The Viral and Rickettsial Disease Laboratory (VRDL) is the oldest state public health virology
laboratory in the United States, established in 1939 as the Influenza Research Laboratory with
support from the Rockefeller Foundation. Dr. Monroe Eaton was the first laboratory director.
The VRDL began offering diagnostic services in 1943. In 1947 when leadership was passed to
Dr. Edwin H. Lennette, the laboratory could test for 14 viral agents or diseases. With a strong
commitment to the development and evaluation of new viral assays, by 1976 the VRDL was able
to perform tests to identify over 300 different viruses. Diagnostic Procedures for Viral,
Rickettsial, and Chlamydial Infections edited by Dr. Lennette and VRDL team members is still
widely used as a laboratory reference. Leadership passed to Dr. Richard Emmons in 1978; to Dr.
Michael Ascher in 1994; to Dr. Mike Janda in 2001; to Dr. Carol Glaser in 2002; to Dr. David
Schnurr in 2009; to Dr. Sharon Messenger in 2011; and to Dr. Dongxiang Xia who assumed the
leadership in 2012 and is our current Branch Chief and Laboratory Director. VRDL has been a
highly recognized resource for laboratory diagnostic consultation, training and research with
active collaboration with epidemiologists, clinicians and other partners.
The Viral and Rickettsial Disease Laboratory provides laboratory support, technical assistance,
and research required for the diagnosis, investigation, and control of viral diseases and for the
development and maintenance of high quality local viral laboratory services in California. VRDL
also provides consultation services to the staff of local public health laboratories, California
Departments of Public Health (CDPH) and Health Care Services, and other state agencies. For
counties not having available public health laboratory services, VRDL functions as the reference
and local public health laboratory for viral and rickettsial diseases. As part of the Department's
laboratory science training program, VRDL trains local public health laboratory personnel in
state-of-the-art standardized laboratory procedures.
The VRDL is composed of five Sections that are responsible for the following functions:
The Vaccine Preventable Diseases and Herpes Viruses Section performs antibody testing and nucleic acid
detection for over 20 different infectious diseases such as herpes simplex, varicella zoster virus, measles,
mumps, rubella and arboviruses [e.g., West Nile Virus (WNV)].
The Respiratory and Gastroenteritis Diseases Section is responsible for the identification of viral
respiratory agents including influenza strain typing and identification and strain typing of Norovirus.
The Zoonotic and Vectorborne Diseases Section is responsible for the identification of rabies virus and
other animal and vectorborne diseases as well as virus isolation and fluorescent antibody and direct
The Retrovirus Diseases Section serves as a statewide reference laboratory for HIV and other
retroviruses and provides extensive consultation to local PHL’s and clinicians throughout the
state. Research activities include the development of new viral assays and monitoring of HIV vaccine
The Medical and Epidemiology Liaison Section coordinates all diagnostic specimens received by VRDL
for testing and answers questions regarding test availability, sample collection and shipment and
interpretation of test results. Our clients include other branches of CDPH, local public health laboratories,
clinical laboratories, and physicians throughout the state. This section coordinates several statewide
surveillance efforts including the Neurologic Surveillance and Testing, West Nile Virus Surveillance,
Sentinel Physician Influenza Surveillance in coordination with CDPH and Centers for Disease Control and