Molecular surveillance detects high prevalence of the neglected parasite Mansonella ozzardi in the Colombian Amazon.

Mansonellosis is an undermapped insect-transmitted disease caused by filarial nematodes that are estimated to infect hundreds of millions of people globally. Despite their prevalence, there are many outstanding questions regarding the general biology and health impacts of the responsible parasites. Historical reports suggest that the Colombian Amazon is endemic for mansonellosis and may serve as an ideal location to pursue these questions in the backdrop of other endemic and emerging pathogens. We deployed molecular and classical diagnostic approaches to survey Mansonella prevalence among adults belonging to indigenous communities along the Amazon River and its tributaries near Leticia, Colombia. Deployment of a loop-mediated isothermal amplification (LAMP) assay on blood samples revealed an infection prevalence of ∼40% for Mansonella ozzardi . This assay identified significantly more infections than blood smear microscopy or LAMP assays performed using plasma, likely reflecting greater sensitivity and the ability to detect low microfilaremias or occult infections. Mansonella infection rates increased with age and were higher among males compared to females. Genomic analysis confirmed the presence of M. ozzardi that clusters closely with strains sequenced in neighboring countries. We successfully cryopreserved and revitalized M. ozzardi microfilariae, advancing the prospects of rearing infective larvae in controlled settings. These data suggest an underestimation of true mansonellosis prevalence, and we expect that these methods will help facilitate the study of mansonellosis in endemic and laboratory settings.

Clinical and nerve conduction features in Guillain-Barré syndrome associated with Zika virus infection in Cúcuta, Colombia.

BACKGROUND AND PURPOSE: Zika virus (ZIKV) infection has been associated with an increased incidence of Guillain-Barré syndrome (GBS) but the relative frequency of acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and axonal GBS subtypes is controversial. METHODS: Twenty GBS patients diagnosed according to the Brighton criteria during the ZIKV outbreak in Cúcuta, Colombia, were evaluated clinically and electrophysiologically. The electrodiagnosis of GBS subtypes was made according to a recently described criteria set that demonstrated a high diagnostic accuracy on the basis of a single test. The electrophysiological features of 34 Italian AIDP patients were used as control. RESULTS: All patients had symptoms compatible with ZIKV infection before the onset of GBS and ZIKV infection was laboratory confirmed through a plaque reduction neutralization test (PRNT90 ) in 100% of patients. The median time from onset of ZIKV infection symptoms to GBS was 5 days (interquartile range 1-6 days). Cranial nerve palsy was present in 85% of patients (facial palsy in 75%, bulbar nerve involvement in 60%), autonomic dysfunction in 85%, and 50% of patients required invasive mechanical ventilation. AIDP was diagnosed in 70% of patients. 40% of nerves of AIDP patients showed a prevalent distal demyelinating involvement but this pattern was not different from the Italian AIDP patients without ZIKV infection. CONCLUSIONS: Guillain-Barré syndrome associated with ZIKV infection in Cúcuta is characterized by a high frequency of cranial nerve involvement, autonomic dysfunction and requirement of mechanical ventilation indicating an aggressive and severe course. AIDP is the most frequent electrophysiological subtype. Demyelination is prevalent distally but this pattern is not specific for ZIKV infection.

Evaluation of several protocols for the application of ultrasound during the removal of cast intraradicular posts cemented with zinc phosphate cement.

AIM: To evaluate several protocols for the application of ultrasound during removal of cast posts with varying core configurations cemented with zinc phosphate. METHODOLOGY: Sixty maxillary canines were distributed into three groups (n = 20): group 1 - core with 5 mm diameter/height and post diameter of 1.3 mm; groups 2 and 3 - core with the same diameter as the post (1.3 mm) and heights of 5 mm and 3 mm, respectively. Posts/cores were cemented using a standard technique with zinc phosphate cement. Each group was divided into two subgroups according to the ultrasonic vibration mode: point vibration - ultrasonic vibration applied to the core surface for 5 s, on each face totalling 25 s; alternate vibration - intermittent application of ultrasonic vibration for 10 s to the labial and lingual surfaces, 10 s to the mesial and distal surfaces and 5 s to the incisal surface, totalling 25 s. The specimens were submitted to the tensile test using an Instron machine (1 mm min(-1)) and results were analysed by anova and t-test. The failure type was also analysed. RESULTS: Statistical analysis showed significant differences between groups relating to the core preparations (P < 0.05). The lowest mean values of traction force were obtained for group 3 (46.1 +/- 7.7 N), followed by group 2 (89.0 +/- 2.7 N) and group 1 (160.4 +/- 7.5 N). Regarding ultrasonic vibration, the lowest mean was observed with alternate vibration (81.1 +/- 10.1 N), which was significantly lower than the point vibration (115.9 +/- 9.5 N) (P < 0.05). Cohesive failure occurred in all cases. CONCLUSION: A reduction in core diameter/height and intermittent ultrasonic application improved the removal of cast posts cemented with zinc phosphate.