There are now eight confirmed cases of Zika in American Samoa.
Initial tests of 25 blood samples had confirmed four Zika cases, one of whom was pregnant.
The samples were later retested and another four positives were found, but none are expectant mothers.
The testing was undertaken in Honolulu and in Colorado.
The American Samoa Health Department is collecting data on pregnant women from the LBJ Hospital, and community health centres are concentrating clean up efforts in the villages with the highest number of expectant women.
The four villages, are Leone, Nuuuli, Tafuna and Iliili.