Uli Wernery and Maria Lipp

Incidents of snake bite in the United Arab Emirates are rarely reported, although anecdotal evidence suggests that they may be more common than reported incidents would suggest. The majority of the eleven snake species thus far recorded in the United Arab Emirates and in neighbouring areas of northern Oman are either non-poisonous, such as the Sand Boa, Eryx jayakari, or are only mildly poisonous, such as the Arabian Rear-fang, Malpolon moilensis. In the latter case, the position of the venom-bearing fangs at the back of the jaw make it unlikely that humans will be injected with venom even if bitten.

There are, however, two groups of snakes present in the area which are highly poisonous, the sea snakes Hydrophiidae and snakes of the viper family, of which four species have been recorded, the Sawscale Viper, Echis carinatus, the Carpet Viper, Echis coloratus, the False Horned Viper, Pseudocerastes persicus, and the Horned Viper (Sand Viper), Cerastes cerastes gasperettii.

In the spring of 1998, perhaps as a result of a milder and wetter winter, observers reported more sightings of vipers than is usual. Two incidents of snake bite were reported. One, in a wadi near Fujairah, involved an Indian expatriate agricultural worker, who was not taken to hospital until 15 hours after he was bitten, and who died of renal failure and myocardial degeneration. The second incident involved a European expatriate who was bitten while stepping out of a pool on to gravel in an Omani wadi near Al Ain.

Medical case notes follow. These are reproduced partly as a warning that, contrary to the opinion of the doctor referred to in the notes, there are highly poisonous snakes in the area, and that caution is advisable.

Thursday 13.03.98 – 14.15 hrs

A suspected saw-scaled viper bit a healthy 40 year-old male, Josef, as he stepped out of a wadi pool and onto some gravel. The bite was underneath the ankle on the left foot. The pain was described as comparable to that caused by a needle. A belt was fastened around the upper leg and Josef walked for ca.10 minutes until he reached the car. From there he was driven for one hour to reach Tawam Hospital, in Al Ain.

15.30 hrs : Tawam Hospital. A South African doctor inspected the bite. According to him there were only non-poisonous and semi-poisonous snakes in the area and, therefore, there was no need to worry. Drugs were administered to combat the swelling and pain. The bite was inspected visually and no other steps were taken. However, the victim was advised that the swelling would get bigger and that they should consult a doctor if they were worried. He was discharged from Tawam at 15.50 hrs.

On the drive back to Dubai, the leg was kept elevated. The swelling grew bigger as anticipated. During the evening the swelling continued slowly to the upper leg. By midnight the family was rather concerned and called the American Hospital. While getting up, Josef started vomiting, broke out into a cold sweat and he seemed to be quite dizzy. The pain was unbearable in an upright position and Josef had to crawl to the car. The vomiting continued. At the American Hospital he was directed straight to Rashid Hospital, which he reached around 00.45.

Blood tests were made immediately and showed serious blood-clotting. Blood pressure was measured and proved to be very low. After discussions with the Emergency Doctor and Dr. Wernery, a general antivenom was administered to which Josef did not show any allergic reaction. The cold sweat and low blood pressure eased towards the early morning.

Friday 14.03.98

The following morning the ‘blood picture’ had improved, but a second dose of antivenom was administered. The swelling had increased slightly and the leg was discoloured. The swelling remained the same for the next two days, slowly turning purple and yellow, mainly at the back of the leg. After 3 days the swelling started to reduce, but the discolouring stayed. The blood picture improved. Antibiotics were given in case the snake’s fangs had infected the leg. The leg could neither be touched nor moved, as it was very painful.

Josef left the hospital on the fourth day and remained at home in bed for another four days with his leg up. After that he slowly started to move on all fours. Twelve days after the incident he began to take a couple of steps in an upright position. As the blood shot into the leg it still turned blue and was rather painful.

Sixteen days after the incident he managed to walk around quite well for some time. However, after being upright for a while he still needed to relax and put the leg up. The discolouring was nearly gone, except for a small area around the bite itself.

TABLE 1

Clinical signs of Envenomation by Saw-scaled Viper

Swelling and oedema at site +3

Pain +3

Discoloration +2

Vesiculation +2

Ecchymosis +2

Prolonged clotting time +3

Haemorrhage +3

Hypotension +2

Nausea and/or vomiting +1

Necrosis +1

Conclusion

It is believed that a Saw-scaled Viper Echis carinatus bit Josef. Most of the clinical signs mentioned in Table 1 were observed during Josef’s illness (Fowler, 1992).

Reference

Fowler, M.B. [1992]. Veterinary Zootoxicology. p. 226.

Professor U. Wernery & Maria Lipp, Central Veterinary Research Laboratory, P.O. Box 597, Dubai, UAE.