A jet injector is a type of medical injecting syringe that uses a high-pressure narrow jet of the injection liquid instead of a hypodermic needle to penetrate the epidermis. It is powered by compressed air or gas, either by a pressure hose from a large cylinder, or from a built-in gas cartridge or small cylinder.
Jet injectors are used for mass vaccination, and as an alternative to needle syringes for diabetics to inject insulin. As well as health uses, similar devices are used in other industries to inject grease or other fluid.
The Jet Injector Gun and the Ped-O-Jet are air-powered medical injector devices designed to administer vaccinations very efficiently. Invented by Aaron Ismach, these medical devices were bought in mass quantities by the US government and provided to governments around the world to eradicate smallpox and other diseases. Servicemen in the Armed Forces were routinely injected with these medical devices to immunize them, and civilian usage included vaccinations during situations such as flu epidemics. The Jet Injector is powered by electricity, while the Ped-O-Jet version is powered by a foot pump and does not require electricity to administer the vaccines. These devices have various specialized nozzles for different medication densities, and can also be used to inoculate animals.
The Biojector 2000 is a make of gas-cartridge-powered jet injector. It is claimed that it can deliver intramuscular injections and subcutaneous injections up to 1 milliliter. The part which touches the patient's skin is single-use and can be replaced easily. It can be powered from a big compressed gas cylinder instead of gas cartridges. It is made by Bioject.
Because the jet injector breaks the barrier of the skin, there is a potential that biological material is transferred from one user to the next. Some infectious viruses such as hepatitis B can be transmitted by less than one millionth of a millilitre so makers of injectors need to ensure there is no cross-contamination between applications. The World Health Organization no longer recommends jet injectors for vaccination due to risks of disease transmission.
An experiment using mice, published in 1985, showed that jet injectors would frequently transmit the viral infection LDV from one mouse to another. Another study used the device on a calf, then tested the fluid remaining in the injector for blood. Every injector they tested had detectable blood in a quantity sufficient to pass on a virus such as hepatitis B.
From 1984–1985 a weight-loss clinic in Brazil injected a pregnancy hormone into their clients, mostly using a jet injector. It was noted that a number of these patients became sick with hepatitis. When studied, 57 out of 239 people who had received the jet injection tested positive for hepatitis B.
As well as transmission between patients, jet injectors have inoculated bacteria from the environment into users. In 1988 a podiatry clinic used a jet injector to deliver local anaesthetic into patients' toes. Eight of these patients developed infections caused by Mycobacterium chelonae. The injector was stored in a container of water and disinfectant between use, but the organism grew in the container. This species of bacteria is sometimes found in tap water, and had been previously associated with infections from jet injectors.
- 19th century: Workmen in France had accidental jet injections with high-powered grease guns
- 1920s: Diesel engines begin to be made in large quantities: thus the start of serious risk of accidental jet-injection by their fuel injectors in workshop accidents.
- 1937: First known recorded accidental jet injection by a diesel engine's fuel injector.
- 1960: Aaron Ismach invented and patented the Jet Injector medical device which was used for quick mass vaccination for smallpox and other diseases. Ismach was assisted by Dr. Abram Benenson in developing the Jet Injector Gun. The new method met with tremendous success as teams vaccinated large numbers of people at collecting points in the affected countries. The foot operated gun was called the Ped-O-Jet and the electric operated gun was called the Jet Injector Gun.
- 1962: Robert Andrew Hingson claimed to have invented a prototype jet injector and called it the peace gun, for quick mass vaccination. But sometimes the injection process dislodged infected matter from a patient onto the nozzle of the injector, risking cross-infection.
- 1964: Aaron Ismach was presented with a Gold Medal from the US government for his efforts related to the Jet Injector Gun. The Jet Injector also appeared on postage stamps as a commemorative of his efforts.
- September 1966: The Star Trek series started, exposing the public to the idea of jet injectors under the name "hypospray".
- 1976: The USA Agency for International Development published a book called War on Hunger which detailed the War Against Smallpox which Ismach's Jet Injector gun was used to eradicate the disease in Africa and Asia. The US government spent $150 million a year to prevent its recurrence in North America.
- 1997: The USA Department of Defense, the jet injector's biggest user, announced that it would stop using it for mass vaccinations due to concerns about infection. The DoD order Veterans info page
Accidental jet injection
Accidents have happened in vehicle repair garages and elsewhere where one of the following has unintentionally acted as a hypodermic jet injector:
- A fuel injector of a diesel engine.
- A high-pressure grease gun.
- A pinhole leak in a tube supplying a high-powered grease gun from a separate grease pressure-tank.
- A pinhole leak in a tube of high pressure hydraulic oil equipment.
- A high pressure paint spray.
- A pressure washer.
Accidental injection of oil or paint by such high-pressure sprays can cause very serious injuries which may require amputation, and can induce fatal blood poisoning.
- Hoffman, P.N; R.A Abuknesha, N.J Andrews, D Samuel, J.S Lloyd (2001-07-16). "A model to assess the infection potential of jet injectors used in mass immunisation". Vaccine 19 (28–29): 4020–7. doi:10.1016/S0264-410X(01)00106-2. PMID 11427278.
- World Health Organization (2005-07-13). "Solutions: Choosing Technologies for Safe Injections". Retrieved 2011-05-06.
- Brink, P.R.G.; Van Loon, M.; Trommelen, J.C.M.; Gribnau, W.J.; Smale-Novakova, I.R.O. (1985-12-01). "Virus Transmission by Subcutaneous Jet Injection". J Med Microbiol 20 (3): 393–7. doi:10.1099/00222615-20-3-393. PMID 4068027.
- Canter, Jeffrey; Katherine Mackey, Loraine S. Good, Ronald R. Roberto, James Chin, Walter W. Bond, Miriam J. Alter, John M. Horan (1990-09-01). "An Outbreak of Hepatitis B Associated With Jet Injections in a Weight Reduction Clinic". Arch Intern Med 150 (9): 1923–1927. doi:10.1001/archinte.1990.00390200105020. PMID 2393323. Retrieved 2011-05-06.
- Wenger, Jay D.; John S. Spika, Ronald W. Smithwick, Vickie Pryor, David W. Dodson, G. Alexander Carden, Karl C. Klontz (1990-07-18). "Outbreak of Mycobacterium chelonae Infection Associated With Use of Jet Injectors". JAMA 264 (3): 373–6. doi:10.1001/jama.1990.03450030097040. PMID 2362334.
- Inman, P.M.; Beck, A.; Brown, A.E.; Stanford, J.L. (1969-08). "Outbreak of injection abscesses due to Mycobacterium abscessus". Archives of Dermatology 100 (2): 141–7. doi:10.1001/archderm.100.2.141. PMID 5797954.
- Rees CE (11 September 1937). "Penetration of tissue by fuel oil under high pressure from diesel engine". JAMA 109 (11): 866–7. doi:10.1001/jama.1937.92780370004012c.