Sullivan also pointed to possible "complicating factors, " such as malnutrition, poor housing or crowded conditions.

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It can spread in markets or places where eggs and birds are sold in crowded conditions.

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The Dowlings said living in such crowded conditions is adversely affecting the family's life.

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However, the increasing numbers of mobile phones in use make it more likely that in crowded conditions such devices will give false alarms by warning you of the ringing of someone else's phone.

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"We expect that our stations, trains and buses will be packed as people head to the Inauguration, and we expect to see even more crowded conditions afterward, " Metro General Manager John Catoe said on the Metro's Web site.

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It hasn't yet taken hold in the capital Port-au-Prince, where it could spread rapidly because of the crowded living conditions.

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Their conditions are abject: crowded, short of drinking water and with poor sanitation.

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Forecasts of similar conditions raised alarms throughout the Plains, leading to crowded stores as residents prepared.

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