Case Report: A Case of Post-Transplant Chagas Reactivation after Negative Trypanosoma cruzi Testing.

Patients with Chagas cardiomyopathy carry a significant risk of reactivation after heart transplantation. Reactivation of Chagas disease can lead to graft failure or systemic complications such as fulminant central nervous system disease and sepsis. As such, careful screening for Chagas seropositivity prior to transplant is crucial to preventing negative outcomes in the post-transplant setting. One challenge in screening these patients is the variety of laboratory tests available and their differing sensitivities and specificities. In this case report, we present a patient who tested positive by a commercial Trypanosoma cruzi antibody assay and later tested negative by CDC confirmatory serological analysis. After the patient underwent orthotopic heart transplant, he underwent protocol-based polymerase chain reaction surveillance for reactivation as a result of persistent concerns for T. cruzi infection. It was discovered shortly thereafter that the patient had reactivation of Chagas disease, confirming that he did have Chagas cardiomyopathy prior to transplantation, despite negative confirmatory testing. This case illustrates the complexities of serological diagnosis of Chagas disease and the importance of additional testing for T. cruzi when the post-test probability remains high even with a commercial, negative serologic test.

Molecular epidemiology and genetic characterization of influenza B virus in Lebanon during 2016-2018.

BACKGROUND: Influenza B viruses are a major cause of serious acute respiratory infections in humans. METHODS: Nasopharyngeal swabs were collected from subjects with influenza-like illness during October 2016-June 2018 and screened for influenza A and B. The hemagglutinin (HA) and neuraminidase (NA) genes of the Lebanese influenza B specimens were sequenced and phylogenetically compared with the vaccine strains and specimens from the Eastern Mediterranean Region and Europe. RESULTS: Influenza A and B viruses co-circulated between October and May and peaked between January and March. During the 2016-2017 season, A/H3N2 (33.4%) and B/Yamagata (29.7%) were the predominantly circulating viruses followed by B/Victoria and A/H1N1pdm09 viruses. During the 2017-2018 season, A/H3N2 (31.5%) and A/H1Npdm09 (29.3%) were most prevalent with co-circulation of B/Yamagata and to a lesser extent B/Victoria viruses. The B/Yamagata specimens belonged to clade-3 while the B/Victoria belonged to clade-1A. None of the analyzed specimens had a mutation known to confer resistance to NA inhibitors (NAIs). CONCLUSION: Multiple subtypes of influenza co-circulate each year in Lebanon with a peak between January and March. The trivalent vaccine included a B/Victoria strain which mismatched the B/Yamagata lineage that predominated during the study period, highlighting the importance of quadrivalent vaccines.