Serology

The Serology section tests blood serum for levels of antibodies resulting from exposure to a particular bacteria or virus. This includes the Interferon-y release assay Quantiferon testing for latent tuberculosis. Quantiferon testing increased in fiscal year 2013 due to the continued growth in the number of incoming foreign-born students attending Iowa universities for which the Hygienic Laboratory provides TB testing. An acute shortage of the antigen used in TB skin tests this year was another factor in the surge in Quantiferon testing.

Arbovirus surveillance continued with very limited funding available for the program. A total of five flocks of eight sentinel chickens were placed around the state and were tested each week for West Nile Virus (WNV) IgM antibody. This surveillance testing is used to predict WNV activity in an area and is a measure of the potential risk of the disease to humans in the area.

FY13 achievements:

• Several tests in the HIV Serology area were updated this year, including the addition of HIV Anitgen/Antibody Combo testing that provides earlier diagnosis by detecting the HIV antigen. Multispot testing was added as the confirmatory test for HIV Combo positive sera, and provides a type-specific result (HIV-1 versus HIV-2).
• The Hygienic Laboratory is now able to access Nucleic Acid Amplification Testing (NAAT) in the event of indeterminate confirmatory HIV test results. This was made possible through an APHL/CDC program that allows labs in low prevalence HIV areas, such as Iowa, to obtain NAAT results. State labs can send samples to regional public health labs for testing that otherwise would not be available due to the low numbers of cases in certain states.