Infectious endocarditis (IE) by Bartonella species is an emerging problem worldwide. We report two cases of native valve Bartonella-associated IE events, both affecting adult male patients with a history of alcohol abuse and a low socioeconomic status. Admissions were due to pancytopenia and bleeding in one case and embolic stroke in the other. Blood cultures were negative and IgG indirect immunofluorescence assays (IFA) were positive for B. henselae/B. quintana in high titers (1/16,384-1/16,384, and 1/32,768-1/16,384, respectively). Cases were classified as definitive IE events according to modified Duke criteria due to the presence of valve vegetations with at least three minor criteria. One patient required aortic mechanical valve replacement and survived, and the other died after a massive hemorrhagic transformation of his stroke. PCR amplification and sequencing of the 16S ribosomal bacterial DNA from a valve tissue sample obtained at surgery in the patient who survived, confirmed B. quintana as the etiological agent. Bartonella-associated IE is an emerging problem in Chile, present in disadvantaged populations. It should be suspected in patients with culture-negative IE. IFA does not discriminate between B. henselae and B. quintana infection, but high titers suggest IE. Complementary PCR techniques may help to elucidate the final causative agent.

Background: Cytomegalovirus (CMV) is an opportunistic infection (OI) in immunosuppressed patients. However, there are no clear cutoff values available for quantitative plasmatic CMV measures (viral load [VL]) to discriminate those with CMV illness from those infected suffering a transient viral reactivation. Aim: To estimate a CMV VL cutoff point that discriminates infected patients and those with CMV related diseases, and to clinically characterize AIDS patients with this OI. Patients and Methods: Retrospective analysis of AIDS patients admitted by any reason between years 2017 and 2019 and who had a positive plasma CMV VL at any titer. Cases were categorized with illness or infected using accepted criteria and the cutoff value was obtained by receiver operating characteristic curve (ROC) analysis. Results: Twelve patients were identified as having a CMV-associated illness and seven with CMV infection. A CMV VL of 3,800 copies/mL had a sensitivity of 91.6% and 100% specificity to discriminate both states. Of the 12 patients with CMV illness, all were in AIDS stage and only five were receiving HIV therapy. Predominant clinical presentations were gastrointestinal (50%), followed by liver involvement (25%) and CMV disease (25%). All patients were treated with ganciclovir or valganciclovir. Ten patients had a favorable response (83.3%), one patient only had a laboratory improvement (8.3%) and one died during treatment (8.3%). Drug toxicity was recorded in nine patients but in only three cases, a dose adjustment was necessary. Conclusions: The predominant clinical manifestation in our series was gastrointestinal. A CMV VL cutoff level of CMV VL of 3,800 copies / mL is useful to discriminate infected patients from those with CMV related disease.