Evaluating plasma holds in the presence of multiple infections

To protect plasma supplies, donors are screened for infectiousdiseases. As an added measure of protection, donations are identifiedand stored for a period of time to allow future discard in theevent that an identified donor subsequently tests positive forsome screened disease. Previous models for evaluating such plasmaholds have only addressed the case of a single infectious disease.This paper extends the analysis to the case of multiple infections.Given knowledge of the marginal incidence rates for those infectionschecked, upper and lower bounds for important quantities suchas the probability of interdicting an infectious but undetecteddonation, the expected number of infections interdicted perdonation, and the net economic benefits of the holding policyare developed. Several examples are developed, illustratinghow the models can be used to evaluate the consequences of aplasma hold.     

Herion addicts infected by HBV and HIV have a low prevalence of HBV DNA in peripheral blood mononuclear cells

Several reports show that the prevalence of HBV (hepatitis B virus) carriers in HIV (human immunodeficiency virus) infected populations is significantly higher than in HIV seronegative individuals, independent of the risk group for HIV, that is, homosexuals or drug abusers. In this context, evaluation of the simultaneous presence of HBV and HIV in PBMCs (peripheral blood monuclear cells) is of particular interest for at least 2 reasons: 1) the possible reciprocal influence of the 2 viruses when they infect the same cell; 2) the possibility that HIV-iduced hematological disorders could indirectly influence the settling of HBV in blood cell populations. We report data on the frequency of PCR positivity for HBV DNA in PBMCs from 62 HIV infected patients, rigorously selected by risk group, that is, intravenous use of heroin for at least 3 years and syringe promiscuity. Sixtyseven HIV negative individuals who never used any drug formed the control group. The analysis of the cases positive for HBV DNA in PBMCs showed that 1) the overall prevalence of PCR positivity found in HIV infected patients was significantly lower than that registered in the control group; 2) PCR positivity among the subjects who were HBsAg negative and anti-HBV positive was extremely low in the HIV infected patients (3.7%) but quite frequent in the HIV negative subjects (37.0%). The results support the hypothesis that, unlike the HIV negative individuals, our HIV infected patients exhibited HBV DNA in PBMCS almost exclusively when they presented with active HBV replication.     

Tuberculosis infection and disease in South African adolescents with perinatally acquired HIV on antiretroviral therapy: a cohort study

IntroductionThere are limited data on Tuberculosis (TB) in adolescents with perinatally acquired HIV (APHIV). We examined the incidence and determinants of TB infection and disease in the Cape Town Adolescent Antiretroviral Cohort (CTAAC).MethodsYouth between nine and fourteen years on antiretroviral therapy (ART) for more than six months in public sector care, and age‐matched HIV‐negative adolescents, were enrolled between July 2013 through March 2015 and followed six‐monthly. Data were censored on 31 October 2018. Symptom screening, chest radiograph, viral load, CD4 count, QuantiFERON (QFT) and sputum for Xpert MTB/RIF, microscopy, culture and sensitivity were performed annually. TB infection was defined by a QFT of >0.35 IU/mL. TB diagnosis was defined as confirmed (culture or Xpert MTB/RIF positive) or unconfirmed (clinical diagnosis and started on TB treatment). Analyses examined the incidence and determinants of TB infection and disease.ResultsOverall 496 HIV+ and 103 HIV‐negative participants (median age at enrolment 12 years (interquartile range, IQR 10.6 to 13.3) were followed for a median of 3.1 years (IQR 3.0 to 3.4); 50% (298/599) were male. APHIV initiated ART at median age 4.4 years (IQR 2.1 to 7.6). At enrolment, 376/496 (76%) had HIV viral load <40 copies/mL, median CD4 count was 713 cells/mm³ and 179/559 (32%) were QFT+, with no difference by HIV status (APHIV 154/468, 33%; HIV negative 25/91, 27%; p = 0.31). The cumulative QFT+ prevalence was similar (APHIV 225/492, 46%; 95%CI 41% to 50%; HIV negative 44/98, 45%; 95% CI 35% to 55%; p = 0.88). APHIV had a higher incidence of all TB disease than HIV‐negative adolescents (2.2/100PY, 95% CI 1.6 to 3.1 vs. 0.3/100PY, 95% CI 0.04 to 2.2; IRR 7.36, 95% CI 1.01 to 53.55). The rate of bacteriologically confirmed TB in APHIV was 1.3/100 PY compared to 0.3/100PY for HIV‐negative adolescents, suggesting a fourfold increased risk of developing TB disease in APHIV despite access to ART. In addition, a positive QFT at enrolment was not predictive of TB in this population.ConclusionsHigh incidence rates of TB disease occur in APHIV despite similar QFT conversion rates to HIV‐negative adolescents. Strategies to prevent TB in this vulnerable group must be strengthened.     

伯氏疏螺旋体与嗜吞噬细胞无浆体混合感染的实验研究

目的应用动物模型探讨蜱传病原体伯氏疏螺旋体和嗜吞噬细胞无浆体混合感染对组织螺旋体载量、莱姆关节炎严重性、宿主免疫功能的影响。方法建立伯氏疏螺旋体和嗜吞噬细胞无浆体混合感染和伯氏疏螺旋体单一感染小鼠模型，在不同时间点研究各组小鼠组织中的螺旋体载量、关节炎严重性和血清IgG效价，并对数据进行统计学分析。结果与单一感染组相比，在螺旋体感染后18d和30d，混合感染组小鼠组织螺旋体载量显著增高，关节炎明显严重，血清IgC效价显著偏低。结论伯氏疏螺旋体和嗜吞噬细胞无浆体混合感染显著增加小鼠组织螺旋体载量、加重关节炎症状和病理改变，且抑制体液免疫功能。     

HIV-1/hepatitis B coinfection

Reviews the epidemiology, natural history and the current status of treatment of HIV/hepatitis B coinfection.     

Guidelines on the Treatment of Chronic Coinfection by Trypanosoma cruzi and HIV Outside Endemic Areas

Abstract

As a result of population migration, Chagas disease is no longer limited to the North and South American continents. In HIV-infected patients, chronic infection by Try-panosoma cruzi behaves as an opportunistic infection in severely immunosuppressed patients and is responsible for high morbidity and mortality. Unlike other opportunistic infections, information on the natural history, diagnosis, treatment, and prevention of Chagas disease is scarce. Spain has the highest number of cases of Chagas disease outside the North and South American continents, and coinfection with HIV is increasingly prevalent. In this article, the Spanish Society for Tropical Medicine and International Health (Sociedad Española de Medicina Tropical y Salud Interna-cional) reviews the current situation of coinfection with HIV and T. cruzi infection and provides guidelines on the diagnosis, treatment, and prevention in areas where Cha-gas disease is not endemic. It also identifies areas of uncertainty where additional research is necessary.     

Cholera‐schistosomiasis coinfection dynamics

The present work investigates the coinfection dynamics of the cholera and schistosomiasis diseases. The steady states of the model are examined. We obtain results for the model in detail and present the stability results whenever the basic reproduction number is less than unity ( ). For each submodel, the existence of backward bifurcation is presented and for the coinfection model. Furthermore, we formulate an optimal control problem with an appropriate set of control variables. The optimal control problem and the associated results are derived and discussed. The optimal control problem and the suggested controls are utilized to obtain optimal control characterizations. Numerical results are presented by choosing various optimal control strategies for the early elimination of both infections from the population. It is suggested that appropriate uses and application to the population could significantly reduce the infection. Therefore, based on our findings, we suggest to the public health department that the only possible cost‐effective strategy for the elimination of schistosomiasis and cholera coinfection is the combination of both diseases' preventive measures and the treatment of schistosomiasis.