Within the framework of the nationwide enterovirus surveillance (EVSurv), all paediatric and neurological clinics in Germany are offered free enterovirus diagnostics for patients with suspected viral meningitis or encephalitis as well as acute flaccid paresis (AFP). Approximately 150 clinics throughout Germany are currently participating in EVSurv. On average, 2,500 samples are examined annually within the EVSurv; enteroviruses (EV) can be detected in 20-30% of the samples (Tab. 1).

Compared to previous years, less than half of the samples were sent to a LaNED in 2020 and 2021. This shows that the infection control measures due to the COVID 19 pandemic are effective in effectively slowing down infection events. Currently, the positive rate is slightly increasing again, but is not yet at the level of the years before the pandemic.

^{Tab. 1: Results of the Enterovirus-Surveillance (EVSurv) in Germany 2006 – December 2024}

					thereof AFP cases
Year	EV-PCR pos	EV-PCR neg	total [n]	% EV PCR pos	AFP total [n]	thereof EV-PCR pos
2006	683	1.241	1.964	34,8	52	3
2007	665	1.534	2.235	29,8	54	3
2008	1.108	2.040	3.216	34,5	66	3
2009	487	2.022	2.556	19,1	62	6
2010	772	2.040	2.947	26,2	54	6
2011	753	2.273	3.074	24,5	61	6
2012	668	2.205	2.926	22,8	50	7
2013	1.242	2.150	3.455	35,9	76	7
2014	501	1.961	2.508	20,0	46	3
2015	429	1.710	2.173	19,7	56	4
2016	527	1.900	2.447	21,5	78	6
2017	448	1.719	2.189	20,5	54	6
2018	421	1.514	1.965	21,4	29	4
2019	446	1.632	2.094	21,3	47	3
2020	34	1.277	1.316	2,6	31	0
2021	60	1.182	1.253	4,8	32	1
2022	174	1.186	1.365	12,7	41	5
2023	285	1.126	1.428	20,0	21	5
2024	322	1.166	1.544	20,9	20	1
Average	528	1.678	2.245	21,7	49	4
Total	10.025	31.878	42.655		930	79

In order to be able to exclude polioviruses with certainty, stool samples are primarily recommended for examination. In total, they make up approx. 68% of the material sent in for examination, and another 27% are cerebrospinal fluid samples. In the case of a polio-like course with preceding respiratory symptoms, the examination of an additional sample taken from the upper respiratory tract is reasonable and is also carried out free of charge within the framework of EVSurv.

About 57% of the samples came from male patients, 42% from female patients. The patients examined were predominantly children <15 years of age (84%, median 4 years), with the highest proportion of EV-positive samples (34%) in the age group of 5 to 9 years over the entire period.

Since 2014, the number of samples received from children over 5 years of age has decreased, while the number of samples received from children under 5 years of age has remained stable.

The EV serotype can be determined in about 80% of the positive samples. Overall, 51 different EV serotypes were detected. Polioviruses were not detected during the entire period.

EV infections show a clear seasonality and dominate in the months of July to September (64% of all EV infections in the year). In the 2013 season, very strong EV activity was observed, characterized by the highest sample volume to date as well as a very high EV PCR positive rate (almost 60% in August). Since then, the annual sample volume has been moderate and -in the pandemic years 2020 and 2021- significantly reduced. In particular, the number of EV-positives declined sharply. In the 2022 season, the number of enterovirus positive samples increased again compared to 2020 and 2021, but was still far below pre-pandemic levels (Fig. 1). This trend continued in the seasons 2023 and 2024.

The predominant enterovirus types so far have been echovirus type 30 (E30), but also echovirus type 6 (E6) and enterovirus A71 (EV-A71), followed by coxsackievirus B5 (CVB5). In 2020 and 2021, no conclusion could be made about the predominance of enterovirus types due to the low number of detections. In 2024, EV-A71 [n=41] E30 [n=31], and E25 [n=22] were detected most frequently.

The number of AFP cases tested per year varied between 20 and 76 in 2010 - 2024, with an enterovirus positive rate between 5 and 24%. In 2024, enteroviruses were detected in one sample of a patient with suspected AFP (total AFP samples in 2024: n=20; Tab1). In this EV-positive sample from an AFP patient, three different EV types (EV76, E3 and E25) were detected simultaneously. To date, a total of 23 different enterovirus types have been detected in patients with AFP in Germany (Fig. 2).

The option to test an additional respiratory specimen from AFP cases for enteroviruses free of charge is still not frequently used (<5 cases per year). The recommendation to do so is based on reports of AFP cases with signs of spinal cord lesion (acute flaccid myelitis, AFM) possibly associated with enterovirus D68 (EV-D68). As this virus type is acid-unstable and hardly tolerates gastrointestinal passage, EV-D68 is rarely detected in stool [n= 10]. A respiratory sample should be taken within the first few days of illness.

Via the link: "Datenbank-Abfrage zur Enterovirus-Surveillance” you also have the option of making your own queries from the EVSurv database (see link below).