Injuries and envenomation by exotic pets in Hong Kong.

INTRODUCTION: Exotic pets are increasingly popular in Hong Kong and include fish, amphibians, reptiles, and arthropods. Some of these exotic animals are venomous and may cause injuries to and envenomation of their owners. The clinical experience of emergency physicians in the management of injuries and envenomation by these exotic animals is limited. We reviewed the clinical features and outcomes of injuries and envenomation by exotic pets recorded by the Hong Kong Poison Information Centre. METHODS: We retrospectively retrieved and reviewed cases of injuries and envenomation by exotic pets recorded by the Hong Kong Poison Information Centre from 1 July 2008 to 31 March 2017. RESULTS: There were 15 reported cases of injuries and envenomation by exotic pets during the study period, including snakebite (n=6), fish sting (n=4), scorpion sting (n=2), lizard bite (n=2), and turtle bite (n=1). There were two cases of major effects from the envenomation, seven cases with moderate effects, and six cases with mild effects. All major effects were related to venomous snakebites. There were no mortalities. CONCLUSION: All human injuries from exotic pets arose from reptiles, scorpions, and fish. All cases of major envenomation were inflicted by snakes.

Comparison of green pit viper and Agkistrodon halys antivenom in inhibition of coagulopathy due to Trimeresurus albolabris venom: an in-vitro study using human plasma.

INTRODUCTION: There are two antivenoms that may be administered in Hong Kong following a bite by Trimeresurus albolabris: the green pit viper antivenom from the Thai Red Cross Society in Thailand and the Agkistrodon halys antivenom from the Shanghai Institute of Biological Products in China. Both are recommended by the Central Coordinating Committee of Accident and Emergency Services of the Hospital Authority for treating patients with a bite by Trimeresurus albolabris. The choice of which antivenom to use is based on physician preference. This study aimed to compare the relative efficacy of the two antivenoms. METHODS: This in-vitro experimental study was carried out by a wildlife conservation organisation and a regional hospital in Hong Kong. Human plasma from 40 adult health care worker volunteers was collected. The Trimeresurus albolabris venom was added to human plasma and the mixture was assayed after incubation with each antivenom (green pit viper and Agkistrodon halys) using saline as a control. Fibrinogen level and clotting time in both antivenom groups were studied. RESULTS: The mean fibrinogen level was elevated from 0 g/L to 2.86 g/L and 1.11 g/L after the addition of green pit viper antivenom and Agkistrodon halys antivenom, respectively. When mean clotting time was measured, the value was 6.70 minutes in the control, prolonged to more than 360 minutes by green pit viper antivenom and to 19.06 minutes by Agkistrodon halys antivenom. CONCLUSIONS: Green pit viper antivenom was superior to Agkistrodon halys antivenom in neutralisation of the thrombin-like and hypofibrinogenaemic activities of Trimeresurus albolabris venom.

Retrospective review of clinical presentations, microbiology, and outcomes of patients with psoas abscess.

OBJECTIVE: The clinical features of patients with psoas abscess in a local setting, including the microbiology, incidence and aetiologies, have not been well described. This study aimed to review such clinical features and patient outcomes. DESIGN: Retrospective case series. SETTING: Regional hospital, Hong Kong. PATIENTS: Adults (aged ≥18 years) with psoas abscess admitted to Tuen Mun Hospital from 1 January 2006 to 31 December 2010 were included. The clinical presentations, aetiologies, microbiology, treatments, hospital stays, intensive care unit admissions, and outcomes of these patients were reviewed. RESULTS: The series entailed 42 patients, five of whom developed their psoas abscess after admission and seven were intravenous drug abusers. The most common presenting symptom in community-onset cases was back, hip, or thigh pain (43% [16/37]). Fever was present at presentation in 41% (15/37) of these patients, four of whom presented with fever only. The diagnosis was made by computed tomography in 95% (40/42) of these cases. In all, 23 abscesses were considered secondary; the most common aetiology being infective spondylitis or spondylodiscitis. The commonest causative organism for a primary psoas abscess was methicillin-sensitive Staphylococcus aureus, while for secondary abscesses they were more commonly from the gastro-intestinal and genitourinary tracts. Overall in-hospital mortality rate was 14% (6/42). Secondary psoas abscess patients had longer hospital stays (mean, 62 vs 34 days; P=0.007). CONCLUSION: Psoas abscess is an uncommon condition. Most patients presented with only non-specific symptoms leading to difficulty in making an early diagnosis. In more than half of these patients, the psoas abscesses were secondary, the aetiology of which differed from reported overseas experience.

Green pit viper antivenom from Thailand and Agkistrodon halys antivenom from China compared in treating Cryptelytrops albolabris envenomation of mice.

OBJECTIVE: To compare the relative efficacy of the green pit viper antivenom from Thailand and Agkistrodon halys antivenom from China. DESIGN. In-vivo experimental study. SETTING: A wildlife conservation organisation, a university, a poison information centre, and a regional hospital in Hong Kong. MAIN OUTCOME MEASURES: Pre- and post-antivenom lethal dose 50 (LD50) of the Cryptelytrops albolabris venom, median effective dose (ED50) of green pit viper antivenom and Agkistrodon halys antivenom against a lethal dose of the venom. SUBJECTS. Adult mice. RESULTS: The intraperitoneal LD50 of the venom from locally caught Cryptelytrops albolabris was 0.14 microL. After post-exposure treatment with 10 microL of antivenom, it was elevated to 0.36 microL and 0.52 microL by the green pit viper antivenom and the Agkistrodon halys antivenom, respectively. The ED50 was 32.02 microL for green pit viper antivenom and 6.98 microL for Agkistrodon halys antivenom. Both green pit viper antivenom and Agkistrodon halys antivenom ameliorated the lethality of Cryptelytrops albolabris venom in mice. CONCLUSION: The overall superior neutralisation capacity of Agkistrodon halys antivenom over green pit viper antivenom may be related to the geographic proximity of the venoms used for antivenom preparation. The results point towards the need for further comparison of the two antivenoms on protein or immunoglobulin weight basis, and with respect to non-lethal clinically significant toxicities.

Centipede bite victims: a review of patients presenting to two emergency departments in Hong Kong.

OBJECTIVE. To review the clinical characteristics of patients presenting after centipede bites in Hong Kong. DESIGN. Descriptive case series. SETTING. Emergency departments of two public hospitals in Hong Kong. PATIENTS. Patients presenting after centipede bites between 2006 and 2010. MAIN OUTCOME MEASURES. Demographics, time and locations of bites, symptoms and signs, treatments and outcomes. RESULTS. A total of 46 relevant patient records were retrieved. The bites were frequently at night, indoors, on lower limbs, and consistently resulted in pain. The majority of the victims were treated with analgesia, anti-histamines, and antibiotics. One patient developed necrosis and five re-attended for delayed pruritus and relapsed/recurrent swelling. CONCLUSIONS. Centipede bites are usually uncomplicated, but may lead to necrosis or delayed hypersensitive reactions.

Prevalence of drugged drivers among non-fatal driver casualties presenting to a trauma centre in Hong Kong.

OBJECTIVE: To investigate the prevalence and characteristics of abusive drug exposure among non-fatal motor vehicle driver casualties presenting to a designated trauma centre in Hong Kong. DESIGN: Cross-sectional study. SETTING: Designated trauma centre/regional accident and emergency department in Hong Kong. SUBJECTS: Non-fatal motor vehicle driver casualties who presented to the trauma centre from 1 January 2007 to 31 December 2007. MAIN OUTCOME MEASURES: Screening of abusive drug exposure using commercial bedside urine immunoassay kits. RESULTS: Drug screening was performed in 395 injured drivers, 10% of whom tested positive for the drugs of interest. Ketamine was the most commonly detected abusive substance (found in 45% of the subjects). A significantly higher proportion of young drivers (aged <25 years) screened positive (odds ratio=2.3; 95% confidence interval, 1.0-5.2; P=0.04), with the rate being 21%. The presence of these drugs in urine was related to the time of occurrence of the crash; those occurring between midnight and dawn revealed a trend towards a higher proportion of casualties testing drug-positive (odds ratio=2.2; 95% confidence interval, 0.9-5.3; P=0.07). There were no significant differences in the frequency of persons testing positive for the screened drugs with respect to gender, class of motor vehicle driven, or the day of the week on which the crash occurred. CONCLUSIONS: The prevalence of drugged driving among non-fatal casualties in our series of Hong Kong drivers was 10%. The frequency of such drivers testing positive for drugs was significantly higher in persons aged less than 25 years. These findings indicate a need to amend existing laws and implement on-site drug screening for suspected drugged drivers.

Five-year experience with Chinese cobra (Naja atra)--related injuries in two acute hospitals in Hong Kong.

OBJECTIVE: To review the clinical features and management of patients with injuries related to the Chinese cobra (Naja atra). DESIGN: Retrospective study. SETTING: Two acute hospitals in Hong Kong. MAIN OUTCOME MEASURES: The nature of injuries, envenoming features, complications, response to antivenom therapy, and outcome. RESULTS: Eighteen patients were recruited during the 5-year study period. Fifteen of them were snake-bitten, the remaining three suffered ocular injuries. Of the 15 patients with cobra bites, 14 (93%) presented with local swelling. No patient developed severe neurotoxic symptoms. Two patients had laboratory features of haemolysis. Fourteen patients received antivenom therapy and five of them subsequently underwent surgical interventions for extensive local tissue damage and necrosis. There was no fatality. CONCLUSION: Bites from Chinese cobra result in serious local complications with extensive tissue necrosis and minimal neurotoxic symptoms. There is an apparent trend of favourable outcomes following the early administration of antivenom to patients without early signs of irreversible tissue damage. Further research is needed to evaluate the effectiveness of early antivenom use in Chinese cobra bites in order to minimise extent of tissue damage.