Progress and Application of Entomological Evidence in Forensic Science.

ABSTRACT: Entomological evidence provides entry points and clues for cases detection, in terms of estimation of the postmortem interval （PMI）, and place and cause of death. In recent years, the feasibility of entomological evidence in practice has been proved by theories and cases. It especially plays an important role in the investigation of cases with unnatural death, no monitoring, and highly corrupt cadaver. However, there are still some key issues to be further studied and standardized before the application of entomological evidence to forensic practice, to improve the effect of entomological evidence in forensic investigation and trial. This paper retrospectively reviews key studies of the application of entomological evidence in forensic science, mainly including discussion of forensic entomology inspection standard, identification studies of sarcosaprophagous insect species, collection of sarcosaprophagous insect growth and succession data under different environments and forensic entomotoxicology. With the rapid development of information technology and biotechnology, applying artificial intelligence and whole genome sequencing technology in forensic entomology has become a new research direction, which can improve the application value and range of entomological evidence in forensic science.

MiR-20a suppresses proliferation and facilitates apoptosis of breast cancer cells via the MTOR signaling pathway.

OBJECTIVE: The paper aimed to explore the role of micro ribonucleic acid (miR)-20a in regulating the proliferation and apoptosis of breast cancer cells. MATERIALS AND METHODS: The expression of miR-20a in breast cancer cells was analyzed via quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assay. Cell Counting Kit-8 (CCK-8) assay, colony formation assay, and flow cytometry were employed to analyze the proliferation and apoptosis of cells. Thereafter, the target proteins of miR-20a were predicted using TargetScan, a website for miRNA target gene prediction, and the interaction between miR-20a and the target genes was detected through the Luciferase reporter gene assay, qRT-PCR assay, and Western blotting. Finally, the miR-20a inhibitor and target gene expression plasmids were co-transfected for rescue experiment to study whether the target genes participate in the inhibitory effect of miR-20a on the proliferation of breast cancer cells. RESULTS: It was found that the expression of miR-20a was upregulated in breast cancer cell lines. Silencing miR-20a expression inhibited the proliferation and promoted the apoptosis of breast cancer cell. Besides, it was demonstrated that late endosomal/lysosomal adaptor, mitogen-activated protein kinase (MAPK), and mammalian target of rapamycin (mTOR) activator 3 (LAMTOR3) were a direct target of miR-20a. The knockdown of LAMTOR3 expression repressed the influence of miR-20a on the proliferation of breast cancer cells. CONCLUSIONS: MiR-20a targets LAMTOR3 gene to regulate the mTOR signaling pathway, thereby suppressing the proliferation and facilitating the apoptosis of breast cancer cells. It suggests that miR-20a exerts a carcinogenic effect in breast cancer, which may be a potential target for the treatment of breast cancer.

LncRNA GIHCG regulates microRNA-1281 and promotes malignant progression of breast cancer.

OBJECTIVE: This study aimed to investigate the expression characteristics of long non-coding RNA (lncRNA) GIHCG in breast cancer (BCa), and further investigate its role in BCa and its relationship with clinical characteristics and prognosis. PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to examine GIHCG expression in 53 pairs of BCa tumor tissues and adjacent tissues. The interaction between the level of GIHCG and the clinical indicators of BCa and the prognosis of patients was then analyzed. Lentivirus was transfected into BCa cell lines to construct the GIHCG knockdown model. The cell counting kit-8 (CCK-8), cell cloning, and 5-Ethynyl-2'-deoxyuridine (EdU) assays were performed to analyze the influence of GIHCG on the biological function of BCa cells, as well as to explore whether it could play a role via modulating microRNA-1281. RESULTS: QRT-PCR results showed that the GIHCG level was remarkably higher in the BCa tumor tissue than in adjacent ones. Compared with patients with low expression of GIHCG, patients with high expression of GIHCG had higher pathological grades and a lower overall survival. Besides, the proliferation ability of BCa cells in GIHCG knockdown group was significantly decreased compared with NC group. QRT-PCR results indicated that silencing GIHCG increased the expression of miR-1281, thereby promoting the malignant progression of BCa. Also, the silence of miR-1281 reversed the effect of GIHCG on the proliferative capacity of BCa, thus increasing the cell anti-apoptotic ability. CONCLUSIONS: GIHCG levels were remarkably increased in both BCa tissues and cells, which was related to the pathological stage and poor prognosis of BCa patients. Besides, GIHCG might promote the malignant progression of BCa by inhibiting microRNA-1281.

Boettcherisca peregrina (Diptera: Sarcophagidae): A flesh fly species of medical and forensic importance.

Boettcherisca peregrine, as a fly with the necrophagous habits found on human corpses and a vector of disease or parasitic, myiasis-producing agent, is a significant flesh fly species in forensic entomology and medical context. This study reviewed the various aspects of this fly species, including morphology, bionomics, molecular analysis, medical and forensic entomology involvement, such as morphological characteristics of larva, puparia and adult, developmental rate of larvae, the effects of heavy metal (such as Cd and Cu) on the growth and developmentin of larvae, and the impact of some specific stimulis on the labellar chemosensory hair of B. peregrina. Species identification, gene and functions, myiasis and forensic case of this species were also outlined. Therefore, the paper has an important implication for improving the role of B. peregrina in medicine and forensic science.

Boettcherisca peregrina (Diptera: Sarcophagidae): A flesh fly species of medical and forensic importance

@#Boettcherisca peregrine, as a fly with the necrophagous habits found on human corpses and a vector of disease or parasitic, myiasis-producing agent, is a significant flesh fly species in forensic entomology and medical context. This study reviewed the various aspects of this fly species, including morphology, bionomics, molecular analysis, medical and forensic entomology involvement, such as morphological characteristics of larva, puparia and adult, developmental rate of larvae, the effects of heavy metal (such as Cd and Cu) on the growth and developmentin of larvae, and the impact of some specific stimulis on the labellar chemosensory hair of B. peregrina. Species identification, gene and functions, myiasis and forensic case of this species were also outlined. Therefore, the paper has an important implication for improving the role of B. peregrina in medicine and forensic science.

Survey of indoor sarcosaphagous insects.

Entomological evidence provides valuable information for estimating postmortem interval and location of death in criminal or legal investigations. The colonization of sarcosaphagous insects are commonly discovered in the decomposed corpses in most indoor cases. Therefore, by analyzing the growth patterns and behavioral rhythms of these insects, the application of indoor sarcosaphagous insects in actual cases can be investigated. This study classifies the common species of indoor sarcosaphagous insects and analyzes the characteristics of these insects (such as foraging, oviposition, and growth). It further discusses the effect of micro-environment on their behavior. In addition, the research status of the application of indoor sarcosaphagous insects in forensic investigations is summarized.

Survey of indoor sarcosaphagous insects

Entomological evidence provides valuable information for estimating postmortem interval and location of death in criminal or legal investigations. The colonization of sarcosaphagous insects are commonly discovered in the decomposed corpses in most indoor cases. Therefore, by analyzing the growth patterns and behavioral rhythms of these insects, the application of indoor sarcosaphagous insects in actual cases can be investigated. This study classifies the common species of indoor sarcosaphagous insects and analyzes the characteristics of these insects (such as foraging, oviposition, and growth). It further discusses the effect of micro-environment on their behavior. In addition, the research status of the application of indoor sarcosaphagous insects in forensic investigations is summarized.

The Origin and Development of Medical Jurisprudence in Xiangya.

The origin of medical jurisprudence in China can be traced back to as early as 1920s, and since then, the discipline has undergone a great development. This paper, based on the disciplinary development of medical jurisprudence at Xiangya School of Medicine, illustrates its evolution in three aspects covering the scientific and theoretic foundation, legal system and policy support. The current investigation reflected a glimpse of the modern forensic science in China, providing useful historical reference for the development of Chinese forensic science.

Influence of feeding alternative fiber sources on the gastrointestinal fermentation, digestive enzyme activities and mucosa morphology of growing Greylag geese.

The objective of this trial was to study the influence of dietary fiber sources on the gastrointestinal fermentation, digestive enzyme activity, and mucosa morphology of growing Greylag geese. In total, 240 Greylag geese (28-day-old) were allocated to 4 treatments (15 pens/treatment) differing in dietary fiber source: corn straw silage (CSS group), steam-exploded corn straw (SECS group), steam-exploded wheat straw (SEWS group), or steam-exploded rice straw (SERS group). At 112 days of age, 15 birds per group were euthanized to collect samples. No difference (P > 0.05) was found on all the gastrointestinal pH values and ammonia-nitrogen concentrations between the groups. The CSS and SERS groups had a lower (P < 0.05) proportion of acetic acid in the gizzard than the SECS and SEWS groups. The CSS group had a higher VFA concentration in the jejunum (P < 0.05) and acetic acid proportion (P < 0.01) in the ceca, and a lower (P < 0.01) butyric acid proportion than the other groups except for the SECS group. The SECS group had a higher (P < 0.01) acetic acid proportion and lower (P < 0.05) proportions of propionic acid and valeric acid in the ceca than the SEWS and SERS groups. Different fiber sources resulted in different VFA profiles, especially in the gizzard and ceca. Almost all gastrointestinal protease activities of the CSS group were higher (P < 0.05) than the other groups, along with lower (P < 0.01) amylase activities in the duodenum, jejunum, ileum, and ceca. Lipase activity in proventriculus was highest (P < 0.01) in the SEWS group and its cecal activity was lower (P < 0.01) in the SECS and SEWS groups than the CSS and SERS groups with a higher (P < 0.01) lipase activity in the CSS group than the SERS group. The SECS and SERS groups had a higher cellulase activity in the ceca than the CSS and SEWS groups, with a higher (P < 0.01) rectal cellulase activity in the SERS group than the other groups. There was no significant effect (P > 0.05) on the intestinal mucosa morphology. These results suggest that corn straw silage improves protein digestion while steam-exploded straw provides more energy.

Plasma levels and placental expression of vaspin in pregnant women with diabetes mellitus

The present study aimed to investigate visceral adipose tissue-specific serpin (vaspin) concentrations in serum and term placentas and relate these values to insulin resistance and lipid parameters in women with gestational diabetes mellitus (GDM). A total of 30 GDM subjects and 27 age-matched pregnant women with normal glucose tolerance (NGT, control) were included. Serum glucose, glycated hemoglobin (HbA1c), lipid profile, insulin, and vaspin were measured at the end of pregnancy, and homeostasis model of assessment-insulin resistance (HOMA-IR) values were calculated. Vaspin mRNA and protein levels in placentas were measured by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blotting, respectively. Serum vaspin levels were significantly lower in the GDM group than in controls (0.49±0.24 vs 0.83±0.27 ng/mL, respectively; P<0.01). Three days after delivery, serum vaspin levels were significantly decreased in subjects with GDM (0.36±0.13 vs 0.49±0.24 ng/mL, P<0.01). However, in the GDM group, serum vaspin levels were not correlated with the parameters evaluated. In contrast, in the control group, serum vaspin levels were positively correlated with triglycerides (TG; r=0.45, P=0.02) and very low-density lipoprotein cholesterol (VLDL-C; r=0.42, P=0.03). Placental mRNA vaspin (0.60±0.32 vs 0.68±0.32, P=0.46) and protein (0.30±0.08 vs 0.39±0.26; P=0.33) levels in the GDM group did not differ significantly from those in the control group, but were negatively correlated with neonatal birth weight in the GDM group (r=-0.48, P=0.03; r=-0.88; P<0.01). Our findings indicated that vaspin may be an important adipokine involved in carbohydrate and lipid metabolism and may also play a role in fetal development.

Meat quality, oxidative stability and blood parameters from Graylag geese offered alternative fiber sources in growing period.

The effects of dietary fiber sources on the meat quality, oxidative stability, and blood parameters of growing Graylag geese (28-112d) were investigated. The birds were randomly allocated into 4 treatments, of which dietary fiber was mainly from corn straw silage (CSS), steam-exploded corn straw (SECS), steam-exploded wheat straw (SEWS), and steam-exploded rice straw (SERS). No influence (P>0.05) on the basic chemical components, oxidative stability, or organoleptic traits of muscle were observed, except that birds fed SECS had a higher (P<0.05) protein proportion than those fed CSS or SERS, and CSS increased (P<0.01) the cholesterol content when compared to SEWS or SERS. Regarding fatty acid profile in meat, CSS and SECS increased (P<0.01) the proportion of C18:2n6t and decreased that of C21:0 and C22:0 when compared to the others. The birds fed SERS had a higher (P<0.05) proportion of C20:0 and C22:0 than the others, a higher proportion of C20:5n3, n-3 fatty acids, Δ-9 desaturase (18) index compared to those fed CSS or SECS, and a lower (P<0.01) proportion of C20:1n9 than those fed SECS or SEWS. Additionally, SEWS resulted in a higher (P<0.01) proportion of C20:2 when compared to the others. In conclusion, these fibers affect just the protein proportion, cholesterol content, and fatty acid profile of breast muscle, along with the concentration of TG and MDA in blood, but not the other characteristics. No superior fiber source exists with respect to meat quality, suggesting that Graylag geese feeding should make the most economically of the convenient fiber source with appropriate pretreatment.

Effects of bedding material composition in deep litter systems on bedding characteristics and growth performance of limousin calves.

The objective of this study was to evaluate the effects of different litter mixture compositions on bedding system temperature, pH and volatile fatty acid and ammonia-N (NH3-N) content, and the serum physico-chemical parameters and growth indices of calves. Thirty-two Limousin calves (280±20 kg) were randomly assigned to four groups (n = 8 for each group) according to the bedding system used: i) control with soil only (CTR); ii) mixture with 50% paddy hulls (PH), 30% saw dusts (SD), 10% peat moss (PM) and 10% corn cobs (CC) (TRT1); iii) mixture with 15% PH, 15% SD, 10% PM, 40% CC, and 20% corn stover (CS) (TRT2); iv) mixture with 30% PH, 10% PM, 40% CC, and 20% CS (TRT3). The litter material combinations of different treatments were based on the cost of bedding system materials in China. The cost of four treatments from low to high: Control

Plasma levels and placental expression of vaspin in pregnant women with diabetes mellitus.

The present study aimed to investigate visceral adipose tissue-specific serpin (vaspin) concentrations in serum and term placentas and relate these values to insulin resistance and lipid parameters in women with gestational diabetes mellitus (GDM). A total of 30 GDM subjects and 27 age-matched pregnant women with normal glucose tolerance (NGT, control) were included. Serum glucose, glycated hemoglobin (HbA1c), lipid profile, insulin, and vaspin were measured at the end of pregnancy, and homeostasis model of assessment-insulin resistance (HOMA-IR) values were calculated. Vaspin mRNA and protein levels in placentas were measured by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blotting, respectively. Serum vaspin levels were significantly lower in the GDM group than in controls (0.49 ± 0.24 vs 0.83 ± 0.27 ng/mL, respectively; P<0.01). Three days after delivery, serum vaspin levels were significantly decreased in subjects with GDM (0.36 ± 0.13 vs 0.49 ± 0.24 ng/mL, P<0.01). However, in the GDM group, serum vaspin levels were not correlated with the parameters evaluated. In contrast, in the control group, serum vaspin levels were positively correlated with triglycerides (TG; r=0.45, P=0.02) and very low-density lipoprotein cholesterol (VLDL-C; r=0.42, P=0.03). Placental mRNA vaspin (0.60 ± 0.32 vs 0.68 ± 0.32, P=0.46) and protein (0.30 ± 0.08 vs 0.39 ± 0.26; P=0.33) levels in the GDM group did not differ significantly from those in the control group, but were negatively correlated with neonatal birth weight in the GDM group (r=-0.48, P=0.03; r=-0.88; P<0.01). Our findings indicated that vaspin may be an important adipokine involved in carbohydrate and lipid metabolism and may also play a role in fetal development.

Effect of different fibre sources on performance, carcass characteristics and gastrointestinal tract development of growing Greylag geese.

1. The effects of different fibre sources on the growth performance, carcass characteristics and gastrointestinal tract development were studied in growing Greylag geese (Anser anser). 2. Four experimental diets were formulated with corn (maize) straw silage (CSS), steam-exploded corn (maize) straw, steam-exploded wheat straw, and steam-exploded rice straw as fibre sources. A total of 224 male Greylag geese at 28 d of age were randomly assigned to one of the 4 experimental diets. 3. The birds fed on the CSS diets had higher average daily feed intakes than those fed on the steam-exploded straws. However, the 4 treatments had similar average daily gain, which contributed to significant differences in feed conversion ratios. The different fibre sources had no significant effects on the carcass characteristics. 4. The CSS-fed birds had larger gizzards and lower relative length of the caeca than the other three groups. However, the relative weights and lengths of the other gut segments, the relative weights of major organs and the pH values of the gastrointestinal contents were similar between the 4 treatments. It was concluded that straw fibres with different physico-chemical properties exerted an effect on daily feed intake and gastrointestinal development, especially for the gizzard. The pretreatment of straw had a large effect on utilisation efficiency and animal performance. Steam explosion is a promising straw pretreatment for inclusion in diets for geese.

Effects of partial or total replacement of maize with alternative feed source on digestibility, growth performance, blood metabolites and economics in limousin crossbred cattle.

Increasing cost and scarcity of maize has stimulated the use of alternative feed sources (AFS) in the diets of cattle. In this study, we investigated the effects of partial or total replacement of maize on nutrient digestibility, growth performance, blood metabolites, and economics in Limousin crossbred feedlot cattle. Forty-five Limousin×Luxi crossbred bulls were randomly assigned to the three treatment groups, orthodox diet (OD; 45.0% maize), partial replacement diet (PRD; 15% maize, 67% AFS), total replacement diet (TRD; 0% maize, 100% AFS). The growth feeding trial lasted for 98 days. Dry matter intake (DMI) and average daily gain (ADG) were recorded. The digestion trial was carried out after the end of the growth trial. Total faeces and feed samples were measured daily. Digestibilities of dry matter (DM) and organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were calculated. After the feeding trial, blood metabolites were measured in 12 animals from each group. Initial and final body weights did not differ significantly among treatment groups (p>0.05). The ADG and DMI were 1.72 and 8.66, 1.60 and 9.10, and 1.40 and 9.11 kg/d for OD, PRD, and TRD, respectively. The PRD and TRD exhibited lower ADG (p<0.01) and higher DMI (p<0.01) than OD. The DMI (%body weight) was comparable between groups (p>0.5). Feed efficiency of PRD and TRD were lower than OD (p<0.01). The DM digestibility decreased with reduced level of maize (p = 0.10), OM digestibility was higher in OD (p<0.05), and CP, NDF and ADF digestibilities were similar for all groups (p>0.05). Blood urea nitrogen (mg/dL) in PRD and TRD was higher than OD (p<0.01), while other blood parameters did not differ significantly. Feed costs ($/head/d) were 1.49, 0.98, and 0.72 for OD, PRD, and TRD, respectively (p<0.01). Feed costs per kg gain ($) were significantly lower for PRD (0.63) and TRD (0.54) than OD (0.89; p<0.01). Overall profit ($/head) and daily profit ($/head/d) did not differ significantly between treatments (p>0.05), although TRD showed the highest economic benefits overall (p<0.01). While a traditional diet maximized the growth rate, partial or total replacement of dietary maize with AFS proved economically feasible due to their lower costs and comparable nutrient digestibilities of DM, CP, NDF, and ADF. Partial replacement may prove economically competitive in the current situation of China.

Isolation and characterization of polymorphic microsatellite loci in the swimming crab Portunus trituberculatus (Portunidae).

The Swimming crab Portunus trituberculatus (Portunidae) is an important economically food species. To provide molecular markers for P. trituberculatus, we isolated and characterized polymorphic microsatellite markers. We developed a 5'-anchored genomic library of P. trituberculatus DNA, and derived 45 positive clones. We designed 30 pairs of primers from the sequences of these clones, and 10 of which were polymorphic. The loci were screened in 31 P. trituberculatus individuals; the number of alleles ranged from 2 to 5. The observed heterozygosity ranged from 0.20 to 0.49 and the expected heterozygosity ranged from 0.50 to 0.78. The polymorphism information content per locus ranged from 0.37 to 0.75. These polymorphic microsatellite markers may provide some useful information for the population genetic studies of swimming crab and other Portunus species.

Further evidence for the contribution of the BRCA1-interacting protein-terminal helicase 1 (BRIP1) gene in breast cancer susceptibility.

BRCA1-interacting protein C-terminal helicase 1 (BRIP1) is a DNA helicase that influences the DNA repair ability and tumor suppressor function of BRCA1. Truncating BRIP1 mutations have been described as cancer susceptibility alleles. To evaluate BRIP1 polymorphisms as risk factors for breast cancer, we performed a detailed analysis of possible single nucleotide polymorphisms (rs2048718, rs4988344, rs8077088, rs6504074, rs4986764, rs4986763, rs11079454, rs7213430, rs34289250, rs4988345, and rs12937080) using the MassARRAY system. A total of 319 patients with breast cancer and 306 healthy control females from the Chinese Han population enrolled in the study. A weak association was found between the rs4986764 allele (exon 18) and breast cancer. The frequency of the rs4986764 C allele was significantly higher in breast cancer patients than in healthy controls [χ(2) = 4.089, P = 0.043, odds ratio (OR) = 0.781, 95% confidence interval (CI) = 0.614-0.992]. Additionally, our study is the first to identify a significant association between rs7213430 and breast cancer. Compared to healthy controls, patients with breast cancer had a higher frequency of the rs7213430 A allele (χ(2) = 8.865, P = 0.003, OR = 0.700, 95%CI = 0.553-0.886). Furthermore, linkage disequilibrium was observed in two blocks (D' > 0.9). While significantly more T-A-C haplotypes (P = 0.001, block 1) were found in breast cancer patients, the frequency of T-T haplotypes (P = 0.008, block 2) was significantly higher in healthy controls. The possible association among rs4986764, rs7213430, and breast cancer risk merits further validation in an independent case-control study.

Effects of a mixture of steam-flaked corn and extruded soybeans on performance, ruminal development, ruminal fermentation, and intestinal absorptive capability in veal calves.

This study investigated the effects of a mixture of steam-flaked corn and extruded soybeans on performance, ruminal development, ruminal fermentation variables, and intestinal absorptive capability in Holstein male calves (n = 39). Calves were assigned to 1 of 3 treatments (13 calves per treatment): 1) milk replacer (MR), 2) one-half of the amount of MR in treatment 1, plus a mixture of 62.1% steam-flaked corn and 30.5% extruded soybeans provided ad libitum (HMCS), or 3) a mixture of 62.1% steam-flaked corn and 30.5% extruded soybeans provided ad libitum (CS). All the calves were started at 2 ± 1 d of age and studied for 150 d. Each 30 d was defined as 1 period. Dry matter intake and growth were measured daily and monthly, respectively. All calves were harvested at 150 d of age, after which rumen fluid was collected. Rumen and intestine samples were gathered. Calves fed MR exhibited greater BW (P = 0.001) and ADG (P < 0.001), compared with calves fed HMCS and CS from period 2 to 3; however, from period 4 to 5, CS calves had greater (P < 0.04) ADG than MR calves. The treatments did not differ in final BW (P = 0.72) and ADG (P = 0.20) from period 2 to 5. Compared with HMCS and MR calves, CS calves had the greatest DMI (P < 0.001) and the least feed efficiency (P < 0.001) from period 2 to 5. For ruminal fermentation parameters, CS calves had decreased (P = 0.04) rumen pH than MR calves. The NH3 concentrations were greater (P = 0.03) in calves fed HMCS than calves fed MR and CS. Total VFA concentrations were greatest in CS calves (P = 0.02). Calves fed CS had the greatest molar concentrations of propionate, butyrate, and valerate (P < 0.002), and calves fed HMCS had the greatest molar concentrations of isobutyrate (P = 0.001) and isovalerate (P = 0.001). The CS calves exhibited greater empty rumen weight (P = 0.001), papillae length (P < 0.001), papillae width (P < 0.001), rumen wall thickness (P = 0.012), and papillae density (P = 0.003). The greatest villus heights in the jejunum (P = 0.04) and ileum (P = 0.005) were observed in CS calves. Compared with HMCS calves, calves fed CS had greater villus:crypt ratios in the duodenum (P = 0.001) and jejunum (P = 0.001). Results indicate that CS improves ADG in period 4 to 5 and positively contributes to ruminal development, ruminal fermentation, and intestinal absorptive capability in veal calves.

Risk factors associated with tuberculosis infection among health care workers in Inner Mongolia, China.

SETTING: Health care workers (HCWs) are at increased risk for tuberculosis (TB) infection. In China, surveys examining TB infection among HCWs have not studied general health care facilities, compared tuberculin tests conducted using local protocols against an internationally accepted test or characterised risk factors. OBJECTIVE: To measure the prevalence of and risk factors for TB infection among HCWs in Inner Mongolia, China. DESIGN: Between April and August 2010, we administered QuantiFERON®-TB Gold In-Tube (QFT-GIT) tests, skin tests using Chinese tuberculin (TST) and surveys among HCWs at an infectious diseases hospital and a general medical hospital. We assessed whether demographic characteristics, personal exposure and work exposure were associated with QFT-GIT and TST positivity, and assessed agreement between test results. RESULTS: Of 999 HCWs, 683 (68%) were QFT-GIT-positive, which was associated with greater age, longer HCW career, TB disease in a co-worker and greater daily patient exposure using multivariable analysis. TST reactions ≥ 5 mm occurred in 69% of the HCWs; agreement between test results was low ( 0.22). CONCLUSIONS: The prevalence of TB infection among HCWs in Inner Mongolia is high; infection was associated with occupational exposure. Results from locally conducted TST are difficult to interpret. In China, TB infection control in health care facilities should be strengthened.