Chrysomya bezziana
Encyclopedia
Chrysomya bezziana, also known as the Old World screwworm fly or screwworm, is an obligate parasite of mammals. Obligate parasitic
flies require a host to complete their development. Named to honor the Italian entomologist Mario Bezzi
, this fly is widely distributed in Asia
, tropical Africa
, India
, and Papua New Guinea
. The adult can be identified as metallic green or blue with a yellow face and the larvae are smooth, lacking any obvious body processes except on the last segment.
The fly
feeds on decaying organic matter, while the fly larva
e feed on the living tissue of warm-blooded
mammal
s as opposed to necrotic tissue that many other fly larvae feed on. Since the larvae can cause permanent tissue damage, C. bezziana has led to much public concern. Management procedures include both prevention of colonization of the fly and treatment of a current infestation. As of early 2009, little research was being conducted on the fly, as it is an unsuitable agent for maggot therapy
(a medical procedure in which maggots are used to clean festering wounds) because the maggots aggressively burrow through living tissue. Recent publications of C. bezziana present medical case studies of the fly.
. It is most prevalent in Southeast Asia, tropical and subtropical Africa, some countries in the Middle East
, India, the Malay Peninsula
, the Indonesia
n and Philippine Islands, and Papua New Guinea. C. bezziana is not found at altitudes higher than 2500 meters above sea level.
In countries where Chrysomya bezziana does not exist, scientists and those in agriculture are worried that commercial flights, boats, or vehicles will distribute the fly. The climates C. bezziana thrives in are present in Australia and the Americas; the fly requires climates similar to its New World relative Cochliomyia hominivorax
. Spread of the pest from Papua New Guinea to Australia has become a concern for Australia, as the presence of C. bezziana could cost livestock industries up to $500 million a year, making it a major quarantine threat.
family Calliphoridae. This family comprises blow flies, carrion flies and cluster flies. Other parasitic screwworms are found in this family, such as Cochliomyia hominivorax and Cochliomyia macellaria.
Another close relative, Chrysomya megacephala
, occurs in many of the same regions as C. bezziana; therefore, it is important to be able to distinguish between the flies. The male fly can be distinguished from Chrysomya megacephala by their eye facets. C. bezziana does not have a boundary dividing the upper and lower eye facets, while C. megacephala does have a boundary distinguishing the upper and lower portions. The female does not have as distinct differences and cannot be as easily distinguished from C. megacephala, but they can be identified by analyzing the frons
(the uppermost part of the head of an insect). The frons of C. bezziana is more parallel, while C. megacephala has a frons that is distinctly narrow in the center.
larvae are smooth, lacking obvious body processes except on the last segment. The posterior spiracles are not hidden in the body cavity, and the peritreme of these spiracles is open. The larvae can be distinguished from its New-World relative C. hominivorax by observing the dorsal tracheal trunks. Those of C. hominivorax are darkly pigmented from the 12th segment to the 10th or sometimes 9th segment, while those of C. bezziana are only pigmented for the last half of the 12th segment. The anterior spiracle has 4-6 lobes, with 7 on occasion.
The pupal stage is temperature dependent with warm weather favoring growth. Depending on the temperature, the pupal stage can last anywhere from 1 week to 2 months. The males become sexually mature after 24 hours of leaving their puparium (the hardened shell the pupae mature in), while females take about 6–7 days to become fully sexually mature. If the weather is tropical (29 °C or 84.2 °F), the entire life cycle will last about 24 days; however, at cooler temperatures (below 22 °C or 71.6 °F), the life cycle can take 2–3 months to complete.
causing myiasis
. Myiasis is the infestation of tissue (living or dead) on a living mammal by fly larvae. Mammals such as sheep, dogs, cattle, pigs, and even humans can become infested.
The adult female will lay her eggs on superficial wounds in live animals preferring wounds that are several days old. Eggs of C. bezziana are commonly laid in the navel
of newborn livestock species or on castration
wounds in cattle. Eggs are also laid on open sores, ulcers, scratches externally or on mucus membranes throughout the body. Wounds as small as a tick
bite are large enough for a female to lay her eggs.
When the eggs hatch, the larvae burrow into the animal’s living tissue and feed on it. Their common name, the “screwworm”, is derived from the maggots that embed themselves into the flesh of their host in a screw-like fashion. The larvae can burrow as deep as 15 centimetres (5.9 in) into the host’s living tissue. As the maggots feed and cause tissue damage, the wound produces a characteristic odor, which can go unnoticed by humans. However, this wound entices female flies to the wound and encourages them to lay their eggs there as well, causing further infestation.
C. bezziana is different from other fly species because tissue infestation can occur in the absence of necrotic tissue. The C. bezziana maggots may cause serious and permanent tissue damage. Extremely infested wounds can lead to death if not treated. The sexually mature adult imago
feeds on decomposing corpses, decaying matter, excreta, and flowers. Due to their diet, these adult flies can be a mechanical vector for pathogens.
s give a time that, at the very earliest, the corpse could have been colonized by insects instead of giving a time of death; this is because the time of colonization is not always concurrent with the time of death. They provide the shortest post mortem interval
(PMI) possible.
The adults are attracted to decaying matter and thus they can be found on dead bodies. However, because C. bezziana can cause myiasis and lay its eggs on a live mammal, it can be more complicated to determine a time of colonization. If the fly laid its eggs and the maggots hatched prior to the death of the corpse and the forensic entomologist does not take this into account, the entomologist could give an incorrect time of colonization.
Wounds should be cleaned and dressed properly to prevent infestation of the fly, as C. bezziana is attracted to wound fluids and blood to lay her eggs in. If a person suspects that their animal or livestock has been a victim of fly-strike, they should bring the case to the attention of their veterinarian
for analysis.
To remove and manage the infestation of larvae in the host, the larvae may be removed with forceps. This removal process should take place daily or as often as needed until the infestation is clear. These larvae can also be killed by applying proper insecticides to the infected areas and making sure the wounds are properly dressed. Organophosphorus insecticides like coumaphos
, dichlofenthion, and fenchlorphos can be applied to wounds with fly larvae. These cause the larvae to leave the wound and fall to the ground, and the larvae will die without a host to feed on. Castration wounds in cattle that have insect growth regulators, such as dicyclanil, have high success rates of preventing the establishment of C. bezziana.
When trying to manage areas that have adult Chrysomya bezziana, one of the first tasks is to improve sanitation of the area. Many types of decaying matter serve as a food source and should be cleared out of the area. Adult flies can also be controlled by the use of insecticides. A few of the insecticides that are available for use in the management of adult C. bezziana include: ectopor, diazinon
, nagasunt and coumaphos. When trying to prevent infestation of livestock and other animals, proper spraying and dipping with these insecticides can help in management control.
(SIT), also known as sterile insect release method (SIRM), is a control method in which sterile insects are released to mate with other wild insects. Usually, the males are sterilized using radiation and then dispersed in a population to compete with wild males. If a sterile male mates with a wild female, she will produce no offspring, reducing the new population.
There have been studies involving Chrysomya bezziana and the sterile insect technique. In 1989, an experiment proved that SIRM had success rates similar to its New World relative Cochliomya hominivorax, which was successfully eradicated from North America in 1982. The success of SIT as an eradication method depends on the number of sterile insects released and on how competitive the sterile insects are in relation to their wild counterparts. SIT is supported by the extensive use of pesticides. To this date, however, Chrysomya bezziana has not been eradicated using this method.
(SCC). A tumor developed as an ulcer on her left cheek and the woman did not keep the wound covered. When the ulcer began to spread, she did not seek any treatment for the myiasis for two years. Ultimately, the case was handled by removal of the larvae using forceps until about 60 larvae were removed. The patient was discharged and two days later returned to have 10 more larvae removed from her face. Infestation of Chrysomya bezziana in cancerous wounds is very rare and most of the cases deal with SCC among elderly patients.
Many cases among humans involve infestation of the oral cavity. According to the Communicable Diseases Watch newsletter, 11 of the 21 infestations in Hong Kong between October 2002 and December 2004 were in the oral cavity.
Another case study, reported in 2008, involved a 9-year-old boy in Indonesia. He was hospitalized due to maggots inside his right ear. The maggots were removed, and while the patient was recovering, it was noticed that the right eye was red. Upon examination, a maggot was found inside a lesion in the bulbar conjunctiva
, and this maggot was then removed.
for use in forensic investigations.
It is not a suitable fly for research in maggot therapy, because it can cause permanent damage by feeding on the underlying tissues, so most studies published on the subject do not include C. bezziana. Currently, most articles published involve case studies of the fly as they are presented.
Obligate parasite
An obligate parasite is a parasitic organism that cannot complete its life cycle without dependence on its host.-See also:*Obligate intracellular parasite*Parasitism*Parasitic plant*Facultative parasite...
flies require a host to complete their development. Named to honor the Italian entomologist Mario Bezzi
Mario Bezzi
Mario Bezzi was an Italian professor of zoology at the University of Turin. He was also Director of the Turin Museum of Natural History...
, this fly is widely distributed in Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, tropical Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, and Papua New Guinea
Papua New Guinea
Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...
. The adult can be identified as metallic green or blue with a yellow face and the larvae are smooth, lacking any obvious body processes except on the last segment.
The fly
Fly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...
feeds on decaying organic matter, while the fly larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e feed on the living tissue of warm-blooded
Warm-blooded
The term warm-blooded is a colloquial term to describe animal species which have a relatively higher blood temperature, and maintain thermal homeostasis primarily through internal metabolic processes...
mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s as opposed to necrotic tissue that many other fly larvae feed on. Since the larvae can cause permanent tissue damage, C. bezziana has led to much public concern. Management procedures include both prevention of colonization of the fly and treatment of a current infestation. As of early 2009, little research was being conducted on the fly, as it is an unsuitable agent for maggot therapy
Maggot therapy
Maggot therapy is a type of biotherapy involving the intentional introduction of live, disinfected maggots into the non-healing skin and soft tissue wound of a human or animal for the purpose of cleaning out the...
(a medical procedure in which maggots are used to clean festering wounds) because the maggots aggressively burrow through living tissue. Recent publications of C. bezziana present medical case studies of the fly.
Geographical distribution
Chrysomya bezziana is widely distributed throughout tropical areas in the Old WorldOld World
The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....
. It is most prevalent in Southeast Asia, tropical and subtropical Africa, some countries in the Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
, India, the Malay Peninsula
Malay Peninsula
The Malay Peninsula or Thai-Malay Peninsula is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southern-most point of the Asian mainland...
, the Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
n and Philippine Islands, and Papua New Guinea. C. bezziana is not found at altitudes higher than 2500 meters above sea level.
In countries where Chrysomya bezziana does not exist, scientists and those in agriculture are worried that commercial flights, boats, or vehicles will distribute the fly. The climates C. bezziana thrives in are present in Australia and the Americas; the fly requires climates similar to its New World relative Cochliomyia hominivorax
Cochliomyia hominivorax
Cochliomyia hominivorax, the New World screw-worm fly, or screw-worm for short, is a species of parasitic fly that is well known for the way in which its larvae eat the living tissue of warm-blooded animals. It is present in the New World tropics...
. Spread of the pest from Papua New Guinea to Australia has become a concern for Australia, as the presence of C. bezziana could cost livestock industries up to $500 million a year, making it a major quarantine threat.
Characteristics
Chrysomya bezziana belongs to the flyFly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...
family Calliphoridae. This family comprises blow flies, carrion flies and cluster flies. Other parasitic screwworms are found in this family, such as Cochliomyia hominivorax and Cochliomyia macellaria.
Adult
The body of the C. bezziana adult is typically metallic green or blue. The face of these flies is typically yellow with soft fine yellow hairs. The length of an adult fly ranges between 8 and 12 millimeters. The abdominal tergites (the segments of the dorsal portion of the fly) have narrow darker bands and the legs are black or dark-brown. Only the bases of the wings are infuscated; the wings have a glassy appearance. The anterior spiracles (small openings on the surface for the respiratory system) range from dark-brown to orange.Another close relative, Chrysomya megacephala
Chrysomya megacephala
Chrysomya megacephala, more commonly known as the oriental latrine fly, is a warm-weather fly with a greenish-blue metallic box-like body which belongs to the family Calliphoridae . This fly can be a nuisance to humans and even cause accidental myiasis. C...
, occurs in many of the same regions as C. bezziana; therefore, it is important to be able to distinguish between the flies. The male fly can be distinguished from Chrysomya megacephala by their eye facets. C. bezziana does not have a boundary dividing the upper and lower eye facets, while C. megacephala does have a boundary distinguishing the upper and lower portions. The female does not have as distinct differences and cannot be as easily distinguished from C. megacephala, but they can be identified by analyzing the frons
Frons
Frons is the term used to describe the frontal area of an insect's head. It covers the upper part of the face above the clypeus and below and between the antennae. It supports the pharyngeal dilator muscles and usually bears an ocellus . The term itself is derived from the Latin frons "forehead"....
(the uppermost part of the head of an insect). The frons of C. bezziana is more parallel, while C. megacephala has a frons that is distinctly narrow in the center.
Larvae
The third-instarInstar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
larvae are smooth, lacking obvious body processes except on the last segment. The posterior spiracles are not hidden in the body cavity, and the peritreme of these spiracles is open. The larvae can be distinguished from its New-World relative C. hominivorax by observing the dorsal tracheal trunks. Those of C. hominivorax are darkly pigmented from the 12th segment to the 10th or sometimes 9th segment, while those of C. bezziana are only pigmented for the last half of the 12th segment. The anterior spiracle has 4-6 lobes, with 7 on occasion.
Life cycle
The female lays approximately 150-200 eggs at a time. The eggs are laid in wounds and mucous membranes of a live mammal and will hatch after 24 hours. The larvae feed on living tissue and are especially attracted to blood. The larvae will feed on the host tissue for 5–7 days while they complete their development, then they will fall to the ground to pupate.The pupal stage is temperature dependent with warm weather favoring growth. Depending on the temperature, the pupal stage can last anywhere from 1 week to 2 months. The males become sexually mature after 24 hours of leaving their puparium (the hardened shell the pupae mature in), while females take about 6–7 days to become fully sexually mature. If the weather is tropical (29 °C or 84.2 °F), the entire life cycle will last about 24 days; however, at cooler temperatures (below 22 °C or 71.6 °F), the life cycle can take 2–3 months to complete.
Medical importance
Chrysomya bezziana usually infects livestockLivestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
causing myiasis
Myiasis
Myiasis is a general term for infection by parasitic fly larvae feeding on the host's necrotic or living tissue. Colloquialisms for myiasis include flystrike, blowfly strike, and fly-blown. In Greek, "myia" means fly....
. Myiasis is the infestation of tissue (living or dead) on a living mammal by fly larvae. Mammals such as sheep, dogs, cattle, pigs, and even humans can become infested.
The adult female will lay her eggs on superficial wounds in live animals preferring wounds that are several days old. Eggs of C. bezziana are commonly laid in the navel
Navel
The navel is a scar on the abdomen caused when the umbilical cord is removed from a newborn baby...
of newborn livestock species or on castration
Castration
Castration is any action, surgical, chemical, or otherwise, by which a male loses the functions of the testicles or a female loses the functions of the ovaries.-Humans:...
wounds in cattle. Eggs are also laid on open sores, ulcers, scratches externally or on mucus membranes throughout the body. Wounds as small as a tick
Tick
Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...
bite are large enough for a female to lay her eggs.
When the eggs hatch, the larvae burrow into the animal’s living tissue and feed on it. Their common name, the “screwworm”, is derived from the maggots that embed themselves into the flesh of their host in a screw-like fashion. The larvae can burrow as deep as 15 centimetres (5.9 in) into the host’s living tissue. As the maggots feed and cause tissue damage, the wound produces a characteristic odor, which can go unnoticed by humans. However, this wound entices female flies to the wound and encourages them to lay their eggs there as well, causing further infestation.
C. bezziana is different from other fly species because tissue infestation can occur in the absence of necrotic tissue. The C. bezziana maggots may cause serious and permanent tissue damage. Extremely infested wounds can lead to death if not treated. The sexually mature adult imago
Imago
In biology, the imago is the last stage of development of an insect, after the last ecdysis of an incomplete metamorphosis, or after emergence from the pupa where the metamorphosis is complete...
feeds on decomposing corpses, decaying matter, excreta, and flowers. Due to their diet, these adult flies can be a mechanical vector for pathogens.
Forensic importance
Forensic entomologistForensic entomologist
Forensic entomologists are those involved in the branch of entomology that involves insects and violent crime or the law, known as forensic entomology. This includes three main branches: medicocriminal entomology, urban entomology, and stored product entomology...
s give a time that, at the very earliest, the corpse could have been colonized by insects instead of giving a time of death; this is because the time of colonization is not always concurrent with the time of death. They provide the shortest post mortem interval
Post mortem interval
Post-mortem interval is the time that has elapsed since a person has died. If the time in question is not known, a number of medical/scientific techniques are used to determine it. This also can refer to the stage of decompostion the person is in....
(PMI) possible.
The adults are attracted to decaying matter and thus they can be found on dead bodies. However, because C. bezziana can cause myiasis and lay its eggs on a live mammal, it can be more complicated to determine a time of colonization. If the fly laid its eggs and the maggots hatched prior to the death of the corpse and the forensic entomologist does not take this into account, the entomologist could give an incorrect time of colonization.
Public concern
Because C. bezziana is an agent of myiasis, public concern has been raised over this fly. However, most human cases documented are debilitated patients not fully capable of taking care of themselves and dressing their own wounds. Caretakers of debilitated patients are encouraged to keep the environment the patient resides in clean. Keeping the area free of decaying organic matter, such as trash, decaying plants or excreta will prevent the flies from being attracted to the patient’s residence, and in turn, the patient. Caretakers should also practice good hygiene themselves to prevent bringing a screwworm with them. The public can take measures to protect themselves from this fly with basic fly-proofing methods like screens.Wounds should be cleaned and dressed properly to prevent infestation of the fly, as C. bezziana is attracted to wound fluids and blood to lay her eggs in. If a person suspects that their animal or livestock has been a victim of fly-strike, they should bring the case to the attention of their veterinarian
Veterinarian
A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....
for analysis.
Management and control
Management of Chrysomya bezziana can be conducted using several different methods, depending upon the adult or larvae form.To remove and manage the infestation of larvae in the host, the larvae may be removed with forceps. This removal process should take place daily or as often as needed until the infestation is clear. These larvae can also be killed by applying proper insecticides to the infected areas and making sure the wounds are properly dressed. Organophosphorus insecticides like coumaphos
Coumaphos
Coumaphos is a non-volatile, fat-soluble phosphorothioate with ectoparasiticide properties: it kills insects and mites. It is well known under manufacturer brand-names as a dip or wash, used on farm and domestic animals to control ticks, mites, flies and fleas...
, dichlofenthion, and fenchlorphos can be applied to wounds with fly larvae. These cause the larvae to leave the wound and fall to the ground, and the larvae will die without a host to feed on. Castration wounds in cattle that have insect growth regulators, such as dicyclanil, have high success rates of preventing the establishment of C. bezziana.
When trying to manage areas that have adult Chrysomya bezziana, one of the first tasks is to improve sanitation of the area. Many types of decaying matter serve as a food source and should be cleared out of the area. Adult flies can also be controlled by the use of insecticides. A few of the insecticides that are available for use in the management of adult C. bezziana include: ectopor, diazinon
Diazinon
Diazinon , a colorless to dark brown liquid, is a thiophosphoric acid ester developed in 1952 by Ciba-Geigy, a Swiss chemical company...
, nagasunt and coumaphos. When trying to prevent infestation of livestock and other animals, proper spraying and dipping with these insecticides can help in management control.
Sterile insect technique
The sterile insect techniqueSterile insect technique
The sterile insect technique is a method of biological control, whereby overwhelming numbers of sterile insects are released. The released insects are normally male as it is the female that causes the damage, usually by laying eggs in the crop, or, in the case of mosquitoes, taking a bloodmeal from...
(SIT), also known as sterile insect release method (SIRM), is a control method in which sterile insects are released to mate with other wild insects. Usually, the males are sterilized using radiation and then dispersed in a population to compete with wild males. If a sterile male mates with a wild female, she will produce no offspring, reducing the new population.
There have been studies involving Chrysomya bezziana and the sterile insect technique. In 1989, an experiment proved that SIRM had success rates similar to its New World relative Cochliomya hominivorax, which was successfully eradicated from North America in 1982. The success of SIT as an eradication method depends on the number of sterile insects released and on how competitive the sterile insects are in relation to their wild counterparts. SIT is supported by the extensive use of pesticides. To this date, however, Chrysomya bezziana has not been eradicated using this method.
Vaccination
In 2000, vaccination of livestock against Chrysomya bezziana was explored. The results were promising in-vitro (outside of the body in controlled environments, like a petri dish) and in-vivo (tested with living animals). The animals vaccinated led to C. bezziana larvae with lower weights. The effects of larvae with lower weights could lessen the damage caused to the living tissue of the maggots, and it is possible that it could also reduce the fly development. The potential of vaccination as a control source was still unresolved, as the immunological mechanisms are very complex and follow-up studies need to be conducted.Case studies
A case study reported in 2009 involving Chrysomya bezziana included a 65-year-old woman with skin cancer. The woman had facial squamous cell carcinomaSquamous cell carcinoma
Squamous cell carcinoma , occasionally rendered as "squamous-cell carcinoma", is a histologically distinct form of cancer. It arises from the uncontrolled multiplication of malignant cells deriving from epithelium, or showing particular cytological or tissue architectural characteristics of...
(SCC). A tumor developed as an ulcer on her left cheek and the woman did not keep the wound covered. When the ulcer began to spread, she did not seek any treatment for the myiasis for two years. Ultimately, the case was handled by removal of the larvae using forceps until about 60 larvae were removed. The patient was discharged and two days later returned to have 10 more larvae removed from her face. Infestation of Chrysomya bezziana in cancerous wounds is very rare and most of the cases deal with SCC among elderly patients.
Many cases among humans involve infestation of the oral cavity. According to the Communicable Diseases Watch newsletter, 11 of the 21 infestations in Hong Kong between October 2002 and December 2004 were in the oral cavity.
Another case study, reported in 2008, involved a 9-year-old boy in Indonesia. He was hospitalized due to maggots inside his right ear. The maggots were removed, and while the patient was recovering, it was noticed that the right eye was red. Upon examination, a maggot was found inside a lesion in the bulbar conjunctiva
Conjunctiva
The conjunctiva covers the sclera and lines the inside of the eyelids. It is composed of rare stratified columnar epithelium.-Function:...
, and this maggot was then removed.
Current research
According to a pest control officer for the Food and Hygiene Department in 2009, the Hong Kong government (where many of the case studies are published) is unaware of any research in this field. The most recent research done on this fly was published in January 2008 and involved identifying fly eggs using a scanning electron microscopeScanning electron microscope
A scanning electron microscope is a type of electron microscope that images a sample by scanning it with a high-energy beam of electrons in a raster scan pattern...
for use in forensic investigations.
It is not a suitable fly for research in maggot therapy, because it can cause permanent damage by feeding on the underlying tissues, so most studies published on the subject do not include C. bezziana. Currently, most articles published involve case studies of the fly as they are presented.