Pan-bocavirus PCR primers were designed that could anneal to both HBoV1 and HBoV2, amplifying a ∼576-nucleotide fragment of the VP1 capsid gene. Nucleic acids from human stools collected from Nigeria, Tunisia, Nepal, and the United States were then analyzed using this nested PCR (Table 1) . Of the 641 samples tested, 101 (16%) had confirmed positive results by PCR sequencing, with the highest prevalence in Tunisian children with AFP (33%). To determine the phylogenetic relationship of these strains, the sequences were aligned with available sequences of HBoV1, HBoV2, and HBoV3. Only 4 of 101 strains (from Nigeria and Tunisia) grouped with HBoV1. The remaining strains shared a more recent common ancestry with HBoV2, although the sequences clustered into 4 distinct genetic lineages, labeled HBoV2A, HBoV2B, HBoV3, HBoV4 ( Figure 1 ). The HBoV2A clade included all published HBoV2 genotypes [7] , plus 4 new strains from Nigeria and Tunisia and the recently reported W153 strain from Australia [8] . Because of the high degree of genetic diversity observed and to reduce splitting of HBoV2 into a multitude of genotypes, all strains in that cluster were reclassified into a new, now more diverse genotype A (HBoV2A). The nearly full genome of a new HBoV2A variant was sequenced (TU-C-114-06) and showed very high protein identity (198%) to the Pakistani HBoV2 prototype PK5510 (FJ170278).