Travel surveillance uncovers dengue virus dynamics and introductions in the Caribbean

Dengue is the most prevalent mosquito-borne viral disease in humans, and cases are continuing to rise globally. In particular, islands in the Caribbean have experienced more frequent outbreaks, and all four dengue virus (DENV) serotypes have been reported in the region, leading to hyperendemicity and increased rates of severe disease. However, there is significant variability regarding virus surveillance and reporting between islands, making it difficult to obtain an accurate understanding of the epidemiological patterns in the Caribbean. To investigate this, we used travel surveillance and genomic epidemiology to reconstruct outbreak dynamics, DENV serotype turnover, and patterns of spread within the region from 2009-2022. We uncovered two recent DENV-3 introductions from Asia, one of which resulted in a large outbreak in Cuba, which was previously under-reported. We also show that while outbreaks can be synchronized between islands, they are often caused by different serotypes. Our study highlights the importance of surveillance of infected travelers to provide a snapshot of local introductions and transmission in areas with limited local surveillance and suggests that the recent DENV-3 introductions may pose a major public health threat in the region.

Introduction and Spread of Dengue Virus 3, Florida, USA, May 2022-April 2023

During May 2022-April 2023, dengue virus serotype 3 was identified among 601 travel-associated and 61 locally acquired dengue cases in Florida, USA. All 203 sequenced genomes belonged to the same genotype III lineage and revealed potential transmission chains in which most locally acquired cases occurred shortly after introduction, with little sustained transmission.

Travel surveillance uncovers dengue virus dynamics and introductions in the Caribbean

Dengue is the most prevalent mosquito-borne viral disease in humans, and cases are continuing to rise globally. In particular, islands in the Caribbean have experienced more frequent outbreaks, and all four dengue virus (DENV) serotypes have been reported in the region, leading to hyperendemicity and increased rates of severe disease. However, there is significant variability regarding virus surveillance and reporting between islands, making it difficult to obtain an accurate understanding of the epidemiological patterns in the Caribbean. To investigate this, we used travel surveillance and genomic epidemiology to reconstruct outbreak dynamics, DENV serotype turnover, and patterns of spread within the region from 2009-2022. We uncovered two recent DENV-3 introductions from Asia, one of which resulted in a large outbreak in Cuba, which was previously under-reported. We also show that while outbreaks can be synchronized between islands, they are often caused by different serotypes. Our study highlights the importance of surveillance of infected travelers to provide a snapshot of local introductions and transmission in areas with limited local surveillance and suggests that the recent DENV-3 introductions may pose a major public health threat in the region.

Development of a family-based preventive intervention for Latinx sexual minority youth and their parents

OBJECTIVE

Latinx sexual minority youth (LSMY) are disproportionately affected by adverse health outcomes, due to stigma and/or lack of family support. There are currently no family-based interventions for LSMY. This qualitative study describes the development of Familias con Orgullo (Families with Pride), a family-based intervention to prevent/reduce substance use, risky sexual behavior, and depressive symptoms in LSMY.

METHOD

Familias con Orgullo was developed using an iterative, user-centered methodology across two study phases. A general inductive approach was used to analyze intervention development individual interviews (N = 24: n = 12 parents, n = 12 LSMY) and post-intervention focus groups (N = 4) to query participants about program components and enhancements to the developed program after delivery. Data were coded into 11 themes representative of program features for LSMY and their families.

RESULTS

An intervention would need LSMY information delivered in a safe space and focused on communication, peer pressure, and mental health. Furthermore, participation would be dependent on parental level of acceptance. Informed by participants, we developed an intervention which addresses the multiple ecological levels of LSMY contexts within a cultural lens. Families gave positive feedback and indicated that additional content should focus on sexual health and intrapersonal topics. The intervention was modified and delivered to a new cohort of families; families felt the new intervention promoted inclusiveness; enriched relationships and communication between families; and enhanced lesbian, gay, bisexual, transgender, or queer (LGBTQ) knowledge.

CONCLUSION

Familias con Orgullo begins to address the significant gap in intervention research with LSMY and their families. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Treatment of stenosis and thrombosis in haemodialysis fistulas and grafts by interventional radiology

BACKGROUND

There are no large series reporting the long-term results after radiological treatment of both stenosis and thrombosis in native fistulas (AVFs) and prosthetic grafts.

METHODS

Between 1987 and 1999, 726 dilations, 135 stent placements and 257 declotting procedures were performed in 209 consecutive forearm AVFs, 74 upper arm AVFs and 156 prosthetic grafts. The stents used were the Wallstent*, the Craggstent*, and the Passager*. Declotting was performed by manual catheter-directed thromboaspiration, with or without previous urokinase infusion.

RESULTS

The initial success rates ranged from 78 to 98%. The rate of significant complications was 2%. Primary patency rates at 1 year were twice as good for forearm AVFs (50%) than for grafts (25%) (P<0.05), and were 34% for upper arm AVFs. Secondary patency rates were similar in the 3 groups at 1 year (80-86%) and at 2 years (68-80%). Reintervention was necessary every 18 months in forearm AVFs compared to every 9 months in grafts (P<0.05). Thrombosed grafts fared worse than failing grafts. Accesses of less than 1 year's duration needed more reinterventions than older accesses (every 16 months versus 30 in forearm AVFs, every 7 months versus 13 in grafts, P<0.05).

CONCLUSIONS

The percutaneous treatment of stenosis and thrombosis in haemodialysis access achieves patency rates similar to those reported in the surgical literature and confirms that grafts must be avoided as much as possible given their poorer outcome, especially after the first thrombosis. Poorer outcome is also demonstrated in accesses of less than 1 year's duration.

Wallstents and Craggstents in hemodialysis grafts and fistulas: results for selective indications

PURPOSE

To report the value of selective placement of self-expandable stents (Wallstent and Craggstent) for the treatment of limitations and, occasionally, of complications of dilation in hemodialysis access, and especially for delaying restenosis.

MATERIALS AND METHODS

This is a retrospective study of a 7-year period, during which 41 Wallstents and 11 Craggstents were placed in 26 polytetrafluoroethylene (PTFE) grafts, 15 native fistulas, and nine central veins of 47 patients. The indications were stenosis recoil (n = 13), recurrent restenosis within 6 months (n = 33), restenosis after 6 months (n = 3), and acute angioplasty-induced rupture (n = 1). Restenosis after stent placement necessitated redilation and percutaneous declotting and 10 additional stent placements.

RESULTS

Two initial misplacements were corrected immediately. Primary patency rates for PTFE grafts were 58% +/- 10% at 6 months and 23% +/- 10% at 1 year, respectively. Secondary patency rates were 100% at 6 months and 88% +/- 8% at 1 year, respectively. For native fistulas, primary patency rates were 47% +/- 12% at 6 months and 20% +/- 18% at 1 year. Secondary patency rates were 95% +/- 6% at 6 months and 79% +/- 14% at 1 year. It was necessary to reintervene after stent placement to maintain or to restore patency every 9 months for PTFE grafts and every 7.3 months for native fistulas. When stents were placed for treatment of early recurring restenosis, the mean interval between radiologic interventions (redilations or declottings) performed to maintain or to restore patency before stent placement was multiplied by 2.1 after stent placement for both grafts (3.2 months increased to 6.9, P < .01) and native fistulas (2.9 months increased to 6.2, P < .02).

CONCLUSIONS

Wallstents and Craggstents are valuable for the treatment of failure of regular dilation and they double the intervals between reinterventions for early (< 6 months) recurring stenoses in PTFE grafts and native fistulas.

Vaccine against hepatitis B--18 months prevention in a high risk setting

The development of a vaccine against hepatitis B prepared with purified and inactivated HBs Ag is described. This vaccine has been applied in patients and staff members of haemodialysis centres. Safety and efficiency of the vaccine are very satisfactory. The response of patients to immunisation was significantly lower compared to the response of the staff members. None of the volunteers who had a primary response to immunisation developed signs of clinical or biological hepatitis.

[Vaccination against hepatitis B in man]

The preparation of a vaccine against hepatitis B is described. The vaccine is prepared from the HB viral coat (HBs Ag) purified and formalin inactivated. The HBs Ag is isolated and purified from the blood of healthy HBs Ag positive donors by means of an immunoadsorbent technique. The inocuity and efficacy were tested on chimpanzees. Vaccination was then applied in an attempt to protect patients and ward staff in a high risk haemodialysis unit. The efficacy of the vaccine was assessed by humoral and cellular anti-HBs immune reactions. The study of HBs antigenaemia in vaccinated and non-vaccinated subjects indicate that this vaccine protects against hepatitis B. Many arguments are in favor of aetiological role of the hepatitis B virus in the genesis of primary liver cancer in tropical areas. Immunization against hepatitis B could be the first example of prevention of a potentially oncogenic viral infection.