Xiao-Ming Wu

Presence of pathogenic Borrelia burgdorferi sensu lato in ticks and rodents in Zhejiang, south-east China.

A molecular epidemiological survey was conducted to investigate the presence of pathogenic Borrelia burgdorferi sensu lato (s.l.) species in the forest areas of Zhejiang province, south-east China. A total of 182 ticks of 6 species and 200 rodents of 8 species were collected and individually examined for the presence of B. burgdorferi s.l. DNA by nested PCR targeting the 5S-23S rRNA intergenic spacer. Forty-one ticks of four species, Haemaphysalis concinna, Haemaphysalis longicornis, Rhipicephalus microplus and Haemaphysalis warburconi, were infected with B. burgdorferi s.l., with an overall infection rate of 23 %. Sixteen rodents of four species, Nivivener confucianus, Nivivener coxingi, Apodemus sylvaticus and Rattus losea, were positive for B. burgdorferi s.l., with an overall prevalence of 8 %. MseI RFLP analysis and sequence analysis of the positive PCR products showed that Borrelia spirochaetes in specimens consisted of Borrelia garinii, Borrelia afzelii and Borrelia valaisiana-related group. Forty (98 %) of the B. burgdorferi s.l.-positive ticks were infected with B. garinii and one (2 %) was infected with B. afzelii. Twelve (75 %) of the positive rodents were infected with B. garinii and four (25 %) were infected with the Borrelia spirochaete belonging to B. valaisiana-related group.

Long-term SARS Coronavirus Excretion from Patient Cohort, China

This study investigated the long-term excretion of severe acute respiratory syndrome–associated coronavirus in sputum and stool specimens from 56 infected patients. The median (range) duration of virus excretion in sputa and stools was 21 (14–52) and 27 (16–126) days, respectively. Coexisting illness or conditions were associated with longer viral excretion in stools.

Tick-borne agents in rodents, China, 2004-2006.

Many rodent species may be involved in the enzootic maintenance of these agents.

Geo-spatial Hotspots of Hemorrhagic Fever with Renal Syndrome and Genetic Characterization of Seoul Variants in Beijing, China

Background Hemorrhagic fever with renal syndrome (HFRS) is highly endemic in mainland China, and has extended from rural areas to cities recently. Beijing metropolis is a novel affected region, where the HFRS incidence seems to be diverse from place to place. Methodology/Principal Findings The spatial scan analysis based on geographical information system (GIS) identified three geo-spatial “hotspots” of HFRS in Beijing when the passive surveillance data from 2004 to 2006 were used. The Relative Risk (RR) of the three “hotspots” was 5.45, 3.57 and 3.30, respectively. The Phylogenetic analysis based on entire coding region sequence of S segment and partial L segment sequence of Seoul virus (SEOV) revealed that the SEOV strains circulating in Beijing could be classified into at least three lineages regardless of their host origins. Two potential recombination events that happened in lineage #1 were detected and supported by comparative phylogenetic analysis. The SEOV strains in different lineages and strains with distinct special amino acid substitutions for N protein were partially associated with different spatial clustered areas of HFRS. Conclusion/Significance Hotspots of HFRS were found in Beijing, a novel endemic region, where intervention should be enhanced. Our data suggested that the genetic variation and recombination of SEOV strains was related to the high risk areas of HFRS, which merited further investigation.

Anaplasma phagocytophilum Infection in Ticks, China–Russia Border

To the Editor: Anaplasma phagocytophilum, an emerging human pathogen of public health importance, is transmitted to humans most commonly by tick bites (1). The agent has been detected in various species of Ixodes ticks around the world (2) and in Dermacentor silvarum ticks in northeastern People’s Republic of China (3), where 3 A. phagocytophilum strains were isolated from wild and domestic animals (4). In the Asiatic region of Russia adjacent to China, A. phagocytophilum was identified in Ixodes persulcatus ticks, and A. bovis in Haemaphysalis concinna ticks (5). Human granulocytic anaplasmosis was reported in the southern area of the Russian Far East that borders China (6). The objectives of this study were to investigate the prevalence of A. phagocytophilum in ticks collected from the China–Russia border and to characterize the agent by molecular biology techniques.

Anaplasma phagocytophilum in livestock and small rodents

To identify the prevalence of Anaplasma phagocytophilum in both wild rodents and domestic animals and to make clear the genetic characteristics of the agents from different animals in China, a total of 105 livestock and 159 small rodents were analyzed by real-time-PCR and sequence analysis. The prevalence rate was 6.7% (7/105) and 14.5% (23/159), respectively. The nucleotide sequences of 16S rRNA (rrs) from the positive livestock and rodents were identical to each other. The phylogenetic analysis based on partial A. phagocytophilum p44ESup1 gene revealed that A. phagocytophilum identified in this study was placed on a separate clade distinct from those in other continents. These findings indicated A. phagocytophilum in rodents might be able to infect livestock and intensified the threats of anaplasmosis to livestock in the area. Further studies on public health significance of the agent are worth investigation in future.

Francisella tularensis in Rodents, China

A total of 420 rodents in China were examined for Francisella tularensis by polymerase chain reaction. The infection rates were 4.76% in total, and 11.65%, 10.00%, 6.56%, 1.77%, and 0% in Jilin, Xinjiang, Heilongjiang, Inner Mongolia, and Zhejiang, respectively. Sequence analysis showed that all the detected agents belonged to F. tularensis subsp. holarctica.

Detection of Francisella tularensis in ticks and identification of their genotypes using multiple-locus variable-number tandem repeat analysis

BackgroundTularemia was reported in China over 50 years ago, however, many epidemical characteristics remain unclear. In the present study, the prevalence of Francisella tularensis in ticks was investigated during an epidemiological surveillance in China and then we measured their genetic diversity by conducting multiple-locus variable- number tandem repeat analysis (MLVA).Results1670 ticks from 2 endemic areas (Inner Mongolia Autonomous Region and Heilongjiang Province) and 2 non-endemic areas (Jilin and Fujian Provinces) were collected and tested for evidence of tularemia by nested PCR. The prevalence of Francisella tularensis in ticks averaged 1.98%. The positive rates were significantly different among tick species, with Dermacentor silvarum and Ixodes persulatus responsible for all positive numbers. All F. tularensis that were detected in ticks belonged to F. tularensis subsp. holarctica and MLVA disclosed genetic diversity. One subtype was identified in 17 of 33 positive tick samples in three different study areas. Another subtype belonging to F. tularensis subsp. holarctica genotype was described for the first time in the current study.ConclusionThe study showed two tick species, D. silvarum and I. persulatus harboring the pathogen of tularemia in natural environment, indicating these two tick species might have a role in tularemia existence in China. MLVA results disclosed the genetic diversity F. tularensis and identified one genotype as the most prevalent among the investigated ticks in China.

A Newly Discovered Anaplasma phagocytophilum Variant in Rodents from Southeastern China

Anaplasma phagocytophilum was detected by polymerase chain reaction in 13 (14.1%) of 92 rodents captured from a mountainous area of Zhejiang Province in southeastern China. The nucleotide sequences of 1442-bp, nearly entire 16S rRNA gene amplified from these rodents, had 100% identity, but varied from all known corresponding sequences of A. phagocytophilum deposited in GenBank. To further identify and classify the variant, fragments of 357-bp partial citrate synthase gene (gltA), 849-bp major surface protein 4 gene (msp4), and 443-bp groESL heat-shock operon gene, were amplified and analyzed. The nucleotide sequences of the partial gltA gene amplified from the rodents were identical to each other, but distinct from previously reported A. phagocytophilum sequences,as were msp4 and groESL. These findings indicate that the newly discovered agent represents a novel A. phagocytophilum variant.

Anaplasma phagocytophilum and Borrelia burgdorferi in rabbits from southeastern China

A total of 54 wild rabbits captured from southeastern China were examined for Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato by polymerase chain reaction (PCR) assays. One and three samples were positive for A. phagocytophilum and B. burgdorferi, respectively. Sequence analyses of PCR products identified a variant of A. phagocytophilum and a B. garinii genotype. This is the first detection of the two tick-borne agents in Chinese rabbits, the role of which in the maintenance of the agents deserve further investigations.