Serum and salivary IgG and IgA response to radiation therapy.

Patients undergoing radiotherapy for malignant tumors of the head and neck invariably develop extensive oral and dental diseases particularly when the major salivary glands are within the radiation fields. Unless the patient receives a strict oral hygiene home care and the teeth are protected by topical application of fluoride gel, caries or gingival disease onset inevitably follows radiation induced xerostomia is. The importance of saliva as a controlling factor in the development of oral diseases is underscored by the dramatic increase in dental decay and gingival diseases that inevitably follows the surgical extirpation of the major salivary glands in animals and the onset of xerostomia in man.

Relevance of detection of immunoglobulin M antibody response in birds used for arbovirus surveillance.

Young chickens were inoculated with 5,000 PFU of eastern equine encephalitis (EEE) virus and bled at intervals thereafter for determinations of hemagglutination-inhibiting (HI), neutralizing (N), immunoglobulin M (IgM), and IgG antibodies. HI, N, and IgM antibodies were first detected 4 days after infection, and IgG was detected 7 days after infection. All four antibodies persisted through day 90 after infection. HI, N, and IgM antibody titers remained elevated and were not cross-reactive with the related alphavirus western equine encephalitis (WEE) virus. IgG antibody titers also remained high, but heterologous reactivity to WEE virus increased with time after infection. Serum samples from sentinel chickens and wild birds infected in nature with EEE, WEE, or St. Louis encephalitis virus and submitted to this laboratory from state and local health departments were tested for IgM antibody by using anti-chicken IgM for capture and for IgG antibodies to the EEE and WEE viruses. There was essentially complete correlation between HI, N, and either IgM (indicating recent infections) or IgG (indicating more remote infections) antibody. We conclude that the IgM antibody capture enzyme immunoassay can be used as a specific and sensitive assay to replace the routinely used HI test for detecting antibody in sentinel chickens and in young, wild birds used for arbovirus surveillance. The test is rapid and relatively inexpensive and can be performed in essentially all adequately supplied laboratories.

Rapid and specific serodiagnosis of western equine encephalitis virus infection in horses.

Paired sera from 28 nonvaccinated horses with serologically confirmed western equine encephalitis (WEE) virus infections were evaluated for immunoglobulin (Ig)M and IgG directed against WEE virus, by use of enzyme immunoassay. Twenty-one of the horses developed greater than or equal to 4-fold increases or decreases in serum IgM titers in paired serum samples, confirming the diagnosis of WEE in these horses. Of the remaining 7 horses, 1 had stable IgM titers, 1 had a 2-fold increase in IgM titer between paired sera, 2 had 2-fold decreases in IgM titer, and for 3 horses adequate volumes were not available for both sera of the pair. Twenty-nine of 56 blood samples collected from these 28 horses had been collected within the first 3 days after clinical disease was recognized; all 28 horses and 48 of 53 available serum samples had IgM antibody to WEE virus. Immunoglobulin M also was detected in sera of 27 of 45 other nonvaccinated horses that had illnesses clinically compatible with WEE. Sera with IgM did not have cross-reacting IgM against eastern equine encephalitis virus. Therefore, the sensitivity, specificity, and lack of persistence of IgM was useful in the rapid diagnosis of WEE virus infections in horses.

Complex-specific immunoglobulin M antibody patterns in humans infected with alphaviruses.

Sera from humans with serologically confirmed eastern equine encephalitis, western equine encephalitis, Pogosta (Ockelbo), Mayaro, Ross River, and chikungunya virus infections were tested by immunoglobulin M (IgM) antibody capture enzyme immunoassay. Diagnostically useful IgM antibody titers were detected, and selected sera with high IgM antibody titers were tested for IgM antibody with nine heterologous alphaviruses. The results provide evidence for the complex specificity of IgM antibody and indicate the usefulness of this test in both individual cases and epidemic situations.

Hepatitis B virus infection in upper and lower Egypt.

The relative prevalence of hepatitis B surface antigen (HBsAg), anti-HBs, and anti-hepatitis B virus core antigen (HBc), as markers of hepatitis B virus infection, among 1,866 apparently healthy residents of two Egyptian provinces representing Upper and Lower Egypt populations was determined using solid-phase radioimmunoassay (SPRIA). The prevalence rate of HBsAg in the Egyptian population was moderately high (10.1%); it was higher in the Upper Egypt (11.7%) than the Lower Egypt (8.0%) population and more frequent in young adults--especially those of Upper Egypt--and males than females in both populations. The prevalence of anti-HBs gradually increased with age; it was higher in the Lower Egypt (51.1%) than the Upper Egypt (41.7%) population, and it was higher in females than males. A remarkably high infection rate, as shown by the prevalence of anti-HBc, was found in both populations (88.0%), with minor variations depending on age, sex, and geographic area.