Australia, China, Japan, Singapore, and South Korea report new cases of influenza A(H1N1)

Report
from World Health Organization
Published on 29 May 2009 View Original
MANILA, 29 May 2009, 16:00 - Australia reported 81 new laboratory-confirmed cases of influenza A(H1N1) to take its total to 147. China, Japan, Singapore and South Korea and also announced new cases. So far no deaths from influenza A(H1N1) have been reported in the Western Pacific Region.

The Western Pacific Region has reported a total 609 laboratory-confirmed cases of influenza A(H1N1):

- 147 in Australia

- 41 in China

- 367 in Japan

- 2 in Malaysia

- 9 in New Zealand

- 6 in the Philippines

- 33 in the Republic of Korea

- 4 in Singapore.

Health officials in the northern Australian state of Queensland confirmed that three crew members on the cruise-liner Pacific Dawn had tested positive to influenza A(H1N1). Australia's cases are clustered mainly in the more populous states of Victoria and New South Wales, where 96 and 33 cases respectively have been reported. A further nine cases have been detected in Queensland, five in South Australia, three in the Australian Capital Territory, and one case in Western Australia.

China declared seven new cases, including a 26-year-old woman who arrived on a flight from the Washington, D.C., via Chicago in the United States of America on 23 May. The number of cases in the Republic of Korea rose by one to 33, and Singapore reported three additional cases, all of whom had recent travel history to the United States of America.

Japan announced three new cases, taking its total to 367. It has 187 cases in Hyogo Prefecture and 156 at Osaka Prefecture, the two prefectures where the majority of infections have occurred. Chiba has reported eight cases, with three each in Tokyo and Shiga, two apiece in Saitama, Kyoto, Shizuoka and Kanagawa, and one each in Fukuoka and Wakayama.

The new cases in Japan are mainly associated with schools and, at this stage, there is no clear sign of the virus transmitting into local communities. Although the majority of cases are related to the initial school outbreaks around Kobe and Osaka, there are a small number of cases where public health authorities are finding it difficult to make a clear link to an affected school. Further information on those cases is expected in the near future as investigations continue.

Dengue fever threatens again in Western Pacific Region

As the number of influenza A(H1N1) cases climbs in the Western Pacific Region, another virus is having a serious but under-recognized impact. There are outbreaks of dengue fever in many parts of the world, including the Western Pacific Region, and early symptoms can be similar to seasonal influenza and the new influenza A(H1N1) virus.

Last year 213 248 cases of dengue were reported in the Western Pacific Region. As the Southern Hemisphere enters its influenza season, with the new influenza (H1N1) virus infecting more people, it is important that communities be aware that a range of febrile illnesses including dengue can be accompanied by symptoms in their initial stages which could be mistaken for influenza.

Nearly half the world's population, or 2.5 billion people, are at risk from dengue. WHO estimates there may be 50 million cases worldwide every year. In the Western Pacific Region, the current dengue season seems to have started early and has the potential to be the most serious in recent years, unless Member States strengthen outbreak preparedness.

Dengue has killed 14 people across 35 provinces in Vietnam since early this year from 16,635 cases reported since January. This is a significantly higher infection rate than 2008, when 11 447 people contracted the illness over the entire year.

From January to April this year dengue outbreaks were reported in Malaysia, Australia, Viet Nam, Fiji, Tonga and New Caledonia. Some countries and areas in the Region reported very high incidence rates: 2983 cases per 100 000 inhabitants in New Caledonia, 797 per 100 000 inhabitants in Cook Islands, and 249 in 100 000 inhabitants for Tonga. Compared to the same period in last year, dengue has risen significantly, particularly in New Caledonia, Australia, Vietnam and Malaysia.

Dengue is characterized by a sudden onset of headaches, severe muscle and joint pains and often also a rash. Nausea and vomiting may also ensue. In its initial phases, dengue as well as other febrile illnesses such as typhus and leptospirosis can be confused with influenza.

The ability to pick dengue from influenza is crucial, as dengue can progress into a more serious illness called Dengue Haemorrhagic Fever (DHF). Communities should be on the alert for possible complications from dengue, such as fainting, a rash, lingering acute fever, less frequent urination, nose and gum-bleeding, and severe pain behind the eyes. Care-givers and health-workers should be particularly vigilant with children, who are vulnerable to complications from dengue and are more likely to die from them.

Globally, complicated cases of dengue hospitalise an estimated 500 000 people each year, mostly children, though this number could be higher due to under-reporting. Without proper treatment, fatality rates can increase significantly. But with early recognition and treatment, death rates can be cut to less than 1%.

Dengue treatments include bed rest and proper management of fluids and aggressive emergency treatment in severe cases. On a community level, the response focuses on the eradication of breeding sites of mosquitoes whose bite causes the illness. Communities are their own first-lines of defence against dengue, as controlling mosquito numbers at the local level is crucial in reducing infections.

Influenza, on the other hand, can be treated with antiviral drugs in combination with isolation and quarantine protocols. Community messaging about hand-washing and social distancing is also very effective.