A Three Year Retrospective Study on Seroprevalence of Syphilis among Pregnant Women at Gondar University Teaching Hospital,Ethiopia

Background

Sexually transmitted infections (STIs) are a serious public health problem in low income countries, including Ethiopia. Syphilis caused by Treponema pallidum remains a major cause of reproductive morbidity and poor pregnancy outcomes in low income countries. Stillbirth, perinatal death, serious neonatal infection and low-birth weight babies are common among seropositive mothers.

Objective

To assess the seroprevalence of syphilis and risk factor correlates of this infection at Gondar University Teaching Hospital, Ethiopia.

Methods

The study was done on 2385 pregnant women attending the antenatal care clinic (ANC) from January 2009 to December 2011. Data was abstracted from the antenatal care clinic medical database. Chi-square test was used, using SPSS version 16 and significance level was chosen at 0.05 level with a two-tailed test.

Results

Of the total, 69(2. 9%) of pregnant women were confirmed as seropositive for syphilis. Pregnant women with an age group of 21–25 years of old were the most seropositive (3.4%), followed by 26–30 years of old (3.1%). The prevalence of syphilis infection was 3.2% in urban and 2.2% in rural pregnant women. Relatively high prevalence of syphilis infection were identified among students (4.2%) followed by governmental employees (3.8%).

Conclusion

The seroprevalence of syphilis among pregnant women attending ANC is declining. However, syphilis is more prevalent in the young and urban pregnant women. Emphasis on education to young people on STI risk behavioral change and partner follow up and notification for exposure to syphilis and treatment should be given.     

Mycobacterium-Specific γ9δ2 T Cells Mediate Both Pathogen-Inhibitory and CD40 Ligand-Dependent Antigen Presentation Effects Important for Tuberculosis Immunity

Numerous pathogens, including Mycobacterium tuberculosis, can activate human γ₉δ₂ T cells to proliferate and express effector mechanisms. γ₉δ₂ T cells can directly inhibit the growth of intracellular mycobacteria and may also act as antigen-presenting cells (APC). Despite evidence for γδ T cells having the capacity to function as APC, the mechanisms involved and importance of these effects on overall tuberculosis (TB) immunity are unknown. We prepared M. tuberculosis-specific γ₉δ₂ T cell lines to study their direct protective effects and APC functions for M. tuberculosis-specific αβ T cells. The direct inhibitory effects on intracellular mycobacteria were measured, and the enhancing effects on proliferative and effector responses of αβ T cells assessed. Furthermore, the importance of cell-to-cell contact and soluble products for γ₉δ₂ T cell effector responses and APC functions were investigated. We demonstrate, in addition to direct inhibitory effects on intracellular mycobacteria, the following: (i) γ₉δ₂ T cells enhance the expansion of M. tuberculosis-specific αβ T cells and increase the ability of αβ T cells to inhibit intracellular mycobacteria; (ii) although soluble mediators are critical for the direct inhibitory effects of γ₉δ₂ T cells, their APC functions do not require soluble mediators; (iii) the APC functions of γ₉δ₂ T cells involve cell-to-cell contact that is dependent on CD40-CD40 ligand (CD40L) interactions; and (iv) fully activated CD4⁺ αβ T cells and γ₉δ₂ T cells provide similar immune enhancing/APC functions for M. tuberculosis-specific T cells. These effector and helper effects of γ₉δ₂ T cells further indicate that these T cells should be considered important new targets for new TB vaccines.     

Comparison of the Cytomegalovirus (CMV) Enzyme-Linked Immunosorbent Spot and CMV QuantiFERON Cell-Mediated Immune Assays in CMV-Seropositive and -Seronegative Pregnant and Nonpregnant Women

Human cytomegalovirus (CMV) infection is a major cause of congenital infection leading to birth defects and sensorineural anomalies, including deafness. Recently, cell-mediated immunity (CMI) in pregnant women has been shown to correlate with congenital CMV transmission. In this study, two interferon gamma release assays (IGRA), the CMV enzyme-linked immunosorbent spot (ELISPOT) and CMV QuantiFERON assays, detecting CMV-specific CMI were compared. These assays were performed for 80 CMV-infected (57 primarily and 23 nonprimarily) pregnant women and 115 controls, including 89 healthy CMV-seropositive pregnant women without active CMV infection, 15 CMV-seronegative pregnant women, and 11 seropositive or seronegative nonpregnant women. Statistical tests, including frequency distribution analysis, nonparametric Kruskal-Wallis equality-of-populations rank test, Wilcoxon rank sum test for equality on unmatched data, and lowess smoothing local regression, were employed to determine statistical differences between groups and correlation between the assays. The CMV ELISPOT and CMV QuantiFERON assay data were not normally distributed and did not display equal variance. The CMV ELISPOT but not CMV QuantiFERON assay displayed significant higher values for primarily CMV-infected women than for the healthy seropositive pregnant and nonpregnant groups (P = 0.0057 and 0.0379, respectively) and those with nonprimary infections (P = 0.0104). The lowess local regression model comparing the assays on an individual basis showed a value bandwidth of 0.8. Both assays were highly accurate in discriminating CMV-seronegative pregnant women. The CMV ELISPOT assay was more effective than CMV-QuantiFERON in differentiating primary from the nonprimary infections. A substantial degree of variability exists between CMV ELISPOT and CMV QuantiFERON assay results for CMV-seropositive pregnant women.     

Avidity of immunoglobulin G directed against human cytomegalovirus during primary and secondary infections in immunocompetent and immunocompromised subjects.

Diagnosis of primary human cytomegalovirus (HCMV) infection is accomplished exclusively by serologic testing. Among the possible methods, the determination of immunoglobulin G (IgG) avidity is one of the least explored. In this work, we used a commercially available kit to test anti-HCMV IgG avidity in 336 serum samples from pregnant women and transplant recipients undergoing virologically proven HCMV primary or nonprimary infections and from latently infected blood donors. Our results demonstrate that the anti-HCMV IgG avidity test differentiates primary from nonprimary HCMV infections in both pregnant women and solid organ transplant recipients. In fact, 88.6% of primary infections and no secondary infections showed low-avidity IgG to HCMV. In particular, low IgG avidity is a marker of primary infection for 18 to 20 weeks after onset of symptoms in both immunocompromised and immunocompetent subjects.     

Primary drug resistance to anti-tuberculosis drugs in major towns of Amhara region, Ethiopia

Drug resistance is a major obstacle to effective TB control program performance. In this study, we assessed the prevalence of primary drug resistance in Mycobacterium tuberculosis (Mtb) isolates in Amhara Region, Ethiopia. A total of 112 Mtb isolates from cases with newly diagnosed pulmonary TB were subjected to drug susceptibility testing (DST) in a cross-sectional study. Isolates were tested for sensitivity to isoniazid, rifampicin, ethambutol, and streptomycin using the MGIT 960 protocol. A total of 93 Mtb isolates yielded valid DST results and 28 (30.1%) were resistant to one or more of first line anti-TB drugs. One isolate (1.0%) was multi-drug resistant (MDR), five (5.4%) were classified as poly-resistant and 22 showed single drug resistance to either streptomycin (n = 19) or isoniazid (n = 3). Isolates from HIV-positive patients were more likely to be resistant to at least one of the four anti-TB drugs compared with HIV-negative individuals (odds ratio 2.76, 95% confidence interval 1.06-7.22; p = 0.03). The study showed a high prevalence of primary drug resistance. Even though the prevalence of MDR was low, conditions that can contribute to the development of MDR are increasing. Therefore, regular monitoring of drug resistance and enhanced implementation of TB/HIV collaborative activities in the study region are imperative.     

Comparison of Cytomegalovirus (CMV) Enzyme-Linked Immunosorbent Spot and CMV Quantiferon Gamma Interferon-Releasing Assays in Assessing Risk of CMV Infection in Kidney Transplant Recipients

Assessing cytomegalovirus (CMV)-specific cell-mediated immunity (CMI) represents an appealing strategy for identifying transplant recipients at risk of infection. In this study, we compared two gamma interferon-releasing assays (IGRAs), Quantiferon-CMV and CMV enzyme-linked immunosorbent spot (ELISPOT), to determine the ability of each test to predict protective CMV-specific T-cell responses. Two hundred twenty-one Quantiferon-CMV and ELISPOT tests were conducted on 120 adult kidney transplant recipients (KTRs), including 100 CMV-seropositive transplant recipients (R⁺) and 20 CMV-seronegative transplant recipients of a CMV-positive donor (D⁺/R⁻). As a control cohort, 39 healthy adult subjects (including 33 CMV-seropositive and 6 CMV-seronegative subjects) were enrolled. CMV IgG serology was used as a reference for both tests. In the CMV-seropositive individuals, the ELISPOT and Quantiferon-CMV assays provided 46% concordance with the serology, 12% discordance, 18% disagreement between ELISPOT or Quantiferon-CMV and the serology, and 24% gray areas when one or both tests resulted in weak positives. None of the CMV-seronegative subjects showed detectable responses in the ELISPOT or the Quantiferon-CMV test. In transplant recipients, both the ELISPOT and Quantiferon-CMV assays positively correlated with each other and negatively correlated with CMV DNAemia in a significant way (P < 0.05). During the antiviral prophylaxis, all 20 D⁺/R⁻ KTRs we examined displayed undetectable Quantiferon-CMV and ELISPOT results, and there was no evidence of CMV seroconversion. The receiving operator curve (ROC) statistical analysis revealed similar specificities and sensitivities in predicting detectable viremia (areas under the curve [AUC], 0.66 and 0.62 for Quantiferon-CMV and ELISPOT, respectively). ELISPOT and Quantiferon-CMV values of >150 spots/200,000 peripheral blood mononuclear cells (PBMCs) and >1 to 6 IU gamma interferon (IFN-γ) were associated with protection from CMV infection (odds ratios [OR], 5 and 8.75, respectively). In transplant recipients, the two tests displayed similar abilities for predicting CMV infection. Both the ELISPOT and Quantiferon-CMV assays require several ameliorations to avoid false-negative results.