Dengue severity by serotype in 19 years of pediatric clinical studies in Nicaragua

Background

Dengue virus, a major global health threat, consists of four serotypes (DENV1-4) that cause a range of clinical manifestations from mild to severe and potentially fatal disease.

Methods

This study, based on 19 years of data from the Pediatric Dengue Cohort Study and Pediatric Dengue Hospital-based Study in Managua, Nicaragua, investigates the influence of serotype and immune status on dengue severity. Study participants 6 months to 17 years old were followed during their hospital stay or as ambulatory patients, with dengue cases confirmed by molecular, serological, and/or virological methods.

Results

We enrolled a total of 14071 participants, of whom 2954 (21%) were positive for DENV infection. Of 2425 cases with serotype result by RT-PCR, 541 corresponded to DENV1, 996 to DENV2, 718 to DENV3 and 170 to DENV4. Severe disease was more prevalent among secondary DENV2 and DENV4 cases, while similar disease severity was observed in both primary and secondary DENV1 and DENV3 cases. According to the 1997 World Health Organization (WHO) severity classification, both DENV2 and DENV3 had a higher proportion of severe disease compared to other serotypes, whereas DENV3 had the greatest percentage of severity under the WHO-2009 classification. DENV2 was associated with pleural effusion and low platelet count, while DENV3 correlated with both hypotensive and compensated shock.

Conclusions

These findings emphasize the critical need for a dengue vaccine with balanced efficacy against all four serotypes, particularly as existing vaccines show variable efficacy by serotype and immune status, posing challenges for comprehensive protection, particularly in dengue-naïve individuals.

Ataxia Severity Correlates with White Matter Degeneration in Spinocerebellar Ataxia Type 7

BACKGROUND AND PURPOSE

There is a scarcity of information on the effect of white matter degeneration in patients with spinocerebellar ataxia type 7. Therefore, we investigated the WM integrity in a large group of patients with spinocerebellar ataxia type 7 by using Tract-Based Spatial Statistics.

MATERIALS AND METHODS

Thirty-three patients with a molecular diagnosis of spinocerebellar ataxia type 7 and their age- and sex-matched healthy controls participated in this study. The patients' ataxia severity was evaluated with the Scale for the Assessment and Rating of Ataxia. Voxelwise analyses of diffusion metrics, including fractional anisotropy and mean diffusivity, were performed with Tract-Based Spatial Statistics. The correlation between WM abnormalities and ataxia severity was then calculated.

RESULTS

Tract-Based Spatial Statistics analysis revealed WM abnormalities in the cerebellum and the cerebellar peduncles, as well as in other major cortical and subcortical pathways. Further analysis between the Scale for the Assessment and Rating of Ataxia score and WM mean diffusivity showed significant associations only in key areas related to motor control and visuospatial processing, including the cerebellar WM, the middle occipital WM, the superior cerebellar peduncle, and bilateral anterior thalamic radiation. No significant associations between fractional anisotropy and the Scale for the Assessment and Rating of Ataxia were found.

CONCLUSIONS

These results suggest a significant contribution of local cerebellar and cerebellar-midbrain connections to ataxic impairment in spinocerebellar ataxia type 7. The results also suggest an involvement of cortical WM abnormalities including tracts within the occipital and frontal cortices. These findings contribute to a more comprehensive view of the clinical impact of the white matter degeneration in spinocerebellar ataxia type 7.

[Ultrasound-guided infraclavicular axillary vein cannulation]

BACKGROUND AND OBJECTIVE

Percutaneous central venous cannulation is a challenging procedure. Traditionally, an external landmark technique has been used to identify puncture site. We wanted to evaluate an ultrasound-guided technique for the axillary vein cannulation, looking specifically at the ease of use, success rate and decreased complications.

METHODS

Sixty consecutive surgical patients scheduled for central venous catheter placement were registered. An ultrasound scanner made for guiding an in plane puncture of axillary vein was used. After locating the vessels, an echo-guided sterile procedure was performed to cannulate the vein.

RESULTS

Cannulation was successful in all patients, and there were no complications during insertion of the catheters. Both axillary veins were cannulated, and the vein was punctured successfully at first attempt in 95% of the patients. The median time from the start of the first puncture (of the skin) until the aspiration of blood was 15 (7- 135) seconds.

CONCLUSION

This ultrasound-guided technique for inserting central venous catheters in axillary vein was easy to apply. This procedure could increase precision and safety in patients undergoing axillary vein cannulation.

Oral autopsy of unidentified burned human remains. A new procedure

Forensic dentistry plays an increasingly important role in medicolegal investigation and identification procedures. The oral examination may be difficult because of postmortem changes, especially those of carbonized corpses. We present a new technique of oral autopsy that includes a new means of access to the oral cavity designed for application on unidentified burned human remains. This technique preserves the facial configuration of the cadaver, allowing visual recognition by family members or other persons that is fundamental if the antemortem dental records do not exist or are not available. Also, this technique permits adequate work productivity by the forensic team members and can be used in difficult working conditions, such as mass-disaster scenarios.

Base rate and simulated symptoms of mild head injury among normals

This study examined the vulnerability of several self-report instruments commonly used in neuropsychological evaluation - the Iowa Interview for Partial Seiwre-Like Symptoms, Postconcussion Checklist (PCL). Postconcussion Syndrome Checklist (PCSC), and Beck Depression Inventory (BDI) - to exaggerated or feigned complaints. Two hundred twenty-nine college student volunteers completed the instruments under one of three conditions: I) Base Rate/Control; simulated Head Injured, but 2) without or 3) with prospect of financial gain for the injury. Although the simulated Head Injured groups did not differ significantly from one another, both groups endorsed more symptoms than the Base Rate group, suggesting that the instruments are vulnerable, to simulation. Base rates of head injury symptoms in the normal population, laypersons' knowledge about the sequelae of mild head injury, and implications of using symptom checklists in medicolegal evaluations were discussed, as was the desirability of replicating this study with noncollege student populations.

Reference values of immunoglobulin E in umbilical cord sera

The National Program for the Prevention of Allergic Diseases, including the determination of IgE concentrations in umbilical cord serum at birth began in 1986. Research was conducted to determine normal umbilical cord serum values in Cuban children since no previous research had been performed. The values consulted corresponded to children from other countries with different characteristics from ours. A total of 900 neonates were examined, excluding those whose mothers had been affected by factors that increase serum IgE concentrations. IgE values higher than 10 IU/ml were also regarded as abnormal. The microELISA-IgE technique, a heterogenous immunoenzymatic sandwich type assay, was used. As reference values, a 0.64 mean, 0.06 lower limit and a 6.83 upper limit were obtained.

Prevention of allergic diseases and IgE dosification in cord sera

In 1986, a Program on Prevention of Allergic Diseases was initiated in our country which was possible on account of the organization conditions of our health system. The program includes IgE measurement in umbilical cord serum by means of an ultramicroanalytic technique for IgE quantification. This is an heterogeneous sandwich-type immunoassay that requires only 10 microliters of reactive on each reaction step and its processing is carried out on the Cuban SUMA equipment. Two groups of children were selected and followed-up: group I included 80 one-year-old infants and group II included 60 18-months-old infants. Both groups followed hypoallergenic diets and had minimal exposure to aeroallergens within their microenvironment. Results were compared with those of respective control groups. Compliance of both groups with the prophylactic measures brought about a reduction in the existence of allergic diseases and a comparison with the control groups offered a statistically significant difference (p less than 0.001). Similarly, incidence of asthma was found more reduced in groups I and II than in the control groups (p less than 0.001). Within the groups treated under the Program on Prevention of Allergic Diseases, IgE values were lower, while the control groups exhibited a higher number of infants with figures of 200 IU/ml or more (p less than 0.05). Our results support the usefulness of preventive measures in avoiding the presence of atopic diseases.