Toxoplasma gondii IgG Serointensity Is Positively Associated With Frailty.

BACKGROUND: Persistent inflammation related to aging ("inflammaging") is exacerbated by chronic infections and contributes to frailty in older adults. We hypothesized associations between Toxoplasma gondii (T. gondii), a common parasite causing an oligosymptomatic unremitting infection, and frailty, and secondarily between T. gondii and previously reported markers of immune activation in frailty. METHODS: We analyzed available demographic, social, and clinical data in Spanish and Portuguese older adults [N = 601; age: mean (SD) 77.3 (8.0); 61% women]. Plasma T. gondii immunoglobulin G (IgG) serointensity was measured with an enzyme-linked immunosorbent assay. The Fried criteria were used to define frailty status. Validated translations of Mini-Mental State Examination, Geriatric Depression Scale, and the Charlson Comorbidity Index were used to evaluate confounders. Previously analyzed biomarkers that were significantly associated with frailty in both prior reports and the current study, and also related to T. gondii serointensity, were further accounted for in multivariable logistic models with frailty as outcome. RESULTS: In T. gondii-seropositives, there was a significant positive association between T. gondii IgG serointensity and frailty, accounting for age (p = .0002), and resisting adjustment for multiple successive confounders. Among biomarkers linked with frailty, kynurenine/tryptophan and soluble tumor necrosis factor receptor II were positively associated with T. gondii serointensity in seropositives (p < .05). Associations with other biomarkers were not significant. CONCLUSIONS: This first reported association between T. gondii and frailty is limited by a cross-sectional design and warrants replication. While certain biomarkers of inflammaging were associated with both T. gondii IgG serointensity and frailty, they did not fully mediate the T. gondii-frailty association.

HIV counseling and testing and access-to-care needs of populations most-at-risk for HIV in Nigeria.

Mobile HIV counseling and testing (mHCT) is an effective tool to access hard-to-reach most-at-risk populations (MARPs), but identifying which populations are not accessing services is often a challenge. We compared correlates of human immunodeficiency virus (HIV) infection and awareness of HIV care services among populations tested through mHCT and at testing facilities in Nigeria. Participants in a cross-sectional study completed a questionnaire and HCT between May 2005 and March 2010. Of 27,586 total participants, 26.7% had been previously tested for HIV; among mHCT clients, 14.7% had previously been tested. HIV prevalence ranged from 6.6% among those tested through a facility to 50.4% among brothel-based sex workers tested by mHCT. Among mHCT participants aged 18-24, women were nine times more likely to be infected than men. Women aged 18-24 were also less likely than their male counterparts to know that there were medicines available to treat HIV (63.2 vs. 68.1%; p=0.03). After controlling for gender, age, and other risk factors, those with current genital ulcer disease were more likely to be HIV-infected (OR(mHCT)=1.65, 1.31-2.09; OR(facility)=1.71, 1.37-2.14), while those previously tested were less likely to be HIV-infected (OR(mHCT)=0.75, 0.64-0.88; OR(facility)=0.27, 0.24-0.31). There is an urgent need to promote strategies to identify those who are HIV-infected within MARPs, particularly young women, and to educate and inform them about availability of HIV testing and care services. mHCT, ideally coupled with sexually transmitted infection management, may help to ensure that MARPs access HIV prevention support, and if infected, access care, and treatment.

Characterization of acute HIV-1 infection in high-risk Nigerian populations.

BACKGROUND: Acute phase of human immunodeficiency virus (HIV) infection (AHI) may account for a significant proportion of HIV-1 transmission. We identified and characterized individuals in Nigeria with AHI. METHODS: Individuals were tested using a combination of rapid HIV testing in mobile units and laboratory-based specimen pooling for nucleic acid amplification testing. Genome sequences were characterized. A linear segmented regression model was fit to serial viral load (VL) measurements to characterize early VL profiles. RESULTS: Sixteen AHIs were identified from 28 655 persons screened. Specimens were genotyped: 7 (43.8%) were CRF02_AG, 6 (37.5%) were subtype G, 1 (6.3%) was CRF06_cpx, and 2 (12.5%) were unique recombinant forms. No antiretroviral resistance mutations were detected. The mean duration of high VL burden from peak to nadir was 76 days (95% confidence interval [CI], 58-93 days), and the mean rate of viremic control was -0.66 log(10) VL per month. The mean VL at set-point was 4.5 log(10) copies/mL (95% CI, 3.9-5.1 log(10) copies/mL). CONCLUSIONS: This study is the first to characterize AHI among Nigerians identified as HIV infected before seroconversion who would be otherwise missed by conventional HIV testing. Infections by HIV subtypes in Nigeria exhibit long periods of high viral burden, which can contribute to increased transmissibility.

Decreasing Tryptophan and Increasing Neopterin Plasma Levels During Pregnancy are Associated with High First Trimester Porphyromonas gingivalis K-Serotype IgG Serointensity in a Cohort of Hispanic Women.

BACKGROUND: Immune activation or high levels of stress may lead to increased metabolism of tryptophan during pregnancy. Porphyromonas gingivalis (Pg), the "keystone" periodontal pathogen, induces immune and indoleamine 2,3-dioxygenase (IDO) activation. Thus, we hypothesized that larger gestational decreases in tryptophan and elevations in neopterin and kynurenine would occur in pregnant women with elevated IgG antibodies to Pg capsular (K) serotypes. METHODS: Venous blood of 52 Hispanic pregnant women with a mean age (SD) of 31.8 (5.9) years was sampled once per trimester of pregnancy (V1, V2, V3), and plasma was obtained and stored. ELISAs were used to measure Pg capsular (K) serotype IgG serointensity (V1 only) and neopterin levels (V1-V3). Tryptophan and kynurenine (V1-V3) were measured with high-performance liquid chromatography. The participants having IgG serointensity for any of the seven Pg K serotypes in the highest quartile were defined as the "High PgK_IgG" group and those having IgG serointensity for all K serotypes in the lowest three quartiles were defined as the "Low PgK_IgG" group. Statistics included multivariable linear and nonparametric methods. RESULTS: Significant decreases in plasma tryptophan levels and increases in neopterin during gestation were found in "High PgK_IgG" women but not in "Low PgK_IgG" women. Kynurenine changes were not significantly different between the two groups. CONCLUSION: If replicated in larger studies and further characterized clinically, radiologically, and microbiologically, our results may potentially lead to novel interventional targets, as well as the development of more complete prognostic and predictive interactive biomarkers for adverse obstetrical outcomes and peripartum depression, and their prevention.

Performance of nucleocapsid and spike-based SARS-CoV-2 serologic assays.

There is an urgent need for an accurate antibody test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We have developed 3 ELISA methods, trimer spike IgA, trimer spike IgG, and nucleocapsid IgG, for detecting anti-SARS-CoV-2 antibodies. We evaluated their performance along with four commercial ELISAs, EDI™ Novel Coronavirus COVID-19 ELISA IgG and IgM, Euroimmun Anti-SARS-CoV-2 ELISA IgG and IgA, and one lateral flow assay, DPP® COVID-19 IgM/IgG System (Chembio). Both sensitivity and specificity were evaluated and the probable causes of false-positive reactions were determined. The assays were evaluated using 300 pre-epidemic samples and 100 PCR-confirmed COVID-19 samples. The sensitivities and specificities of the assays were as follows: 90%/100% (in-house trimer spike IgA), 90%/99.3% (in-house trimer spike IgG), 89%/98.3% (in-house nucleocapsid IgG), 73.7%/100% (EDI nucleocapsid IgM), 84.5%/95.1% (EDI nucleocapsid IgG), 95%/93.7% (Euroimmun S1 IgA), 82.8%/99.7% (Euroimmun S1 IgG), 82.0%/91.7% (Chembio nucleocapsid IgM), 92%/93.3% (Chembio nucleocapsid IgG). The presumed causes of false positive results from pre-epidemic samples in commercial and in-house assays were mixed. In some cases, assays lacked reproducibility. In other cases, reactivity was abrogated by competitive inhibition (spiking the sample with the same antigen that was used for coating ELISAs prior to performing the assay), suggesting positive reaction could be attributed to the presence of antibodies against these antigens. In other cases, reactivity was consistently detected but not abrogated by the spiking, suggesting positive reaction was not attributed to the presence of antibodies against these antigens. Overall, there was wide variability in assay performance using our samples, with in-house tests exhibiting the highest combined sensitivity and specificity. The causes of "false positivity" in pre-epidemic samples may be due to plasma antibodies apparently reacting with the corresponding antigen, or spurious reactivity may be directed against non-specific components in the assay system. Identification of these targets will be essential to improving assay performance.

Specificity and Performance of Nucleocapsid and Spike-based SARS-CoV-2 Serologic Assays.

There is an urgent need for an accurate antibody test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this paper, we have developed 3 ELISA methods, trimer spike IgA, trimer spike IgG, and nucleocapsid IgG, for detecting anti-SARS-CoV-2 antibodies. We evaluated their performance in comparison with four commercial ELISAs, EDI™ Novel Coronavirus COVID-19 ELISA IgG and IgM, Euroimmun Anti-SARS-CoV-2 ELISA IgG and IgA, and one lateral flow assay, DPP® COVID-19 IgM/IgG System (Chembio). Both sensitivity and specificity were evaluated and the causes of false-positive reactions were determined. The assays were compared using 300 pre-epidemic samples and 100 PCR-confirmed COVID-19 samples. The sensitivities and specificities of the assays were as follows: 90%/100% (in-house trimer spike IgA), 90%/99.3% (in-house trimer spike IgG), 89%/98.3% (in-house nucleocapsid IgG), 73.7%/100% (EDI nucleocapsid IgM), 84.5%/95.1% (EDI nucleocapsid IgG), 95%/93.7% (Euroimmun S1 IgA), 82.8%/99.7% (Euroimmun S1 IgG), 82.0%/91.7% (Chembio nucleocapsid IgM), 92%/93.3% (Chembio nucleocapsid IgG). The presumed causes of positive signals from pre-epidemic samples in commercial and in-house assays were mixed. In some cases, positivity varied with assay repetition. In other cases, reactivity was abrogated by competitive inhibition (spiking the sample with analyte prior to performing the assay). In other cases, reactivity was consistently detected but not abrogated by analyte spiking. Overall, there was wide variability in assay performance using our samples, with in-house tests exhibiting the highest combined sensitivity and specificity. The causes of "false positivity" in pre-epidemic samples may be due to plasma antibodies apparently reacting with the analyte, or spurious reactivity may be directed against non-specific components in the assay system. Identification of these targets will be essential to improving assay performance.

Human herpesvirus 8 infection in HIV-1-infected and uninfected pregnant women in Ethiopia.

BACKGROUND: Human Herpes Virus (HHV-8) is related to Kaposi Saracoma, an opportunistic infection occurring with HIV infection. Little is known about the seroepidemiology of Human Herpesvirus 8 (HHV-8) infection among Ethiopian women, even though women are a major HIV risk group in Ethiopia. OBJECTIVES: This study aimed at determining the seroprevalence of HHV-8 infection in HIV-1-infected and uninfected pregnant women in five selected regions of Ethiopia. METHODS: A cross-sectional study was conducted from December 2006 to June 2007 where pregnant women were recruited after age-matching in groups. A total of 400 pregnant women were enrolled, with 200 being HIV-infected and 200 being HIV-uninfected Sera were screened for IgG lytic antibody to HHV-8 using an Indirect Fluorescence Assay (IFA) in Virology Unit of Ethiopian Health and Nutrition Research Institute (EHNR1). RESULTS: Of 400 pregnant women attending antenatal clinic (ANC) testing sites of five regions in Ethiopia, 212 (53.0%) were positive for HHV-8 IgG lytic antibody. There was a high prevalence of HHV-8 infection among HIV-1-infected pregnant women (138, 69.0%) as compared with HIV-1-uninfected pregnant women (74, 37.0%). CONCLUSION: The study shows a high prevalence of HHV-8 infection among HIV-1-infected pregnant women as compared with HIV-1-uninfected pregnant women. Therefore, creating awareness and educating women on safe sexual practice and avoiding deep kissing may be a fundamental ways to limit the roots of transmission. Moreover, initiating strong antiretroviral therapy (ART) for HIV infected women would be best treatment prior to the development of Kaposi's sarcoma (KS).

A simple and inexpensive particle agglutination test to distinguish recent from established HIV-1 infection.

OBJECTIVES: We sought to modify the Serodia HIV-1/HIV-2 particle agglutination assay (PA), a simple and cost-effective HIV assay that is used globally for the detection of HIV antibodies, as a sensitive/less sensitive test (S/LS) to identify recently infected individuals and to estimate HIV incidence. METHODS: The Serodia PA test was modified as an S/LS test (PA-LS) by using HIV antigen-coated gelatin particles at a dilution of 1:68 and a specific diluent, and calibrated using 37 HIV clade B seroconversion panels (309 samples) from Trinidad and from a commercial source that were tested at dilution intervals from 1:10 to 1:80,000. The greatest sensitivity for correctly classifying samples from recent and established infections was determined by receiver operator curve (ROC) analysis. RESULTS: At a 1:40,000 sample dilution and a days post-seroconversion cutoff of 190 days, the PA-LS test yielded a 97% sensitivity for classifying recent and established infection samples. Furthermore, at a 1:20,000 dilution, the positive predictive value for correctly identifying recently infected individuals was 99%. The PA-LS test offers a 30-44-fold cost saving over currently available S/LS tests. CONCLUSION: A modified, low cost and simple-to-perform PA test is appropriate for use in resource-limited countries, and has exhibited excellence in distinguishing recent from established HIV infection.

Assessment of Two Rapid Assays for Diagnostic Capability to Accurately Identify Infection by Treponema pallidum.

BACKGROUND: Rapid, point-of-care tests that accurately identify syphilis are gaining popularity and offer several advantages over classic tests. METHODS: The SD Bioline Syphilis 3.0 and the Chembio DPP Syphilis Screen and Confirm Assay (CB) were assessed using 1283 samples that had been characterized by reference tests. The challenge samples included 5 commercial panels (seroconversion, mixed-titer), archived samples, fresh samples, and a dilution series. Both tests detect specific anti-treponemal antibodies, and the CB additionally detects antibodies to a non-treponemal (NT) component. The evaluation was used to determine performance indices and compare with those cited by the manufacturers. RESULTS: When assessing reactivity to treponemal, the sensitivities for the 2 tests were 98.3% and 93.2%, with specificities of 100% and 99.4%, respectively. For both tests, precision, whole blood testing, and high-temperature testing produced perfect results, and there were no invalid results. Comparisons of 2 different lots of each test indicated excellent concordance (100% and 99.5%), and reproducibility was 100% and 98.0%, respectively. For the CB, the sensitivity for the NT component was between 65.3% and 80.9%, but increased to 98.5% with samples having a rapid plasma regain (RPR) titer of ≥8. The specificity for NT was found to be 100%, and the reading of results visually and when using a battery-operated reader indicated a concordance for all challenges of 95%-100%. CONCLUSIONS: Both rapid tests produced impressive results for the detection of antibodies to treponemal for all challenges and exceeded, met, or closely approached the performance characteristics as cited by the manufacturers.

Update on the laboratory diagnosis and monitoring of HIV infection.

In China, the estimated number of HIV infected cases is approaching one million. Although public education has been initiated for awareness and behavioral modification for this devastating infection, better diagnostic methods are needed to identify infected persons and manage infection. Simple and more accurate diagnostic tools have become available, particularly for early detection and to monitor treatment in those who receive anti-retroviral treatment. In this short review, we summarize some of the common and new methodologies that can be used in clinical laboratories, in the field, or in private laboratories. These range from simple antibody tests to more sophistical methods that are used to monitor disease progression and identify drug resistance. These tools can assist physicians, medical practitioners, and laboratory personnel to select suitable diagnostic tools for the diagnosis, blood screening, monitoring of disease progression, and for detection of drug resistance to anti-retroviral therapies.

A 10-minute, US Food and Drug Administration-approved HIV test.

It is now an established fact that rapid HIV tests have important applications in a number of testing situations. Currently, four rapid HIV assays have been approved by the US Food and Drug Administration, including the one discussed in this review. A rapid, lateral flow HIV assay was evaluated at the University of Maryland, USA, one of several sites involved in the clinical evaluation. Samples used in the evaluation totaled 9000 and consisted of serum, plasma and venous whole-blood sets of samples from 3000 study subjects that included population groups considered to be at high risk for HIV infection (n=1000), from HIV-positive individuals (n=1000), and from population groups considered at low risk for HIV infection (n=1000). US Food and Drug Administration-licensed screening and confirmatory assays were used as reference tests. The rapid assay exhibited a sensitivity of 100% across all three sample media and exhibited a specificity of 99.8% using whole blood and plasma and 99.7% using serum. This rapid assay is an excellent addition to the existing US Food and Drug Administration-approved rapid HIV tests, and provides versatility by allowing the testing of venipuncture and fingerstick whole-blood samples in addition to serum and plasma.

Detection of ultra-low levels of pathologic prion protein in scrapie infected hamster brain homogenates using real-time immuno-PCR.

Pathologic prion protein (PrP(Sc)), implicated in transmissible spongiform encephalopathies, is detected by antibody-based tests or bioassays to confirm the diagnosis of prion diseases. Presently, the Western blot or an ELISA is officially used to screen the brain stem in cattle for the presence of PrP(Sc). The immuno-polymerase chain reaction (IPCR), a technique whereby the exponential amplification ability of PCR is coupled to the detection of proteins by antibodies in an ELISA format, was applied in a modified real-time IPCR method to detect ultra-low levels of prion protein. Using IPCR, recombinant hamster PrP(C) was consistently detected at 1 fg/mL and proteinase K (PK)-digested scrapie infected hamster brain homogenates diluted to 10(-8) (approximately 10-100 infectious units) was detected with a semi-quantitative dose response. This level of detection is 1 million-fold more sensitive than the levels detected by Western blot or ELISA and poises IPCR as a method capable of detecting PrP(Sc) in the pre-clinical phase of infection. Further, the data indicate that unless complete PK digestion of PrP(C) in biological materials is verified, ultrasensitive assays such as IPCR may inaccurately classify a sample as positive.

HIV testing technologies after two decades of evolution.

Over the past two decades, HIV diagnostics have been essential in detecting and monitoring infection, and continue to play a major role in saving lives throughout the world. As technology evolved, screening, confirmatory, and HIV monitoring assays have been improved and offer better alternatives to address blood screening, surveillance, diagnosis, and patient management. Molecular methods are critical in detecting early infection and for managing patients on anti retroviral therapy whose viral infection may become resistant to therapy. In addition, modifications to conventional methods have introduced new assays, such as sensitive/less sensitive (detuned) assays that can estimate when someone was infected, thereby providing a useful tool for epidemiologic incidence estimates and enrollment into specific intervention programmes for recently infected persons. Many of the newly evolving technologies are essential for use in resource-limited countries because they can address cost issues, limited infrastructure, and a lack of formally trained personnel. Newer rapid HIV kits can be stored in a wide range of temperatures (2-30 degrees C) to address cold-chain issues, can use easily-collected fingerstick blood and oral fluids, and have one-step procedures that are relatively foolproof. Manual CD4 lymphocyte count assays that require only a light microscope and haemacytometer and more simple assays to estimate viral load are appropriate for developing countries where sophisticated instrumentation cannot be supported. Technologic advances with HIV diagnostics continue to address outstanding and new issues associated with diagnosis and the monitoring of infection by providing more simplified, cost-effective, and accurate testing throughout the world.

Molecular-based laboratory testing and monitoring for human immunodeficiency virus infections.

Applications of laboratory testing for human immunodeficiency virus type 1 (HIV-1) infection have made significant impact on clinical care of HIV-infected patients globally. As these technologies continue to evolve and new technologies emerge, unique and highly sensitive nucleic acid-based testing methods will offer more and better means for us to guide physicians in anti-retroviral treatment strategies and clinical management of HIV infected patients. In this review we discuss a variety of current molecular-based methods that are available for HIV testing including diagnosis, monitoring disease progression, and detection of drug resistance to anti-retroviral therapy. Newer approaches that could be used in future HIV testing are also introduced.

Lowering the detection limits of HIV-1 viral load using real-time immuno-PCR for HIV-1 p24 antigen.

Presently, the assay that attains maximal sensitivity and dynamic range of HIV-1 viral copy number (50 copies per milliliter) is nucleic acid amplification of HIV RNA in plasma. Enzyme-linked immunosorbent assay (ELISA) methods for quantification of HIV-1 p24 antigen have been relatively insensitive. In this report, we show data that indicate real-time immuno-polymerase chain reaction (IPCR), a combination of the ELISA and PCR techniques, is more sensitive for HIV-1 p24 antigen detection than other currently reported methods. When derived from an IPCR standard curve, a dose response was observed from patient samples with known viral loads diluted within a 3-log range (1.68-6,514 viral RNA copies per milliliter). IPCR detected 42% (22/52) of patient samples that had fewer than 50 viral RNA copies per milliliter by reverse transcriptase-PCR. IPCR shows the potential to become the most analytically sensitive test available for determination of HIV-1 viral load by the detection of HIV-1 p24 antigen.

Rapid confirmation of HIV infection.

OBJECTIVE: To investigate the utility of a prototype rapid confirmatory HIV assay which offers specific results in 5 min and has applications in a variety of important testing situations. METHODS: The performance of the rapid confirmatory assay was assessed with 849 blood samples, including serum, plasma, venipuncture whole blood, and peripheral blood collected via fingerstick. Included were over 700 HIV Western blot (WB)-confirmed antibody positive sera, and others which were classified as negative or indeterminate by WB. The analytic sensitivity of the rapid confirmatory assay was assessed using 13 HIV-1 seroconversion panels, and all results were compared to those of an FDA-licensed WB reference test. RESULTS: The rapid test exhibited 100% concordance with the reference test when testing HIV-1 WB-confirmed positive samples, and 92.3% concordance with samples having WB-inconclusive results. The sensitivity for confirming recent seroconversion was as good, or better than, the FDA-licensed HIV-1 WB in 10/13 panels. The rapid assay performed accurately with whole blood collected from fingerstick, and exhibited excellent precision and reproducibility. CONCLUSION: We conclude that this rapid HIV confirmatory assay, the first of its kind, demonstrates proof of principle for the accurate confirmation of HIV-1 infection and offers important advantages in public health and clinical testing venues.

Hepatitis C virus transfusion-transmitted infection in Brazilian cardiac surgery patients.

In the past two decades, major improvements in blood safety have been achieved, particularly for HIV and hepatitis C virus (HCV). A prospective study was carried out between 1996 and 1999 in Brazil to determine the incidence of post-transfusion infection in surgery patients caused by HCV. One hundred sixty-four patients who received a blood transfusion during cardiac surgery were followed for six months and blood samples collected before and after surgery were assessed to investigate HCV infection. Alanine aminotransferase levels were serially determined, as well as clinical data related to hepatitis. Prior to surgery, HCV infection was detected by anti-HCV ELISA III in 6 patients. Any post-surgical samples which were positive by a third generation ELISA test were confirmed by immunoblot and reverse-transcription polymerase chain reaction (RT-PCR), as were the pre-transfusion samples to exclude pre-transfusion HCV infection not detected by ELISA screening. Results indicated that one patient who was previously considered negative for HCV antibody in the pre-surgical sample was later found to be positive for HCV by RT-PCR in that sample. Seroconversion for HCV antibody after surgery was observed in two patients, one of them with clinical hepatitis; their genotypes were 1a and 1b. The overall prevalence of HCV infection was 4.26% (7/164) and the incidence rate of HCV infection after surgery was 1.27% (2/157). This study shows a high rate of HCV infection acquired post-transfusion in a cohort of surgery patients in Brazil and suggests that better screening methods such as viral RNA assessment may be effective in lowering this rate.

Risk factors for HIV, hepatitis B, and hepatitis C among persons with severe mental illness.

OBJECTIVE: Previous reports have indicated that persons with severe mental illness have an elevated risk of contracting HIV, hepatitis B, and hepatitis C compared with the general population. This study extends earlier findings by examining the factors that are most predictive of serologic status among persons with severe mental illness. METHOD: S: A total of 969 persons with severe mental illness from five sites in four states were approached to take part in an assessment involving testing for blood-borne infections and a one-time standardized interview containing questions about sociodemographic characteristics, substance use, risk behaviors for sexually transmitted diseases, history of sexually transmitted diseases, and health care. RESULTS: The greater the number of risk behaviors, the greater was the likelihood of infection, both for persons in more rural locations (New Hampshire and North Carolina), where the prevalence of infection was lower, and those in urban locations (Hartford, Connecticut; Bridgeport, Connecticut; and Baltimore, Maryland), where the prevalence was higher. Although no evidence was found that certain behaviors increase a person's risk of one blood-borne infection while other behaviors increase the risk of a different infection, it is conceivable that more powerful research designs would reveal some significant differences among the risks. CONCLUSION: S: Clinicians should be attentive to these risk factors so as to encourage appropriate testing, counseling, and treatment.

Comparison of HIV oral fluid and plasma antibody results during early infection in a longitudinal Nigerian cohort.

BACKGROUND: Oral fluid (OF) testing is a less-invasive alternative to blood-based testing for HIV. The performance of HIV OF tests has not been extensively evaluated in serially collected paired specimens from seroconverters. OBJECTIVE: To compare paired OF and plasma test performance in a cohort of HIV-1 seroconverters from Nigeria. STUDY DESIGN: Paired plasma and OF specimens from 14 seroconverters collected during 24 months of longitudinal follow up were included in the study. Plasma and OF were tested using Avioq HIV-1 Microelisa System, and first reactivity in plasma and OF specimens was compared. OF specimens reactive by Avioq were subsequently tested by OraSure HIV-1 Western blot. Genetic Systems HIV-1 Western blot was also performed on the corresponding plasma of the first 2 Avioq-OF positive time-points. RESULTS: Of the 14 seroconverters, 5 (35.7%) had concordant results between plasma and OF for all time points tested, whereas 9 (64.3%) showed reactivity on plasma before OF specimens early in infection. The median delay between plasma and OF reactivity was 29 days (range: 0 day-20 months) (p<0.0039); the median overall delay for OF compared to RNA testing was 69.5 days. Delayed antibody response with OF was observed in both males and females regardless of viral load or HIV subtypes. CONCLUSIONS: Results demonstrate decreased sensitivity of OF testing compared to blood-based testing with specimens obtained early after HIV infection. Programs that utilize OF testing in populations with increased risk of incident HIV infection should understand these limitations of OF testing.

Toxoplasma gondii immunoglobulin G antibodies and nonfatal suicidal self-directed violence.

OBJECTIVE: The primary aim was to relate Toxoplasma gondii seropositivity and serointensity to scores on the self-rated Suicide Assessment Scale (SUAS-S). Another aim was to reevaluate the previously reported positive association between T gondii serointensity and a history of nonfatal suicidal self-directed violence. METHOD: This cross-sectional, observational study compared T gondii serointensity and seropositivity in plasma from 54 adult suicide attempters (inpatients at Lund University Hospital, Lund, Sweden) and 30 adult control subjects (randomly selected from the municipal population register in Lund, Sweden) recruited between 2006 and 2010. The potential of patients and controls for self-directed violence was evaluated with the SUAS-S. Psychiatric diagnoses were made according to DSM-IV criteria. Plasma samples were tested for immunoglobulin G antibodies to T gondii, cytomegalovirus, and herpes simplex virus type 1. Data were analyzed using multivariable logistic regression to investigate the association between T gondii serointensity or seropositivity and a history of nonfatal suicidal self-directed violence; multivariable linear regression was used to explore the relationship between T gondii serointensity or seropositivity and the SUAS-S. Both regression models included sex, age, and body mass index as covariates. RESULTS: Seropositivity of T gondii (adjusted odds ratio [OR] = 7.12; 95% CI, 1.66-30.6; P = .008) and serointensity of T gondii (adjusted OR = 2.01; 95% CI, 1.09-3.71; P = .03) were positively associated with a history of nonfatal suicidal self-directed violence. Seropositivity of T gondii was associated with higher SUAS-S scores, a relationship significant for the whole sample (P = .026), but not for suicide attempters only. No significant associations with other pathogens were identified. CONCLUSIONS: These results are consistent with previous reports on the association between T gondii infection and nonfatal suicidal self-directed violence. Confirming these results in future large longitudinal studies and including suicide as an outcome may lead to novel individualized approaches in suicide prevention.