Update on Zika virus Outbreak in Tonga 8th February 2016

The Ministry of Health, Tonga (MOHTO) had declared on the 1st February, 2016 that Tonga is experiencing an outbreak of the Zika virus.  The declaration was based on the initial detection of a sudden increase in the syndrome of Acute Fever and Rash (AFR) from the MOH Communicable Disease Syndromic Surveillance System.  In addition, blood samples taken from patients were sent to New Zealand and Tahiti (French Polynesia) for confirmatory testing. The results were positive for the Zika virus which confirms the virus to be in circulation in Tonga for the first time. There were two batches of blood samples sent for confirmatory tests overseas in January. The first batch involved 9 samples sent to Lab Plus New Zealand. Of the 9 samples sent, two results were positive for the Zika virus. The second batch involved 35 samples being sent to Tahiti for confirmatory tests and results are still pending.

The data collected from sentinel sites shows a total of 549 cases of Zika (542 suspected and 7 confirmed). Of the confirmed cases, two were local cases and five cases were tested in New Zealand with a travel history to Tonga. It is estimated that the number of Zika cases are in fact higher than the reported statistics. This is due to a large number of patients experiencing mild symptoms and do not present to the health-care facilities for medical consultation. There have been no reported hospital admissions or deaths.  In addition, there are 3 pre-natal mothers who have been reported with the symptoms of the Zika virus infection in Tonga. The current trend on the Epi-curve shows the weekly case reports of Zika to be increasing.

The main mode of transmission of the Zika virus is through the bites of infected mosquitoes. There are also other modes of potential transmission such as perinatal transmission, blood transfusion and sexual transmission. Moreover, Tonga is concerned with the current Zika virus outbreak in Brazil, especially, on the neurological and congenital complications that are being observed in their population and its implications   to the people of Tonga. In response to these concerns, specific surveillance and monitoring mechanisms are being set up for pregnant women and reproductive health policies are to be reviewed and discussed.   

The strategic response program to the community includes extensive multimedia awareness programs, social mobilization, vector control programs and partner engagement, executed by the relevant stakeholders, MOH co-ordinated activities through Government and Non- Government Organizations (NGO’s).  The MOH Epidemic Taskforce is supported in its co-coordinating role of the response to this Emerging disease by the National Emergency Management Office (NEMO) under the auspices of the Ministry of Meteorology, Energy, Information, Disaster Management, Climate Change and Communications (MEIDECC).

General Advice

  1. General prevention from being bitten by the Aedes aegypti mosquitoes include:
    1. National campaigns to destroy breeding places of Aedes aegypti mosquitoes.
    2. Use of mosquito repellents; light mosquito coils around houses but make sure they are well ventilated; sleep under mosquito nets; cover windows, doors and louvers with mosquito screens, and wear long, loose clothes.
  2. Advise to all travellers to Tonga;
    1. Since Tonga is experiencing a Zika virus outbreak, travellers are advised to take the necessary precautions to protect themselves from mosquito bites.
    2. If travellers experience symptoms of Zika virus such as fever, rash, joint pain and red eyes, they should consult the nearest health-care facility for medical assistance.
    3. Pregnant women should reconsider travelling to Tonga during the Zika outbreak.
  3. For pregnant women who are ill with the Zika virus:  Should request blood screening for the Zika virus on booking, and to inform the Obstetrician accordingly.
    1. New-born-babies to mothers who have had a history of Zika illness, should be tested for the Zika virus.
    2. Mothers during prenatal phase should be advised to receive screening for potential fetal congenital malformations.
  1. For young women (and partner) who wish to have a baby during this period of Zika outbreak are advised to delay pregnancy by using any form of contraceptives that is available in the country.
  2. Prevention measures for the other potential mode of transmission that should be taken into consideration may include:
    1. All bloods for transfusion may need to be screened for Zika.

For further information, please contact Ministry of  Health :

Dr Reynold Ofanoa

(676) 23-200 ext 1321.

Dr Seini Kupu

(676) 23-200 ext 1408;

Dr Eugene Taoi

(676) 23-200 ext 1437