The Director of Health in Tonga says health authorities are struggling to locate carriers of typhoid following two new cases in the last month.
Dr Siale 'Akau'ola says two brothers living in the same household on 'Eua are the most recent cases of typhoid.
Last year there were eight confirmed cases.
Dr 'Akau'ola says some people can transmit the infection unknowingly.
"They're pretty asymptomatic and that's the difficulty of this problem. For example a healthy carrier can live in any community be it here in Tonga or New Zealand but if they live in Tonga or other Pacific Island countries with vulnerable environments they have a higher chance of passing it on to people."
Dr 'Akau'ola says people need to ensure they clean their hands thoroughly and protect food from flies.