The Leishmaniases are a group of diseases whose clinical presentation is in part determined by the infecting species. Until recently, mucosal leishmaniasis was attributed exclusively to Leishmania (Viannia ) braziliensis; however, the capacity of other species of the subgenus Viannia to invade mucosal tissue has been documented. This report examines the clinical characteristics of 23 parasitologically diagnosed patients with mucosal leishmaniasis due to L. (V.) panamensis from the Pacific Coast of Colombia seen at CIDEIM between 1985 and 1996. Most of the mucosal lesions 74% (17 of 23) were mild, with a short time of evolution (median ϭ 2.5 months) and were present concomitantly with an active cutaneous lesion in 61% (14 of 23) of the cases. The simultaneous presentation of mucosal and active cutaneous lesions contrast with classical descriptions of mucosal leishmaniasis caused by L. (V.) braziliensis, and highlights the importance of early diagnosis of mucosal disease by the examination of mucosa in all cases of cutaneous leishmaniasis.
The effect of antimalarials on gametocytes can influence transmission and the spread of drug resistance. In order to further understand this relationship, we determined the proportion of gametocyte carriers over time post-treatment in patients with uncomplicated Plasmodium falciparum malaria who were treated with either chloroquine (CQ) or sulfadoxine/pyrimethamine (SP) In spite of several in vivo and in vitro studies (Hogh et al. 1998, Buckling et al. 1999, Robert et al. 2000, the effect of chloroquine (CQ) and sulfadoxine/pyrimethamine (SP) on gametocytes in patients with Plasmodium falciparum malaria remains unclear. If after treatment a considerable proportion of patients carry gametocytes this would increase transmission. Likewise, if resistant parasites are more likely to develop gametocytes after treatment, the spread of drug resistance would be favoured. The present study examines the effect of these two antimalarials on gametocytaemia and explores the influence of treatment failure on gametocyte carriage.
MATERIALS AND METHODSIn 1998, a 14-day in vivo randomized trial of the efficacy of CQ and SP to treat uncomplicated P. falciparum malaria in Quibdó, Colombia was conducted (Osorio et al. 1999). Thick blood film slides from 98 out of 141 patients who had participated in this study were examined for the presence and density of asexual and sexual parasites. Asexual parasitaemia was measured by dividing the number of asexual parasites found in 300 leukocytes by 300 and multiplying by 8,000 (the estimated number of leukocytes per microliter of blood). The presence of gametocytes was evaluated in 1,000 leukocytes (approximately 200 fields), and gametocyte density was estimated by counting the number of sexual forms in 1,000 leukocytes and multiplying by 8. Two laboratory technicians with expertise in malaria microscopy read all slides blinded. Discordant results were evaluated by a qualified third reader, who did not know the results of the previous readers. EPINFO 6.04b (CDC 1997) was used for data analysis. Data was compared using 2 x 2 tables. Continous variables were compared by Kruskal-Wallis test, and categorical data by Chi-squared or Fisher's exact test when required.
RESULTSForty-two patients received CQ and 56 SP. As in the original study, in this subset CQ-and SP-treated groups were similar in demographic and malaria characteristics at enrollment but differed in the presence of CQ in urine and treatment failure (Table). The overall proportion of patients with gametocytes at enrollment was 25.5% (25/98). Most patients in the study developed gametocytes over 14 days of follow up, and the proportion of patients carrying gametocytes in blood peaked on day 7 (85.7% in CQtreated and 86% in SP-treated patients) (Figure). Factors such as age, parasite density at enrollment, duration of symptoms (fever) and presence of CQ in urine were not associated with gametocyte carriage at enrollment, nor at follow up.The geometric mean gametocyte density was comparable between groups at enrollment (61 gametocytes/µ...
Background
Adequate testing is critically important for control of the SARS-CoV-2 pandemic. Antibody testing is an option for case management and epidemiologic studies, with high specificity and variable sensitivity. However, characteristics of local populations may affect performance of these tests. For this reason, the National Institute of Health (INS) and regulatory agencies in Colombia require verification of diagnostic accuracy of tests introduced to the Colombian market.
Methods
We conducted a validation study of the Abbott SARS-CoV-2 test for qualitative detection of IgG using the Abbott Architect i2000SR. Participants and retrospective samples were included from patients with suspected SARS-CoV-2 infection, age ≥18 years, and ≥8 days elapsed since initiation of symptoms. Pre-pandemic plasma samples (taken before October 2019) were used as controls. We estimated the sensitivity, specificity and agreement (kappa) of the Abbott IgG test compared to the gold standard (RT-PCR).
Results
The overall sensitivity was 83.1% (95% CI: 75.4–100). Sensitivity among patients with ≥14 days since the start of symptoms was 85.7%, reaching 88% in samples collected from patients with COVID-19 symptoms onset >60 days. Specificity was 100% and the kappa index of agreement was 0.804 (95% CI: 0.642–0.965).
Conclusions
Our findings show high sensitivity and specificity of the Abbott IgG test in a Colombian population, which meet the criteria set by the Colombian INS to aid in the diagnosis of COVID-19. Data from our patient groups also suggest that IgG response is detectable in a high proportion of individuals (88.1%) during the first two months following onset of symptoms.
Background
Several laboratory techniques for anti double-stranded (ds) DNA detection in systemic lupus erythematosus (SLE) are available, with variable diagnostic performance. We aimed to evaluate anti-dsDNA’s diagnostic performance by indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (EIA).
Methods
We conducted a single-center retrospective (2015 to 2020) study. Patients with anti-dsDNA tests by IIF and EIA were included. We evaluated the indications, applications, concordance, positive predictive value (PPV) of anti-dsDNA to confirm SLE diagnosis or flares, and associations of disease manifestations with positivity with each technique.
Results
A total of 1368 reports of anti-dsDNA tests by IIF and EIA and the corresponding medical records of the patients were analyzed. The main indication for anti-dsDNA testing was to help in the diagnosis of SLE in 890 (65%) of the samples, and the main application after obtaining the results was SLE exclusion in 782 (57.2%) cases. The combination with the highest frequency was the negativity result by both techniques in 801 (58.5%) cases (Cohen kappa 0.57). Both methods were positive in 300 patients with SLE (Cohen kappa 0.42). The PPVs of anti-dsDNA tests to confirm diagnosis/flare was 79.64% (95% CI, 75.35–83.35) by EIA, 78.75% (95% CI, 74.27–82.62) by IIF, and 82% (95% CI, 77.26–85.93) when both were positive.
Conclusions
Anti-dsDNA detection by IIF and EIA are complementary and may indicate different clinical patterns in patients with SLE. The detection of anti-dsDNA antibodies by both techniques has a higher PPV than either separately for confirming SLE diagnosis or flares. These results highlight the need for evaluating both methods in clinical practice.
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