Although polyomavirus JC (JCV) is the proven pathogen of progressive multifocal leukoencephalopathy, the fatal demyelinating disease, this virus is ubiquitous as a usually harmless symbiote among human beings. JCV propagates in the adult kidney and excretes its progeny in urine, from which JCV DNA can readily be recovered. The main mode of transmission of JCV is from parents to children through long cohabitation. In this study, we collected a substantial number of urine samples from native inhabitants of 34 countries in Europe, Africa, and Asia. A 610-bp segment of JCV DNA was amplified from each urine sample, and its DNA sequence was determined. A worldwide phylogenetic tree subsequently constructed revealed the presence of nine subtypes including minor ones. Five subtypes (EU, Af2, B1, SC, and CY) occupied rather large territories that overlapped with each other at their boundaries. The entire Europe, northern Africa, and western Asia were the domain of EU, whereas the domain of Af2 included nearly all of Africa and southwestern Asia all the way to the northeastern edge of India. Partially overlapping domains in Asia were occupied by subtypes B1, SC, and CY. Of particular interest was the recovery of JCV subtypes in a pocket or pockets that were separated by great geographic distances from the main domains of those subtypes. Certain of these pockets can readily be explained by recent migrations of human populations carrying these subtypes. Overall, it appears that JCV genotyping promises to reveal previously unknown human migration routes: ancient as well as recent.

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Rotavirus remains the most common cause of severe, dehydrating diarrhea among children worldwide. Several rotavirus vaccines are under development. Decisions about new vaccine introduction will require reliable data on disease impact. The Asian Rotavirus Surveillance Network, begun in 2000 to facilitate collection of these data, is a regional collaboration of 36 hospitals in nine countries or areas that conduct surveillance for rotavirus hospitalizations using a uniform World Health Organization protocol. We summarize the Network's organization and experience from August 2001 through July 2002. During this period, 45% of acute diarrheal hospitalizations among children 0–5 years were attributable to rotavirus, higher than previous estimates. Rotavirus was detected in all sites year-round. This network is a novel, regional approach to surveillance for vaccine-preventable diseases. Such a network should provide increased visibility and advocacy, enable more efficient data collection, facilitate training, and serve as the paradigm for rotavirus surveillance activities in other regions.

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The effects of relative humidity and temperature on the survival of human rotavirus in a thin layer of faeces on an impervious surface and on absorbent material was investigated using the indirect immunofluorescence technique in LLC-MK2 cells to titrate infectivity. Rotavirus was found to be very stable at low and high relative humidities but not in the medium range of relative humidity. Rotavirus infectivity was lost more rapidly under all humidities at 37 degrees C than at 4 degrees or 20 degrees C.

Bovine leukemia virus (BLV) is the etiological agent of enzootic bovine leukosis, which is the most common neoplastic disease of cattle. BLV infects cattle worldwide and affects both health status and productivity. However, no studies have examined the distribution of BLV in Myanmar, and the genetic characteristics of Myanmar BLV strains are unknown. Therefore, the aim of this study was to detect BLV infection in Myanmar and examine genetic variability. Blood samples were obtained from 66 cattle from different farms in four townships of the Nay Pyi Taw Union Territory of central Myanmar. BLV provirus was detected by nested PCR and real-time PCR targeting BLV long terminal repeats. Results were confirmed by nested PCR targeting the BLV env-gp51 gene and real-time PCR targeting the BLV tax gene. Out of 66 samples, six (9.1 %) were positive for BLV provirus. A phylogenetic tree, constructed using five distinct partial and complete env-gp51 sequences from BLV strains isolated from three different townships, indicated that Myanmar strains were genotype-10. A phylogenetic tree constructed from whole genome sequences obtained by sequencing cloned, overlapping PCR products from two Myanmar strains confirmed the existence of genotype-10 in Myanmar. Comparative analysis of complete genome sequences identified genotype-10-specific amino acid substitutions in both structural and non-structural genes, thereby distinguishing genotype-10 strains from other known genotypes. This study provides information regarding BLV infection levels in Myanmar and confirms that genotype-10 is circulating in Myanmar.

Papillomatous digital dermatitis (PDD) is an infectious foot disease of cattle that is prevalent throughout the world. Although it has been prevalent in Japan since the first case was reported in 1992, full epidemiological and bacteriological examinations have not been conducted. We collected 91 lesions of PDD from 80 dairy cattle on 12 farms in eight regions of Japan to isolate the spirochetes that are frequently detected in lesions. We isolated 40 strains of spirochetes from 24 cattle (30.0%) by a simple two-step culture technique, in which the biopsy samples were incubated at 4°C for 48 to 72 h in an enrichment broth supplemented with antibiotics, which improved the rate of isolation, and then inoculated on selective agar plates. All spirochetes examined were catalase positive and oxidase negative and showed weak beta-hemolytic activity. Enzyme activities were identical to those of Treponema phagedenis ATCC 27087. Sequencing of the 16S rRNA gene showed that all strains isolated had >99% identity to those of the T. phagedenis type strain and of T. phagedenis-like strains isolated from PDD lesions in the United States and Europe. Pulsed-field gel electrophoresis and PCR-based random amplified polymorphism DNA methods revealed considerable diversity among strains isolated not only from different cattle but also from the same individuals. These findings may provide further evidence for the role of these treponemes in the pathogenesis of persistent PDD.Papillomatous digital dermatitis (PDD) is an infectious foot disease in cattle that was first reported in Italy in 1974 (4) and is now recognized throughout the world (3,8,31). In Japan, PDD in dairy cattle is now found in most regions (24,26,37) since the first case was reported in 1992 (20). PDD begins as a superficial dermatitis with an erosive lesion and later forms a hyperkeratotic papillomatous lesion with long hairlike projections (12). These lesions are usually located on the rear of the foot between the bulbs of the heel (3). PDD often leads to lameness and decreases in body weight and milk production, causing economic loss and animal welfare problems (30).It is suspected that PDD is caused by bacteria, since treatment with antibiotics such as oxytetracycline and penicillin G results in rapid resolution of the lesions (19,29,46). Microscopic examinations of biopsy samples or direct stamp preparations of the lesions show various bacterial morphotypes, including long filaments, rods, coccoids, and helices. Although several culturable bacteria have been isolated from PDD lesions (3,7,22,30,36), it remains unclear whether all are involved in the etiology.Among the bacteria detected in PDD lesions, a large number of spirochetes are observed (6,10,25,32,39). Choi et al. detected five spirochetal phylotypes using 16S rRNA gene sequence analysis (6). Similarly, Moter et al. detected four spirochetal phylotypes by using in situ hybridization with oligonucleotide probes of the 16S rRNA gene from treponemes (23). Indeed, several Treponema species have been isolated fr...

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