key: cord-310149-8idvf79g
authors: Antinori, Spinello; Torre, Alessandro; Antinori, Carolina; Bonazzetti, Cecilia; Sollima, Salvatore; Ridolfo, Anna Lisa; Galli, Massimo
title: SARS-COV-2 infection: Across the border into the family
date: 2020-06-09
journal: Travel Med Infect Dis
DOI: 10.1016/j.tmaid.2020.101784
sha: 
doc_id: 310149
cord_uid: 8idvf79g

nan

Spinello Antinori 1,2 , Alessandro Torre 1 , Carolina Antinori 3 Dear Editor, Italy has been one of the countries most affected by the COVID-19 pandemic since 21 February 2020 and, as of 18 April 2020, the Lombardy region alone has recorded 64,135 confirmed cases and 11,851 deaths, respectively 36.5% and 51% of the national burden. During the first weeks of the epidemic, before lockdown measures had been put in place, the dramatic increase in the number of patients requiring hospitalisation and intensive care led to the complete saturation of the region's hospital beds despite the rapid effort of the regional health authority to satisfy the demand [1] . At the same time, the number of laboratories equipped to confirm COVID-9 diagnoses by means of the real-time reverse transcriptase-polymerase chain reaction (RT-PCR) testing of nasopharyngeal swabs was very limited. In this dramatic context, the patients who turned to the regional emergency service for influenza-like illness (ILI) were advised to stay at home and request assistance only in the case of dyspnea. However, as there was no surveillance programme with the possible As shown in Figure 1 , the wife and children proved to be IgG positive (three by both tests, and one by the Orient Gene test alone), and the index case was also positive for IgM at the Orient Gene test.

This family cluster of probable COVID-19 cases merits a number of comments regarding the dynamics of the spread of COVID-19 and the importance of adding new controls, particularly in the light of the future gradual relaxation of containment measures. Firstly, although formally unproven, it is likely that our index case became infected outside Italy, a fact that underlines the importance of the rapid sharing of surveillance measures in order to increase our ability to detect imported cases in this globalised world.

Secondly, although the index case voluntarily isolated himself from the rest of his family as soon as he developed symptoms, it is also likely that he transmitted the infection to the rest of his family during the pre-symptomatic phase of infection. Initial studies carried out in China found that asymptomatic patients are associated with a 5% transmission rate [2] , but this figure was found to be as high as 42% in a recent northern Italian study, which supports the view that asymptomatic (or pre-symptomatic) subjects have played a major role in fuelling the COVID-19 outbreak in Italy [3] . It should be highlighted that self-quarantine is not the same of isolation, a measure which separates subjects identified as infected from othesr who are not. Nevertheless, proactive case finding with case management as adopted by the model of Veneto Region in Italy [4] or by drive-through

Coronavirus testing centers such as those employed in China, South Korea and Israel have shown to be valid measures to contain the epidemic [5] However, although COVID-19 transmission by asymptomatic subjects is a critical factor for ensuring an effective public health response to the epidemic, the best method of identifying asymptomatic infections is still unclear. The decision not to search for SARS-COV-2 in people with mild symptoms and not to include them in surveillance programmes is at least questionable, particularly because the future relaxation of containment measures will require even more active surveillance in order to ensure the early detection of new cases or clusters. The clinical definition of COVID-19 has so far mainly concentrated on patients with severe disease, and much less is known about the fraction of mildly symptomatic infections not requiring hospitalisation. It is interesting to note that all but one of the family members described in this report complained of altered smell and taste, and that an increasing number of reports suggest that these are so frequent in the early phase of COVID-19 that they may be considered clinical markers of the disease [6] . 5 Thirdly, we retrospectively identified this family cluster using two rapid serological tests. A number of such tests have become available but none have been approved by the regulatory authorities and their diagnostic accuracy is still being debated. However, the findings of recent studies suggest that they are sufficiently accurate to be used for public health purposes as well as being an invaluable epidemiological means of screening a large number of subjects.

Finally, it should be mentioned that people with suspected COVID-9 (such as the members of our family) do not appear in the official statistics concerning the COVID-19 epidemic. Given that it is unlikely that ours an isolated event, it is possible that overlooking mildly symptomatic cases is leading to a serious underestimate of the real burden of COVID-19.

. Serological testing of the five family members involved in a probable COVID-19 cluster

Baseline characteristics and outcomes of 1591 patients infected with SARS-CoV-2 admitted to ICUs of the Lumbardy Region

Characteristics of COVID-19 infection in Beijng

Suppression of COVID-19 outbreak in the municipalità of Vò

Covid-19 in Italy: lesson from the Veneto Region

Drawing on Israel's experience organizing volunteers to operationalize drive-through Coronavirus testing centers

Self-reported olfactory and taste disorders in SARS-CoV-2 patients: a cross-sectional study

Dr Carlo Parravicini for assistance in figure production

Written informed consent was obtained from all of the subjects, including the parents of the children

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