Unmasking "masked" SARS in elders

Abstract

This is a research study based on the public hospitals database of Severe Acute Respiratory Syndrome (SARS) among elders aged over 65 years in Hong Kong during the SARS epidemics in the year 2003. The objective is to gain insight into "masked" SARS among elders, with special attention to delayed presentation and detection including post-mortem diagnosis, as well as outbreaks from unsuspected index cases. Previous literature reports on “masked” SARS are also reviewed. Conclusion: The presentations of SARS in elders are diverse and complex, with non-specific global rather than focal features (blunted fever response, confusion, falls, poor feeding, tiredness, social crisis, masked by multiple diseases). Predicting laboratory-confirmed SARS from typical clinical features of SARS is less accurate in older compared with younger adults (61% vs. 88%). Thus, there is need for careful observations on any change in physical, functional and mental states (team approach) during the SARS epidemics, as well as need for appropriate diagnostic workup to avoid under-diagnosis or over-diagnosis.

The publicized reports of “masked” or “invisible” SARS in elders have aroused much fear and anxiety among elders, the public, and healthcare workers. Of the 1755 SARS patients reported in Hong Kong during the SARS epidemics in the year 2003, 324 are aged over 65 years, and of these, 65 are residents of residential care homes for the elderly (RCHE). Elders (aged over 65) are over-represented among the SARS victims compared with the total population (18.5% versus 11.7%), and their risk of contracting SARS is 1.58 times that of the general population (0.041% versus 0.026%). This risk rises with age and frailty: being 2x for elders aged over 75 and 4x for elders residing in RCHE.

The dawn of Geriatric Medicine has uncovered many of the atypical and “silent” presentations of illnesses in old age and revealed that they often masquerade as geriatric syndromes or geriatric giants especially among frail elders. The atypical and altered presentations of pneumonia and tuberculosis among elders have been well described in the literature. With a view to gain insight into “masked” SARS, the database of elderly SARS (aged over 65) in Hong Kong are examined and studied, with special attention being paid to delayed presentation and detection including post-mortem diagnosis, as well as outbreaks from unsuspected index cases. Previous literature reports on “masked” SARS are also reviewed.