SARS-CoV-2 has now crossed the 1 million number of cases and tens of thousands of deaths. It´s R0 has been calculated between 2 and 5.7 solely based on clinical symptoms but it is estimated to likely be higher. Serologic evidence of infection has not been analyzed.

Transverse, observational and descriptive study involving household contacts of documented patients with COVID-19 infection: contacts will be invited to participate and a blood sample will be drowned: IgM and IgG qualitative and quantitative measurements will be performed. Demographic data regarding age, comorbidities, calculated time spent before and after the patients diagnosis, isolation practices etc.

Inclusion Criteria:

1. Persons over 1 years of age.

2. .Meet COVID-19 confirmed case intradomestic contact definition:

   1. Living in the same home as the patient with SARS-CoV-2 PCR test detected (nasopharyngeal and/or oropharyngeal swab) performed in the Acute Respiratory Infection Diagnostic Unit.
   2. Living in the same home as the patient with a PCR test for SARS-CoV-2 Indeterminate (nasopharyngeal and/or oropharyngeal swab) performed in the Acute Respiratory Infection Diagnostic Unit and that the initial patient has positive IgM/IgG serology for SARS-CoV-2.

3. .Informed Consent.

Exclusion Criteria:

1. .Have fever, cough, pharyngeal pain or clinically have symptoms compatible with COVID-19 at the time of recruitment.
2. .Autoimmune disease, cancer, neutropenia.
3. .Under 1 years of age.
4. .Patients who, in the investigator's opinion, should be excluded from the research protocol.

The intradomiciliary contacts of the patients with a detected SARS-CoV-2 PCR test (nasopharyngeal and / or oropharyngeal swab) performed at the Acute Respiratory Infection Diagnosis Unit between March 2020 and May 2020 will be located: will invite to participate in the study to record their clinical and demographic data and to take serological samples by venipuncture or fingerstick to perform rapid tests for antibodies against SARS-CoV-2 (IVD COVID-19 IgM / IgG test kit, Singclean).

Informed consent shall be obtained from each person for the collection of samples. The data collected will be captured in an electronic database in Excel.