Spatio-temporal aggregation of hemorrhagic fever with renal syndrome in Shandong Province from 2017 to 2020 / 中华地方病学杂志

Objective:To study the epidemiological characteristics and spatio-temporal aggregation of hemorrhagic fever with renal syndrome (HFRS) in Shandong Province, and to provide reference for formulating reasonable prevention and control strategies.Methods:Retrospective analysis was used to collect HFRS surveillance data and confirmed case data in Shandong Province from 2017 to 2020 in the "China Disease Prevention and Control Information System Infectious Disease Surveillance System". Geoda 1.18 software was used for global and local spatial autocorrelation analysis, SaTScan 9.6 software was used for spatio-temporal scanning analysis, and ArcGis 10.7 software was used for map drawing and visual display.Results:A total of 3 753 cases of HFRS were reported in Shandong Province from 2017 to 2020, including 56 deaths. The annual incidence rate was 1.26/100 000, 1.22/100 000, 0.75/100 000 and 0.53/100 000, respectively, with an average annual incidence rate of 0.94/100 000. The incidence of HFRS was obviously seasonal, mainly concentrated in autumn and winter from October to December, accounting for 50.41% (1 892/3 753). The age of onset was mainly 30-59 years old, accounting for 61.68% (2 315/3 753). The male to female ratio was 2.76 ∶ 1.00 (2 756 ∶ 997). The occupation distribution was mainly farmers, accounting for 81.99% (3 077/3 753). The global spatial autocorrelation analysis showed that HFRS showed spatial aggregation areas in each year from 2017 to 2020 (Moran' I = 0.38, 0.33, 0.59, 0.46, Z = 7.47, 7.23, 10.69, 8.66, P < 0.001). The local spatial autocorrelation analysis showed that "high-high" aggregation areas were mainly concentrated in central and southeast of Shandong Province, while "low-low" aggregation areas were mainly concentrated in northwest of Shandong Province. Spatio-temporal scanning analysis revealed 1 type Ⅰ agglomerations and 2 type Ⅱ aggregation areas. The type Ⅰ aggregation areas occurred from October to November 2018, covering 22 counties (districts) of 5 cities in Qingdao, Yantai, Weifang, Weihai and Rizhao. The first type Ⅱ aggregation area occurred from October to November 2017, involving 23 counties (districts) of 8 cities in Jinan, Zibo, Zaozhuang, Weifang, Jining, Tai 'an, Rizhao and Linyi. The second type Ⅱ aggregation area occurred in Jinxiang County, Jining City from February to March 2017. Conclusion:The incidence of HFRS in Shandong Province from 2017 to 2020 has obvious spatio-temporal aggregation, and the hot spots are concentrated in central and southeast of Shandong Province, which should be regarded as a key area for prevention and control of HFRS.

Epidemiological investigation of predominance tick and the infectious status of severe fever thrombocytopenia syndrome virus in Penglai and Laizhou counties, Shandong province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the predominance ticks and the infectious status of severe fever with thrombocytopenia (SFTSV) in Penglai and Laizhou counties, Shandong province.</p><p><b>METHODS</b>Two towns with high incidence rate were selected in Penglai and Laizhou, respectively, then three villages were selected in each towns. Parasitic ticks were collected from the host skin by hand manually and free ticks manually with white cloth from the grassland, monthly, during April to December in 2011. Samples were classified by original, varieties, developmental stages, then extracted RNA, using Realtime RT-PCR to test severe fever thrombocytopenia syndrome virus, S fragments were amplified with nested PCR, then isolated virus. By neighbor joining method in the phylogenetic tree, the minimum infection rate (MIR) was used to represent the infection status of ticks in novel bunyavirus.</p><p><b>RESULTS</b>A total of 3 145 ticks were collected totally from 5 categories, there were 3 048(96.92%) of Haemaphysalis longicornis, 73(2.32%) of Rhinpicephalus sanguineus, 10(0.32%) of microplus Boophilus, 9(0.29%) of Haemaphysalis campanulata, 5(0.16%) of Dermacentor sinicus, respectively. The positive rate of nucleic acid of 2 044 samples was 6.16% (126/2 044), minimum infection rate (MIR) was 4.01%, there were 122(96.83%) of Haemaphysalis longicornis, 3(2.38%) of Rhinpicephalus sanguineus, and 1(0.79%) of microplus Boophilus, MIR was 4.00%, 4.11%, and 10.00%, respectively. There were no nucleic acid positive samples in Haemaphysalis campanulata and Dermacentor sinicus. The 11 S segments were amplified in 126 positive samples, the homology of S fragment was 95.6%-99.9% with 11 strains isolated from the identified SFTS cases in local area, 3 strains isolated from animals, and 11 strains isolated from other areas. There was no significant difference among original, varieties and developmental stages.</p><p><b>CONCLUSION</b>Haemaphysalis longicornis was the predominant species in Penglai and Laizhou counties, it could be propagation medium with Rhipicephalus sanguineus and microplus Boophilus, S sequence in ticks was higher homology with virus isolated from local SFTS cases.</p>

Prevalence and homology analysis on human and animals severe fever with thrombocytopenia syndrome virus infection in Yantai of Shandong province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To learn the prevalence of infection of human and animals severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) in Yantai, Shandong province, and to analyze the pathogenic features of SFTSV as well as its relationship between human and animal hosts.</p><p><b>METHODS</b>From April to November in 2011, 3 576 serum samples were collected from domesticated animals, including sheep, cattle, pigs, dogs, chickens, in Laizhou and Penglai areas where fever with thrombocytopenia syndrome frequently occurred among local residents. Total SFTSV antibodies and virus-specific nucleic acids of the serum were tested by ELISA and Real time RT-PCR, respectively. SFTSV infection on each animal was observed in different months. 2 590 human serum samples were also collected in Laizhou and Penglai areas, with IgG antibodies tested by ELISA. Virus was isolated with Vero cells from the serum which SFTSV viral nucleic acids were positive. S fragments were amplified by RT-PCR and sequenced, with homology analysis conducted on these sequences.</p><p><b>RESULTS</b>The overall positive rate of serum samples from animals on the total SFTSV antibodies was 40.24% (1 439/3 576) while the positive rate for specific nucleic acids was 4.56% (163/3 576). The positive rates for SFTSV antibodies were 62.78%, 52.97%, 45.56%, 28.73%, 1.45% and the positive rates for specific nucleic acids were 5.72%, 4.63%, 3.02%, 5.25% and 3.73%, in sheep, cattle, chickens, dogs, pigs, respectively. The antigens/antibodies for SFTSV in animals changed seasonally. The overall positive rate for SFTSV IgG antibody from 2 590 human samples was 5.41%. Thirteen virus strains were isolated from these serum samples (10 strains from human and 3 strains from animals). The nucleotide homology of 13S fragments' sequences ranged from 95.23% to 100.00% and the nucleotide homology with the isolates from other provinces were between 94.72% and 99.13%. The homology was considered to be high.</p><p><b>CONCLUSION</b>High prevalence of SFTSV infections occurred both in human and domestic animals in Yantai city. The nucleotide sequences of SFTSV were highly homologous among human and domestic animals. The findings suggested that domesticated animals might serve as SFTSV proliferation and the hosts for transmission thus should be attached great importance.</p>

Prevalence and homology analysis on human and animals severe fever with thrombocytopenia syndrome virus infection in Yantai of Shandong province / 中华流行病学杂志

Objective To learn the prevalence of infection of human and animals severe fever with thrombocytopenia syndrome bunyavirus(SFTSV)in Yantai,Shandong province,and to analyze the pathogenic features of SFTSV as well as its relationship between human and animal hosts. Methods From April to November in 2011,3 576 serum samples were collected from domesticated animals,including sheep,cattle,pigs,dogs,chickens,in Laizhou and Penglai areas where fever with thrombocytopenia syndrome frequently occured among local residents. Total SFTSV antibodies and virus-specific nucleic acids of the serum were tested by ELISA and Real time RT-PCR,respectively. SFTSV infection on each animal was observed in different months. 2 590 human serum samples were also collected in Laizhou and Penglai areas,with IgG antibodies tested by ELISA. Virus was isolated with Vero cells from the serum which SFTSV viral nucleic acids were positive. S fragments were amplified by RT-PCR and sequenced,with homology analysis conducted on these sequences. Results The overall positive rate of serum samples from animals on the total SFTSV antibodies was 40.24%(1 439/3 576)while the positive rate for specific nucleic acids was 4.56%(163/3 576). The positive rates for SFTSV antibodies were 62.78%,52.97%,45.56%,28.73%,1.45%and the positive rates for specific nucleic acids were 5.72%,4.63%,3.02%,5.25%and 3.73%,in sheep,cattle,chickens,dogs, pigs,respectively. The antigens/antibodies for SFTSV in animals changed seasonally. The overall positive rate for SFTSV IgG antibody from 2 590 human samples was 5.41%. Thirteen virus strains were isolated from these serum samples(10 strains from human and 3 strains from animals). The nucleotide homology of 13S fragments’sequences ranged from 95.23%to 100.00%and the nucleotide homology with the isolates from other provinces were between 94.72%and 99.13%. The homology was considered to be high. Conclusion High prevalence of SFTSV infections occured both in human and domestic animals in Yantai city. The nucleotide sequences of SFTSV were highly homologous among human and domestic animals. The findings suggested that domesticated animals might serve as SFTSV proliferation and the hosts for transmission thus should be attached great importance.

Prevalence and homology analysis on human and animals severe fever with thrombocytopenia syndrome virus infection in Yantai of Shandong province / 中华流行病学杂志

Objective To learn the prevalence of infection of human and animals severe fever with thrombocytopenia syndrome bunyavirus(SFTSV)in Yantai,Shandong province,and to analyze the pathogenic features of SFTSV as well as its relationship between human and animal hosts. Methods From April to November in 2011,3 576 serum samples were collected from domesticated animals,including sheep,cattle,pigs,dogs,chickens,in Laizhou and Penglai areas where fever with thrombocytopenia syndrome frequently occured among local residents. Total SFTSV antibodies and virus-specific nucleic acids of the serum were tested by ELISA and Real time RT-PCR,respectively. SFTSV infection on each animal was observed in different months. 2 590 human serum samples were also collected in Laizhou and Penglai areas,with IgG antibodies tested by ELISA. Virus was isolated with Vero cells from the serum which SFTSV viral nucleic acids were positive. S fragments were amplified by RT-PCR and sequenced,with homology analysis conducted on these sequences. Results The overall positive rate of serum samples from animals on the total SFTSV antibodies was 40.24%(1 439/3 576)while the positive rate for specific nucleic acids was 4.56%(163/3 576). The positive rates for SFTSV antibodies were 62.78%,52.97%,45.56%,28.73%,1.45%and the positive rates for specific nucleic acids were 5.72%,4.63%,3.02%,5.25%and 3.73%,in sheep,cattle,chickens,dogs, pigs,respectively. The antigens/antibodies for SFTSV in animals changed seasonally. The overall positive rate for SFTSV IgG antibody from 2 590 human samples was 5.41%. Thirteen virus strains were isolated from these serum samples(10 strains from human and 3 strains from animals). The nucleotide homology of 13S fragments’sequences ranged from 95.23%to 100.00%and the nucleotide homology with the isolates from other provinces were between 94.72%and 99.13%. The homology was considered to be high. Conclusion High prevalence of SFTSV infections occured both in human and domestic animals in Yantai city. The nucleotide sequences of SFTSV were highly homologous among human and domestic animals. The findings suggested that domesticated animals might serve as SFTSV proliferation and the hosts for transmission thus should be attached great importance.