BK and JC virus infections in healthy patients compared to kidney transplant recipients in Tunisia.

The human polyomaviruses BKPyV and JCPyV are members of Polyomaviridae family and after primary infections they persist as latent infection especially in the kidneys. BKVPy reactivation is mainly related to a renal nephropathy and JCV reactivation can induce the progressive multifocal leukoencephalopathy. The aim of this study was to investigate and to compare the presence of BKPyV and JCPyV in urine and plasma samples from immunocompromised and immunocompetent groups. The viral detection and quantification was done by a real time PCR from 100 healthy individuals and from 72 kidney transplanted patients (KTx) enrolled in a prospective study. Polyomavirus DNA urinary shedding was identified in 19% of healthy person, BKPyV in 6%; JCPyV more frequent in 13%. No individuals in this group developed polyomavirus viremia. BKPyV and JCPyV viruria was seen in 36% and 28% of KTx respectively, and 11% had a concomitant BKPyV and JCPyV viruria. Only BKPy viremia was detected in 5.5% of the KTx. In healthy persons, JCPyV shedding was associated with older individuals. However, in KTx, BKPyV was associated with younger age and male gender. No significant association was found between the patient's origin and BKPyV or JCPyV infection. In conclusion and consisting with previous reports, BKPyV and JCPyV prevalence and urinary loads were significantly higher in immunosuppressed compared to non-immunosuppressed individuals. In Addition and by contrast to KTx, JCPyV was more frequent than BKPyV in healthy individuals. Furthermore, the shedding of both polyomaviruses was differently associated with the age and the sex according to each population.

BK and JC polyomavirus infections in Tunisian renal transplant recipients.

The aim of this prospective study was to investigate the rate of BK (BKPyV) and JC (JCPyV) polyomavirus infections and their influence on allograft function in Tunisian renal transplant recipients. A total of 72 renal transplant recipients were studied. BKPyV and JCPyV were detected and quantified by real-time PCR in urine and plasma. Demographic and laboratory characteristics were collected for each patient. Polyomavirus DNAuria was detected in 54 (75%) of renal transplant recipients: 26 (36%) had BKPyV DNAuria, 20 (28%) had JCPyV DNAuria, and 8 (11%) had a dual BKPyV/JCPyV DNAuria. BKPyV DNAemia was detected in four (5.5%) patients, whereas no patient had JCPyV viremia. More than 70% of BKPyV and JCPyV infections started within the first 3 months post-transplant. The risk for positive DNAemia was observed in patients with DNAuria level >10(7) copies/ml. BK Polyomavirus-associated nephropathy (BKPyVAN) was observed in two patients. This study highlights the high frequency of BKPyV and JCPyV viruria during the first year post-transplant with the highest incidence observed in the third month. We identified several risk factors that were associated with BKV DNAuria including age, sex of patients, and the use of tacrolimus instead of cyclosporine A at month 3. The use of cyclosporine A instead of tacrolimus was identified as risk factor for JCV viruria in month 3. No statistical difference in the allograft function was found between BKPyV and/or JCPyV infected and uninfected patients.

Distribution of JC polyomavirus genotypes in Tunisian renal transplant recipients between January 2008 and January 2011.

The polyomavirus JC (JCPyV) is a ubiquitous virus in humans, causing progressive multifocal leukoencephalopathy, a fatal demyelinating disease. JCPyV propagates in the adult kidney and excretes its progeny in urine, from which its DNA can be recovered readily. JCPyV isolates worldwide can be classified into 14 subtypes or genotypes, each associated with a specific geographical region. The European genotypes EU-a-b-c are spread throughout Europe and Mediterranean areas. The major African genotype Af2 is spread not only throughout Africa but also in West and South Asia. A minor African genotype (Af1) occurs in Central and West Africa. Partially overlapping domains in Asia were occupied by various genotypes (e.g., B1-a, -b, -d, B2, CY, MY, and SC). To characterize the subtypes of JCPyV prevalent in Tunisia, the presence of the virus was investigated by real-time PCR in urine samples from 98 renal transplant recipients. For subtype identification, a 610 bp typing region of the JCPyV genome was amplified from each urine sample, and its DNA sequence was determined. In the patients studied, the major African subtype Af2 was the predominant (62.5%), followed by the European subtype EU (33.5%). Only one case clustering with the Asian genotype SC (4%) was identified. The presence of the European subtype with high prevalence in this population suggests that the epidemiological distribution of JCPyV virus sequences in North Africa is related partially to the epidemiological data in Europe.

Detection of herpes simplex virus (1 and 2), varicella-zoster virus, cytomegalovirus, human herpesvirus 6 and enterovirus in immunocompetent Tunisian patients with acute neuromeningeal disorder.

Enteroviruses (EVs) and human herpesviruses (HHVs) are involved frequently in acute neurological disorders of viral etiology. This study aimed to investigate the incidence of herpes simplex virus types-1 (HSV-1) and 2 (HSV-2), varicella-zoster virus (VZV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6) and human enteroviruses (EVs) in cerebrospinal fluid (CSF) samples of Tunisian immunocompetent patients with neuromeningeal disorders. The patients had been hospitalized at the Fattouma Bourguiba University Hospital (Monastir, Tunisia) between September 2007 and June 2009. At least one viral genome was detected in 58 (46%) out of 126 CSF samples collected. Enterovirus was detected in 31 of the positive samples (53.4%), CMV in 20 (34.5%), HSV-1 in 3 (5.2%), HSV-2 in 6 (10.3%), VZV in 4 (6.9%), HHV-6 in 2 (3.4%). More than one viral genome was detected in seven CSF samples, including CMV DNA in six of the samples. The high frequency of enteroviral infections in aseptic meningitis was confirmed. The detection of CMV DNA only suggests a direct role of this virus in the etiology of acute neuromeningeal disorder.

Distribution of BK polyomavirus genotypes in Tunisian renal transplant recipients.

BK polyomavirus (BKV) is a ubiquitous virus in humans that remains latent in the urogenital tract after a primary infection during childhood. The virus, which is reactivated frequently and excreted in urine, can cause nephropathy in renal transplant recipients. BKV sequences are classified into four subtypes (I-IV). Subtype I and IV are divided further into four and six subgroups, respectively. To characterize the subtypes of BKV prevalent in Tunisia, the presence of the virus was investigated by real-time PCR in urine samples from 77 renal transplant recipients. For subtype identification, a DNA fragment in the VP1 coding region, amplified by nested PCR from positive samples, was sequenced and a phylogenetic analysis was performed. In the studied population, subtype I (75.5%), II (14.5%), and IV (2.5%) were identified with a clear predominance of subtype Ib-2 (73%) as observed in European population. This study suggests that in North Africa, the BKV genotype distribution is similar to that of Europe and different from that of sub-Saharan Africa.