The latest case marks Cambodia's ninth since early June.
In a related development, details surfaced about another recent fatal case in a young child.
The patients had contact with sick poultry, a feature of most H5N1 infections in Cambodia.
US officials confirm the nation's first H5N1 avian flu detection in US dairy cattle in 3 weeks.
Listed in critical condition, the woman had recently handled and cooked sick poultry.
Some of the recent wild bird positives were sampled recently in a region where outbreaks were reported at Arizona layer farms.
It is not yet known which strain of H5N1 was involved in the latest Cambodian case.
The patient's neighbor had chickens, but no illnesses or deaths were reported in the flock.
Pakistan reported a new wild poliovirus type 1 case, while five countries reported cases of vaccine-derived polio.
Sequencing linked the cases to an older H5N1 clade still circulating in India and Bangladesh.
