Prevalence and diversity of small rodent-associated Bartonella species in Shangdang Basin, China.

The aim of this study was to investigate the occurrence and molecular characteristics of Bartonella infections in small rodents in the Shangdang Basin, China. Small rodents were captured using snap traps, and their liver, spleen, and kidney tissues were harvested for Bartonella detection and identification using a combination of real-time PCR of the ssrA gene (296 bp) and conventional PCR and sequencing of the gltA gene (379 bp). Results showed that 55 of 147 small rodents to be positive for Bartonella, with a positivity rate of 37.41%, and 95% confidence interval of 29.50%- 45.33%. While the positivity rate across genders (42.62% in males and 33.72% in females, χ2 = 1.208, P = 0.272) and tissues (28.57% in liver, 33.59% in spleen, and 36.76% in kidney, χ2 = 2.197, P = 0.333) of small rodents was not statistically different, that in different habitats (5.13% in villages, 84.44% in forests, and 54.17% in farmlands, χ2 = 80.105, P<0.001) was statistically different. There were 42 Bartonella sequences identified in six species, including 30 B. grahamii, three B. phoceensis, two B. japonica, two B. queenslandensis, one B. fuyuanensis and four unknown Bartonella species from Niviventer confucianus, Apodemus agrarius and Tscherskia triton. In addition to habitat, Bartonella species infection could be affected by the rodent species as well. Among the Bartonella species detected in this area, B. grahamii was the dominant epidemic species (accounting for 71.43%). B. grahamii exhibited four distinct clusters, and showed a certain host specificity. In addition, 11 haplotypes of B. grahamii were observed using DNASP 6.12.03, among which nine haplotypes were novel. Overall, high occurrence and genetic diversity of Bartonella were observed among small rodents in the Shangdang Basin; this information could potentially help the prevention and control of rodent-Bartonella species in this area.

Molecular detection and genetic characterization of small rodents associated Bartonella species in Zhongtiao Mountain, China.

The prevalence and molecular characteristics of Bartonella infections in small rodents in the Zhongtiao Mountain, China have been explored. In this study, the liver, spleen and kidney tissues of captured rodents were used for Bartonella spp. detection and identification by combination of real-time PCR of transfer-mRNA (ssrA) gene and traditional PCR and sequencing of citrate synthase (gltA) gene. It was shown that 49.52% of the rodents (52/105) were positive for Bartonella spp.. The infection rate in different gender (χ2 = 0.079, P = 0.778) and tissues (χ2 = 0.233, P = 0.890) of small rodents did not have statistical difference, but that in different small rodents (Fisher's exact test, P < 0.001) and habitats (χ2 = 5.483, P = 0.019) had statistical difference. And, the sequencing data suggests that Bartonella sequences (n = 31) were identified into three species, including 14 of B. grahamii, 3 of B. queenslandensis and 14 of unknown Bartonella species. Phylogenetic analysis showed that B. grahamii sequences were clustered with the isolates from South Korea and China, and B. queenslandensis sequences were mainly closely related to the isolates from China and Thailand. The genetic diversity analysis showed that B. grahamii and B. queenslandensis sequences exhibited noticeable intraspecies diversity. Taken together our data demonstrates the high prevalence and genetic diversity of Bartonella infections in small rodents in the Zhongtiao Mountain, especially a potential novel Bartonella specie was detected, which could benefit the prevention and control of rodent-Bartonella species in this area.

Spatiotemporal clustering and meteorological factors affected scarlet fever incidence in mainland China from 2004 to 2017.

OBJECTIVE: To analyze the spatiotemporal dynamic distribution and detect the related meteorological factors of scarlet fever from an ecological perspective, which could provide scientific information for effective prevention and control of this disease. METHODS: The data on scarlet fever cases in mainland China were downloaded from the Data Center of the China Public Health Science, while monthly meteorological data were extracted from the official website of the National Bureau of Statistics. Global Moran's I, local Getis-Ord Gi⁎ hotspot statistics, and Kulldorff's retrospective space-time scan statistical analysis were used to detect the spatial and spatiotemporal clusters of scarlet fever across all settings. A spatial panel data model was conducted to estimate the impact of meteorological factors on scarlet fever incidence. RESULTS: Scarlet fever in China had obvious spatial, temporal, and spatiotemporal clustering, high-incidence spatial clusters were located mainly in the north and northeast of China. Nine spatiotemporal clusters were identified. A spatial lag fixed effects panel data model was the best fit for regression analysis. After adjusting for spatial individual effects and spatial autocorrelation (ρ = 0.5623), scarlet fever incidence was positively associated with a one-month lag of average temperature, precipitation, and total sunshine hours (all P-values < 0.05). Each 10 °C, 2 cm, and 10 h increase in temperature, precipitation, and sunshine hours, respectively, was associated with a 6.41% increment and 1.04% and 1.41% decrement in scarlet fever incidence, respectively. CONCLUSION: The incidence of scarlet fever in China showed an upward trend in recent years. It had obvious spatiotemporal clustering, with the high-risk areas mainly concentrated in the north and northeast of China. Areas with high temperature and with low precipitation and sunshine hours tended to have a higher scarlet fever incidence, and we should pay more attention to prevention and control in these places.

Spatial transmission and meteorological determinants of tuberculosis incidence in Qinghai Province, China: a spatial clustering panel analysis.

BACKGROUND: Tuberculosis (TB) is the notifiable infectious disease with the second highest incidence in the Qinghai province, a province with poor primary health care infrastructure. Understanding the spatial distribution of TB and related environmental factors is necessary for developing effective strategies to control and further eliminate TB. METHODS: Our TB incidence data and meteorological data were extracted from the China Information System of Disease Control and Prevention and statistical yearbooks, respectively. We calculated the global and local Moran's I by using spatial autocorrelation analysis to detect the spatial clustering of TB incidence each year. A spatial panel data model was applied to examine the associations of meteorological factors with TB incidence after adjustment of spatial individual effects and spatial autocorrelation. RESULTS: The Local Moran's I method detected 11 counties with a significantly high-high spatial clustering (average annual incidence: 294/100 000) and 17 counties with a significantly low-low spatial clustering (average annual incidence: 68/100 000) of TB annual incidence within the examined five-year period; the global Moran's I values ranged from 0.40 to 0.58 (all P-values < 0.05). The TB incidence was positively associated with the temperature, precipitation, and wind speed (all P-values < 0.05), which were confirmed by the spatial panel data model. Each 10 °C, 2 cm, and 1 m/s increase in temperature, precipitation, and wind speed associated with 9 % and 3 % decrements and a 7 % increment in the TB incidence, respectively. CONCLUSIONS: High TB incidence areas were mainly concentrated in south-western Qinghai, while low TB incidence areas clustered in eastern and north-western Qinghai. Areas with low temperature and precipitation and with strong wind speeds tended to have higher TB incidences.

Bartonella Species Detected in the Plateau Pikas (Ochotona curzoiae) from Qinghai Plateau in China.

Bartonella species can infect a variety of mammalian hosts and cause a broad spectrum of diseases in humans, but there have been no reports of Bartonella infection in Ochotonidae. This is the first study to detect Bartonella in plateau pikas in the Qinghai plateau, providing baseline data for the risk assessment of human Bartonella infection in this area. We obtained 15 Bartonella strains from 79 pikas in Binggou and Maixiu areas of Qinghai with a positive rate of 18.99%. Based on the phylogenetic analysis of the Bartonella citrate synthase (gltA) gene sequences, most strains were closely related to B. taylorii (3/15) and B. grahamii (12/15). The latter is a pathogenic strain in humans. Our results suggest that a corresponding prevention and control strategy should be taken into consideration in the Qinghai province.

[Genetic characteristics of influenza A/H3N2 virus neuraminidase gene: a survey from 2010 to 2012 in Qinghai Province, China].

This study aims to perform a survey of genetic variation in neuraminidase (NA) gene of influenza A/H3N2 virus, as well as related resistance to NA inhibitors, in Qinghai Province of China, 2010 to 2012. Strains of influenza A/H3N2 isolated during an influenza survey from 2010 to 2012 in Qinghai were enrolled by random sampling. Viral RNA was extracted and amplified by RT-PCR. Purified PCR products were sequenced thereafter. Genetic analysis of nucleic acid and the derived amino acid sequences was performed by MEGA 4.0. Phylogenetic trees were also constructed. Strains isolated during 2010-2011 in this study clustered closely with World Health Organization (WHO) 2010-2012 reference vaccine strain A/Perth/16/2009 and 2008-2010 reference vaccine strain A/Brisbane/10/2007 on the phylogenetic tree, while the 2012 isolates were located on another branch. In analysis of derived amino acid sequences, the 2010 isolates mutated at K81T, the 2011 isolates mutated at I26V and D127N, while the 2012 isolates mutated at E41K, P46A, I58V, T71N, L81P, D93G, D127N, D151N, and I307M. The D151N mutation added a glycosylation site to the activity center of NA. No significant variation was discovered in H3N2 NA gene of 2010-2011 isolates in Qinghai, China. Isolates of 2012 were found with significant mutation, which has the potential of inducing minor resistance to NA inhibitors like zanamivir and oseltamivir.

[Acute infection of Toxoplasma gondii affects the level of oxygen free radicals in serum and testes of mice].

OBJECTIVE: To observe the impact of Toxoplasma gondii infection on the level of oxygen free radicals and antioxidant enzyme in serum and testes of mice. METHODS: 40 BALB/c male mice were randomly divided into four groups. Five mice from each group were injected intraperitoneally with 2.5 x 10(3) tachyzoites of T. gondii, the others received PBS. Mice were sacrificed on the 1st, 3rd, 5th, and 7th day after inoculation. Samples of serum and testes were collected to determine the content of oxygen free radicals and superoxide dismutase (SOD). RESULTS: The concentration of the oxygen free radicals (NO, *OH, O2-) in serum and testes of the mice increased along with the days of infection. The concentration of SOD reached a peak on the 3rd day after the injection and then decreased. Both of oxygen free radicals and SOD showed a statistical difference with the control (P < 0.01). CONCLUSION: Acute infection of T. gondii leads to n increase of oxygen free radicals and SOD in the serum and testes of mice.