Molecular Detection of Tick-borne Pathogens in Ticks Collected from Hainan Island, China / 生物医学与环境科学（英文）

Pathogens like bacteria and protozoa, which affect human and animal health worldwide, can be transmitted by vectors like ticks. To investigate the epidemiology and genetic diversity of bacteria and protozoans carried by ticks in Chengmai county of Hainan province, China, 285 adult hard ticks belonging to two species [

Serological Survey of Zika Virus in Humans and Animals in Dejiang Prefecture, Guizhou Province, China / 生物医学与环境科学（英文）

OBJECTIVE@#The current outbreak of Zika virus (ZIKV) poses a severe threat to human health. Two ZIKV strains were isolated from mosquitoes collected from the Dejiang prefecture in China in 2016, which was the first isolation of ZIKV in nature in China.@*METHODS@#In this study, serum samples were collected from 366 healthy individuals and 104 animals from Dejiang prefecture in 2017, and the plaque reduction neutralization test (PRNT) was used to evaluate the seroprevalence of ZIKV.@*RESULTS@#None of the 366 residents from whom the samples were collected were seropositive for ZIKV. None of the 11 pigs from whom the samples were collected were seropositive for ZIKV, while 1 of 63 (1.59%) chickens and 2 of 30 (6.67%) sheep were seropositive for ZIKV.@*CONCLUSION@#The extremely low seropositivity rate of ZIKV antibodies in animals in the Dejiang prefecture, Guizhou province in this study indicates that ZIKV can infect animals; however, there is a low risk of ZIKV circulating in the local population.

Analysis on molecular epidemiological features of enterovirus type 71 in Guizhou Province, 2008-2011 / 病毒学报

To study the genotype and molecular epidemiological features of enterovirus type 71 (EV71) in Guizhou Province. The hand-foot-mouth disease(HFMD) patients since 2008 in Guizhou Province were surveyed. EV71 RNA positive samples, including mild cases, death cases and cases of serious conditions, were used for subsequent cell culture and sequencing of VP1 complete gene. Genotypes were compared between domestic and foreign epidemic strains. The results showed that the main pathogenwas EV71 subtype C4a in 2008, 2009 and 2011. The nucleotide homology was 95. 3 - 99. 7% among 109 sequenced strains isolated in Guizhou Province. Guizhou strains were more similar to the representative strains from neighbor Province or City, including Shandong, Shanghai, Nanjing, Jilin and Ningbo. There was no distinct sequence difference among the isolates from either of death, mild case or case of serious condition at the nucleotide and amino acid levels. The diversity of nucleotide sequence of isolates was less within same region and year than those trans-regional strains or strains in different year.

Identification and genetic characteristics on the bacteria isolate from a case of human Brucellosis in Guizhou province / 中华流行病学杂志

<p><b>OBJECTIVE</b>A suspected Brucella (B.) strain(GZZA), isolated from a case of anti-Brucella antibody positive patient was identified and its' genetic characteristics was analyzed, to provide etiologic basis for the confirmation of patient in Guizhou province.</p><p><b>METHODS</b>Conventional methods and polymerase chain reaction(PCR)were used to identify the bacteria strain, with genetic characteristics analyzed by MLVA-16.</p><p><b>RESULTS</b>The bacteria strain was identified as B. melitensis biovar 3 under the conventional and PCR methods. Results from the MLVA-16 analysis indicated that the bacteria strain was closely clustered with B. melitensis biovar 3, and differences of repeated numbers at VNTR loci bruce42, bruce04, bruce09 and bruce16 were also displayed.</p><p><b>CONCLUSION</b>Both traditional and molecular methods to identify one bacteria strain isolated from the human patient as B. melitensis biovar 3 and the genetic characteristics of the strain was closely related to that of B. melitensis biovar 3. Differences of repeated numbers at part of VNTR loci were also showed. The results of this study provided etiologic evidences for the confirmation of Brucella infection of the patient, also providing scientific basis for the control and prevention of Brucellosis in Guizhou province.</p>

Fever monitoring program in areas with high incidence of typhoid and paratyphoid fever in Guizhou province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the incidence rates of both typhoid fever and paratyphoid fever in the high prevalent areas of Guizhou province so as to provide evidence for the development of programs on comprehensive intervention and effectiveness evaluation.</p><p><b>METHODS</b>Six townships in Pingba county were selected as intervention areas while six townships in Kaiyang county were taken as control. All hospitals and clinics were classified into A, B and C types according to its level and the capacity of the blood culture. Surveillance on typhoid and paratyphoid fever was conducted based on all population and all hospitals, clinics and county CDCs among the patients with unknown fever.</p><p><b>RESULTS</b>In the surveillance area in those two counties, there were 12 944 blood samples from patients with unknown fever which have been tested and cultured. Among them, 200 strains of Salmonella including 16 typhoid strains, 184 paratyphoid A strains were identified, with the total positive rate as 1.55%. The positive rate before the intervention program was higher than the after. The detection rate was 1.91% in the type A hospitals. 39 strains of Salmonella have been cultured from 2039 samples which accounting for 19.50% (39/200) of the total strains. 4315 blood samples were cultured at the 'Class B' sites which isolated 82 strains of Salmonella, accounting for 41.00% (82/200), with a detection rate as 1.90%. 6590 samples were cultured at the 'Class C' sites, which identified 79 strains of Salmonella, accounting for 39.50% (79/200), with a detection rate as 1.20%. The detection rate was much higher before the use of antibiotics than after using them (P < 0.05). The annual peak time of positive detection was in spring and fall. The outbreaks or epidemics often appeared in the same places, with farmers, students as the high-risk populations. Symptoms of both typhoid and paratyphoid fever were not typical.</p><p><b>CONCLUSION</b>Typhoid and paratyphoid monitoring programs which covered primary health care institutions in the high incidence area seemed to be effective in reflecting the pictures as well as the burden of both typhoid and paratyphoid.</p>

Etiologic diagnosis and analysis of the first case of human brucellosis in Guizhou province / 中国地方病学杂志

Objective To etiologically diagnose and analyze a patient with suspected cases of brucellosis,and to provide a experimental basis for the confirmation of the first case of human brucellosis in Guizhou province.Methods Conventional and molecular techniques [genus specific Brucella surface protein 31 PCR (BCSP31-PCR)and Brucella suis species-specific PCR (AMOS-PCR)] were used to identify suspicious bacteria strains isolated from the suspected patient of brucellosis.Results The results showed that the Brucella suspicious colonies were identified as Brucella melitensis biotype 3 using conventional tests and were further identified as Brucella spp.by genus specific Brucella surface protein 31 PCR (BCSP31-PCR) and classified as Brucella melitensis with Brucella abortus,Brucella melitensis,Brucella ovis,Brucella suis species-specific PCR(AMOS-PCR).Conclusions Laboratory diagnostic results show that the bacteria strain isolated from the suspected patient of brucellosis is Brucella melitensis biotype 3.It is the first case of human brucellosis in Guizhou province.

Analysis of the genetic differences in the nucleoprotein between rabies virus and its vaccine strains in Guizhou province from year 2005 to 2010 / 中华预防医学杂志

<p><b>OBJECTIVE</b>This study was to explore the differences in the nucleoprotein gene between rabies virus (RABV) and its vaccine strains in Guizhou province from year 2005 to 2010.</p><p><b>METHODS</b>Samples from 4 rabies patients and cerebral tissue samples of 28 rabies infected dogs were collected from different districts in Guizhou province between year 2005 and 2010. Direct Immunofluorescence Assay (DFA) and RT-nested PCR assay were applied to detect the overall length of N gene sequence. Meanwhile, based on the comparison between the homology and phylogenetic tree, the differences in N gene sequence between the prevalent RABV and the RABV vaccine strains collected from NCBI database in these years.</p><p><b>RESULTS</b>According to DFA and RT-nested PCR assay, the antigen and nucleic acid of the 21 dogs and 4 human samples were both confirmed positive; whose full length of N gene sequences were both 1353 bp. The homological analysis showed that the 25 strains of RABV virus and the RABV type I virus stored by GenBank database shared a high homology in N gene nucleotide and amino acid sequences, which were 89%-100% and 98%-100%, respectively. Besides, the homology between the 25 strains of RABV virus and its vaccines in nucleotide and amino acid sequences were separately 86%-95% and 96%-100%. The N gene of vaccines for livestock shared the highest homology with HEP-Flury strain in the nucleotide and amino acid, which were 88%-89% and 98%-99%, respectively. The vaccines for human use showed its greatest homology with the CTN strain in nucleotide (86%-100%) and amino acid (96%-100%). The phylogenetic tree analysis indicated that the 25 strains of RABV virus, RABV type I virus and the CTN vaccine strains constituted one individual cluster, which was least different from the CTN vaccine for human use.</p><p><b>CONCLUSION</b>The prevalent RABV virus, the vaccine HEP-Flury for livestock and the vaccine CTN for human use were found to be highly similar in N gene expression in Guizhou province from 2005 to 2010.</p>

Molecular typing of Leptospira interrogans strains isolated from Rattus tanezumi in Guizhou Province, Southwest of China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To identify and type three leptospires isolated from Rattus tanezumi in Guizhou Province by using three molecular techniques (PFGE, MLVA, and MLST), reveal the molecular characteristic of causative agents of local leptospirosis and evaluate these three molecular methods based on their detection resolution and efficiency.</p><p><b>METHODS</b>Three Leptospira strains were isolated from the kidney of Rattus tanezumi and cultured with EMJH medium. PFGE, MLVA, and MLST assays were applied to type the three strains isolated from Rattus tanezumi in Guizhou Province.</p><p><b>RESULTS</b>PFGE, MLVA, and MLST typing showed that the three leptospiral isolates matched with leptospiral serogroup Icterohaemorrhagiae serovar Lai. The findings of the genotyping methods were consistent. MLVA and MLST defined genotypes, whereas PFGE allowed the recognition of additional subgroups within the genotypes, and the findings of molecular typing were also consistent with those of traditional techniques.</p><p><b>CONCLUSION</b>Three leptospiral isolates from Guizhou Province matched with leptospiral serogroup Icterohaemorrhagiae serovar Lai, and PFGE, MLVA, and MLST, as reliable molecular techniques for identifying and typing of Leptospira interrogans, would contribute to the active surveillance, outbreak investigation and source tracking for leptospirosis in Guizhou Province.</p>

Analysis on nucleoprotein gene sequence of 25 rabies virus isolates in Guizhou Province, China / 病毒学报

To analyze 25 nucleoprotein gene (N gene) sequences of rabies viruses circulating in Guizhou province during 2005-2010, China, and to explore the epidemic characteristics and the probable mutant of rabies in Guizhou Province. Rabies virus RNA in human brain tissues, human saliva, and domestic dog brain tissues derived from different prefectures of Guizhou Province were detected with RT-nested PCR, and the amplified products were then sequenced. Bioinformatics software was used to determine the genetic characteristics of these rabies viruses. The sequences of N gene of 25 Guizhou provincial isolates were identical with homogeny between 97.5% - 99.3% and 98.4% - 99.8% at nucleotide and deduced amino acid level, respectively, while the identities between them and isolated strains from other province of China were 88% - 99.1% and 88% - 99.7%. There were several amino acid substitutions in the nucleoprotein of 25 Guizhou isolates compared with the known genotype 1 isolates. The analysis of phylogenetic tree of 25 Guizhou isolates was demonstrated to be genetically divided into two groups, indicating that the virus presented a unique characteristics in geographic distribution and in a time dependent-manner. And phylogenetic tree of 25 Guizhou isolates and 7 genotype 1 strains isolated from other Province of China was also divided into two groups, which were further composed of several subgroups, respectively. From these observations, the rabies viruses derived from Guizhou province were still genotype 1. These isolates of rabies virus were diverged from the strains isolated from other provinces in both gene sequences and deduced amino acid sequences, and these divergences were characterized in geographic distribution and in a time-dependent manner.

Feasibility study of enforcing immunization certificate check before primary school or kindergarten enrollment in Guizhou Province, China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the feasibility of enforcing immunization certificate check before children enroll in primary schools or kindergartens in Guizhou Province.</p><p><b>METHODS</b>Quantitative and qualitative studies were conducted. The multi-stage and cluster sampling approach was adopted for the quantitative part of the study. A questionnaire was designed and 996 children and their keepers were interviewed. Principals, doctors or teachers of the primary schools, directors and child care nurses of kindergarten, and staff of immunization agencies were invited to take part in 12 focus group discussions; meanwhile, face-to-face individual in-depth interviews with 16 officials of the Health, Education and Governmental Departments at various levels were conducted.</p><p><b>RESULTS</b>The total number of subjects was 996. 16.7% of the children in the study completed all the procedures of the National Immunization Programme. 34.3% of them had immunization certificates while the remainder 44.7% registered in immunization agencies. Factors, including the migrant children, doubt about vaccine efficiency, mother's occupation and educational background, knowledge of the National Immunization Programme on targeted vaccines, played an important role in obtaining or not immunization certificates. 95% of the keepers interviewed thought the immunization certificates were useful; 94.8% of them considered the check was critical while only 3.6% of them thought it unnecessary. The first reason from those who found it unnecessary was that they feared that repeated immunization might affect their children's health. The second reason was the cost of immunization, which some of them could not afford to pay. However, the Health Department expressed a favorable attitude to the checking scheme. Though the Education Department agreed that the scheme was essential, they worried that it would affect the enrollment rate.</p><p><b>CONCLUSION</b>In spite of the difficulty in administering immunization certificate check, the effort would be rewarding for raising the immunization coverage rate among the children in Guizhou Province.</p>

Distribution of hepatitis B virus genotype among population of Dong, Miao minority and Han in Guizhou / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the distribution of hepatitis B virus (HBV) genotype in population of Dong, Miao minority and Han in Guizhou.</p><p><b>METHODS</b>S region nucleotides were compared in 127 strains whole sequence of HBV and three restriction enzymes which can be used for genotyping were found by DNA software analysis system. The partial gene fragment of HBV S region was amplified by nested polymerase chain reaction (nPCR). The products were digested with Mbo I, BstN I or BsmA I and subjected to electrophoresis on agarose gel, respectively. The patterns of restriction fragment length polymorphism (RFLP) were analysed. The genotypes were determined by nPCR-RFLP in 166 asymptomatic HBV carriers (ASC), including 48 Dong minority, 52 Miao minority and 66 Han subjects. Some of the ASC were also analysed by direct sequencing of PCR products.</p><p><b>RESULTS</b>The nPCR-RFLP method was simple and accurate. Of the 166 ASC, 138 (83.13%) were genotype B, and 28 (16.87%) were genotype C. Of the 48 Dong minority subjects, 47 (97.2%) were genotype B and 1 (2.08%) was type C. Of the 52 Miao minority subjects, 49 (94.23%) were genotype B and 3 (5.77%) were genotype C. Of the 66 Han subjects, 42 (63.64%) were genotype B and 24 (36.36%) were genotype C. There was a statistical significance in the distribution of genotype C between Dong, Miao minority and Han (7.85% vs 36.36% P less than 0.005).</p><p><b>CONCLUSION</b>Genotype B and C exist in Guizhou and genotype B is the major genotype. Genotype C is found more frequently in Han than in Dong and Miao minority.</p>