Needle stick injuries in the community

Mechanical transmission of dengue virus by Aedes aegypti may influence disease transmission dynamics during outbreaks

BACKGROUND

Dengue virus outbreaks are increasing in number and severity worldwide. Viral transmission is assumed to require a minimum time period of viral replication within the mosquito midgut. It is unknown if alternative transmission periods not requiring replication are possible.

METHODS

We used a mouse model of dengue virus transmission to investigate the potential of mechanical transmission of dengue virus. We investigated minimal viral titres necessary for development of symptoms in bitten mice and used resulting parameters to inform a new model of dengue virus transmission within a susceptible population.

FINDINGS

Naïve mice bitten by mosquitoes immediately after they took partial blood meals from dengue infected mice showed symptoms of dengue virus, followed by mortality. Incorporation of mechanical transmission into mathematical models of dengue virus transmission suggest that this supplemental transmission route could result in larger outbreaks which peak sooner.

INTERPRETATION

The potential of dengue transmission routes independent of midgut viral replication has implications for vector control strategies that target mosquito lifespan and suggest the possibility of similar mechanical transmission routes in other disease-carrying mosquitoes.

FUNDING

This study was funded by grants from the National Health Research Institutes, Taiwan (04D2-MMMOST02), the Human Frontier Science Program (RGP0033/2021), the National Institutes of Health (1R01AI143698-01A1, R01AI151004 and DP2AI152071) and the Ministry of Science and Technology, Taiwan (MOST104-2321-B-400-016).

Spatiotemporal trends in discarded needle reports near schools in Boston, Massachusetts, between 2016-2019

BACKGROUND

Childhood exposures to discarded needles pose a direct risk for infection with blood-borne pathogens and psychological trauma for caregivers and children. Little is known about environmental predictors of discarded needles relative to areas where children are frequent, such as schools.

OBJECTIVE

We investigated spatiotemporal trends in discarded needle reports and the density near schools in Boston, Massachusetts, between 2016 and 2019.

METHODS

We used the kernel density estimation (KDE) and a relative risk function (RRF) to explore their spatial distribution and temporal changes of discarded needles reported through the 311 service request system in Boston. The density of needle pick-up requests around schools was investigated by using Thiessen polygons.

RESULTS

Between January 2016 and December 2019, 18,272 discarded needle reports were made. Publicly reported discarded needles in Boston sharply increased over the 4 years and the highest density of needles was found in 2 central neighborhoods. The density of reports of discarded needles near schools increased among the majority of schools. About 30% of schools demonstrated an increase of 100% or more in reports of discarded needles.

CONCLUSION

This analysis provides insight into potential risk of exposure to needle stick injuries for children based on utilizing publicly available crowd-sourced data. Monitoring the density of discarded needles near schools may be a novel approach to improve public health efforts to distribute safe needle disposal locations and reduce injection drug use in public.

Syringe Services Programs' Role in Ending the HIV Epidemic in the U.S.: Why We Cannot Do It Without Them

Diagnoses of HIV among people who inject drugs have increased in the U.S. during 2014-2018 for the first time in 2 decades, and multiple HIV outbreaks have been detected among people who inject drugs since 2015. These epidemiologic trends pose a significant concern for achieving goals of the federal initiative for Ending the HIV Epidemic in the U.S. Syringe services programs are cost effective, safe, and highly effective in reducing HIV transmission and are an essential component of a comprehensive, integrated approach to addressing these concerns. Yet, geographic coverage of these programs remains limited in the U.S., and many jurisdictions continue to have laws and policies that limit or disallow syringe services programs. An in-depth literature review was conducted on the role of syringe services programs in the Ending the HIV Epidemic initiative. Empirical and model-based evidence consistently shows that syringe services programs have the highest impact in HIV prevention when combined with access to medications for substance use disorder and antiretroviral therapy. Their effectiveness is further maximized when they provide services without restrictions and include proven and innovative strategies to expand access to harm-reduction and clinical services (e.g., peer outreach, telehealth). Increasing geographic and service coverage of syringe services programs requires strong and sustainable policy, funding, and community support and will need to address new challenges related to the COVID-19 pandemic. Syringe services programs have a key role in all 4 Ending the HIV Epidemic initiative strategies-Prevent, Diagnose, Treat, and Respond-and thus are instrumental to its success in preventing disease and saving lives.