DISEASE SURVEILLANCE FOR APR-JUN 2017

17.7.2017

Dengue fever

There has been an increase (~120%) in the number of cases of dengue fever for the three months between April and June. A lesser increase (~50%) has occurred if the last quarter results are compared with the corresponding quarter in the last three years. Dengue is endemic in much of Asia, including India, and South East Asia, so consider the diagnosis in febrile patients returning from these regions. The incidence of dengue fever in many of the South Pacific islands is rising (including Cook Islands, Federated States of Micronesia, French Polynesia, Fiji, New Caledonia, Niue, Samoa, Tonga and Vanuatu). Since 2014 there have been an increase in confirmed cases from these islands.

Mumps

The mumps outbreak in Auckland continues, with the majority of cases occurring among those aged 10 to 19 years and arising in West Auckland. Overseas incursions continue (15%), however the majority of transmission is occurring in the community. Low levels of immunity among cases (73% who have not received two mumps containing vaccines) are likely to be responsible.

Typhoid

The large increase in typhoid cases seen in Q2 was driven by a well-publicised outbreak in a Samoan community. It is believed to have been spread from a point source, ultimately leading to 23 notifications in the Auckland region, including one death. The outbreak is now considered over, but it is a timely reminder of the need for vigilance in considering the diagnosis since the disease is frequently imported from the Pacific and Asia.

Whooping Cough (Pertussis)

Pertussis case numbers have increased compared to the same period in 2016, however the increase is not unusual, considering the number notifications that have occurred over the same three month period during the last three years.