Oral Fluid Sample Collection Research Articles

Pilot study of oral fluid and plasma meropenem and piperacillin concentrations in the intensive care unit

BackgroundTherapeutic drug monitoring (TDM) of β-lactam antibiotics may be used to optimize dosing for patients in the intensive care unit (ICU). A noninvasive matrix such as oral fluid may be interesting in selected patient groups. We compared the oral fluid concentrations of piperacillin and meropenem with the respective unbound and total concentrations in plasma. A secondary objective was to evaluate feasibility of the collection of oral fluid samples in this specific patient population. MethodsThe study included 20 non-intubated ICU patients, age 22 to 77 y, receiving piperacillin or meropenem via continuous intravenous infusion. The standard protocol consisted of collecting a paired plasma-oral fluid sample for 3 consecutive days. Oral fluid was obtained from the patients using a standardized procedure by spitting in a plastic container after 2 min of gathering oral fluid in the mouth. ResultsAntibiotic concentrations of piperacillin and meropenem are measurable, albeit very low, in unstimulated oral fluid of ICU patients. For piperacillin, a poor correlation was found between oral fluid and both total and unbound plasma concentrations (Spearman’s correlation coefficients (Rs) 0.46 and 0.48 respectively). For meropenem this correlation was better (Rs for oral fluid versus total and unbound plasma meropenem concentration 0.92 and 0.93 respectively). Dispersion of antibiotic concentrations was greater in oral fluid than in blood. Collecting oral fluid samples was difficult in non-intubated ICU patients. ConclusionsOral fluid from non-intubated ICU patients, obtained through a standardized procedure, cannot be recommended as an alternative matrix for quantitative meropenem or piperacillin TDM.

Molecularly imprinted polymer-based device for field collection of oral fluid samples for cocaine identification

In this paper, a low–cost, rapid, easy, and potentially portable tool for the identification of cocaine and its semi-quantitative determination in oral fluid has been proposed. A field collection device has been designed, based on a cotton pad with an indicator and a molecularly imprinted polymer (MIP) sorbent, to selective retain cocaine from oral fluid components. After sample collection, cocaine is transferred by using phosphate buffer to the MIP and then eluted with 2-propanol. The obtained extract is analysed by ion mobility spectrometry (IMS), providing a cut-off value of 20 µg L−1 that identifies 100 % true-positive and 95 % true-negative samples. The MIP-IMS procedure has been validated by the analysis of oral fluid samples, collected from cocaine users at recreation environments, by comparing the results with lateral flow immunoassay and chromatographic reference methods. Thus, the proposed methodology allows a simple and fast cocaine identification that can be carried out in field by non-specialized personnel, such as health personnel, law enforcement bodies, and customs staff.

Evaluation of swabs from 15 commercially available oral fluid sample collection devices for the analysis of commonly abused substances: doping agents and drugs of abuse.

Oral fluid testing is steadily building its position as a valuable complement or alternative to plasma and urine analyses in everyday laboratory practice. However, the great significance of the sample collection process in the attainment of representative results is not always paralleled by the attention given to its informed selection. Few evaluations of commercially available sample collection devices have been published until now, and the current work intends to fill this gap by presenting an evaluation of swabs from 15 different devices for the analysis of 49 popular drugs. Swabs, derived from sample collection devices, were used to collect a drug-fortified mixture. Then, swab-retrieved samples were subjected to instrumental analysis with the high-performance liquid chromatography coupled with tandem mass spectrometry method. Results within the 80-120% range were considered to have no significant impact on analyte concentration (thus satisfactory) and were observed in 44.1% of all results. Out of the 15 evaluated swabs, 7 provided results in the aforementioned range for more than half of the substances under study. The possibility of matrix effects originating from swab materials was also investigated. The selection of an appropriate oral fluid sample collection method plays a critical role in the success of the analytical procedure, a fact that is well-illustrated by the tremendous differences between analyte concentrations observed in this research. Perhaps, the tedious labour of improving sample preparation and analysis methods already in-use could be spared if only greater emphasis were to be put on the improvement and better selection of suitable solutions for oral fluid collection.

Recommendations for pen-based oral-fluid collection in growing pigs

Sampling guidelines were developed by observing pigs during oral-fluid sample collection in commercial herds. Pigs with previous oral-fluid collection experience (“trained”) should be allowed 20 minutes access to the rope. Pigs with no prior experience (“untrained”) should be allowed 60 minutes. One collection is enough to train pigs.

Measuring risk of HIV and HCV among injecting drug users in the Russian Federation

The aim of the study was to measure risk of HIV and HCV infection among injecting drug users (IDUs) through force of infection (FOI) models in three cities of the Russian Federation and assess the value of behavioural data and FOI in predicting risk of infection as a method of second-generation surveillance. FOI models were fitted to prevalence data collected through an anonymous, cross-sectional community-recruited survey of IDUs with oral fluid sample collection for antibodies to HIV and HCV. Risk of infection was estimated from FOI estimates obtained by fitting a model to prevalence data by length of injecting career for each city and then overall. Risk behaviours were examined by injecting career length. A total of 1473 IDUs were recruited. Prevalence of HIV was 8.1% (95% CI 6.7-9.6%) and HCV 63.4% (95% CI 60.9-65.9%). A higher FOI in new initiates to injecting (injecting career length <1 year) was found for both HIV and HCV compared with experienced IDUs (injecting career length <5 years). Increased risk of infection was not corroborated by injecting risk behaviours among new initiates into injecting (n = 38). Only 5.7% (n = 2) reported receptive sharing in the last 4 weeks, 57.9% (n = 22) sharing any injecting paraphernalia, 2.6% (n = 1) frontloading and 8.5% (n = 3) ever injecting with used needles/syringes. However, 29% of new initiates reported exchanging sex in the last 4 weeks (29%) compared with 11% long term IDUs. FOI models can play an important role in surveillance of HIV but caution is needed in the interpretation of behavioural data for predicting current or future risk of HIV.

Feasibility of collecting oral fluid samples in the home setting to determine seroprevalence of infections in a large-scale cohort of preschool-aged children

Oral fluid is a non-invasive biological sample, which can be returned by post, making it suitable for large-scale epidemiological studies in children. We report our experience of oral fluid collection from 14 373 preschool-aged children in the UK Millennium Cohort Study. Samples were collected by mothers in the home setting following the guidance of trained interviewers, and posted to the laboratory. Samples were received from 11 698 children (81.4%). Children whose mothers were of Black Caribbean ethnicity and who lived in non-English-speaking households were less likely to provide a sample, and those with a maternal history of asthma more likely to provide a sample [adjusted risk ratio (95% CI) 0.85 (0.73-0.98), 0.87 (0.77-0.98) and 1.03 (1.00-1.05) respectively]. Collection of oral fluid samples is feasible and acceptable in large-scale child cohort studies. Formal interpreter support may be required to increase participation rates in surveys that collect biological samples from ethnic minorities.

Prevalence of HIV, hepatitis C and syphilis among injecting drug users in Russia: a multi‐city study

To estimate the prevalence of HIV, hepatitis C virus (HCV) and syphilis in injecting drug users (IDUs) in Russia. Unlinked anonymous cross-sectional survey of 1473 IDUs recruited from non-treatment settings in Moscow, Volgograd and Barnaul (Siberia), with oral fluid sample collection for HIV, HCV antibody (anti-HIV, anti-HCV) and syphilis testing. Prevalence of antibody to HIV was 14% in Moscow, 3% in Volgograd and 9% in Barnaul. HCV prevalence was 67% in Moscow, 70% in Volgograd and 54% in Barnaul. Prevalence of positive syphilis serology was 8% in Moscow, 20% in Volgograd and 6% in Barnaul. Half of those HIV positive and a third of those HCV positive were unaware of their positive status. Common risk factors associated with HIV and HCV infection across the cities included both direct and indirect sharing of injecting equipment and injection of home-produced drugs. Among environmental risk factors, we found increased odds of anti-HIV associated with being in prison in Moscow, and some association between official registration as a drug user and anti-HIV and anti-HCV. No associations were found between sexual risk behaviours and anti-HIV in any city. HIV prevalence among IDUs was markedly higher than city routine surveillance data suggests and at potentially critical levels in terms of HIV prevention in two cities. HCV prevalence was high in all cities. Syphilis prevalence highlights the potential for sexual risk and sexual HIV transmission. Despite large-scale testing programmes, knowledge of positive status was poor. The scaling-up of harm reduction for IDUs in Russia, including sexual risk reduction, is an urgent priority.

Hepatitis C virus infection, HIV co-infection, and associated risk among injecting drug users in Togliatti, Russia

The objective of this study was to estimate the prevalence of hepatitis C virus (HCV) infection and co-infection with HIV among injecting drug users (IDUs) in Togliatti City, Russia. Unlinked anonymous cross-sectional survey of IDUs recruited from community settings, with oral fluid sample collection for HCV and HIV antibody (anti-HCV, anti-HIV) testing, was carried out. The anti-HCV prevalence was 87% (357/411), anti-HIV prevalence 56% (234/418), and 93% (214/230) of HIV-positive IDUs were co-infected with HCV. Only 23% (94/411) of those HCV positive self-reported as such. In an adjusted model, increased odds of HCV positivity were associated with needle and syringe, as well as injecting paraphernalia sharing in the last four weeks. IDUs injecting more than once with the same needle also had raised odds. There were no marked associations between HCV positivity and the duration of injecting or age group. Almost all IDUs were HCV positive, and almost all HIV-positive IDUs were HCV co-infected. There is an urgent need to maximize syringe distribution coverage, develop health promotion targeting HCV prevention for IDUs, and improve access among IDUs to treatments for HIV and HCV infection.

Oral fluid collection by post—a pilot study of two approaches

This pilot study aimed to assess the feasibility of the postal collection of oral fluid samples for surveillance purposes and the effect of two different approaches on the response rates. This cross-sectional, antibody prevalence study collected oral fluid samples and questionnaire data from randomly selected individuals, aged under 45 y, through the post. The individuals were recruited from four general practice registers. In a one stage approach patients were sent the oral fluid kit with the initial invitation letter. In a two stage approach the kits were sent out after written consent had been received. There was little difference in the overall response rates between the two approaches (38% two stage and 41% one stage), though the response rate for the one stage approach was 10% higher in the under-20-y-olds in practices from areas of greater deprivation. The low response partly reflected poor uptake in young adults who may need to be approached through more targeted surveys. In the other age groups additional reminders could prove a cost-effective way of increasing the response rate further. Public Health (2002) 116, 113–119

Oral fluid collection by post—a pilot study of two approaches

This pilot study aimed to assess the feasibility of the postal collection of oral fluid samples for surveillance purposes and the effect of two different approaches on the response rates. This cross-sectional, antibody prevalence study collected oral fluid samples and questionnaire data from randomly selected individuals, aged under 45 y, through the post. The individuals were recruited from four general practice registers. In a one stage approach patients were sent the oral fluid kit with the initial invitation letter. In a two stage approach the kits were sent out after written consent had been received. There was little difference in the overall response rates between the two approaches (38% two stage and 41% one stage), though the response rate for the one stage approach was 10% higher in the under-20-y-olds in practices from areas of greater deprivation. The low response partly reflected poor uptake in young adults who may need to be approached through more targeted surveys. In the other age groups additional reminders could prove a cost-effective way of increasing the response rate further. Public Health (2002) 116, 113–119

HIV-1 prevalence, HIV-1 subtypes and risk factors among fishermen in the Gulf of Thailand and the Andaman Sea.

Mobile populations are thought to be at high risk for HIV-1 infection. This study aims to determine the prevalence of HIV-1 infection, HIV-1 subtypes and socio-demographic and behavioural risk factors among fishermen in the Gulf of Thailand and the Andaman Sea. A cross-sectional survey, consisting of face-to-face interviews and the collection of oral fluid samples, was conducted in Samut Sakorn, Ranong, Songkhla and Traat Provinces, Thailand, between January and April 1998. Oral fluid samples were double-tested for HIV-1 antibody by IgG antibody capture enzyme-linked immunosorbent assay and enzyme immunoassay, and confirmed by Western blot. The presence of subtypes B' and E was assessed using a peptide enzyme immunoassay. Of the 818 fishermen (582 Thai, 137 Burmese, 99 Khmer) 15.5% were HIV-1 positive: 14.6% among Thai, 16.1% among Burmese and 20.2% among Khmer. Of the 119 HIV-1 positive samples available for subtyping, 72 (61%) were subtype E, 15 (13%) were subtype B'; the subtype could not be determined for 32 (27%) samples. Sixteen per cent of subjects had ever visited a commercial sex worker outside Thailand. This behaviour was more prevalent among Khmer (40%) than among Thai and Burmese (12%). In univariate logistic regression analysis, being 25 to 32 years of age, compared with being older or younger; working as a fisherman between 4 and 10 years, compared with working for a shorter or longer period; being unmarried; being a steersman or mechanic, compared with being a skipper or ship hand; greater number of visits to commercial sex workers; having visited a commercial sex worker outside Thailand; alcohol or drug use before or during sex; being tattooed; and having a history of sexually transmitted disease were significantly related to prevalent HIV-1 infection. Male-to-male sex and injection drug use were rarely reported in this population. In multivariate analysis, being 25 to 32 years of age, being unmarried, having a tattoo and a greater number of visits to commercial sex workers remained in the model to predict HIV-1 prevalence. A history of drug injection was predictive for infection with HIV-1 subtype B'. These findings indicate a high HIV-1 prevalence among fishermen in the Gulf of Thailand and the Andaman Sea. Risk factor analysis suggests that heterosexual intercourse is the major mode of transmission in this population. Increased efforts to reduce the spread of HIV-1 among this epidemiologically important group are urgently needed.