WHO team working with Chinese health authorities is reassured over swine flu outbreak

Aug 22 2005

Greater co-operation by the Ministry of Health of China with the World Health Organisation (WHO), has seen a sharing of more details about the outbreak of swine flu in China.

The WHO gathered together a group of international specialists on Streptococcus suis (swine flu), and they have made an assessment, based on the information provided by the Ministry of Health, that the current outbreak in humans is very likely Streptococcus suis.

According to the Ministry of Health in China, there have been 215 reported cases of the human disease associated with this outbreak, and 39 of these have been fatal.

Apparently no new cases have been reported since 5 August.

The data provided by China describes an outbreak that peaked from the second through the fourth week of July, and then rapidly dwindled.

Officials say several human cases were discovered later, once the epidemiological investigation had begun.

It was initially suspected that the early cases were of haemorrhagic fever with renal syndrome, but laboratory tests ruled that out.

As more cases were reported, with a range of symptoms such as high fever, malaise, nausea and vomiting, followed by meningitis, subcutaneous haemorrhage, toxic shock and coma in severe cases, that diagnosis was questioned; particularly as almost all of the patients were reported to be local farmers and butchers by profession, and mainly male.

All had been either killing sick pigs or processing and selling the meat, and more than 40 percent of the cases were aged between 50 to 60 years.

Subsequent tests confirmed the infection was Streptococcus suis serotype 2 and was also discovered in pigs in the area.

Authorities confirm that so far there is no evidence of human-to-human transmission, and no healthcare workers tending to the patients have been infected.

The group of international specialists on Streptococcus suis, which included WHO technical staff, are happy and reassured with the validity of the laboratory identification of Streptococcus suis serotype 2, but suggest further testing on samples from the Sichuan outbreak might be helpful.

The Chinese authorities are apparently eager for such studies to be conducted.

The team also note the lack of evidence suggesting any human spread in the present outbreak.

The group also reiterated that although consumption of raw or undercooked pork may lead to disease, eating properly cooked pork is unlikely to represent an increased risk, even if the strain of Streptococcus suis involved is more virulent.

The Chinese authorities and the specialist team agreed that the movements of live pigs, and the trade of pig carcasses and meat within and from the outbreak area, had to be carefully regulated and monitored, in order to prevent the possible national and international spread of the outbreak.

China has confirmed it has put strict measures in place to safeguard against this.

Throughout the course of this outbreak the Chinese Ministry of Health has provided WHO with regular updates, and the WHO will continue to monitor the situation, and offer support.