Hong Kong health officials investigate psittacosis outbreak in Sheung Shui
Hong Kong health officials are investigating an outbreak of psittacosis that has infected five male employees at the New Territories North Animal Management Centre (NTNAMC) in Sheung Shui, according to a Centre for Health Protection (CHP) press release Nov. 27.
The investigation into the outbreak is performed in conjunction with the Agriculture, Fisheries and Conservation Department (AFCD).
According to the CHP, respiratory specimens from three patients ( 55-year-old patient at Queen Mary Hospital, 62-year-old patient in Alice Ho Miu Ling Nethersole Hospital and 27-year-old patient who had been discharged from Yan Chai Hospital) were tested positive for Chlamydophila psittaci by polymerase chain reaction as confirmed by the CHP’s Public Health Laboratory Centre, suggesting that they were suffering from psittacosis infection.
So far, a total of five staff of AFCD working in NTNAMC developed respiratory symptoms (mostly pneumonia) requiring admission to hospitals. One recovered and the other four are currently in hospitals in Hong Kong (three) and Australia (one).
CHP has successfully contacted 59 AFCD staff working in the NTNAMC and eight of them are found currently with upper respiratory symptoms. Arrangement will be made with the Hospital Authority for these eight persons for medical assessment and laboratory investigation to rule out psittacosis.
Most wild and domestic birds can be natural reservoirs of the causative bacteria, Chlamydophila psittaci; however parrots, parakeets, and cockatiels are among the birds most commonly implicated in human infection.
The vast majority of cases of psittacosis, or parrot fever are a direct result of human exposure to pet birds, either as owners or pet shop employees. The remainder of human cases is due to occupational exposure; turkey processing workers, vets, and zoo workers to name a few.
In the bird, infection may not become apparent unless resistance is compromised through conditions like crowding, transport, deficiencies in nutrition or other stressors.
The infection in the bird is mostly gastrointestinal and respiratory with the bird showing the following symptoms: diarrhea, nasal discharge, fever and discharge from the eyes.
The organism is shed in the liquid feces or nasal discharge of a sick bird. Even healthy birds can be carriers of psittacosis and may shed the organism intermittently.
Here it can contaminate the environment, the bird’s cage and the feathers. As the feces dries, the bacteria become airborne from the motion of the feathers and this is where humans can get infected.
The aerosolized, airborne particles are very small and do not settle easily and remain suspended in the atmosphere for long periods of time.
The infection in people can range from an inapparent illness to a systemic disease and severe pneumonia with some fatalities reported.
The onset of disease may be fever, headache, body aches, cough and shortness of breath. The illness is usually self-limiting (up to 2 weeks).
More severe disease may show diarrhea, vomiting and enlarged liver and spleen. The organism can affect some organ systems other that the respiratory. Cases of endocarditis, arthritis and hepatitis have been seen.
Psittacosis is treatable with doxycycline. The fatality rate of patients treated with antibiotics is very low, less than 1%.
To prevent psittacosis, the CHP is advising members of the public to take heed of the following measures:
* Wear gloves and face masks when handling droppings and secretions of birds;
* Wash both hands thoroughly after handling birds;
* Avoid close contacts with birds;
* Disinfect bird cages and surfaces contaminated by bird droppings and secretions; and
* Seek medical treatment if symptoms develop.
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