New Zealand must remain aware of international trends.
The report, produced by Te Kunenga ki Pūrehuroa Massey University's Environmental Health Intelligence New Zealand (EHINZ) examines overseas infectious diseases of priority concern including polio, mpox, measles and non-seasonal influenza, which have the potential to spread internationally through travel and migration.
EHINZ Senior Intelligence Analyst Dr Mui Nguyen says ongoing surveillance plays an important role in helping New Zealand understand and prepare for emerging health risks.
“In today’s interconnected world, infectious diseases can cross borders quickly through international travel. Monitoring overseas disease trends helps us identify emerging threats and supports preparedness efforts in New Zealand.”
The report found that polio cases remained high in several African countries during 2025, particularly Nigeria (73 cases), Chad (55 cases) and Ethiopia (40 cases).
“While significant progress has been made towards eliminating polio worldwide, cases continue to occur in some regions. Continued international efforts are needed to reduce transmission and move closer to eradication.”
Mpox cases have increased significantly across the globe, rising from 9,666 cases in 2023 to 53,562 cases in 2025. A surge in infections, including the emergence of a new strain, prompted the World Health Organization (WHO) to declare mpox a Public Health Emergency of International Concern (PHEIC) in August 2024, a status that remained in place during 2025.
Dr Nguyen says the rapid increase in mpox cases and the emergence of a new strain demonstrate how quickly infectious disease situations can evolve.
“Ongoing surveillance is essential for understanding these changes and informing public health responses,” Dr Nguyen explains.
The report also highlights a concerning rise in measles. Global rates increased steadily from 25.7 cases per million people in 2022 to 82.8 cases per million people in 2024, while vaccination coverage remained below optimal levels in many countries.
Dr Nguyen states that the trend underscores the importance of maintaining high vaccination rates.
“The rise in measles cases globally is concerning, particularly as vaccination coverage in many countries remains below the levels needed to prevent outbreaks. Vaccination continues to be one of the most effective tools for protecting individuals and communities from this highly infectious disease.”
In contrast, reports of non-seasonal influenza declined, with cases identified in just three countries in 2025, down from 10 in 2024. All reported events were contained with limited spread beyond one or two human cases.
Despite some encouraging trends, Dr Nguyen says international disease surveillance remains critical.
“Although many of these diseases are occurring overseas, it is important that New Zealand remains aware of international trends. Understanding what is happening globally helps ensure our public health systems are prepared and responsive.”
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