Chrysomya bezziana, the Old World Screw-worm fly, is distributed in sub- Saharan Africa, Middle East, Indian subcontinent, SE Asia and New. Chrysomya bezziana Villeneuve. (Figures and ). ETYMOLOGY:Chryso = gold + myia = fly; along with bezziana for Dr. Bezzi. Chrysomya bezziana (Diptera: Calliphoridae) infestation: case report of three dogs in Malaysia treated with spinosad/milbemycin. Hock Siew.
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Cutaneous Myiasis Caused by Chrysomya bezziana Larvae, Mexico
Figures brzziana Rovere described several cases of traumatic myiasis in cattle from the Congo. He sent some of the adults he reared to a Professor Bezzi in Turin, Italy, who incorrectly identified them as Chrysomya megacephala. Also inGedoelst reported similar findings from the Congo, and also referred to the larvae as Chrysomya megacephala. Roubaud and Bouet studied this fly again in West Africa and found its behavior different from other species of Chrysomya in this area.
They also believed erroneously that they were dealing with Chrysomya megacephala. Villenueve reexamined the type specimen, which had an incorrect locality designation, and found it conspecific with Chrysomya dux from the Orient.
The species which Roubaud and the others were dealing with had to be renamed, so Villeneuve did so in honor of Professor Bezzi, who had already noted that this fly was different from Chrysomya dux Zumpt, Chrysomya bezzianathe Old World screw-worm, is a primary myiasis-producing fly that attacks a wide range of warm-blooded animals throughout Africa, the Indian sub-continent, and Southeast Asia from Taiwan in the north to Papua New Guinea in the south. The only continent with a tropical zone still free of primary screw-worm is Australia Davidson,Spradbery, There are secondary myiasis producing flies in Australia that can be of significant importance, such as Chrysomya rufifacies Figs.
The larvae of Chrysomya bezziana are obligatory wound parasites and never develop in carcasses or other chrysoyma matter. fhrysomya
The female flies are attracted to the open wounds of man and domesticated animals. Any slight, bleeding wound, even the smallest sore caused by a feeding tick, inflicted accidentally on domestic animals is subject to infestation Zumpt, Adult Chrysomya bezziana are non-parasitic and as a result will not be chrysoma by the client or the veterinarian.
The adults are rarely chrydomya in the field Zumpt, They are never hcrysomya feeding on food in open air markets Patton and Evans, This fly possesses a dark metallic green or blue body with abdominal segments with narrow dark bands along the posterior margins.
The legs are black or partially dark brown; the face is orange-yellow Zumpt, The first larval stage will probably go unnoticed due to its small size, up to 3.
The second stage is quite similar to the third, but is from 4 to 9 mm in length. The third stage larva is a large larva, up to 18 mm in length. The body is composed of twelve segments which have broad encircling bands of spinules. All three stages are “maggot-like” in their appearance and exhibit cephalopharyngeal sclerites and posterior spiracles that are unique to the species Zumpt, The posterior end of the larva has its spiracular plate located in a deep cleft at the end of the eighth abdominal segment.
The spiracular plates are large and well separated. The peritreme is wide with a break in its infero-internal border. The button is situated in the break in the peritreme. The three breathing slits are very wide Patton and Evans, The second and third stage larval Chrysomya bezziana are the stages that will be usually observed in the skin of an infested cat by either the owner or the veterinarian.
These stages can probably be best identified by an entomologist. Extensive descriptions of these morphologic stages do bezziwna Patton and Evans,Zumpt, Chrysomya bezziana has been described as a fly that produces a “particularly vile” myiasis Davidson, Female flies lay their eggs in masses of to chrywomya the edge or wounds Harwood and James, or near body orifices Davidson, Larvae develop to the third stage about 2 days following hatching.
They burrow deep into the wound to such a depth that only their caudal ends are observable. The chrjsomya larval stage lasts 5 to 6 days. Under tropical conditions, the pupal stage lasts 7 to 9 days, however this time will increase in cooler ecosystems Harwood and James, The adult flies merge later to mate, locate a new host, and continue the cycle. The female flies mate only once during their lifetime.
Under favorable conditions, there may be eight or more generations per year Zumpt, Myiasis due to Chrysomyia bezziana is extremely rare in cats.
Secondary infestation with the facultative myiasis-producing flies may complicate treatment and control of the infestation Davidson, The larvae of Chrysomya bezziana are obligatory wound parasites, never developing in carcasses or decomposing organic material. The female flies are attracted to open wounds of man and domesticated and wild animals. Occasionally eggs are deposited on the unbroken, soft skin of various parts of the body, especially if it is contaminated by blood or mucous discharge Zumpt, When the larvae hatch, they burrow into the flesh of the host, using their hooked mouthparts to scrape away at the tissues and lacerate bfzziana fine blood vessels.
Larvae actively feed on the host’s blood. Because of the voracious feeding activity and their appetite for host blood, Chrysomya bezziana is often described as being “vampiric” or “blood-hungry. As many as 3, maggots have been observed in some wounds Chrsyomya, In untreated wounds, the destructive activity of the larvae may lead to the death of the animals within a very short period of time Zumpt, Treatment of screwworm infestation involves killing the larvae in the lesions, promoting healing, and preventing secondary reinfestation with larvae of the facultative myiasis-producing flies.
The extent of the lesions is determined by clipping the haircoat and removing as many larvae as possible. The larvae that are removed should be killed to prevent them from pupating and developing to the adult fly.
The larvae located deep within tissues must be extracted. The dressing should be bland and nontoxic to the cat and should promote healing.
At this dosage residual protection lasted 16 to 20 days, two to three times that produced by most insecticide smears. These mortality rates were very conservative; many of the larvae that survived ivermectin therapy bezzixna to develop to the adult stage Spradbery et al.
The product should not be given to kittens O’Dair and Shaw, The effects of infestation with Chrysomya bezziana are particularly devastating. Strike bzziana naturally occurring wounds, e. Fly strike also has the ability to follow elective feline surgical procedures bezzianw. All warm-blooded animals are subject to infestation by Chrysomya bezziana. The animals most commonly infested are cattle Zumpt, Other known hosts include sheep, goats, buffalo, pigs, chickens, dogs and horses.
Patton,Davidson, Reports of infestations on wild animals are rare. A survey of the records of the Malaysian National Zoo revealed 91 cases of myiasis in 21 host species during the period to Those animals included the honey bear, polar bear, camel, fallow deer, hog deer, red deer, sambar deer, donkey, Asian elephant, gnu, Chysomya horse, striped hyena, red kangaroo, African lion, Asian lion, slow loris, puma, rhinoceros, sheep, Malay tapir, and agile wallaby Spradbery and Vanniasingham, Infestations of humans with the larvae of Chrysomya bezziana are very common in India and other parts of Asia Patton, This parasite has been reported to occur in humans in Africa Zumpt, Children are often subject to infestation on scalp wounds Davidson, All wounds on domesticated animals should be properly dressed.
All elective surgical procedures should be avoided during the fly season. Screw-worm stowaways – assessing the risk. Entomology in Human and Animal Health7th ed. Mite treatment of cats. Efficacy of ivermectin against Cheyletiella blakei infestation in cats. J Am An Hosp Assoc Some notes on Indian Calliphorinae.
InsectsTicksMites and Venomous Chrywomya. The efficacy of ivermectin against screw-worm fly Chrysomya bezziana i n vitro and in cattle. Austr Vet J Incidence of the screw-worm fly, Chrysomya bezzianaat the Zoo Negara, Malaysia. Mal Vet J 7: Villeneuve, the common Indian Calliphorine whose larvae cause cutaneous myiasis in man and animals.
Ind J Bezzizna Res 8: Myiasis in Man and Animals in the Old World. The larvae of Chrysomya rufifacies from Australia. Two pupal cases of Chrysomya rufifacies from Australia. Chrysomya bezziana by Anastasia Bowman Jun 25, Aust Vet J