While the number of deaths from the disease has so far been low, the WHO said in the report: "It continues to spread across Iraq and dissemination to as yet unaffected areas remains highly possible."
A new case in Baghdad has taken the number of confirmed infections there to two, said WHO spokeswoman Fadela Chaib.
A woman in the Iraqi capital died from the disease on Monday.
Six cases have also been confirmed in Tikrit and two have been confirmed in Mosul, both to the northwest of Baghdad.
One case has been confirmed in Dahuk, in the far north of the country near the Turkish border.
Chaignat said a further confirmed case in Basra was likely to be unrelated to the other outbreaks, as cholera is endemic to the southern district.
Cholera is a gastrointestinal disease that is typically spread by drinking contaminated water and can cause severe diarrhoea that can lead to fatal dehydration in serious cases.