inclusion criteria: - this study will include volunteers household contact of covid 19 confirmed cases who attend the triage clinic in the participating centers. included persons should be > 18 years old and below 65 years, without any contraindications for mefloquine usage.

inclusion criteria: - this study will include volunteers household contact of covid 19 confirmed cases who attend the triage clinic in the participating centers. included persons should be > 18 years old and below 65 years, without any contraindications for mefloquine usage.