CHP conducts comprehensive investigation into suspected Shiga toxin-producing Escherichia coli infection cluster at PMH
The Head of the Communicable Disease Branch of the Centre for Health Protection (CHP) of the Department of Health, Dr Albert Au, said today (February 11) that the CHP is conducting a comprehensive investigation into a suspected Shiga toxin-producing Escherichia coli (STEC) infection cluster, involving three doctors in the Oncology Department of Princess Margaret Hospital (PMH), with one of them passed away on February 7.
After receiving notification from PMH yesterday (February 10), the CHP representatives, together with representatives from PMH and the Chair of Infectious Diseases of the Department of Microbiology of the University of Hong Kong (HKU), Professor Yuen Kwok-yung, conducted an inspection of the workplace of the Oncology Department and other facilities of the hospital this morning.
"The case involves three oncologists at the hospital. Initial investigation revealed that they developed symptoms on February 4, 6 and 10 respectively. Symptoms included fever, abdominal pain and diarrhea. One of them, who had onset of symptoms on February 4, was admitted to PMH for treatment on February 6 and passed away the following day. The other two affected persons had mild symptoms," Dr Au said.
"Preliminary test results showed that the stool specimen from one of the three affected persons tested positive for STEC, while that of the other two affected persons (including the deceased patient) tested negative. Taking into account the clinical and epidemiological information, the CHP tentatively believed that the cluster may be associated with STEC infection," he said.
The CHP's epidemiological and environmental investigations are ongoing. The CHP will continue to collaborate with the Hospital Authority and the Department of Microbiology of the HKU to investigate the incident and trace the potential source of infection.
PMH has strengthened the monitoring of the gastrointestinal symptoms among its staff and has requested any staff members with relevant symptoms to report immediately for laboratory tests. The PMH has also arranged comprehensive disinfection of the oncology office area.
In general, STEC infections are usually associated with the consumption of contaminated food or water, such as raw or undercooked meat products, contaminated fruits and vegetables, and unpasteurised dairy products. Direct person-to-person transmission through the faecal-oral route can also occur.
CHP investigates imported measles case
The Centre for Health Protection (CHP) of the Department of Health (DH) today (December 23) is investigating an imported measles case and reminded members of the public who are non-immune to measles to ensure that they have completed two doses of measles vaccination before travelling to reduce the risk of infection.
The case involves a seven-month-old boy who developed fever, cough and runny nose on December 17. He was brought to seek medical attention from a private doctor on December 19. The boy developed a rash on December 21. He was brought to the Accident and Emergency Department of Caritas Medical Centre and admitted on the same day for treatment. His clinical specimen was tested positive for the measles virus upon nucleic acid testing. He is isolated for treatment and is currently in stable condition.
The patient stayed outside Hong Kong from October 1 to December 16. As he spent the whole incubation period outside Hong Kong, the case was classified as an imported case.
An epidemiological investigation revealed that the boy has not yet reached the age to receive the first dose of the measles vaccine. His parents are household contacts and also his travel collaterals. They had not received measles vaccination. The patient's mother presented a fever on December 18. The CHP is arranging testing for her.
Apart from seeking medical attention, the patient mainly stayed at home during the communicable period. The CHP is reaching out contacts who visited the private clinic during the same period on December 19, to identify if high risk persons were involved. The CHP will assess if they had immunity against measles and will arrange vaccinations for contacts who are non-immune. The CHP will continue to put the relevant contacts under medical surveillance. Management of relevant private clinic was requested to report to the CHP if any persons develop measles symptoms for follow up.
The CHP's investigation is ongoing.
"Measles remain as an endemic infection in many places around the world. The number of measles cases in some overseas countries has been increasing recently. The outbreaks in North America (including the United States and Canada), Europe and Southeast Asia areas (including Vietnam, Cambodia and the Philippines) are ongoing due to the relatively low vaccination rate. Furthermore, an increasing number of measles cases have also been recorded in Japan and Australia this year. Overseas cases mainly affected people who were unvaccinated or had unknown vaccination status. This shows the importance of maintaining a high vaccination rate and herd immunity within the community. For those who plan to travel to areas with measles transmission, they should check their vaccination records and medical history as early as possible. If they have not been diagnosed with measles through laboratory tests and have never received two doses of measles vaccine or are not sure if they have received a measles vaccine, they should consult a doctor at least two weeks prior to their trip for vaccination. Pregnant women and women preparing for pregnancy who are non-immune to measles as well as children aged under one year who are not due for the first dose of Measles, Mumps and Rubella (MMR) combined vaccine under theHong Kong Childhood Immunisation Programme, are advised not to travel to places with outbreaks of measles," the Controller of the CHP, Dr Edwin Tsui, said.
"The incubation period of measles (i.e. the time from infection to onset of illness) is seven to 21 days. Symptoms include fever, skin rash, cough, runny nose and red eyes. If travellers returning from places with high incidence or outbreak of measles develop symptoms of measles (e.g. fever and rash), they should seek medical advice immediately and avoid contact with non-immune persons, especially pregnant women and infants under one year old. They should also report their symptoms and prior travel history to the healthcare workers so that appropriate infection control measures can be implemented at the healthcare facilities to prevent any potential spread," Dr Tsui added.
"Under the Hong Kong Childhood Immunisation Programme, the overall immunisation coverage in Hong Kong has been maintained at a very high level through the immunisation services provided by the DH's Maternal and Child Health Centres and School Immunisation Teams. As evidenced by the findings on vaccination coverage of primary school students and the territory-wide immunisation surveys conducted regularly by the DH, the two-dose measles vaccination coverage has remained consistently high, well above 95 per cent, and the local seroprevalence rates of measles virus antibodies reflect that most people in Hong Kong are immune to measles. However, Hong Kong, as a city with a high volume of international travel, still faces the potential risk of importation of the measles virus and its further spread in the local community. Hence, a small number of people who have not completed a measles vaccination (such as non-local-born people including new immigrants, foreign domestic helpers, overseas employees and people coming to Hong Kong for further studies) are still at risk of being infected and spreading measles to other people who do not have immunity against measles, such as children under 1 year old who have not yet received the first dose of the measles vaccine," he continued.
People born before 1967 could be considered to have acquired immunity to measles through natural infection, as measles was endemic in many parts of the world and in Hong Kong at that time. People born in or after 1967 who have not yet completed the two doses of measles vaccination or whose measles vaccination history is unknown, should consult their family doctors as soon as possible to complete the vaccination and ensure adequate protection against measles.
Besides being vaccinated against measles, members of the public should take the following measures to prevent infection:
Maintain good personal and environmental hygiene;
Maintain good indoor ventilation;
Keep hands clean and wash hands properly;
Wash hands when they are dirtied by respiratory secretions, such as after sneezing;
Cover the nose and mouth while sneezing or coughing and dispose of nasal and mouth discharge properly;
Clean used toys and furniture properly; and
Persons with measles should be kept out of school till four days from the appearance of a rash to prevent the spread of the infection to non-immune persons in school.
For more information on measles, the public may visit the CHP'smeasles thematic page. Members of the public who are going to travel can visit the website of the DH'sTravel Health Servicefor news of measles outbreaks outside Hong Kong.
Source: AI-found images
