Infectious Disease and Infection Control Time Line

Clinicians and students in health professional programs commonly want to know how far science has progressed in the control of infectious diseases. The following time line was developed to allow the reader to obtain a better appreciation for the historical progression of control of microbial disease, from early disease investigations and attempted solutions, to later issues, challenges, and strategies. The central theme is the recognition and application of scientific principles and data in the development of effective infection control practices.

The time line arbitrarily begins with one of the historical milestones linking microorganisms to infectious disease etiology. Emphasis has been placed on more recent events and publications in order to include primarily information that is of use to today’s patient care providers.

First reports of disease transmission by contagion (i.e., minute bodies capable of self-multiplication).

Introduction of smallpox vaccination by Dr. Edward Jenner as effective preventive method against disease epidemics.

Application of epidemiology principles to demonstrate infectious nature of puerperal fever.

* Demonstration of transmission from physicians and nurses.

Introduction of antisepsis in prevention of cross-infection.

* Importance of hand hygiene demonstrated.

* Introduction of antiseptic technique for surgical procedures.

* Introduction of chemical agents (carbolic acid) for antisepsis, disinfection, and sterilization use.

Introduction of rubber gloves for use during hospital surgeries.

Penicillin first isolated by Sir Arthur Fleming from Penicillium notatum. Initial observations showed that the antibiotic was bactericidal against Staphylococcus aureus.

First patients administered penicillin G against infections caused by streptococci and staphylococci.

Growing number of reports of adaptive penicillin resistance in strains of Staphylococcus aureus. Primary mechanism of drug resistance found to be bacterial synthesis of penicillinases, enzymes that inactivate penicillin by cleavage of the drug’s beta-lactam ring.

Commercial production of penicillin G accomplished. This antibiotic was available for general use in the United States by the end of the 1940s.

First occupational case of serum hepatitis (later termed hepatitis B) reported in a health care worker. Infection developed following needlestick exposure to contaminated blood.

Earliest American Dental Association infection control guidelines published in Accepted Dental Remedies. Guidelines related to use of chemical agents for disinfection and emphasized precleaning and heat sterilization of instruments.

First published description of microbial contamination of dental unit waterlines. High levels of microbial contamination were isolated in water samples taken from handpiece and syringe lines.

Description of hepatitis B surface antigen by Blumberg and colleagues.

* Led to characterization of hepatitis B virus (HBV) and development of sensitive serologic tests for detection of blood markers following infection.

Occupational Safety and Health Administration (OSHA) created by Congress.

Twenty-seven percent of oral surgeons and 13.6 percent of general dentists show serologic evidence of prior infection with HBV compared to 2 percent to 5 percent of general public.

Reports of clusters of HBV transmission from health care workers to patients.

Through mid-1980s, 20 clusters involving 300 patients were reported; nine clusters involved dentists/oral surgeons.

Congress passes Rehabilitation Act of 1973.

Outbreak of pneumonia (subsequently called Legionnaires’ disease) at Philadelphia hotel during American Legion convention. A total of 221 cases were reported, including 34 fatalities.

Isolation of Legionella pneumophilia accomplished from lung tissue of patients in Philadelphia.

ADA report on infection control for dental offices published in Journal of the American Dental Association.

* Suggested procedures for reducing microbial contamination, cross-infection, and cross-infection.

* Included recommendation: "All instruments, burs, mirrors, bands, and other devices used in intraoral treatment should be routinely sterilized."

* Included initial consideration of waterline contamination along with possible solutions.

First reports of Acquired Immunodeficiency Syndrome (AIDS) cases:

June -- Unusual occurrence of five cases of Pneumocystis carinii pneumonia in previously healthy male homosexuals in Los Angeles.

July -- Aggressive Kaposi’s sarcoma seen in 26 young males in New York and California.

First hepatitis B vaccine (Heptavax-B) becomes commercially available.

Centers for Disease Control (CDC) releases occupational infection control guidelines for health care workers: Recommendations include use of gloves, gowns, and extraordinary steps to avoid injury.

CDC isolation guidelines include recommendations for dental health care workers: 1) wear gloves, mask, and protective eyewear; and 2) sterilize instruments.

Health care worker unions petition OSHA for an emergency standard to make employers pay for HBV vaccine. The request was denied. OSHA begins rule-making process for a standard on bloodborne disease transmission in health care settings.

Human immunodeficiency virus (HIV) identified.

* Found to be a retrovirus.

* Initially called by different names: In the United States -- human T-lymphotropic virus type III (HTLV-III); In France -- lymphadenopathy-associated virus (LAV).

First case reported of occupational HIV infection of health care worker. Transmission occurred via accidental needlestick from an HIV-infected patient to a nurse in Africa.

Last reported outbreak of hepatitis B transmission in a dental care setting, from an HBV-infected oral surgeon to four patients (New Hampshire).

First HIV antibody test for screening blood donors is licensed for commercial use. Blood donation centers initiate screening of all donated blood.

First generation enzyme immunoassay allows for better investigation of HIV surveillance, detection, and assessment of risks to health care workers.

Reported data suggest more HIV infections than reported AIDS cases.

CDC publishes first comprehensive dental infection control guidelines. The central recommendation was a shift from selective precautions to routine use of universal infection control precautions.

CDC reinforces universal precautions as basis for infection control. Agency emphasizes that blood, saliva, and gingival fluid in dentistry should be considered infectious. Also, universal precaution recommendations for HIV- and HBV-infected health care workers are made.

No further reports of HBV transmission from dentists to patients reported; still cases reported for viral infection from physicians to patients.

Sterilization of handpieces arises as an infection control issue for dentistry.

Dental unit waterlines identified as a source of postoperative wound infections in two cancer patients.

Hepatitis C virus (HCV) identified.

* First form of Non-A, Non-B (NANB) hepatitis identified.

* HCV believed to be major cause of hepatitis associated with blood transfusions.

Hepatitis E virus identified.

* Cause of enterically transmitted NANB hepatitis.

* Transmission primarily related to contaminated water supplies.

* Multiple, large hepatitis E outbreaks reported in developing countries.

Number of reported U.S. AIDS cases passes 100,000.

First case report of HIV transmission from a health care worker to a patient (HIV-infected Florida dentist).

Americans with Disabilities Act passed, with implementation to occur in phases.

First generation anti-HCV serologic blood test developed.

Reports of multiple drug-resistant Mycobacterium tuberculosis continue to increase.

FDA sends "Dear Colleague" letter to dentists concerning handpiece sterilization.

Continued reports of infected patients in case of HIV transmission involving Florida dentist.

FDA publishes initial recommendations for people with latex hypersensitivity following more than 1,100 submitted reports of latex allergies with 15 deaths attributed to natural rubber latex barium enema tips.

CDC releases HBV-/HIV-infected health care workers guidelines.

* Adherence to universal precautions.

* HIV transmitted much less readily than HBV.

* Recommendations for establishment of review panels in health care facilities.

OSHA Bloodborne Pathogen Standard becomes U.S. law.

Reports of occupational dental injuries demonstrate downward trend from 12 per year to three to four per year.

CDC publishes report on second 100,000 U.S. AIDS cases.

* First 100,000 cases occurred during an eight-year period.

* Second 100,000 cases reported during two-year interval.

* Trends for second 100,000 cases reflect increasing proportion of people with AIDS who had heterosexual exposure to people at risk for HIV infection.

* One AIDS death reported every 15 minutes.

CDC publishes report titled "Management of Persons Exposed to Multidrug-Resistant Tuberculosis." Included were suggestions for evaluating and managing people exposed to patients with strains of Mycobacterium tuberculosis that exhibit resistance to isoniazid and rifampin.

Women surpass intravenous drug users in frequency of new AIDS cases.

OSHA petitioned by health care unions for workplace standard on tuberculosis control.

HBV incidence reported down to 9 percent in general dentists and 20 percent in oral surgeons.

CDC publishes updated dental infection control guidelines.

* Tuberculosis precautions included.

* Recommendations for dental unit waterline infection control precautions.

Large waterborne outbreak of cryptosporidiosis reported in Milwaukee as a result of problems with municipal water treatment processes.

* Estimated 403,000 people infected.

* Immune-compromised people at greatest risk for life-threatening illness.

CDC reports 55 percent decrease in rate of HBV infection.

CDC finalizes tuberculosis infection control guidelines. Occupational risks for dental health care workers generally considered to be low in most practice settings.

Pediatric AIDS study reports benefits of prenatal AZT use; decrease from 25.5 percent to 8.3 percent perinatal risk.

Public Health Service reports AIDS incidence growing faster among women than men:

* Women account for 22 percent of new AIDS cases and 22 percent of total AIDS cases.

* HIV continues as leading cause of death in males ages 25 to 44.

ADA publishes statement on dental unit waterlines: suggestion of microbial target level for year 2000.

CDC reports AZT reduces HIV infection risk by 79 percent in health care workers when used as postexposure prophylaxis.

HIV protease inhibitors receive FDA approval.

Hepatitis G virus identified.

* Virus may be transfusion-transmissible.

* Global distribution.

* Thought to be present in U.S. volunteer blood donor population.

ADA Council on Scientific Affairs and Council on Dental Practice publish latest infection control recommendations for the dental office and the dental laboratory.

As of June, 51 health care workers documented with HIV infection resulting from occupational exposure, with 108 additional possible occupational infections.

* No dental health care workers documented with occupational HIV infection.

FDA licenses HIV home test kits.

* First saliva test for HIV.

* HIV antigen test for screening blood donations.

CDC revises HIV postexposure prophylaxis to include use of reverse transcriptase inhibitors and protease inhibitors in either mono or combination therapy.

Viral load testing becomes routine HIV evaluation.

President signs Safe Drinking Water Act ($7.6 billion) to improve U.S. water processing systems and water quality.

FDA publishes latex policy statement "requirement for manufacturers" in product labeling.

* Hypoallergenic label deemed inappropriate and misleading.

French Health Ministry issues findings of epidemiological investigation concerning HIV-infected orthopedic surgeon who transmitted HIV to patient during surgery.

First cases of vancomycin-resistant Staphylococcus aureus infection in humans.

* First case reported in Japan, followed soon after by two U.S. cases.

As of June, 52 health care workers documented with HIV infection resulting from occupational exposure, with 114 additional possible occupational infections.

* Still no dental workers with documented occupational HIV infection.

In September, CDC publishes notice of draft guidelines for infection control in health care personnel to update and replace 1983 recommendations.

* Broad recommendations for reducing transmission of infections from patients to health care workers and from health care workers to patients, including immunizations, isolation precautions, exposure management, and work restrictions.

* Recommendation made for anti-hepatitis B surface antigen postvaccination testing in health care workers who receive hepatitis B vaccine.

National Institute for Occupational Safety and Health research agenda targets health care worker latex allergy problems. Research direction investigating latex exposures and allergic reactions in health care industry.

CDC reports 1996 AIDS data, which show first decline in U.S. AIDS deaths and AIDS opportunistic infections.

Public Health Service reports continued decline in reported U.S. cases of tuberculosis for 1997 (19,855 cases, 7.4 cases per 100,000 population).

FDA-mandated latex regulations for manufacturers become effective.

CDC publishes recommendations for prevention and control of HCV infection and HCV-related chronic disease.

U.S. Appeals Court for the First District rules there is no direct threat in providing dental care to an HIV-positive woman.

As of Dec. 31, 1998, 54 health care workers documented with HIV infection resulting from occupational exposure, with 134 additional possible occupational infections.

* To date, no dental workers with documented occupational HIV infection.

OSHA pushes for new legislation to reduce needlesticks among health care workers.

* Ten states have passed legislation, and 10 states have pending legislation in this area.

Conclusion

Although the time line has been set up to be representative of many areas, it most certainly has omitted events or reports some readers consider important. If any readers have information they believe should be included, please send them to the address below. The present time line can then be made more inclusive and useful to treatment care providers and health professional students alike.

Authors/

John A. Molinari, PhD, is professor and chairman of the Department of Biomedical Sciences at the University of Detroit Mercy School of Dentistry.

Helene Bednarsh, RDH, MPH is the director of the HIV Dental Ombundsperson Program for the Boston Public Health Commission in Massachusetts.

To request a printed copy of this article, please contact / John A. Molinari, PhD, UDM School of Dentistry, 8200 W. Outer Drive, Detroit, MI 48219-0900.