Genetic diversity of Trypanosoma cruzi infecting raccoons (Procyon lotor) in 2 metropolitan areas of southern Louisiana: implications for parasite transmission networks.

Trypanosoma cruzi, the aetiological agent of Chagas disease, exists as an anthropozoonosis in Louisiana. Raccoons are an important reservoir, as they demonstrate high prevalence and maintain high parasitaemia longer than other mammals. Given the complex nature of parasite transmission networks and importance of raccoons as reservoirs that move between sylvatic and domestic environments, detailing the genetic diversity of T. cruzi in raccoons is crucial to assess risk to human health. Using a next-generation sequencing approach targeting the mini-exon, parasite diversity was assessed in 2 metropolitan areas of Louisiana. Sequences were analysed along with those previously identified in other mammals and vectors to determine if any association exists between ecoregion and parasite diversity. Parasites were identified from discrete typing units (DTUs) TcI, TcII, TcIV, TcV and TcVI. DTUs TcII, TcV and TcVI are previously unreported in raccoons in the United States (US). TcI was the most abundant DTU, comprising nearly 80% of all sequences. All but 1 raccoon harboured multiple haplotypes, some demonstrating mixed infections of different DTUs. Furthermore, there is significant association between DTU distribution and level III ecoregion in Louisiana. Finally, while certain sequences were distributed across multiple tissues, others appeared to have tissue-specific tropism. Taken together, these findings indicate that ongoing surveillance of T. cruzi in the US should be undertaken across ecoregions to fully assess risk to human health. Given potential connections between parasite diversity and clinical outcomes, deep sequencing technologies are crucial and interventions targeting raccoons may prove useful in mitigating human health risk.

Raccoons As an Important Reservoir for Trypanosoma cruzi: A Prevalence Study from Two Metropolitan Areas in Louisiana.

Raccoons are an important reservoir for Trypanosoma cruzi infection, having been reported to maintain a high and lengthy parasitemia. Although raccoon populations have historically been abundant in Louisiana, the prevalence rate of T. cruzi infection in raccoons in this state is unknown. Here, we tested raccoon tissues from two urban areas in Louisiana, namely Orleans Parish (OP) and East Baton Rouge Parish (EBRP), to investigate prevalence in these areas using direct detection through polymerase chain reaction. Overall, 33.6% of raccoons tested were positive. The prevalence in OP (42.9%) was significantly higher than the prevalence in EBRP (23.2%). There was no significant difference in prevalence between sexes or based on age, but there was a significant difference in infection prevalence based on season of trapping. These results suggest the importance of raccoons as a reservoir host, maintaining T. cruzi infection and potentially posing a risk to human health.

HIV-associated comorbidities as mediators of the association between people living with HIV and hospital-acquired infections.

BACKGROUND: Hospital-acquired infections (HAIs) lead to poor health outcomes in hospitalized patients and may be disproportionately affecting the aging population of people living with HIV (PLWH). This study determined the association between HIV and HAIs, and analyzed the potential mediating effects of comorbidities. METHODS: The Louisiana Hospital Inpatient Discharge Database for the years 2011-2015 was used. All patients with at least 1 HAI diagnosis within this source population were included as cases in the case-control study, and a 1:1 ratio of controls was randomly selected from the same hospitals. RESULTS: Of the 1,852,769 eligible hospital discharges that occurred from 2011 through 2015, there were 7,422 patients with at least 1 HAI. Marginal logistic regressions of the case-control sample showed a strong association between HIV and central line-associated bloodstream infections (CLABSIs), but an inverse association between HIV and any HAI. However, the mediation analyses revealed that having at least 1 comorbidity mediates the association between HIV and CLABSIs. DISCUSSION: The unexpected inverse association between HIV and HAI could be attributed to the sample size of the exposed group of patients, or it could be explained by the mechanisms of treatment for HIV patients. CONCLUSIONS: This study found that people living with HIV are at an increased risk of developing a CLABSI, which is consistent with the published literature. The mediation analyses indicated that having at least 1 comorbidity mediated the association between HIV and CLABSI diagnosis.