Urine samples as a possible alternative to serum for human immunodeficiency virus antibody screening

Utilization and Assessment of Throat Swab and Urine Specimens for Diagnosis of Chikungunya Virus Infection

Chikungunya is a mosquito-borne infection with clinical presentation of fever, arthralgia, and rash. The etiological agent Chikungunya virus (CHIKV) is generally transmitted from primates to humans through the bites of infected Aedes aegypti and Aedes albopictus mosquitoes. Outbreaks of Chikungunya occur commonly with varied morbidity, mortality, and sequele according to the epidemiological, ecological, seasonal, and geographical impact. Investigations are required to be conducted as a part of the public health service to understand and report the suspected cases as confirmed by laboratory diagnosis. Holistic sampling at a time of different types would be useful for laboratory testing, result conclusion, and reporting in a valid way. The use of serum samples for virus detection, virus isolation, and serology is routinely practiced, but sometimes serum samples from pediatric and other cases may not be easily available. In such a situation, easily available throat swabs and urine samples could be useful. It is already well reported for measles, rubella, and mumps diseases to have the virus diagnosis from throat swabs and urine. Here, we present the protocols for diagnosis of CHIKV using throat swab and urine specimens.

HIV testing in 2006: issues and methods

Infection with HIV and subsequent development of AIDS is a pandemic. The Joint United Nations Program on HIV/AIDS together with the WHO and many relevant funding bodies demand that those infected should be reliably identified so that people who need, or will need, therapy may be provided for over time. This means that there is a renewed interest in testing for HIV and in laboratories' performances and quality. Whatever the conditions under which testing is performed, and whatever the levels of training, the tests and their outcomes must exhibit equivalent, high standards of performance and reliable results. This is regardless of whether testing is conducted in the most sophisticated laboratories (either diagnostic or transfusion screening) to voluntary testing and counseling centers where those conducting testing may not be technically trained. This is not currently the case, especially in some places where HIV is most prevalent. To achieve uniformly high performance standards, quality assurance programs are imperative, but currently not sufficiently valued to be well supported with adequate funding or human resources. Accurate HIV testing is a cornerstone of blood safety, diagnosis of infection, patient management and surveillance.

Evaluation of a commercial enzyme immunoassay for HIV screening in urine

A cross-sectional study was conducted to evaluate the utility of a commercial enzyme immunoassay (EIA) as a screening test for detecting HIV-1 antibody in urine in a population at risk for HIV infection in Catalonia, Spain. Paired urine and serum samples were collected consecutively from 99 patients who attended two drug-dependency treatment centres and 151 patients who attended a sexually transmitted diseases (STD) clinic in Barcelona. Antibodies against HIV in urine samples were detected using the Calypte HIV-1 Urine EIA (Calypte Biomedical Corporation, Berkeley, CA, USA) and confirmed by urine-based Western blot (WB) analysis. Sera were analysed using Bioelisa HIV-1+2 EIA (Biokit Laboratories, Barcelona, Spain), and the results were verified using serum-based WB analysis. Results of both urine and serum testing were available for 246 of 250 participants. For 52 individuals the results of both urine and serum testing were positive and for five the results were discordant (2 with urine-negative/serum-positive results and 3 with urine-positive/serum-negative results). The respective sensitivity and specificity values obtained for the urine EIA were 100% and 96.2% for intravenous drug users (IDUs) and 80% and 99.3% for persons attending the STD clinic. According to the 1997 UNAIDS/WHO strategy I recommendations, these values are acceptable for surveillance purposes, particularly in populations with a high prevalence of HIV infection.

Anti-hepatitis A virus immunoglobulin M antibodies in urine samples for rapid diagnosis of outbreaks

The main goal of this study was to test the feasibility of using urine for diagnosing hepatitis A virus (HAV) infections. A correlation of 90.78% between the test results of urine and serum samples was obtained. Four outbreaks of hepatitis A were confirmed by testing only urine samples. The levels of anti-HAV immunoglobulin M (IgM) antibodies in urine samples remained stable during 6 months of storage at -70 degrees C but decreased when the samples were stored at 4 degrees C. The results of tests of samples obtained 2 and 6 months after infection suggested that IgM levels decline more rapidly in urine than in serum.

Evaluation of urine as a clinical specimen for diagnosis of hepatitis a

The present study pertains to the evaluation of urine as a specimen for detection of anti-hepatitis A virus (anti-HAV) antibodies. Immunoglobulin M (IgM), IgG, and IgA capture enzyme-linked immunosorbent assays for hepatitis A were performed on paired serum and urine specimens collected from hepatitis A patients (n = 92), healthy individuals (n = 100), non-A hepatitis patients (n = 70), and patients with nonhepatic diseases (n = 64, including 37 renal disease patients). Hepatitis A patients seropositive for anti-HAV IgM showed 95.65% uropositivity. No false-positive reactions were observed in control groups. The uropositivity of anti-HAV IgM persisted during the convalescent phase of the disease. Anti-HAV IgG uropositivity correlated well with corresponding seropositivity in all groups (P > 0.05 for each). No significant difference between the proportions of serum and urine positivity for anti-HAV IgA was noted (P > 0.05 for each). Using seroreactivity as a "gold standard," the sensitivity and specificity for anti-HAV IgM, anti-HAV IgG, and anti-HAV IgA tests with urine as a specimen were found to be 95.65 and 100%, 97.76 and 76.47%, and 92.23 and 88.18%, respectively. Urine appears to be comparable to serum for diagnosis of recent and past infection with hepatitis A.

Testing for rubella-specific IgG antibody in urine

BACKGROUND

In Japan rubella vaccination is generally done once during a lifetime, and the vaccination rate decreased after a revised vaccination law in 1995. History of rubella or vaccination may still be unreliable. Testing for rubella antibody is significant to prevent the occurrence of congenital rubella syndrome. However, the collection of blood samples to detect antibodies from young children is invasive and difficult.

METHODS

For this study we obtained 853 matched serum and urine samples from 904 healthy students 10 or 14 years of age in the Ibara and Yoshii districts of Okayama, Japan, for a comparison of antibodies for rubella in the matched samples. The serum and urine antibodies were measured with hemagglutination-inhibition and enzyme-linked immunosorbent assays, respectively, and with our urine-based antibody test.

RESULTS

The sensitivity, specificity and concordance rates of this urine-based antibody test were 96, 99 and 97% based on the serum antibody results of both assays. The coefficiency was 0.627 between the titers of the urinary and serum antibodies by the enzyme-linked immunosorbent assay. The urinary antibodies were stable for at least 5 months at 4 degrees C and 25 degrees C.

CONCLUSIONS

Urine-based assay methods are helpful not only because they avoid the invasive approach of venipuncture but also because unprocessed urine specimens can be used and urinary antibody is stable for a long period. Therefore this test is suitable for screening. In addition protective amounts of rubella antibody in blood can be reliably assessed by means of urine samples.

Human immunodeficiency virus antibody testing by enzyme-linked fluorescent and western blot assays using serum, gingival-crevicular transudate, and urine samples

The aim of the present study was to evaluate the possible utilization of saliva and urine as alternative samples to serum for the diagnosis of human immunodeficiency virus (HIV) infection. A total of 302 individuals participated in the study: 187 HIV-infected individuals (106 had Centers for Disease Control and Prevention [CDC] stage II infection, 19 had CDC stage III infection, and 62 had CDC stage IV infection) and 115 noninfected persons (46 of the noninfected persons were blood donors and 69 belonged to a group at high risk of HIV infection). Paired saliva and urine samples were taken from each of the participants in the study. The presence of HIV-specific antibodies was detected by an enzyme-linked fluorescent assay (ELFA), and the result was confirmed by Western blot analysis (WB). The ELFA with saliva gave maximum sensitivity and specificity values, while ELFA had lower sensitivity (95.2%) and specificity (97. 4%) values for detection of HIV antibody in urine samples. WB with all saliva samples fulfilled the World Health Organization criterion for positivity, while only 96.8% of the urine samples were confirmed to be positive by WB. Among the four reactivity patterns found by WB of these alternative samples, the most frequent included bands against three groups of HIV structural proteins (was ENV, POL, and GAG). The reactivity bands most frequently observed were those for the proteins gp160 and gp120. The least common reactivity band was the band for protein p17. The detection of HIV antibodies in saliva samples by means of ELFA with the possibility of later confirmation by WB makes saliva an alternative to serum for possible use in the diagnosis of infection. In contrast, HIV antibody detection in urine samples by the same methodology (ELFA) could be taken into consideration for use in epidemiological studies.

Detection of immunoglobulin G and A antibodies to rubella virus in urine and antibody responses to vaccine-induced infection

Urine and serum samples from 89 healthy volunteers and three healthy individuals who underwent rubella vaccination were tested for immunoglobulin G (IgG), IgA, and IgM to rubella virus (RV) by enzyme-linked immunosorbent assay methods. Subjects with positive (n = 68) or negative (n = 21) results for serum IgG were exactly the same as those with the corresponding results for urinary IgG. Both urinary and serum IgG levels remained elevated from the 3rd or 4th week after vaccination until the end of the study. Both urinary IgA and serum IgM levels tended to increase rapidly between the 3rd and 5th week and then gradually decrease until the end of the study, but the levels of both remained positive except for one sample each at the end (26th week). On the other hand, the ratio of anti-RV IgA titer to anti-RV IgG titer in urine (urinary anti-RV IgA/IgG ratio) increased rapidly between the 3rd and 4th week after vaccination and then rapidly returned to the ratio levels of the subjects positive for serum IgG from among the healthy volunteers. In summary, detection of urinary anti-RV IgG should be useful for screening for previous RV infection, and measurement of urinary anti-RV IgA/IgG ratio might be useful for diagnosing recent infection.