Clinical characteristics, diagnosis and treatment of human babesiosis: a review / 中国血吸虫病防治杂志

Babesiosis is an important tick-transmitted zoonosis caused by hematotropic parasites of the genus Babesia, zoonosis disease, which is widely distributed across the world. There are 12 species of Babesia causing human diseases, including B. microti, B. divergens, B. venatorum and B. duncani. The clinical symptoms of human Babesia infections mainly include fever, headache, chills, myalgia and fatigue, and severe infections may cause death. The diagnosis of babesiosis mainly depends on laboratory testing combined with clinical manifestations and epidemiological surveys, and the diagnostic techniques mainly include microscopic examinations of the blood smears, serological tests and molecular biological assays. Currently, azithromycin-atova-quone or clindamycin-quinine combinations are common treatments for babesiosis. This review summarizes the clinical features following human infections with various species of Babesia, the diagnostic techniques and diagnostic criteria of babesiosis and the currently available treatments for babesiosis.

Infection of Babesia in domestic animals in Western Yunnan Province, China / 中国人兽共患病学报

The objective of this study was to investigate Babesia infection among domestic animals in Western Yunnan Province and provide scientific evidence for developing control measures.A total of 1 073 domestic animals blood samples (274cattle,395 sheep,354 dogs,33 horses and 17 donkeys) were collected in 12 counties in Western Yunnan Province.Genomic DNA was extracted and a near full-length 18S rRNA gene sequence of Babesia was amplified by using nested PCR.Babesia species was identified by Blast program and phylogenetic tree.It was indicated that 50 samples were infected with Babesia,belonging to 5 species and with the infection rate of 4.66％.Among 274 cattle blood samples,11 were infected with Babesia (4.01％).Four of them were Babesia bovis and seven of them were Babesia bigemina.Among 395 sheep blood samples,38 were infected with Babesia (9.62 ％),37 of them were Babesia odocoilei-like parasites and 1 of them was Babesia capreoli-like parasites.Horses and donkeys were negative.In conclusion,domestic animals in Western Yunnan Province are infected with many kinds of Babesia,which threaten stock raising development and human health.It is necessary to strengthen prevention of babesiosis and investigate infection rate of babesiosis in human.

Complete sequence of the M segment of Amur virus in rodent from China / 中华流行病学杂志

Objective To study the complete sequence of M segment of Amur virus in rodents and to explore their molecular characteristics. Methods Complete M segment of Amur virus in rodent from China was amplified by RT-PCR. The purified PCR product was cloned into pGEM-T Easy vector and then sequenced. Phylogenetic analysis on multiple nucleotide sequences was performed with the Tree PUZZLE and DNAStar software. Results The full-length of its M gene comprised of 3615 nucleotides with one open reading frame (ORF) including 3408 nucleotides and encoding a protein which comprised 1135 amino acids. The ORF was located at bases 41 to 3448. The phylogenetic analysis of JilinAP06 with other hantaviruses revealed that the complete sequence of M segment of JilinAP06 strain was closely related to those Amur viruses such as B78 strain, Liu strain and H5 strain were all from the patients. The complete sequence of M segment of JilinAP06 had only 79.5% identities with the nucleotide sequence of HTNV strain 76-118. Conclusion The complete sequence on M segment of Amur virus in rodent was first time identified in this country.

Identification of Amur like virus in Apodemus peninsulae and its molecular characteristics in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To confirm the existence of Amur-like viruses in Apodemus peninsulae in China, and to understand the molecular characteristics of these viruses.</p><p><b>METHODS</b>Total RNA was extracted from lungs of A. peninsulae captured in Jilin of Northeast China with Trizol reagent. Complete S and partial M segments of Amur virus were amplified and sequenced. Phylogenetic analyses on multiple nucleotide sequences were performed with the Clustal method and DNASTAR software.</p><p><b>RESULTS</b>383 bp cDNA of M segment and 1696 bp of S segment of Amur like virus were recovered from lung tissue of A. peninsulae, named JilinAP06. The full-length of its S gene comprised of 1696 nucleotides with ORF including 1287 nucleotides and encoding a protein which comprised 429 amino acids. The phylogenetic analysis of this sample with other hantaviruses revealed that the complete S and partial M segment sequence of JilinAP06 both were closely related to those Amur viruses such as AP63, AP61, AP1371 and AP1168 found in A. peninsulae from Far East region of Russia and B78 strain, Liu strain and H5 strain, which were all from Chinese patients. The complete S and partial M segment sequence of JilinAP06 had only 81.0% identities with the nucleotide sequences of HV prototype 76-118 strain.</p><p><b>CONCLUSION</b>Amur-like viruses did exist in A. peninsulae from Northeasern China while A. peninsulae might be the natural reservoir of Amur-like viruses in China and was the important infectious source to HFRS patients which were caused by Amur-like viruses.</p>

Investigation on Anaplasma phagocytophilum infection in rodents from forest areas in northeastern China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the prevalence of Anaplasma phagocytophilum in rodents from forest areas in northeastern China.</p><p><b>METHODS</b>PCR amplification, followed by sequence analysis was carried out. The sequences of 16S rRNA and gltA gene fragment amplified from rodent specimens were compared with corresponding part of the sequences deposited in GenBank.</p><p><b>RESULTS</b>A total number of 276 rodents were tested, including 102 in Jilin province, 61 in Helongjiang province and 113 in Inner Mongolia autonomous region. The positive rates were 8.82%, 1.64% and 0.00%, respectively. The infection rate in rodents infected by ticks was 11.30 times higher than that in rodents without ticks (P = 0.002). The S. A. phagocytophilum 16S rRNA sequences from rodents in Jilin and Heilongjiang were identical and differed in 3-5 bases compared with the corresponding parts of A. phagocytophilum from America, Sweden and Japan. Compared with the sequences registered in GenBank, the nucleotide sequence of gltA varied from 87%-97% and its deduced amino acid sequence changed from 84%-99%.</p><p><b>CONCLUSION</b>A. phagocytophilum infection was presented in rodents from Jilin and Heilongjiang province.</p>

Investigation on hantaviruses infection in rodents from free markets in Beijing areas / 中华流行病学杂志

<p><b>OBJECTIVE</b>In order to find out the factors related to hemorrhagic fever with renal syndrome (HFRS) infection, and to evaluate the probability of ecdemic hantaviruses (HV) infection in rodents in Beijing areas.</p><p><b>METHODS</b>Rodents were collected in a large-scale railway station and a produce market with 'trap nights' method from April to May, 2004. The IgG reacting sera to HV antigen were detected using ELISA. The partial M and S segment of HV from captured rodent lung samples were amplified with RT-PCR. The PCR products were purified and sequenced. BLAST program was then used to perform on nucleotide pairwise alignment with all available sequence in GenBank. The alignment of the multiply nucleotide and the deduced amino acid sequences, together with phylogenetic analysis were completed with DNASTAR software.</p><p><b>RESULTS</b>The average population density was 3.49% (24/690). The overall seroprevalence of HV infection was 8.3% (2/24). RT-PCR positive rates were 8.3% (2/24). The nucleotide sequences of 356 bp region (1958 - 2313) of M segment obtained from 2 samples were all identified to Seoul virus (SEOV), with 7.6% heterogeneity. The dc501 strain from railway station was closely related to SD227 and Hebei4 from Shandong and Hebei provinces respectively. BjFT01 strain from the farm product market had more special nucleotide transitional mutations than other known SEOV from Beijing in GenBank. This strain, together with known HN71 from Hainan province, K24-E7 from Zhejiang province, L99 from Jiangxi province and R22 from Henan province, represented a monophylogentic linkage.</p><p><b>CONCLUSION</b>The higher HV prevalence of rodents in transportation center was the potential and important risk for HFRS epidemic in Beijing. The increasing prevalence of M. musculus should call for attention. It was possible that SEOV in Beijing was imported by infected rodents through vehicles from other provinces.</p>

Study on the association between hantavirus infection and Rattus norvegicus / 中华流行病学杂志

<p><b>OBJECTIVE</b>To further understand the association of hantavirus (HV) harbored and transmitted in wild brown rats.</p><p><b>METHODS</b>Rattus norvegicus (n = 570) were trapped in 10 sites in Beijing. RT-PCR was used to test rodent lung samples for hantavirus infection. Unconditional multivariate logistic regression analysis was performed, with PCR positive as the dependent variable and the characteristics of Rattus norvegicus population as independent variables.</p><p><b>RESULTS</b>The overall HV prevalence in Rattus norvegicus was 9.1% (52/570). Significant association between HV infection in Rattus norvegicus and some biological characteristics of host population was observed. Adult Rattus norvegicus had a higher HV prevalence than juveniles. Males in the reproduction periods and rats with wounds were more likely to be infected with HV than others.</p><p><b>CONCLUSION</b>It was further confirmed that there existed parallel transmission of HV in Rattus norvegicus hosts. Aggression might be the primary mode of HV transmission among male Rattus norvegicus.</p>

Study on the molecular epidemiology of hantaviruse carried by hosts in northern suburb of Beijing / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate hantanvirus infection of captured rodents in Haidian district and Changping district of Beijing and to type hantavirus using molecular technique.</p><p><b>METHODS</b>The captured mice were classified and the density of distribution was calculated. Reverse transcription-polymerase chain reaction (RT-PCR) technique was used to amplify the partial M fragnments of hantaviruse. Several representative positive samples were sequenced and analysed by ClustalX (5.0) and DNAClub software.</p><p><b>RESULTS</b>A total of 414 animals were captured, among which Battus norvegicus was the dominant group. In Haidian district, the median infection rates with hantavirus were 13.14% in Battus norvegicus and 0 in Mus musculus Linnaeus. In Changping district, the average infection rates were 17.46% in Battus norvegicus and 3.57% in Mus musculus Linnaeus. Nucleotide sequences analysis showed that the virus detected all belonged to SEO-type. They clustered with Z37 virus and could be branched into 2 different subclades.</p><p><b>CONCLUSION</b>The major hosts of hantavirus in Haidian and Changping district were Battus norvegicus and the epidemic strains in the two districts of Beijing were genotyped as SEO-type. Nucleotide sequence and deduced amino acid sequence from different rodents were highly homologous, while nucleotide mutation had also been observed. Further studies are required to explore the possible virus sequence mutation.</p>

A case-control study on the risk factors of severe acute respiratory syndromes among health care workers / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the factors in relation to severe acute respiratory syndromes (SARS) among health care workers and to develop related protective measures.</p><p><b>METHODS</b>Case-control study was applied. A standardized questionnaire was used to collect SARS related information for health care workers who had contacted or treated SARS patients. Univariate analysis was conducted using SPSS 10.0 software package and multivariate logistic regression analysis was conducted using SAS 6.12.</p><p><b>RESULTS</b>Twenty-seven of the 49 factors under study were significantly associated with SARS infection, in which 22 factors were protective, and the other 5 were risk factors. 27 factors were included for multivariate logistic regression analysis. Results showed that six factors as wearing eye glasses, wearing protection gowns, exposure to secrets/mode of contact with SARS patients, types of mask and the working years atc, remained significant association with hospital infection of SARS.</p><p><b>CONCLUSION</b>SARS infection in heath care workers was related to many factors during the process of diagnoses and/or treatment. It is recommended that adequate masks, eye-protection and protective gowns should be adopted for heath care workers during the process of clinical diagnoses and treatment of SARS patients.</p>