Part 2 – CDC Retests the Safety of Jet Injectors in 1986

June 19, 2017

“Hepatitis Outbreak Laid to Contaminated Jet Injection Gun,” read the headline of the June 13th, 1986 edition of the LA Times (Maugh, 1986).  Between 1985 and 1986, the CDC thoroughly investigated a Hepatitis B outbreak caused by a jet injector at a LA weight reduction clinic.

Assessing the Outbreak
The weight reduction clinic in Long Beach was administering regular injections of human chorionic gonadotropin (HCG) to its patients via a Med-E-Jet injector and by syringe and needle at the time the outbreak was identified by local health officials.

Analyses by CDC found twenty-one percent (60/287) of those attending the clinic had an acute infection of Hepatitis B.  Twenty-seven individuals were infected with Hepatitis B and another thirty-three individuals were IgM positive meaning each had the antibody to hepatitis B core antigen (Canter et al., 1990; CDC,1986).  For a person to test IgM positive is indicative that he or she was infected with the hepatitis B virus within the last 6-months.  Two individuals identified with Hepatitis B were found to have other risk factors for acquiring Hepatitis B virus within the previous six-months (CDC, 1986).  Therefore, two individuals already infected with Hepatitis B were identified amongst the cohort receiving jet injections and were likely the culprits who unknowingly infected the others.

Amongst those individuals who exclusively received HCG by jet injection, twenty-four percent (57/239) had developed an acute Hepatitis B virus infection.  Interestingly, the 22 patients who received injections exclusively by a syringe never acquired the hepatitis B virus (CDC, 1986; Canter et al., 1990).  This data indicates that a total of 57 individuals had evidence of acute infection with hepatitis B virus as the result of receiving injections with a multi-use nozzle jet injector.

“Everyone always assumed that jet guns were safe,” said Dr. Steve Hadler, Chief of Epidemiology Activity within CDC’s Hepatitis Branch, in a newspaper article (Hendrick, 1986).

CDC’s assessment of the outbreak found 57 individuals had been infected from receiving injections with a jet injector.  Throughout the years, the Department of Veterans Affairs (VA) has grossly minimized this outbreak. VA states, “there is at least one case report of hepatitis B being transmitted by an airgun injection” (VBA Fast Letter 211 (04-13)).  A case report is defined as a detailed report listing the signs, symptoms, diagnosis and treatment of an individual patient.  Therefore, contrary to VA’s reporting, there are in actuality 57 documented cases, or rather 57 cases reports, of Hepatitis B being transmitted by jet injection.

The outbreak prompted CDC to retest the safety of jet injectors.

CDC’s Laboratory Investigations
“Five Med-E-Jet injectors used in these weight reduction clinics were sent to the Centers for Disease Control, Atlanta, Ga, for further evaluation,” stated a report by the researchers (Canter et al., 1990).

CDC’s 1986 investigations evaluated the threat of cross-contamination of blood-borne pathogens when using a Med-E-Jet injector.  The researchers explained their 1986 investigations within a medical journal.  “A series of in vitro and in vivo laboratory experiments were carried out to assess the potential for a contaminated Med-E-Jet to transmit HBV from patient to patient and to assess the potential for HBsAg contamination of this jet injector during actual use,” stated the article (Canter et al., 1990).  Within these experiments detection of the Hepatitis B surface antigen (HBsAg) would be presumptive evidence of Hepatitis B contamination.

Analysis of the outbreak and investigations of the Med-E-Jet were published twice; once within a 1986 CDC report and again in a 1990 medical journal.  It is interesting to also note that CDC microbiologist Walter Bond, who was a part of the 1977 investigations of the Ped-O-Jet, was also a part of the 1986 laboratory investigations of the Med-E-Jet in Atlanta.

Firing Into Vials – In Vitro Experiments
Several in vitro tests were implemented to assess the frequency of contamination when using the Med-E-Jet.  Within the first experiment, the Med-E-Jet nozzle was artificially contaminated with Hepatitis B surface antigen (HBsAg) to see if the antigen would be sucked back into the nozzle head and contaminate the next dosage to be fired.
Results found, after the nozzle was contaminated, the ejected fluid of the next shot fired was positive for HBsAg in 40 out of 50 (80%) of the samples.  Med-E-Jet surfaces were also tested for contamination.  Results showed HBsAg contamination upon the exterior of the nozzle in 9 out of 10 (90%) of the samples.  Samples from within the nozzle interior were HBsAg-positive in 8 out of 10 (80%) occurrences.  The nozzle tip was HBsAg-positive in 9 out of 10 (90%) of the samples (Weniger, 2003).  This data demonstrated gross contamination of the Med-E-Jet due to fluid suck-back.

In a second set of experiments, researchers assessed if wiping the nozzle between consecutive patients would remove any contamination from the nozzle surface.  Using a cotton ball moistened in acetone researchers wiped the contaminated Med-E-Jet nozzle to see if the HBsAg would be reduced or eliminated.

The results after wiping the nozzle found the ejected fluid of the next shot fired was positive for HBsAg in 29 out of 45 (64%) of the samples.  Results of Med-E-Jet surfaces were positive for HBsAg in 7 out of 9 (78%) of the samples from the nozzle exterior, 5 out of 9 (56%) of the samples from the nozzle interior, and 6 out of 9 (67%) of the samples from the nozzle tip.  This data indicated wiping the Med-E-Jet with acetone after each injection did not significantly reduce the frequency of HBsAg contamination (Weniger, 2003).

Jet Injecting Chimpanzees – In Vivo Experiments
In this in vivo experiment the CDC assessed if the Med-E-Jet would become contaminated with Hepatitis B surface antigen after injecting a chimpanzee infected with the pathogen.  Immediately following the injection the next shot to be delivered was fired into a vial and tested for blood and HBsAg.  This test was repeated five times.

Results could not detect HBsAg in the ejected fluid in any of the five injections with the Med-E-Jet.  The researchers, however, did state, “Bleeding did occur at the four of the five injection sites, even though injections were carefully done according to the manufacturer’s recommendation” (Canter et al., 1990).

Despite these findings it is duly noted that the exact Med-E-Jet injectors documented in the 1985 Hepatitis B outbreak of 57 individuals did not demonstrate such cross-contamination when tested upon a chimpanzee.  This finding calls into question the validity of relying upon chimpanzee studies to assess the safety of jet injectors.  It appears, in this regard, comparing humans to chimpanzees is like comparing apples to oranges.

Possibly the assay used by CDC within their laboratory investigations was not able to detect HBsAg.  The report did not specifically mention which assay product was used within the laboratory investigations.  Although it was noted that within the investigation of the outbreak serum specimens of those attending the Long Beach clinic were evaluated using Auszyme by Abbott Laboratories (Canter et al., 1990).  Assuming the assays were the same for both procedures would call into question the validity of the animal model used.  If the assays were different it would call into question the capability of the assay used within the laboratories investigation to detect low levels of HBsAg.

Summary of Findings
In 1986, the CDC investigated the Med-E-Jet in a laboratory setting to assess the degree of contamination caused by this particular model of device.  The official 1986 report stated,

the estimated volume of contaminating material transferred in downstream injections was 0.53 micro liters (0.53 x 10–3ml).  Therefore, it can be estimated that viruses that circulate in high titers in blood, such as HBV (10-8/ml) and LDH virus (10-7/ml), could be transferred during a procedure if gun contamination occurred.  The probability of transferring microorganisms present in lower concentration ( < 10-3/ml) would be correspondingly lower (CDC, 1986).

Herein the CDC recognizes highly infectious viruses can be transferred via jet injection.

Canter and colleagues (1990) concluded, “This epidemiologic and laboratory investigation suggests that when this model of jet injector [Med-E-Jet] becomes contaminated with blood, transmission of HBV can occur” (Canter et al., 1990).

A newsletter submitted within a congressional hearing on HBV remarked of Canter and colleagues, saying, “The CDC proved that such a jet injector could transmit HBV despite proper swabbing of the tip, due to the inaccessability of contaminated surfaces under the nozzle and cap” (U.S. Congress, 1999).


  • (Canter et al., 1990) Canter J, Mackey K, Good LS, Roberto RR, Chin J, Bond WW, Alter MJ, Horan JM. An outbreak of hepatitis B associated with jet injections in a weight reduction clinic. Arch Intern Med. 1990 Sep; 150(9):1923-7. 
  • (CDC, 1986) Centers of Disease Control. Epidemiologic Notes and Reports Hepatitis B Associated with Jet Gun Injection — California. MMWR 1986;35(23):373-376.
  • (Hendrick, 1986) Hendrick O. Jet gun injector causes hepatitis outbreak. United Press International 12 June 1986. Accessed at:
  • (Maugh, 1986) Maugh TH. Hepatitis outbreak laid to contaminated jet injection gun. Los Angeles Times. 13 June 1986. Accessed at:
  • (U.S. Congress, 1999) United States. Committee on Government Reform. Hearings, 18 May 1999. 106th Cong. 1st sess. Washington: GPO 2000.
  • (VBA Fast Letter 211 (04-13)) VBA Fast Letter 211 (04-13). Relationship Between Immunization with Jet Injectors and Hepatitis C Infection as it Relates to Service Connection, Veterans Benefit Admin. (VBA) Fast Letter No. 04-13, 211 (April 29, 2004).
  • (Weniger, 2003) Weniger BG. Jet Injection of Vaccines: Overview and challenges for mass vaccination with jet injectors. Innovative Administration Systems for Vaccines (conference). Rockville, Maryland, USA, 18-19 December 2003.

© Jet Infectors, 2016 – 2021
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