Predominance of alcohol and illicit drugs among traffic accidents fatalities in an urban area of Brazil.

OBJECTIVE: The objective of this study was to determine the prevalence of alcohol and illicit drug use among victims of fatal traffic accidents in the Metropolitan Region of Vitória, Brazil, during the period 2011-2012. METHODS: Blood samples were collected and analyzed for the presence of drugs from 391 deceased victims of traffic crashes that occurred in the Metropolitan Region of Vitória, Brazil. The victims included drivers, passengers, and pedestrians. Sociodemographic variables such as age, gender, day of the week, and period of the year in which the accidents occurred were recorded. The analyses were performed by a gas chromatography-flame ionization method for alcohol and by a gas chromatography-mass spectrometry for amphetamines, cocaine, and cannabis. RESULTS: The results showed that 44.8% (n = 175) of all cases were positive for alcohol and/or illicit drugs. The detection of alcohol and/or drugs was more frequent in young males, aged 17 to 34, whose samples were positive in 46.8% of cases. Small differences among drivers, passengers, and pedestrians were observed (drivers = 45.9%, passengers = 46.4%, and pedestrians = 45.6%). In general, the most prevalent drug was alcohol, with 141 positive cases (36.1%), followed by cocaine, with 47 positive cases (12%). Amphetamines and cannabis had positivity rates of 4.1 and 4.3%, with 16 and 17 positive cases, respectively. The combined use of alcohol and other drugs was found in 36 cases (9.2%). Crack cocaine use was observed in 27.7% of the positive cases for cocaine. CONCLUSIONS: For the effective reduction of traffic accidents related to driving under influence of drugs (DUID), we suggest the intensification of enforcement actions against the use of alcohol by drivers, the definition of which illicit drugs should be surveyed, as well the cutoff values, the promotion of changing legislation to oblige drivers to provide samples for toxicological testing, and the establishment of public information programs and specific actions aimed at young drivers to promote behavioral changes.

A one-step extraction procedure for the screening of cocaine, amphetamines and cannabinoids in postmortem blood samples.

A gas chromatography-mass spectrometric (GC-MS) method was developed and validated for the simultaneous detection and quantification in postmortem whole blood samples of cocaine (COC), amphetamines (AMPs) and cannabis; the main drugs involved in cases of impaired driving in Brazil. The analytes were extracted by solid-phase extraction by means of Bond-Elute Certify cartridges, derivatized with N-methyl-N-(trimethylsilyl)trifluoroacetamide at 80°C for 30 min and analyzed by GC-MS. Linearity ranged from 10 to 500 ng/mL, except for ecgonine methyl ester, for which linearity ranged from 10 to 100 ng/mL. Inter- and intra-day imprecision ranged from 2.8 to 18.4% and from 1.5 to 14.9%, respectively. Accuracy values lay between 86.9 and 104.4%. The limit of quantitation for all drugs was 10 ng/mL and recoveries were >74% for all analytes, except for cannabinoids, which showed poor recovery (∼30%). The developed method was applied to real samples collected from deceased victims due to traffic accidents. These samples were selected according to the results obtained in immunoassay screening on collected urine samples. Five samples were positive for the presence of COC and metabolites, four samples were positive for cannabinoids, six samples were positive for AMPs and two samples were drug negative. Some samples were positive for more than one class of drug. Results obtained from whole blood samples showed good agreement with urine screening. The developed method proved capable of quantifying all three classes of drugs of abuse proposed in this study, through a one-step extraction procedure.

Upgrading the flow-cytometric analysis of anti-Leishmania immunoglobulins for the diagnosis of American tegumentary leishmaniasis.

We have previously described a flow cytometry-based assay to detect anti-live Leishmania (Viania) braziliensis promastigote antibodies (FC-ALPA) with prominent performance of FC-ALPA to diagnosis American tegumentary leishmaniasis (ATL). However, the laboriousness to work with live parasites represented the major drawback for using FC-ALPA in routine clinical laboratory. Herein, we have presented an upgraded technology using fixed Leishmania (Leishmania) amazonensis promastigotes as antigen (FC-AFPA). Our data demonstrated that FC-AFPA-IgG displays outstanding performance for ATL diagnosis with high sensitivity (99%) and specificity (100%). Moreover, Likelihood Ratio indicated that positive results (LR+) has an infinite times more chance to come from ATL than from non-infected individuals (NI). Despite the high frequency of cross-reactivity with putative ATL co-endemic diseases, including visceral leishmaniasis, Chagas disease and malaria, FC-AFPA-IgG showed remarkable potential for differential diagnosis with other dermatological illnesses such as leprosy and sporotrichosis. FC-AFPA-IgG subclasses analysis revealed that LTA is characterized by IgG1>IgG3>IgG2 = IgG4 anti-L. amazonensis profiling, electing FC-AFPA-IgG1 and IgG3 with better performances to diagnosis ATL diagnosis. Additionally, FC-AFPA-IgG3 showed to be a better diagnostic tool in endemic areas for malarial disease. Despite the substantial advance to work with fixed promastigotes that contributes to its higher sensitivity, the lower specificity of FC-AFPA represented the major flaws as compared to FC-ALPA, suggesting that further improvement is still required to minimize the cross-reactivity with trypanosomatidae infections. Perspectives for using a flow cytometry multiplex based methodology to simultaneously assess anti-L. amazonensis, anti-L. chagasi and anti-Trypanosoma cruzi IgG reactivity is currently under investigation.

Detection of anti-leishmania (Leishmania) chagasi immunoglobulin G by flow cytometry for cure assessment following chemotherapeutic treatment of American visceral leishmaniasis.

The residual serological reactivity observed in patients cured of visceral leishmaniasis (VL) represents the major factor underlying the low efficiency of most anti-Leishmania serological approaches to assess posttherapeutic cure in VL. Herein, we have described a detuned flow cytometry-based methodology to detect anti-live (FC-ALPA-immunoglobulin G [IgG]) and anti-fixed (FC-AFPA-IgG) L. chagasi promastigote IgG, along the titration curve (1:2,000 to 1:128,000), as a tool to assess late (12 months after treatment [12 mAT]) and early (2 and 6 mAT) posttherapeutic cure of pediatric American visceral leishmaniasis. Reactivities were reported as the percentage of positive fluorescent parasite (PPFP), using a PPFP of 50% as a cutoff to segregate positive and negative results. Our data demonstrated that both FC-ALPA-IgG at 1:4,000 and FC-ALPA-IgG at 1:32,000 are useful for late cure assessment in VL, with 100% specificity and outstanding likelihood ratio indices. Cure assessment at 6 mAT also showed promising performance indices, identifying 81% and 71.4% of the treated patients with negative results. However, new interpretation parameters were necessary to monitor cure at 2 mAT. We then introduced the differential PPFP (DeltaPPFP) of 25% as a new cutoff for early cure assessment at specific serum dilutions to analyze IgG reactivity by FC-ALPA-IgG and FC-AFPA-IgG. Our data demonstrated that at 2 mAT, DeltaPPFP was >25% in 60% and 57.1% of treated patients, whereas at 6 mAT, a DeltaPPFP of >25% was observed in 100% and 95.2% of samples assayed by FC-ALPA-IgG and FC-AFPA-IgG, respectively. Together, our findings showed the potential of both FC-ALPA-IgG and FC-AFPA-IgG regarding their applicability to detect differential serological reactivity and further contribution to posttherapeutic cure assessment in VL.