KI and WU Polyomaviruses in Patients Infected with HIV-1, Italy

To the Editor: Before 2007, two human polyomaviruses were known to infect humans: BK virus and JC virus (1,2). Recently, 2 novel polyomaviruses, KI polyomavirus (KIPyV) and WU polyomavirus (WUPyV), were identified in the respiratory secretions of children with signs of acute respiratory signs (3,4); little evidence exists to suggest that these viruses are causative agents of respiratory tract disease (5). To determine the prevalence of WUPyV and KIPyV in the plasma of HIV-1–infected patients, we screened 62 persons who were HIV-1 positive by using PCR to detect the 2 viruses. We also conducted phylogenetic analysis of the identified strains.

Our patient likely had rickettsial infection acquired in Honduras. We present this case to alert clinicians to consider the diagnosis of rickettsial infections in the Americas, even if infections have not been previously documented in a specific country or region. Because rickettsial infections can be severe and are treatable, the clinician should consider rickettsial infections in returned travelers with compatible clinical findings. Our case also demonstrates the potential role of travelers as sentinels of emerging infectious diseases.

KI and WU Polyomaviruses in Patients Infected with HIV-1, Italy
To the Editor: Before 2007, two human polyomaviruses were known to infect humans: BK virus and JC virus (1,2). Recently, 2 novel polyomaviruses, KI polyomavirus (KIPyV) and WU polyomavirus (WUPyV), were identified in the respiratory secretions of children with signs of acute respiratory signs (3,4); little evidence exists to suggest that these viruses are causative agents of respiratory tract disease (5). To determine the prevalence of WUPyV and KIPyV in the plasma of HIV-1-infected patients, we screened 62 persons who were HIV-1 positive by using PCR to detect the 2 viruses. We also conducted phylogenetic analysis of the identified strains.
Plasma specimens were collected at Istituto di Ricovero e Cura a Carattere Scientifico Instituto Fisioterapico Ospetaliere-San Gallicano Institute and Tor Vergata University Hospital, Rome, Italy, from April 2005 through September 2008. Patients were adults (37-54 years of age, median age 45.5 years) and were being treated with antiretroviral drugs. HIV-1 viral load determination, CD4+ counts, and HIV-1 genotyping were performed as part of the routine investigation. Plasma viremia levels ranged from <50 to 2,877,764 copies/mL, and CD4+ counts ranged from 150 to 1,218. Most patients (64.5%) were infected by HIV-1 subtype B. Other subtypes found were F, G, and C.
To date, KIPyV and WUPyV have been detected in respiratory secretions and stool and serum specimens from pediatric patients with acute respiratory symptoms and have been found in respiratory tissue of adults and children (3,4,6,8). Few data are available on the detection and reactivation of these novel polyomaviruses in immunocompromised patients (9,10). In this study, KIPyV and WUPyV sequences were found in 3.2% and 1.6% of HIV-1-infected patients, respectively. None of the patients had respiratory symptoms, so the presence of the 2 viruses in plasma raises the question of whether they play a pathogenic role in immunocompromised patients.
Molecular analysis of the KIPyV and WUPyV identified in plasma showed that these polyomaviruses were not closely related to strains identified previously in other countries nor to the KIPyVs and WUPyVs identified in Italy in stool, respiratory tract tissue, and tonsils. Whether this difference reflects a tropism of some strains for a particular tissue or organ remains to be established. Further studies are needed to clarify the possible patho-  (6,7) and the prototype strains for KIPyV (GenBank accession nos. EF127906, EF127908, EF520288) and WUPyV (GenBank accession nos. EF444549-EF444554, EU711054-EU711058, EU296475, EU358768, and EU358769). GenBank accession numbers for all virus strains are shown in parentheses. Multiple nucleotide sequence alignments were performed by using ClustalX software (http://bips.u-strasbg. fr/fr/documentation/clustalx/#g), and the phylogenetic tree was constructed by using the neighbor-joining algorithm with LogDet-corrected distances (http://paup.csit.fsu.edu/about. html) (8). An asterisk (*) beside a branch represents significant statistical support for the clade subtending that branch (p<0.001 in the zero-branch-length test) and bootstrap support >75%. Scale bar indicates nucleotide substitutions per site. genic role of KIPyV and WUPyV in immunocompromised patients.