,160 hospitalisations (81% of expected), 3,303 ICU admissions (89% of expected) and 15,985 deaths (87% of expected).

When Omicron predominated, the COVID-19 vaccination programme averted symptomatic and severe COVID-19 cases, including deaths due to COVID-19. In line with other international vaccine impact studies, these findings emphasise the benefits of COVID-19 vaccination for population health and the healthcare system and are relevant for informing COVID-19 booster vaccination programmes, pandemic preparedness and communicating the reason for and importance of COVID-19 vaccination in Ireland and internationally.