Border screening for SARS

Nicola Petrosillo,* Vincenzo Puro,^† Giuseppe Ippolito^‡

* Clinical Director, † Epidemiologist, ‡ Scientific Director, National Institute for Infectious Diseases “L. Spallanzani”, Rome, 00149, Italy. petrosillo@inmi.it

to the editor: In their article describing the Australian experience of border screening for severe acute respiratory syndrome (SARS), Samaan and coworkers add new insights about the low efficacy of this measure in identifying SARS cases at entry into a country. ¹ To our knowledge, this is the first report on this issue from a low‐risk area for SARS. ² Indeed, as summarised by Samaan et al, other available data derive from countries where people with SARS, entering at the early stage of the epidemic, generated a sustained local transmission of SARS‐associated coronavirus (SARS‐CoV) disease. Among the reasons for a low sensitivity of entry screening, Samaan suggests that subjects may evade screening by making false declarations or by taking anti‐pyretic drugs, or by simply being in the incubation period with no symptoms or only mild symptoms.

To contribute to this debate, we report the experience of our Institute, which was designated as a referring centre for SARS by the Italian Ministry of Health. In Italy, where only four imported probable cases of SARS were identified and no local transmission occurred, ³ entry screening was implemented at the two international airports of Milan and Rome. In particular, travellers and crews arriving from World Health Organization SARS‐designated areas, directly or after transiting in other EU countries, were provided with health alert cards and screened for body temperature. ⁴ Suspected SARS cases identified at Rome airport were to be referred to our institute.

However, of the 72 subjects attending our admission unit for clinical evaluation for possible SARS, none was referred by the airport authorities. Among these patients was one of the four people with SARS arriving in Italy: an airline flight crew member coming from a SARS‐designated area who passed both exit and entry screening, despite complaining of mild fever before his departure. He was admitted 6 days after arrival, at which time the clinical picture had evolved into full‐blown SARS. He was discharged after 2 weeks.

Among the measures recommended by WHO to reduce SARS‐CoV spread, the identification of symptomatic subjects at border departure screening was the only measure with some evidence of efficacy, although this only reduced on‐flight transmission. ⁵

Conversely, evidence from several sources, including Samaan et al, showed that screening travellers (visual inspection and screening for fever) as they disembark identifies very few SARS cases and is of questionable value. ¹ We agree with the conclusions of Samaan et al that, in the light of a possible resurgence of SARS or similar diseases (avian flu), entry screening should, at least, be more focused, and needs further evaluation, including cost‐effectiveness analysis.

Acknowledgements

Acknowledgement: Ministero della Salute Ricerca Finalizzata e Ricerca Corrente IRCCS.