A spread may pertain-to an avian (influenza virus).Logical formLearned from12 sentences. A virus may be found in a us-state.Logical formLearned from12 sentences. A virus may bounce.Logical formLearned from12 sentences. A virus can be spiritual.Logical formLearned from12 sentences. A hunt can be for an origin of a virus.Logical formLearned from12 sentences. A virus can be from a (lung tissue) of a patient.Logical formLearned from12 sentences. A relationship can be with viruses.Logical formLearned from12 sentences. A source may pertain-to a (bird flu virus).Logical formLearned from12 sentences. A (polio virus) can be in a country.Logical formLearned from12 sentences. An outbreak may be caused by a virus.Logical formLearned from12 sentences. A virus may attack internal organs.Logical formLearned from12 sentences. Vaccination can be against virus.Logical formLearned from11 sentences. A (bird flu virus) may remain over a period.Logical formLearned from11 sentences. A virus may undergo deaths.Logical formLearned from11 sentences. Some persons may be infected by virus.Logical formLearned from11 sentences.