Background: Human herpesviruses (HHVs) remain latent after primary infection and can be reactivated in response to immunosuppression and chemotherapy. Little is known about their incidence, potential relationships, risk factors and clinical impact in non-transplant leukemia patients. This study investigated prospectively incidence, risk factors, clinical impact and possible association of HHVs-(1-7) infections in patients with newly diagnosed acute leukemia. Methods: Study design involved longitudinal sampling before chemotherapy and in different phases of chemotherapy: post-induction, post-remission, and post-salvage during 2016-2018. A total of 734 plasma samples from 95 patients were analyzed by a qualitative, multiplex PCR for HHVs detection and a quantitative real-time PCR was used for cytomegalovirus (CMV) quantification. HHVs-(1-6) IgG and IgM antibodies were tested using immunoassays. Risk factors were analyzed by binary logistic regression and relationships between viruses were analyzed using the Chi-square or Fisher's exact test as appropriate. Results: The overall seroprevalences of HHV-(1-6) IgG were high (> 80%). At least one herpes viral agent was detected in 60 patients (63.3%). CMV was the most commonly detected virus in the different phases of chemotherapy (19.4%), followed by HHV-6 (9.7%), HHV-7 (5.2%) and EBV (2.7%). HSV-1/2 and VZV DNA were not detected. Twenty-seven patients (28.4%) had more than one virus detected in the follow-up, with 23 who were co-infected. CMV/HHV-6 was the most frequent co-infection (69.5%, 16/23). HHV-6 infection (p = 0.008) was identified as a risk factor for CMV infection while salvage treatment (p = 0.04) and CMV infection (p = 0.007) were found to be independent risk factors for HHV-6 infection. CMV co-infection was associated with severe lymphopenia with an absolute lymphocyte count (ALC) (< 500/μL) (p = 0.009), rash (p = 0.011), pneumonia (p = 0.016) and opportunistic infections [bacteremia, p < 0.001 and invasive fungal infection, (p = 0.024)] more frequently than CMV mono-viral infections.

Background The human Adenovirus (HAdV) is a common agent of acute respiratory infections (ARIs). Its clinical impact in immunocompetent children and in the context of coinfections remains unclear in Tunisia. Material and methods HAdV‐ARIs were studied in hospitalized patients from birth to the age of 5 years from 2013 to 2014. Clinical and demographic characteristics, coinfections, and molecular characterization of HAdV were established. Results HAdV‐positivity was detected in 114/583 specimens (19.6%) including 6.1% single infections and 93.9% coinfections. Adenoviral coinfections mostly comprised human Rhinovirus (50.9%), Streptococcus pneumoniae (34.2%), human Respiratory Syncytial virus A/B (29.8%), and human Coronaviruses (21.9%). HAdV infection was predominant in the pediatric population (25.0% vs 10.0% in neonates, P < .001) and peaked in February 2014 (21.1%). HAdV severity of pediatric cases is characterized by low saturation of oxygen (<94%, 33.8%, P = .05) and long duration of oxygen support (≥5 days, 32.7%, P = .02). Severe HAdV infections were described with S. pneumoniae coinfection, which seemed to increase the risk of death. HAdV genotyping identified HAdV‐C as the most common species. Severe ARIs were observed in all HAdV‐identified types. Phylogenetic analysis revealed that sequences were variable suggesting the circulation of different HAdV strains sharing more similarities to strains circulating in Europe or Asia than those from Africa. Conclusion This first molecular study of HAdV in Tunisia demonstrated that it has an important role in severe ARIs with HAdV‐C being the most common species. S. pneumoniae codetection seems to increase the severity of HAdV‐ARIs.