Oat silage in milk production systems in the Western Cape

Thesis (MScAgric)--Stellenbosch University, 2002.ENGLISH ABSTRACT: The objectives of this study were to determine the effects of supplementing oat silage (OS) with lucerne (LH) and oat hay (OH) on the production performance of lactating Jersey cows, as well as comparing the ruminal degradability of LH, OH and OS III Holstein and Jersey cows receiving a high forage diet and a high concentrate diet. In the first trial, five diets containing different combinations of OS and LH together with concentrate mixtures providing 26, 23, 20, 17 and 14% crude protein (CP) were fed to lactating Jersey cows. Lucerne hay was fed at 0, 2, 4, 6, and 8 kg DM/day while OS was fed ad libitum. Cows receiving only OS as a forage source had a lower (P<0.05) dry matter (DM) intake and produced less milk protein (P<0.05). Milk and fat yields as well as milk urea nitrogen (MUN) levels did not differ (P>0.05) between treatments. In the second trial, OS was fed with OH and a concentrate mixture containing 26% CP to lactating Jersey cows. Oat hay was fed at 0, 2, 4, 6, and 8 kg DMiday while OS was fed ad libitum. Cows that received OS together with 4 and 6kg OH, respectively had higher (PO.05) between treatments. The ruminal degradability of LH, OH and OS in Holstein and Jersey cows receiving (i) a high forage and (ii) a high concentrate diet was determined. The two breeds were also compared in terms of rumen pH levels, volatile fatty acids (VF A) and rumen ammonia nitrogen (NH3-N) concentrations as affected by time after feeding. The ruminal degradability of freeze dried (FD), oven dried (OD) and fresh oat silage (FS) in Jersey cows receiving a high forage diet was also determined. The ruminal DM, CP and NDF degradability of LH was higher (P<O.05) than that of OH and OS in both Holstein and Jersey cows when they were fed either a high forage or a high concentrate diet. When cows were fed a high forage diet, the effective DM degradability of OS was higher (P<O.05) in Holsteins although the CP degradation rates of LH and OH were higher (P<O.05) in Jerseys. When they were fed a high concentrate diet, Jerseys had higher (P<O.05) effective DM and NDF degradabilities and higher (P<O.05) DM and NDF degradation rates in LH while Holsteins had higher (P<O.05) effective CP degradability levels than Jerseys in OS. After feeding a high forage diet, pH levels declined while VFA and NH3-N concentrations increased (P<O.05) in both breeds. Jerseys had higher rumen pH, lower (P<O.05) VFA and lower NH3-N concentrations than Holsteins throughout the study. When cows were fed a high concentrate diet, Jerseys had higher (P<O.05) pH than Holsteins. A post-feeding decline (P<O.05) in pH was observed in both breeds. Fresh oat silage had a lower (P<O.05) effective degradability and degradation rates for DM, CP and NDF in comparison to FD and OD oat silage. The DM, CP and NDF degradation rates, as well as effective NDF degradability were higher (P<O.05) for FD silage, but effective DM and CP degradabilities were higher (P<O.05) for OD oat silage. It was concluded that on an oat silage diet, lactating Jersey cows should receive a minimum of 2kg LH or 4 to 6kg oat hay together with ad libitum OS to improve DM intake. When cows were fed a high concentrate diet, the ruminal degradability appeared to be superior in Jerseys than Holsteins. Jerseys also had higher rumen pH levels lower VFA and NH3-N concentrations than Holsteins. Feeding interval affects the rumen environment, pH declines while VF A and NH3-N concentrations increased.AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die effek van die aanvulling van hawerkuilvoer met lusemhooi (LH) en hawerhooi (HH) op die melkproduksie van Jerseykoeie te bepaal. Hiermee saam is die rumen degradeerbaarheid van hawerkuilvoer en lusemhooi ondersoek in Jersey en Holsteinkoeie wat 'n hoe-ruvoer en 'n hoe-kragvoer gebaseerde dieet ontvang het. In die eerste proef is vyf diete met verskillende peile van hawerkuilvoer en lusernhooi saam met kragvoere van verskillende ruproteienpeile (26, 23, 20, 17 en 14% RP) aan 10 lakterende Jerseykoeie gevoer. Hawerkuilvoer is ad libitum voorsien en lusemhooi is teen vlakke van 0, 2, 4,6 en Skg droemateriaal (DM) per dag gevoer. Die DM-inname en melkproteienproduksie van koeie wat hawerkuilvoer as die enigste ruvoerbron ontvang het, was laer (P<0.05) as ander ruvoerkombinasies. Die melk- en vetproduksie, asook melk-ureumstikstofpeile het nie tussen behandelings verskil nie (P>0.05). In die tweede proef is hawerkuilvoer saam met hawerhooi (soortgelyk as Proef 1) gevoer. Die kragvoerkomponent van al die ruvoerkombinasies het 26% RP bevat. Die koeie wat hawerkuilvoer en 4 of 6kg hawerhooi as ruvoere ontvang het, het hoer (P<O.05) droemateriaalinnames gehad. Melk, vet en proteienproduksie asook melk-ureumstikstofpeile het nie tussen ruvoerkombinasies verskil nie (P>O.05). Die rumendegradeerbaarheid van lusemhooi, hawerhooi en hawerkuilvoer is bepaal in Holstein en Jerseykoeie wat (i) 'n hoe ruvoer- en (ii) 'n hoe kragvoerdieet ontvang het. Die rumen pH, vlugtige vetsuur en rumen-ammoniakkonsentrasies, soos beinvloed deur tyd na voeding, is ook tussen rasse vergelyk. Die rumendegradeerbaarheid van vars, oondgedroogde en vriesgedroogde hawerkuilvoer is ook bepaal. Die rumen DM, RP en NDF degradeerbaarhede van lusemhooi was hoer (P<O.05) as by hawerhooi en hawerkuilvoer in beide Holstein en Jerseykoeie wat (i) 'n hoe ruvoer- en (ii) 'n hoe kragvoerdieet ontvang het. Op 'n hoe ruvoerdieet, was effektiewe DM degradeerbaarheid van hawerkuilvoer by Holsteins hoer (P<O.05) as by Jerseys. Jerseykoeie het egter 'n hoer (P<O.05) RP degradeerbaarheidstempo van lusemhooi en hawerhooi gehad. Jerseykoeie op 'n hoe kragvoerdieet, het hoer (P<O.05) effektiewe DM en NDF degradeerbaarhede getoon. Hulle het egter 'n laer (P<O.05) effektiewe ruprotein (RP) degradeerbaarheid by hawerkuilvoer as Friese gehad. Jerseykoeie op lusemhooi het ook 'n hoer (P<O.05) DM en NDF degradeerbaarheidstempo getoon. Jerseykoeie wat 'n hoe ruvoerdieet ontvang het, het 'n hoer (P<O.05) rumen- pH en laer (P<O.05) vlugtige vetsuur- en rumen-ammoniak konsentrasies as Holsteinkoeie gehad. Jerseykoeie wat 'n hoe kragvoerdieet ontvang het, het ook 'n hoer (P<O.05) rumen- pH as Holsteinkoeie gehad. By al die koeie is gevind dat rumen- pH na voeding afgeneem het (P<O.05). Vlugtige vetsuur- en rumen-ammoniakkonsentrasies was laag voor voeding en het daama toegeneem (P<O.05). Vars hawerkuilvoer het laer (P<O.05) effektiewe DM, RP en NDF degradeerbaarhede en degradeerbaarheidstempo's as oond- en vriesgedroogde hawerkuilvoer gehad. Die vriesgedroogde kuilvoer het hoer (P<O.05) DM, RP en NDF degradeerbaarheidstempo's sowel as effektiewe NDF degradeerbaarhede gehad. Oondgedroogde kuilvoer het daarinteen hoer (P<O.05) effektiewe DM en RP degradeerbaarhede gehad. Die gevolgtrekking is gemaak dat lakterende Jerseykoeie ten minste 2kg lusemhooi of 4- 6kg hawerhooi per dag moet ontvang wanneer hulle hawerkuilvoer as ruvoerbron ontvang. Op 'n hoe kragvoerdieet, het dit gebleik dat die rumendegradeerbaarheid van vesel by Jerseys beter is as by Holsteins. Die rumen- pH is hoog voor voeding, maar dit neem af nadat die koeie gevreet het. Die rumen- pH van Jerseys was hoer as by Holsteins. Die vlugtige vetsure en rumen-ammoniakkonsentrasies blyk laag te wees voor voeding en neem daama toe. Konsentrasies was hoer by Holstein as by Jerseys

Differential Effect of Viable Versus Necrotic Neutrophils on Mycobacterium tuberculosis Growth and Cytokine Induction in Whole Blood.

Neutrophils exert both positive and negative influences on the host response to tuberculosis, but the mechanisms by which these differential effects are mediated are unknown. We studied the impact of live and dead neutrophils on the control of Mycobacterium tuberculosis using a whole blood bioluminescence-based assay, and assayed supernatant cytokine concentrations using Luminex™ technology and ELISA. CD15+ granulocyte depletion from blood prior to infection with M. tuberculosis-lux impaired control of mycobacteria by 96 h, with a greater effect than depletion of CD4+, CD8+, or CD14+ cells (p < 0.001). Augmentation of blood with viable granulocytes significantly improved control of mycobacteria by 96 h (p = 0.001), but augmentation with necrotic granulocytes had the opposite effect (p = 0.01). Both augmentations decreased supernatant concentrations of tumor necrosis factor and interleukin (IL)-12 p40/p70, but necrotic granulocyte augmentation also increased concentrations of IL-10, G-CSF, GM-CSF, and CCL2. Necrotic neutrophil augmentation reduced phagocytosis of FITC-labeled M. bovis BCG by all phagocytes, whereas viable neutrophil augmentation specifically reduced early uptake by CD14+ cells. The immunosuppressive effect of dead neutrophils required necrotic debris rather than supernatant. We conclude that viable neutrophils enhance control of M. tuberculosis in blood, but necrotic neutrophils have the opposite effect-the latter associated with induction of IL-10, growth factors, and chemoattractants. Our findings suggest a mechanism by which necrotic neutrophils may exert detrimental effects on the host response in active tuberculosis.Wellcome Trust (087754 to DL, 097684 to NB, 104803 and 203135 to RW, FC00110218 to Francis Crick Institute); Cancer Research UK (FC00110218 to Francis Crick Institute); Medical Research Council UK (FC00110218 to Francis Crick Institute); European Union (FP7-HEALTH-F3-2012-305578 to RW); National Research Foundation of South Africa (96841 to RW) and Barts Charity (MGU0292)

Effects of tuberculosis and/or HIV-1 infection on COVID-19 presentation and immune response in Africa

Few studies from Africa have described the clinical impact of co-infections on SARS-CoV-2 infection. Here, we investigate the presentation and outcome of SARS-CoV-2 infection in an African setting of high HIV-1 and tuberculosis prevalence by an observational case cohort of SARS-CoV-2 patients. A comparator group of non SARS-CoV-2 participants is included. The study includes 104 adults with SARS-CoV-2 infection of whom 29.8% are HIV-1 co-infected. Two or more co-morbidities are present in 57.7% of participants, including HIV-1 (30%) and active tuberculosis (14%). Amongst patients dually infected by tuberculosis and SARS-CoV-2, clinical features can be typical of either SARS-CoV-2 or tuberculosis: lymphopenia is exacerbated, and some markers of inflammation (D-dimer and ferritin) are further elevated (p < 0.05). Amongst HIV-1 co-infected participants those with low CD4 percentage strata exhibit reduced total, but not neutralising, anti-SARS-CoV-2 antibodies. SARS-CoV-2 specific CD8 T cell responses are present in 35.8% participants overall but undetectable in combined HIV-1 and tuberculosis. Death occurred in 30/104 (29%) of all COVID-19 patients and in 6/15 (40%) of patients with coincident SARS-CoV-2 and tuberculosis. This shows that in a high incidence setting, tuberculosis is a common co-morbidity in patients admitted to hospital with COVID-19. The immune response to SARS-CoV-2 is adversely affected by co-existent HIV-1 and tuberculosis

Utility of interferon-γ ELISPOT assay responses in highly tuberculosis-exposed patients with advanced HIV infection in South Africa

BACKGROUND: Interferon-gamma (IFN-gamma) ELISPOT assays incorporating Mycobacterium tuberculosis-specific antigens are useful in the diagnosis of tuberculosis (TB) or latent infection. However, their utility in patients with advanced HIV is unknown. We studied determinants of ELISPOT responses among patients with advanced HIV infection (but without active TB) living in a South African community with very high TB notification rates. METHODS: IFN-gamma responses to ESAT-6 and CFP-10 in overnight ELISPOT assays and in 7-day whole blood assays (WBA) were compared in HIV-infected patients (HIV+, n = 40) and healthy HIV-negative controls (HIV-, n = 30) without active TB. Tuberculin skin tests (TSTs) were also done. RESULTS: ELISPOTs, WBAs and TSTs were each positive in >70% of HIV- controls, reflecting very high community exposure to M. tuberculosis. Among HIV+ patients, quantitative WBA responses and TSTs (but not the proportion of positive ELISPOT responses) were significantly impaired in those with CD4 cell counts <100 cells/mul compared to those with higher counts. In contrast, ELISPOT responses (but not WBA or TST) were strongly related to history of TB treatment; a much lower proportion of HIV+ patients who had recently completed treatment for TB (n = 19) had positive responses compared to those who had not been treated (11% versus 62%, respectively; P < 0.001). Multivariate analysis confirmed that ELISPOT responses had a strong inverse association with a history of recent TB treatment (adjusted OR = 0.06, 95%CI = 0.10-0.40, P < 0.01) and that they were independent of CD4 cell count and viral load. Among HIV+ individuals who had not received TB treatment both the magnitude and proportion of positive ELISPOT responses (but not TST or WBA) were similar to those of HIV-negative controls. CONCLUSION: The proportion of positive ELISPOT responses in patients with advanced HIV infection was independent of CD4 cell count but had a strong inverse association with history of TB treatment. This concurs with the previously documented low TB risk among patients in this cohort with a history of recent treatment for TB. These data suggest ELISPOT assays may be useful for patient assessment and as an immuno-epidemiological research tool among patients with advanced HIV and warrant larger scale prospective evaluation

Oat silage in milk production systems in the Western Cape

Thesis (MScAgric)--Stellenbosch University, 2002.ENGLISH ABSTRACT: The objectives of this study were to determine the effects of supplementing oat silage (OS) with lucerne (LH) and oat hay (OH) on the production performance of lactating Jersey cows, as well as comparing the ruminal degradability of LH, OH and OS III Holstein and Jersey cows receiving a high forage diet and a high concentrate diet. In the first trial, five diets containing different combinations of OS and LH together with concentrate mixtures providing 26, 23, 20, 17 and 14% crude protein (CP) were fed to lactating Jersey cows. Lucerne hay was fed at 0, 2, 4, 6, and 8 kg DM/day while OS was fed ad libitum. Cows receiving only OS as a forage source had a lower (P<0.05) dry matter (DM) intake and produced less milk protein (P<0.05). Milk and fat yields as well as milk urea nitrogen (MUN) levels did not differ (P>0.05) between treatments. In the second trial, OS was fed with OH and a concentrate mixture containing 26% CP to lactating Jersey cows. Oat hay was fed at 0, 2, 4, 6, and 8 kg DMiday while OS was fed ad libitum. Cows that received OS together with 4 and 6kg OH, respectively had higher (PO.05) between treatments. The ruminal degradability of LH, OH and OS in Holstein and Jersey cows receiving (i) a high forage and (ii) a high concentrate diet was determined. The two breeds were also compared in terms of rumen pH levels, volatile fatty acids (VF A) and rumen ammonia nitrogen (NH3-N) concentrations as affected by time after feeding. The ruminal degradability of freeze dried (FD), oven dried (OD) and fresh oat silage (FS) in Jersey cows receiving a high forage diet was also determined. The ruminal DM, CP and NDF degradability of LH was higher (P<O.05) than that of OH and OS in both Holstein and Jersey cows when they were fed either a high forage or a high concentrate diet. When cows were fed a high forage diet, the effective DM degradability of OS was higher (P<O.05) in Holsteins although the CP degradation rates of LH and OH were higher (P<O.05) in Jerseys. When they were fed a high concentrate diet, Jerseys had higher (P<O.05) effective DM and NDF degradabilities and higher (P<O.05) DM and NDF degradation rates in LH while Holsteins had higher (P<O.05) effective CP degradability levels than Jerseys in OS. After feeding a high forage diet, pH levels declined while VFA and NH3-N concentrations increased (P<O.05) in both breeds. Jerseys had higher rumen pH, lower (P<O.05) VFA and lower NH3-N concentrations than Holsteins throughout the study. When cows were fed a high concentrate diet, Jerseys had higher (P<O.05) pH than Holsteins. A post-feeding decline (P<O.05) in pH was observed in both breeds. Fresh oat silage had a lower (P<O.05) effective degradability and degradation rates for DM, CP and NDF in comparison to FD and OD oat silage. The DM, CP and NDF degradation rates, as well as effective NDF degradability were higher (P<O.05) for FD silage, but effective DM and CP degradabilities were higher (P<O.05) for OD oat silage. It was concluded that on an oat silage diet, lactating Jersey cows should receive a minimum of 2kg LH or 4 to 6kg oat hay together with ad libitum OS to improve DM intake. When cows were fed a high concentrate diet, the ruminal degradability appeared to be superior in Jerseys than Holsteins. Jerseys also had higher rumen pH levels lower VFA and NH3-N concentrations than Holsteins. Feeding interval affects the rumen environment, pH declines while VF A and NH3-N concentrations increased.AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die effek van die aanvulling van hawerkuilvoer met lusemhooi (LH) en hawerhooi (HH) op die melkproduksie van Jerseykoeie te bepaal. Hiermee saam is die rumen degradeerbaarheid van hawerkuilvoer en lusemhooi ondersoek in Jersey en Holsteinkoeie wat 'n hoe-ruvoer en 'n hoe-kragvoer gebaseerde dieet ontvang het. In die eerste proef is vyf diete met verskillende peile van hawerkuilvoer en lusernhooi saam met kragvoere van verskillende ruproteienpeile (26, 23, 20, 17 en 14% RP) aan 10 lakterende Jerseykoeie gevoer. Hawerkuilvoer is ad libitum voorsien en lusemhooi is teen vlakke van 0, 2, 4,6 en Skg droemateriaal (DM) per dag gevoer. Die DM-inname en melkproteienproduksie van koeie wat hawerkuilvoer as die enigste ruvoerbron ontvang het, was laer (P<0.05) as ander ruvoerkombinasies. Die melk- en vetproduksie, asook melk-ureumstikstofpeile het nie tussen behandelings verskil nie (P>0.05). In die tweede proef is hawerkuilvoer saam met hawerhooi (soortgelyk as Proef 1) gevoer. Die kragvoerkomponent van al die ruvoerkombinasies het 26% RP bevat. Die koeie wat hawerkuilvoer en 4 of 6kg hawerhooi as ruvoere ontvang het, het hoer (P<O.05) droemateriaalinnames gehad. Melk, vet en proteienproduksie asook melk-ureumstikstofpeile het nie tussen ruvoerkombinasies verskil nie (P>O.05). Die rumendegradeerbaarheid van lusemhooi, hawerhooi en hawerkuilvoer is bepaal in Holstein en Jerseykoeie wat (i) 'n hoe ruvoer- en (ii) 'n hoe kragvoerdieet ontvang het. Die rumen pH, vlugtige vetsuur en rumen-ammoniakkonsentrasies, soos beinvloed deur tyd na voeding, is ook tussen rasse vergelyk. Die rumendegradeerbaarheid van vars, oondgedroogde en vriesgedroogde hawerkuilvoer is ook bepaal. Die rumen DM, RP en NDF degradeerbaarhede van lusemhooi was hoer (P<O.05) as by hawerhooi en hawerkuilvoer in beide Holstein en Jerseykoeie wat (i) 'n hoe ruvoer- en (ii) 'n hoe kragvoerdieet ontvang het. Op 'n hoe ruvoerdieet, was effektiewe DM degradeerbaarheid van hawerkuilvoer by Holsteins hoer (P<O.05) as by Jerseys. Jerseykoeie het egter 'n hoer (P<O.05) RP degradeerbaarheidstempo van lusemhooi en hawerhooi gehad. Jerseykoeie op 'n hoe kragvoerdieet, het hoer (P<O.05) effektiewe DM en NDF degradeerbaarhede getoon. Hulle het egter 'n laer (P<O.05) effektiewe ruprotein (RP) degradeerbaarheid by hawerkuilvoer as Friese gehad. Jerseykoeie op lusemhooi het ook 'n hoer (P<O.05) DM en NDF degradeerbaarheidstempo getoon. Jerseykoeie wat 'n hoe ruvoerdieet ontvang het, het 'n hoer (P<O.05) rumen- pH en laer (P<O.05) vlugtige vetsuur- en rumen-ammoniak konsentrasies as Holsteinkoeie gehad. Jerseykoeie wat 'n hoe kragvoerdieet ontvang het, het ook 'n hoer (P<O.05) rumen- pH as Holsteinkoeie gehad. By al die koeie is gevind dat rumen- pH na voeding afgeneem het (P<O.05). Vlugtige vetsuur- en rumen-ammoniakkonsentrasies was laag voor voeding en het daama toegeneem (P<O.05). Vars hawerkuilvoer het laer (P<O.05) effektiewe DM, RP en NDF degradeerbaarhede en degradeerbaarheidstempo's as oond- en vriesgedroogde hawerkuilvoer gehad. Die vriesgedroogde kuilvoer het hoer (P<O.05) DM, RP en NDF degradeerbaarheidstempo's sowel as effektiewe NDF degradeerbaarhede gehad. Oondgedroogde kuilvoer het daarinteen hoer (P<O.05) effektiewe DM en RP degradeerbaarhede gehad. Die gevolgtrekking is gemaak dat lakterende Jerseykoeie ten minste 2kg lusemhooi of 4- 6kg hawerhooi per dag moet ontvang wanneer hulle hawerkuilvoer as ruvoerbron ontvang. Op 'n hoe kragvoerdieet, het dit gebleik dat die rumendegradeerbaarheid van vesel by Jerseys beter is as by Holsteins. Die rumen- pH is hoog voor voeding, maar dit neem af nadat die koeie gevreet het. Die rumen- pH van Jerseys was hoer as by Holsteins. Die vlugtige vetsure en rumen-ammoniakkonsentrasies blyk laag te wees voor voeding en neem daama toe. Konsentrasies was hoer by Holstein as by Jerseys

Effect of Antiretroviral Therapy on HIV-mediated Impairment of the Neutrophil Antimycobacterial Response

Experimental and epidemiological evidence suggests that neutrophils are important in the host response to tuberculosis. HIV infection, which increases the risk of tuberculosis, adversely affects neutrophil function.To determine the impact of HIV and antiretroviral therapy on neutrophil antimycobacterial activity.We performed a cross-sectional comparison of neutrophil functions in 20 antiretroviral-naive HIV-infected and 20 HIV-uninfected individuals using luminescence-, flow cytometry-, and ELISA-based assays. We then conducted a prospective study in the HIV-infected individuals investigating these parameters during the first 6 months of antiretroviral therapy. Surface markers of neutrophil activation were investigated in a separate cohort using flow cytometry.HIV infection impaired control of Mycobacterium tuberculosis by neutrophils (mean ratio of mycobacterial luminescence in neutrophil samples vs. serum controls at 1 hour in HIV-infected participants, 0.88 ± 0.13 vs. HIV-uninfected participants, 0.76 ± 0.14; P = 0.01; at 24 hours, 0.82 ± 0.13 vs. 0.71 ± 0.13; P = 0.01). The extent of impairment correlated with log[HIV viral load]. Neutrophil cell death after 24 hours incubation with M. tuberculosis was higher in the HIV-infected cohort (85.3 ± 11.8% vs. 57.9 ± 22.4% necrotic cells; P < 0.0001). Neutrophils from HIV-infected participants demonstrated significantly more CD62L-negative cells (median, 23.0 vs. 8.5%; P = 0.008) and CD16-negative cells (3.2 vs. 1.3%, P = 0.03). Antiretroviral therapy restored mycobacterial restriction and pattern of neutrophil death toward levels seen in HIV-uninfected persons.Neutrophils in antiretroviral-naive HIV-infected persons are hyperactivated, eliminate M. tuberculosis less effectively than in HIV-uninfected individuals, and progress rapidly to necrotic cell death. These factors are ameliorated by antiretroviral therapy

Screening for cryptococcal antigenemia in patients accessing an antiretroviral treatment program in South Africa.

BACKGROUND: Cryptococcal meningitis is a leading cause of death in patients with acquired immunodeficiency syndrome and contributes substantially to the high early mortality in antiretroviral treatment (ART) programs in low-resource settings. Screening for cryptococcal antigen in patients who enroll in ART programs may identify those at risk of cryptococcal meningitis and permit targeted use of preemptive therapy. METHODS: In this retrospective study, cryptococcal antigen was measured in stored plasma samples obtained from patients when they enrolled in a well-characterized ART cohort in South Africa. The predictive value of screening for cryptococcal antigen before initiation of ART for development of microbiologically confirmed cryptococcal meningitis or death during the first year of follow-up was determined. RESULTS: Of 707 participants with a baseline median CD4 cell count of 97 cells/microL (interquartile range, 46-157 cells/microL), 46 (7%) were positive for cryptococcal antigen. Antigenemia was 100% sensitive for predicting development of cryptococcal meningitis during the first year of ART, and in multivariate analysis, it was an independent predictor of mortality (adjusted hazard ratio, 3.2; 95% confidence interval, 1.5-6.6). Most cases (92%) of cryptococcal meningitis developed in patients with a CD4 cell count or 1:8 was 100% sensitive and 96% specific for predicting incident cryptococcal meningitis during the first year of ART in those with no history of the disease. CONCLUSIONS: Cryptococcal antigen screening before initiation of ART in patients with a CD4 cell count <or=100 cells/microL is highly effective for identifying those at risk of cryptococcal meningitis and death and might permit implementation of a targeted preemptive treatment strategy

Suffering whether You Tell or Don’t Tell: Perceived Re-Victimization as a Barrier to Disclosing Child Sexual Abuse in Zimbabwe

Disclosing child sexual abuse (CSA) is a necessary first step to access the legal, health, and psycho-social services that survivors and their families need. However, disclosure rates are low: of young women who experienced CSA in Zimbabwe, only 9% disclosed the first incident. The purpose of this qualitative study was to explore and describe perceived barriers to disclosing CSA in Zimbabwe. We conducted focus group discussions with children aged 10–14 years (n = 40) and their parents/caregivers aged 20–62 years (n = 40), participating in an intervention trial in Chitungwiza, Zimbabwe. We found that potential retaliation against survivors and their families is a major barrier to disclosing CSA. These retaliatory acts, which we refer to as “re-victimization,” arise from stigma or the victim feeling blamed or doubted and manifest through physical violence, emotional violence, and deprivation of family life and education. Our findings suggest that addressing social and cultural norms related to sex and strengthening legal protection for CSA survivors and their families could encourage CSA disclosure and could help end this violence. Our findings also highlight a need to increase children’s awareness of their rights and to create safe systems for disclosure of sexual abuse

Risk Factors Associated with Indeterminate Gamma Interferon Responses in the Assessment of Latent Tuberculosis Infection in a High-Incidence Environment

Immunogenetics and cellular immunology of bacterial infectious disease