Fabrizio Carletti

Role of hepatitis C virus (HCV) viremia and HCV genotype in the immune recovery from highly active antiretroviral therapy in a cohort of antiretroviral-naive HIV-infected individuals.

BACKGROUND The roles of hepatitis C virus (HCV) viremia and HCV genotype in the immune response to highly active antiretroviral therapy (HAART) are poorly understood. Our aim was to assess the CD4+ cell count recovery after HAART in human immunodeficiency virus (HIV)-infected patients with HCV viremia and HIV-infected patients who tested negative for HCV antibody (HCV-Ab). We also aimed to assess whether the response to HAART in these patients varied according to HCV genotype. METHODS The analysis focused on 1219 HCV-Ab-negative patients and 284 HCV-viremic patients from a cohort of HIV-infected subjects that includes persons who were antiretroviral naive before initiating HAART after cohort enrollment. HCV RNA load and HCV genotype were determined in plasma specimens obtained and stored during the 6-month period preceding the initiation of HAART. RESULTS The chance of achieving a CD4+ cell count increase of > or = 100 cells/microL from the pre-HAART level tended to be poorer in HCV-viremic patients than in patients who tested negative for HCV-Ab (adjusted relative hazard [RH], 0.82; 95% confidence interval [CI], 0.66-1.01; P = .06). In contrast, a comparison of patients who had a HCV RNA load >1 x 10(6) IU/mL with patients who had a HCV RNA load of 5-1 x 10(6) IU/mL revealed no significant association between HCV RNA load and achievement of an increased CD4+ cell count (adjusted RH, 0.97; 95% CI, 0.75-1.27; P = .83). There was no clear association between HCV genotype and the probability of achieving a CD4+ cell count increase. CONCLUSIONS An association between the presence of HCV-Ab and immune reconstitution after HAART has been shown elsewhere. Results of our large, prospective study support a direct role of HCV viremia in the CD4+ cell count response to HAART. Moreover, our results underline the fact that, in individuals coinfected with HIV and HCV, the goal of treating HCV infection is to eradicate HCV, to both slow the rate of HCV progression and limit potential interference with the response to HAART.

Unique human immune signature of Ebola virus disease in Guinea

Despite the magnitude of the Ebola virus disease (EVD) outbreak in West Africa, there is still a fundamental lack of knowledge about the pathophysiology of EVD. In particular, very little is known about human immune responses to Ebola virus. Here we evaluate the physiology of the human T cell immune response in EVD patients at the time of admission to the Ebola Treatment Center in Guinea, and longitudinally until discharge or death. Through the use of multiparametric flow cytometry established by the European Mobile Laboratory in the field, we identify an immune signature that is unique in EVD fatalities. Fatal EVD was characterized by a high percentage of CD4+ and CD8+ T cells expressing the inhibitory molecules CTLA-4 and PD-1, which correlated with elevated inflammatory markers and high virus load. Conversely, surviving individuals showed significantly lower expression of CTLA-4 and PD-1 as well as lower inflammation, despite comparable overall T cell activation. Concomitant with virus clearance, survivors mounted a robust Ebola-virus-specific T cell response. Our findings suggest that dysregulation of the T cell response is a key component of EVD pathophysiology.

Crimean-Congo hemorrhagic fever, southwestern Bulgaria.

To the Editor: Crimean-Congo hemorrhagic fever virus (CCHFV) causes a severe multisystem disease characterized by profuse bleeding with a case-fatality rate as high as 30%. The infection is endemic to the Balkans (1,2). In Bulgaria, most cases are reported from the central and eastern parts of the country (3,4). We report a cluster of cases observed in early spring 2008 in southwestern Bulgaria, an area considered at low risk for CCHF outbreaks.

Phylogenetic analysis of West Nile virus isolates, Italy, 2008-2009.

To determine the lineage of West Nile virus that caused outbreaks in Italy in 2008 and 2009, several West Nile virus strains were isolated from human specimens and sequenced. On the basis of phylogenetic analyses, the strains isolated constitute a distinct group within the western Mediterranean cluster.

Human Herpesvirus 8 and Pulmonary Hypertension

Human herpesvirus 8 (HHV-8) antibodies were detected in 1 of 33 patients with pulmonary hypertension (including in 1 of 16 with idiopathic pulmonary arterial hypertension), 5 of 29 with cystic fibrosis, and 3 of 13 with interstitial lung disease. No relationship between HHV-8 infection and pulmonary hypertension was found.

Cowpox virus in llama, Italy.

Cowpox virus (CPXV) was isolated from skin lesions of a llama on a farm in Italy. Transmission electron microscopy showed brick-shaped particles consistent with orthopoxviruses. CPXV-antibodies were detected in llama and human serum samples; a CPXV isolate had a hemagglutinin sequence identical to CPXV-MonKre08/1–2-3 strains isolated from banded mongooses in Germany.

Design and clinical application of a molecular method for detection and typing of the influenza A/H1N1pdm virus

In March/April 2009, Mexico experienced an outbreak of respiratory illness, due to a new influenza of swine origin virus, which spread rapidly via human-to-human transmission, and became pandemic (A/H1N1pdm). Because of its unique genome composition, which includes gene segments of swine, avian and human origin, and to the considerable differences to the human influenza A viruses that have circulated so far, the currently used molecular methods proved inadequate. Based on published sequences, a primer set targeting the nucleoprotein gene was designed, which provided enhanced sensitivity for the new strain and proved suitable for sequence-based strain identification. The novel nucleoprotein reverse-transcription-PCR showed higher sensitivity for A/H1N1pdm than a commercial test for influenza A, and was comparable to the real-time-based method developed by the Centers for Disease Control and Prevention. It was used to screen 177 clinical samples referred to the laboratory for suspected A/H1N1pdm infection, detecting 17 (9.6%) infections that were confirmed by sequence analysis (100% sensitivity as compared to the real-time kit). The novel method is suitable for the diagnosis of A/H1N1pdm, and is also suitable, at least in the screening phase, for laboratories not equipped with the real-time PCR technology.

Infection with Human Herpesvirus Type 8 and Kaposi’s Sarcoma in Sardinia

Background:A cross-sectional study was conducted in the provinces of Sassari (northern Sardinia, covered by a population-based cancer registry), and of Cagliari (southern Sardinia) to estimate the prevalence of infection with human herpesvirus type 8 (HHV8) and the incidence of classic Kaposi’s sarcoma (KS) among HHV8-infected individuals.Patients and Methods:Sera from 297 hospitalized persons potentially at risk of developing classic KS (i. e., those aged 50 years or older) were tested for antibodies against HHV8. HHV8 seroprevalence rates (with 95% confidence intervals—CI) and yearly incidence rates (IR/100,000) of KS were calculated according to age and sex.Results:Of tested individuals, 32.0% had antibodies against HHV8 in Sassari and 30.0% in Cagliari. Estimated IR of KS among HHV8-positive persons and KS:HHV8 ratio were two times higher in Sassari (1:3,891) than in Cagliari (1:8,114), and higher in men (1:2,846 in Sassari; 1:5,483 in Cagliari) as compared to women (1:6,827 in Sassari; 1:12,489 in Cagliari).Conclusions:Although the overall prevalence of HHV8 seemed similar in Sassari and in Cagliari, the risk of KS was higher in Sassari, suggesting that different cofactor(s), or different distribution of the same cofactor(s) between the two provinces of Sardinia, might have played a role in KS development.

Analysis of Diagnostic Findings From the European Mobile Laboratory in Guéckédou, Guinea, March 2014 Through March 2015

Background. A unit of the European Mobile Laboratory (EMLab) consortium was deployed to the Ebola virus disease (EVD) treatment unit in Guéckédou, Guinea, from March 2014 through March 2015. Methods. The unit diagnosed EVD and malaria, using the RealStar Filovirus Screen reverse transcription–polymerase chain reaction (RT-PCR) kit and a malaria rapid diagnostic test, respectively. Results. The cleaned EMLab database comprised 4719 samples from 2741 cases of suspected EVD from Guinea. EVD was diagnosed in 1231 of 2178 hospitalized patients (57%) and in 281 of 563 who died in the community (50%). Children aged <15 years had the highest proportion of Ebola virus–malaria parasite coinfections. The case-fatality ratio was high in patients aged <5 years (80%) and those aged >74 years (90%) and low in patients aged 10–19 years (40%). On admission, RT-PCR analysis of blood specimens from patients who died in the hospital yielded a lower median cycle threshold (Ct) than analysis of blood specimens from survivors (18.1 vs 23.2). Individuals who died in the community had a median Ct of 21.5 for throat swabs. Multivariate logistic regression on 1047 data sets revealed that low Ct values, ages of <5 and ≥45 years, and, among children aged 5–14 years, malaria parasite coinfection were independent determinants of a poor EVD outcome. Conclusions. Virus load, age, and malaria parasite coinfection play a role in the outcome of EVD.

Improved detection of human influenza A and B viruses in respiratory tract specimens by hemi-nested PCR.

Abstract RT-PCR is the most sensitive assay for diagnosis of influenza, due to enhanced rapidity and sensitivity as compared to classical methods. Hemi-nested RT-PCR was developed, targeting NP gene for influenza A and NS gene for influenza B, based on a previous single round RT-PCR method. The new method was compared with the previous technique for analytical sensitivity and specificity, and was applied to clinical samples from the lower and upper respiratory tract. The analytical sensitivity of hemi-nested RT-PCR was 10 (influenza A) and 4 times (influenza B) higher than the previous method. A high specificity of the new hemi-nested RT-PCR assay was observed by using whole respiratory viruses. When applied to lower respiratory tract specimens, the new method showed an increased rate of positivity as compared to the previous technique (9.3% versus 0.7% for influenza A, and 0.9% versus 0.2% for influenza B). Screening of upper respiratory tract samples collected during the seasonal 2005–2006 outbreak indicated 26.4% and 5.8% positivity for influenza A and B, respectively. The results were confirmed by sequence analysis: apart from influenza B, both influenza A subtypes H3N2 and H1N1, associated with the seasonal outbreak, were detected.