Analysis of Dietary and Nutritional Status of Tuberculosis Patients in Hulunbuir Region.

Objective: Tuberculosis (TB) is a major public health problem that affects millions of people worldwide. Malnutrition is a common complication of TB and can worsen the disease outcome. The purpose of this study was to investigate the dietary and nutritional status, as well as the dietary structure, of TB patients in Hulunbuir City, Inner Mongolia, China. Additionally, the study aimed to analyze the factors that influence the nutritional status in order to provide a theoretical foundation for the prevention and treatment of TB and related issues. Methods: A cross-sectional study was conducted on 334 randomly selected TB patients from Hulunbuir City Second Hospital. A questionnaire survey was administered to collect information on demographic characteristics, dietary habits, and food intake. Nutritional status was assessed by body mass index (BMI). Dietary diversity score (DDS) was calculated based on the number of food groups consumed in the previous 24 hours. Statistical analysis was performed using SPSS 20.0 software. Descriptive statistics employed rates and composition ratios, and categorical data was represented using frequencies and percentages. The chi-square test was used to analyze the association between nutritional status and other variables, with a significance level set at α=0.05. Multivariable ordinal logistic regression analysis was performed to identify the independent factors affecting the nutritional status of TB patients. Results: The univariate analysis revealed statistically significant differences (P < 0.05) in the nutritional status (as measured by BMI) among tuberculosis patients, considering ethnicity, educational level, smoking, meat-based diet, vegetable consumption, and DDS grading. No statistically significant differences were found regarding gender, age, marital status, occupation, sleep duration, alcohol consumption, and consumption of rice and flour dishes. Statistically significant variables from the univariate analysis were included in a multivariable ordinal logistic regression analysis model. The findings highlighted that educational level (high school or below), smoking, meat-based diet, DDS scores of 1-3, and a primarily vegetable-based diet had independent effects on the nutritional status of tuberculosis patients (all P < 0.05). No significant difference was found in nutritional status between the Han ethnic group and other ethnicities. Conclusion: The study revealed that the dietary and nutritional status of TB patients in Hulunbuir City was suboptimal and influenced by several factors. Smoking, meat-based diet, and low dietary diversity score were the primary risk factors for malnutrition among TB patients. The study suggests that nutritional education and intervention programs should be implemented for TB patients to improve their dietary quality and nutritional status.

Transcriptomics-based investigation of manganese dioxide nanoparticle toxicity in rats' choroid plexus.

Manganese dioxide nanoparticles (MnO2-NPs) have a wide range of applications in biomedicine. Given this widespread usage, it is worth noting that MnO2-NPs are definitely toxic, especially to the brain. However, the damage caused by MnO2-NPs to the choroid plexus (CP) and to the brain after crossing CP epithelial cells has not been elucidated. Therefore, this study aims to investigate these effects and elucidate potential underlying mechanisms through transcriptomics analysis. To achieve this objective, eighteen SD rats were randomly divided into three groups: the control group (control), low-dose exposure group (low-dose) and high-dose exposure group (high-dose). Animals in the two treated groups were administered with two concentrations of MnO2-NPs (200 mg kg-1 BW and 400 mg kg-1 BW) using a noninvasive intratracheal injection method once a week for three months. Finally, the neural behavior of all the animals was tested using a hot plate tester, open-field test and Y-type electric maze. The morphological characteristics of the CP and hippocampus were observed by H&E stain, and the transcriptome of CP tissues was analysed by transcriptome sequencing. The representative differentially expressed genes were quantified by qRT-PCR. We found that treatment with MnO2-NPs could induce learning capacity and memory faculty decline and destroy the structure of hippocampal and CP cells in rats. High doses of MnO2-NPs had a more obvious destructive capacity. For transcriptomic analysis, we found that there were significant differences in the numbers and types of differential genes in CP between the low- and high-dose groups compared to the control. Through GO terms and KEGG analysis, high-dose MnO2-NPs significantly affected the expression of transporters, ion channel proteins, and ribosomal proteins. There were 17 common differentially expressed genes. Most of them were transporter and binding genes on the cell membrane, and some of them had kinase activity. Three genes, Brinp, Synpr and Crmp1, were selected for qRT-PCR to confirm their expression differences among the three groups. In conclusion, high-dose MnO2-NPs exposure induced abnormal neurobehaviour, impaired memory function, destroyed the structure of the CP and changed its transcriptome in rats. The most significant DEGs in the CP were within the transport system.

CRP, SAA, LDH, and DD predict poor prognosis of coronavirus disease (COVID-19): a meta-analysis from 7739 patients.

Understanding factors associated with disease severity and mortality from coronavirus disease (COVID-19) was critical for effective risk stratification. We aimed to investigate the association between biomarkers of clinical laboratory tests, including serum C-reactive protein (CRP), serum amyloid protein (SAA), lactate dehydrogenase (LDH), and D-dimer (DD) and poor prognosis of COVID-19. We have searched many studies on COVID-19 on PubMed (Medline), Web of Science and Cochrane until 1 March 2021. The interest of this study was original articles reporting on laboratory testing projects and outcome of patients with COVID-19 that comprises mortality, acute respiratory distress syndrome (ARDS), need for care in an intensive care unit (ICU), and severe COVID-19. After synthesizing all data, we performed meta-analysis of random effects, and determined mean difference (MD) and standard mean difference at the biomarker level for different disease severity. A total of 7,739 patients with COVID-19 were pooled from 32 studies. CRP was significantly associated with poor prognosis of COVID-19 (SMD = 0.98, 95% CI = (0.85, 1.11), p < .001). Elevated SAA was associated with an increased composite poor outcome in COVID-19 (SMD = 1.06, 95% CI = (0.39, 1.72), p = .002). An elevated LDH was associated with a composite poor outcome (SMD = 1.18, 95% CI = (1.00, 1.36), p < .001). Patients with a composite poor outcome had a higher DD level (SMD = 0.91, 95% CI = (0.79, 1.02), p < .001). This meta-analysis showed that elevated serum CRP, SAA, LDH, and DD were associated with a poor outcome in COVID-19.

Regulation of P300 and HDAC1 on endoplasmic reticulum stress in isoniazid-induced HL-7702 hepatocyte injury.

P300 and HDAC1 can be involved in the development of various liver diseases by regulating gene transcription. Endoplasmic reticulum stress (ERS) is one of the main pathways of apoptosis and is activated during inflammatory responses, but the roles of P300 and HDAC1 in ERS in antituberculosis drug-induced liver injury (ADLI) are not clear. This study confirms that isoniazid can change the states of P300 and HDAC1 in HL-7702 hepatocyte metabolism and induce ERS, causing hepatocyte injury and apoptosis. When combined with C646, however, P300 can be reduced. HL-7702 cells were flattened, and the cytoplasm became crinkled. To a certain extent, ERS was relieved, but hepatocytes suffered worse damage, and the rate of cell apoptosis markedly increased. When MS-275 was applied, HDAC1 level was increased, cell fusion appeared, and fluorescence intensity of endoplasmic reticulum was weakened. In addition, ERS was aggravated, but liver injury was relieved, and the apoptosis rate significantly decreased. Therefore, alteration of P300 and HDAC1 status and ERS are involved in ADLI, and changes in P300 and HDAC1 can regulate ERS and then affect cell damage.

Involvement of histone hypoacetylation in INH-induced rat liver injury.

This study explores the mechanism of histone acetylation under the effect of oxidative stress in rat liver injury induced by isoniazid (INH). Fifty-six adult SD rats were selected and divided randomly into INH groups (48) and control (8). Rats in INH groups were intragastrically injected with 55 mg kg-1 day-1 for 3, 7, 10, 14, 21, and 28 days, and control rats were given an equal volume of distilled water. Pathological changes in liver tissues were observed by HE staining. Western blot analysis was conducted to measure the expression levels of H3k14ac and H4k8ac. The activities of HAT, HDAC and IL-1ß, and TNF-α were detected by ELISA in liver tissues. Real-time RT-PCR analysis was performed to determine the protein expression levels of HAT, HDAC, and IL-1ß and the mRNA expression of TNF-α. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were assayed by biochemical methods in liver tissues. At different time points, the SOD activity decreased, whereas the MDA content significantly increased after 14 days (FSOD = 11.15, FMDA = 7.42, P < 0.01). During this period, the expression of histone acetylated H3K14 and H4K8 acetylation decreased compared with the control group (FH3K14 = 4.18, FH4K8 = 3.87, P < 0.05); by contrast, HDAC1 and HDAC2 showed a high expression level compared with those in the control group (FHDAC1 = 29.13, FHDAC2 = 58.34, P < 0.01). Moreover, the expression of CBP/P300 was lower than that in the control group (FCBP/P300 = 12.18, P = 0.001), and the protein contents of IL-1ß and TNF-α in rat liver tissues were up-regulated (FIL-1ß = 44.88, FTNF-α = 41.56, P < 0.01). These results suggest that histone acetylation is involved in INH-induced rat liver injury. Furthermore, the hypoacetylation of histones H3K14 and H4K8 is negatively correlated with oxidative stress-mediated rat liver injury.

High Physical Activity is Associated with an Improved Lipid Profile and Resting Heart Rate among Healthy Middle-aged Chinese People.

OBJECTIVE: To investigate the effects of physical activity (PA) on dyslipidemia and elevated resting heart rate (RHR) in a large-scale cross-sectional study in China. METHODS: We recruited community-based individuals who were 40-60 years old using a cluster sampling method. The PA levels of the participants were classified as low, moderate, or high, using the International Physical Activity Questionnaire. Dyslipidemia was defined as the detection of abnormalities in lipid indicators, and 4 lipid parameters were evaluated using fasting blood samples. Multivariate logistic regression analyses were used to evaluate the associations of PA with dyslipidemia and RHR. RESULTS: A total of 10,321 participants (38.88% men) were included in this study. The percentages of individuals with high, moderate, and low PA levels were 46.5%, 43.9%, and 9.6%, respectively. In both men and women, high PA provided odds ratios of 0.88 [95% confidence interval (CI): 0.83, 0.94] for dyslipidemia and 0.82 (95% CI: 0.73, 0.92) for elevated RHR, compared to participants with low PA. CONCLUSION: Our data suggested that substantial health benefits (related to dyslipidemia and elevated RHR) occurred at higher intensity PA, with greater energy consumption, in middle-aged Chinese people, and particularly in men.

[Relationship between the polymorphisms of UGT1A6 genes and anti-tuberculosis drug induced hepatic-injury].

OBJECTIVE: To investigate the relationship between the polymorphisms of UGT1A6 genes and anti-tuberculosis drug induced hepatic-injury (ADIH). METHODS: 202 cases and 239 controls were collected and a case-control study was conducted. Information on related risk factors of tuberculosis was collected. The genotypes of UGT1A6-19T/G, UGT1A6-308C/A and UGT1A6-541A/G genetic polymorphisms were detected by polymerase chain reaction and restriction fragment length polymorphism technique (PCR-RFLP) in patients received anti-tuberculosis therapy. The Hha I, Dpn II and Nsi I enzyme were employed. Univariate and multivariate conditional logistic analyses were conducted using SPSS13.0 for windows software. RESULTS: The allele frequency of gene UGT1A6-19T/T, UGT1A6-19T/G, UGT1A6-19G/G, GT1A6-308C/C, UGT1A6-308C/A, UGT1A6-308A/A, UGT1A6-541AA, UGT1A6-541A/G and UGT1A6-541G/G in ADIH group were 51.5%, 39.6%, 8.9%, 52.0%, 40.6%, 7.4%, 57.9%, 33.7%, 8.4% and 71.1%, 25.5%, 3.3%, 79.1%, 19.2%, 1.7%, 79.5%, 19.2%, 1.3% in control group, respectively. Univariate analysis demonstrated that the frequency of UGT1A6-19T/G, UGT1A6-308C/A and UGT1A6-541A/G genotype in cases were significantly higher than that in controls (P less than 0.05). CONCLUSION: A positive association is found between UGT1A6 genotype and the occurrence of ADIH. The synergetic effect is proved on susceptibility to pulmonary tuberculosis between UGT1A6 mutant genotypes.

Association of TNF-alpha-238G/A and 308 G/A gene polymorphisms with pulmonary tuberculosis among patients with coal worker's pneumoconiosis.

OBJECTIVES: Tumor necrosis factor-alpha (TNF-alpha) may play an important role in host's immune response to mycobacterium tuberculosis (M. tuberculosis) infection. This study was to investigate the association of TNF-alpha gene polymorphism with pulmonary tuberculosis (TB) among patients with coal worker's pneumoconiosis (CWP). METHODS: A case-control study was conducted in 113 patients with confirmed CWP complicated with pulmonary TB and 113 non-TB controls with CWP. They were matched in gender, age, job, and stage of pneumoconiosis. All participants were interviewed with questionnaires and their blood specimens were collected for genetic determination with informed consent. The TNF-alpha gene polymorphism was determined with polymerase chain reaction of restriction fragment length polymorphism (PCR-RFLP). Frequency of genotypes was assessed for Hardy-Weinberg equilibrium by chi-square test or Fisher's exact probability. Factors influencing the association of individual susceptibility with pulmonary TB were evaluated with logistic regression analysis. Gene-environment interaction was evaluated by a multiplicative model with combined OR. All data were analyzed using SAS version 8.2 software. RESULTS: No significant difference in frequency of the TNF-alpha-308 genotype was found between CWP complicated with pulmonary TB and non-TB controls (chi2 = 5.44, P = 0.07). But difference in frequency of the TNF-alpha-308 A allele was identified between them (chi2 = 5.14, P = 0.02). No significant difference in frequencies of the TNF-alpha-238 genotype and allele (P = 0.23 and P = 0.09, respectively) was found between cases and controls either, with combined (GG and AA) OR of 3.96 (95% confidence interval of 1.30-12.09) at the -308 locus of the TNF-alpha gene, as compared to combination of the TNF-alpha-238 GG and TNF-alpha-308 GG genotypes. Multivariate-adjusted odds ratio of the TNF-alpha-238 GG and TNF-alpha-308 GA genotypes was 1.98 (95% CI of 1.06-3.71) for risk for pulmonary TB in patients with CWP. There was a synergic interaction between the TNF-alpha-308 GG genotype and body mass index (OR = 4.92), as well as an interaction between the TNF-alpha-308 GG genotype and history of BCG immunization or history of TB exposure. And, the interaction of the TNF-alpha-238 GG genotype and history of BCG immunization or TB exposure with risk for pulmonary TB in them was also indicated. CONCLUSIONS: TNF-alpha-308 A allele is associated with an elevated risk for pulmonary TB, whereas TNF-alpha-238 A allele was otherwise.

[The effect of GST M1 and GST T1 gene mutations on anti-tuberculous drug induced hepatic injury].

OBJECTIVE: To study the relationship between the polymorphisms of GST M1 and GST T1 genes and anti-tuberculous drug induced hepatic injury (ADIH). METHODS: A 1:1 matched case-control study was carried out. One hundred and six patients [age (49 +/- 19) years, 73 men and 33 women] fulfilling the criteria of ADIH during the 3 month follow-up after the initiation of anti-tuberculous therapy were included, while 106 cases [age (49 +/- 19) years, 73 men and 33 women] without any hepatic injury served as the controls. The genotypes of GST M1 and GST T1 genetic polymorphisms were detected by polymerase chain reaction (PCR) in patients who received anti-tuberculosis therapy. Using SPSS 11.5 for windows software, univariate and multivariate conditional logistic analyses were conducted for studying the relationship between the polymorphisms and ADIH. RESULTS: Univariate analysis demonstrated that the "null" genotype of GST M1 gene occurred in 50 (47.2%) of the cases, more frequent than in the controls [25 (23.6%)], with a crude OR (95%CI) 2.786 (1.513 - 5.130). No significant association was observed between ADIH and GST T1 polymorphism. Among the risk factors analyzed, body mass index and alcohol drinking were significantly associated with ADIH. In the multivariate analysis, a significant association between ADIH and the "null" genotype of GST M1 existed, after adjusting for body mass index and drinking status, adjusted OR (95%CI) being 3.022 (1.540 - 5.926). Again, no significant association was observed between GST T1 polymorphism and ADIH. CONCLUSION: This study demonstrated that patients carrying GST M1-"null" genotype may be susceptible to ADIH.

[Meta-analysis of relationship of vitamin D receptor gene polymorphism and tuberculosis susceptibility].

OBJECTIVE: To provide a quantitative summary in estimating the association between polymorphisms of 2 loci of FokI and TaqI in vitamin D receptor gene and susceptibility to tuberculosis by means of meta-analysis. METHODS: Databases CNKI, CBM, WanFang DATA, MEDLINE and PubMed were searched using "VDR", "polymorphisms" or "alleles", in combination with "tuberculosis", and a manual search of citations from relevant original studies and literature was also performed between January 1980 and November 2007. RevMan 4.2 was applied in the process of analyzing the data of 14 case-control studies. RESULTS: The summary ORs for studies with polymorphisms of FokI, TaqI loci of the VDR gene were 1.12 (95%CI: 0.98 - 1.28) in Ff vs FF, 1.66 (95%CI: 1.12 - 2.46) in ff vs FF, 0.97 (95%CI: 0.82 - 1.14) in Tt vs TT, 1.27 (95%CI: 0.96 - 1.69) in tt vs TT. The fail-safe number was 109.69 for FokI and 75.24 for TaqI. The analysis result was reliable. CONCLUSION: Polymorphisms at FokI loci (VDR-ff) showed statistically significant association between the VDR variants and susceptibility to tuberculosis, and variant in the TaqI locus failed to show statistically significant association.

[Study on the association of INT4 and 3'UTR polymorphism of natural-resistance-associated macrophage protein 1 gene with susceptibility to pulmonary tuberculosis].

OBJECTIVE: To investigate the association between natural-resistance-associated macrophage protein 1 (NRAMP1) gene polymorphisms and susceptibility to pulmonary tuberculosis (TB) in Han nationality from Northern part of China. METHODS: A 1:1 matched case-control study was adopted. Polymerase chain reaction and restriction fragment length polymorphism technique were used to type the two NRAMP1 polymorphisms: INT4 and 3'UTR. Information on environmental-related risk factors and pathological changes of tuberculosis was collected using a pre-tested standard questionnaire. Univariate and multivariate conditional logistic analyses were conducted using SPSS for window software. RESULTS: A sample consisting 124 pairs of cases and controls was studied. Univariate analysis demonstrated that the 3'UTR TGTG+/del genotype occurred more frequently in the cases than in the controls, with crude OR (95% CI) being 2.923 (1.557 - 5.487). No significant association was observed between TB and INT4 polymorphism. In multivariate analysis, associations of TB and 3'UTR TGTG+/del genotype remained, after adjusting for scar of bacillus Calmette-Guérin vaccine, marriage status, body mass index and exposure history. Adjusted OR (95% CI) was 2.955 (1.369 - 6.381). Again, no significant association between INT4 polymorphism and TB was found. Among different INT4 genotypes, the pathological characters of pulmonary tuberculosis were also found different (chi(2) = 9.634, P < 0.05). CONCLUSION: Polymorphism of 3'UTR locus in NRAMP1 gene might affect their susceptibility to TB in Han nationality living in the northern part of China, and polymorphism of INT4 might affect the pathological characters of tuberculosis.

[A study of chronic hepatitis B infection superinfected with hepatitis E infection].

OBJECTIVES: To compare the influence of hepatitis E virus (HEV) infection on the replication of hepatitis B virus (HBV) by observing clinical features, the relationship between the number of HBV DNA copies in serum, the degree of hepatic function impairments and prognosis of chronic hepatitis B patients with hepatitis E superinfection. METHODS: One hundred and fifteen chronic hepatitis B (CHB) patients and 115 CHB patients with hepatitis E (HE) superinfection were studied and compared. 74 liver tissue biopsy samples of the CHB and 51 of the CHB-HE sufferers were obtained. HBsAg, anti-HBs, HBeAg, anti-HBe, anti-HBc, anti-HBc-IgG, anti-HBc-IgM, HBV DNA and anti-HEVIgM were detected respectively by enzyme linked immunosorbent assay and polymerase chain reaction. RESULTS: The number of HBV DNA copies in sera in the CHB-HE group and the severity of the clinical features were significantly higher than those in the CHB group. The former group had a poorer prognosis with a 49.6% occurrence rate of severe hepatitis and a 25.2% death rate while in the latter group the corresponding rates were just 4.4% and 1.7%. CONCLUSION: Re-infection with HEV, in those CHB patients, severely damaged their hepatic functions and increased their mortality; the older the patient and the higher the level of HBV DNA, the poorer the prognosis.

[Study on mannose-binding protein gene polymorphisms and susceptibility to pulmonary tuberculosis].

OBJECTIVE: To explore the association between the genetic polymorphisms of mannose-binding protein (MBP) alleles and susceptibility to pulmonary tuberculosis. METHODS: 125 pulmonary tuberculosis cases and 198 healthy controls were collected. A case-control study was conducted. Three structural gene mutations in exon 1 of MBP gene (codon 52, codon 54 and codon 57) were studied. Polymerase chain reaction with sequence-specific primers (PCR-SSP) was carried out in the polymorphism in MBP alleles. Information on related risk factors of tuberculosis was collected, using a pre-tested questionnaire. Univariate and multivariate logistic analyses were conducted with SPSS software package. RESULTS: The frequencies of mutant heterozygote or homozygote of MBP-52, 54, 57 were 8.0%, 7.2% and 0.4% for cases and 5.3%, 4.3%, 0.5% for controls, respectively. The distribution of mutant genotypes of MBP did not show significant difference between tuberculosis patients and control by Mantel-Haenszel chi2 on sex. The univariate analysis demonstrated that body mass index, marital status, vaccinal vestige, bacillus of Calmette-Guerin vaccine immunization, contacted with pulmonary tuberculosis patients, familial traits were the risk factors of pulmonary tuberculosis. After adjusting those related environmental factors in the multivariate logistic analyses, the total MBP (MBP-52, MBP-54 and MBP-57) and MBP-52 heterozygote genotypes were significantly overrepresented in cases, with adjusted OR (95% CI) being 2.182 (1.058-4.499) and 2.574 (1.028-6.446). CONCLUSION: Total MBP and MBP-52 mutant genotypes might be associated with the susceptibility to pulmonary tuberculosis.

[Cloning and characterization of a full-length HIV-1 genome of a prevalent subtype B-Thai strain in Henan Province].

OBJECTIVE: To clone, identify and phylogenetically characterize a clade B-Thai HIV isolate representing the most prevalent virus in Henan province. METHODS: Peripheral blood mononuclear cells (PBMCs) from an HIV-1 infected patient in Henan Province were separated, and co-cultivated with phytohemagglutinin-stimulated healthy donor PBMCs. Proviral DNA was extracted from productively infected PBMCs. The full-length HIV-1 genome was amplified by using the LA Tag long template PCR system. Primers were positioned in conserved regions within the HIV-1 long terminal repeats. Purified PCR products were T-A ligated into a pWSK29-T vector(CNHN 24 clone). Three recombinant clones containing virtually full-length HIV-1 genome were identified by PCR. The full-length genome was sequenced by using the primer-walking approach. Nucleotide sequence similarities were calculated by the local-homology algorithm. Phylogenetic trees of gag, pol and env reading frames were constructed using the Phylip software. RESULTS: HIV-1 C3V4 sequences indicate that the epidemic in this area was B-Thai subtype. V3 loop multiple amino acid sequence alignments showed amino acid alterations at nine positions. The 9,010 bp genomic sequence derived from isolate CNHN 24 contained all known structural and regulatory genes of an HIV-1 genome. No major deletions, insertions, or rearrangements were found. The highest homologies of the gag, pol, vpr, and vif reading frames to the corresponding clade B-Thai RL 42 sequences were 95.42%-97.08%. Phylogenetic trees showed the closest relationship of CNHN 24 and RL 42. CONCLUSION: The cloning and characterization of a virtually full-length HIV-1 B-Thai subtype in central China was completed in our laboratory. The data should be helpful to future studies on the genetic diversity of HIV-1.

[Study on factors associated with heterosexual-transmission of human immunodeficiency virus in central China].

OBJECTIVE: To investigate the factors of the human immunodeficiency virus (HIV) associated with sexual-transmission in central China. METHODS: (1) Cross-sectional study: couples that one was HIV positive were selected in Henan and Hebei province of China. The couples must be 20 - 50 years old with normal function on sexual intercourse. Cordant couples that subsequently infected partners were at risk of infection solely through sexual contact with the HIV-seropositive partner and the discordant couples that the seronegative partners were at risk of infection solely through sexual contact with the HIV-seropositive partner, were selected. Plasma viral load, CD4 cell count were tested. (2) Case-control study was used to compare 7 sexual transmitted cases and 56 nontransmitted controls with respect to the frequency of sexual intercourse, plasma viral load and CD4 cell count. RESULTS: (1) A total of 87 couples that at least one partner was HIV positive were recruited include 56 discordant couples and 7 cordant couples with whom sexual transmission had happened. The rate of sexual transmission was 11.1% among those at the risk of sexual transmission. (2) Of the discordant couples, male positive rate 25%, female positive was 75%. (3) The risk for transmission was higher in those couples with the frequency of unprotected vaginal sexual intercourse (> or = 4 times per month) than the reference group (< 4 times per month) (Fisher's exact test, P = 0.047, OR = 8.0). Median plasma viral load was significantly higher in the antecedent infected partners of cordant couples than the positive partner of discordant couples (378,285.71 vs 136,578.57 copies/ml, t = 3.591, P < 0.01). The odds ratio was 22.0 for plasma viral load > or = 100,000 copies/ml compared with the reference group of < 100 000 copies/ml (Fisher's exact test, P = 0.016). The CD4 cell count and CD4/CD8 of the transmitted group were significantly lower than that of the nontransmitted (t = 2.767, P < 0.05; t = 6.06, P < 0.05). CONCLUSIONS: The frequencies of heterosexual-transmission in central China were relatively low. The risk of heterosexual transmission was related to the frequency of sexual intercourse. Higher plasma viral load and lower CD4 count was strongly correlated with high risk of heterosexual transmission.