University of Zambia

About: University of Zambia is a education organization based out in Lusaka, Lusaka, Zambia. It is known for research contribution in the topics: Population & Health care. The organization has 2593 authors who have published 4402 publications receiving 122411 citations. The organization is also known as: UNZA.

Host immune responses during Taenia solium Neurocysticercosis infection and treatment.

Abstract: Taenia solium cysticercosis and taeniasis (TSCT), caused by the tapeworm T. solium, is a foodborne and zoonotic disease classified since 2010 by WHO as a neglected tropical isease. It causes considerable impact on health and economy and is one of the leading causes of acquired epilepsy in most endemic countries of Latin America, Sub-Saharan Africa, and Asia. There is some evidence that the prevalence of TSCT in high-income countries has recently increased, mainly due to immigration from endemic areas. In regions endemic for TSCT, human cysticercosis can manifest clinically as neurocysticercosis (NCC), resulting in epileptic seizures and severe progressive headaches, amongst other neurological signs and/or symptoms. The development of these symptoms results from a complex interplay between anatomical cyst localization, environmental factors, parasite's infective potential, host genetics, and, especially, host immune responses. Treatment of individuals with active NCC (presence of viable cerebral cysts) with anthelmintic drugs together with steroids is usually effective and, in the majority, reduces the number and/or size of cerebral lesions as well as the neurological symptoms. However, in some cases, treatment may profoundly enhance anthelmintic inflammatory responses with ensuing symptoms, which, otherwise, would have remained silent as long as the cysts are viable. This intriguing silencing process is not yet fully understood but may involve active modulation of host responses by cyst-derived immunomodulatory components released directly into the surrounding brain tissue or by the induction of regulatory networks including regulatory T cells (Treg) or regulatory B cells (Breg). These processes might be disturbed once the cysts undergo treatment-induced apoptosis and necrosis or in a coinfection setting such as HIV. Herein, we review the current literature regarding the immunology and pathogenesis of NCC with a highlight on the mobilization of immune cells during human NCC and their interaction with viable and degenerating cysticerci. Moreover, the immunological parameters associated with NCC in people living with HIV/AIDS and treatments are discussed. Eventually, we propose open questions to understand the role of the immune system and its impact in this intriguing host-parasite crosstalk.

Impact of Antiretroviral Therapy on Liver Fibrosis Among Human Immunodeficiency Virus-Infected Adults With and Without HBV Coinfection in Zambia.

Abstract: Background We investigated changes in hepatic fibrosis, based on transient elastography (TE), among human immunodeficiency virus (HIV)-infected patients with and without hepatitis B virus (HBV) coinfection on antiretroviral therapy (ART) in Zambia. Methods Patients' liver stiffness measurements (LSM; kiloPascals [kPa]) at ART initiation were categorized as no or minimal fibrosis (equivalent to Metavir F0-F1), significant fibrosis (F2-F3), and cirrhosis (F4). TE was repeated following 1 year of ART. Stratified by HBV coinfection status (hepatitis B surface antigen positive at baseline), we described LSM change and the proportion with an increase/decrease in fibrosis category. Using multivariable logistic regression, we assessed correlates of significant fibrosis/cirrhosis at 1 year on ART. Results Among 463 patients analyzed (61 with HBV coinfection), median age was 35 years, 53.7% were women, and median baseline CD4+ count was 240 cells/mm3. Nearly all (97.6%) patients received tenofovir disoproxil fumarate-containing ART, in line with nationally recommended first-line treatment. The median LSM change was -0.70 kPa (95% confidence interval, -3.0 to +1.7) and was similar with and without HBV coinfection. Significant fibrosis/cirrhosis decreased in frequency from 14.0% to 6.7% (P < .001). Increased age, male sex, and HBV coinfection predicted significant fibrosis/cirrhosis at 1 year (all P < .05). Conclusion The percentage of HIV-infected Zambian adults with elevated liver stiffness suggestive of significant fibrosis/cirrhosis decreased following ART initiation-regardless of HBV status. This suggests that HIV infection plays a role in liver inflammation. HBV-coinfected patients were more likely to have significant fibrosis/cirrhosis at 1 year on ART. Clinical Trials Registration NCT02060162.

Improving understanding of clinical trial procedures among low literacy populations: an intervention within a microbicide trial in Malawi.

Abstract: The intervention reported in this paper was a follow up to an empirical study conducted in Malawi with the aim of assessing trial participants’ understanding of randomisation, double-blinding and placebo use. In the empirical study, the majority of respondents (61.1%; n= 124) obtained low scores (lower than 75%) on understanding of all three concepts under study. Based on these findings, an intervention based on a narrative which included all three concepts and their personal implications was designed. The narrative used daily examples from the field of Agriculture because Malawi has an agro-based economy. The intervention was tested using a sample of 36 women who had been identified as low scorers during the empirical study. The 36 low scorers were randomly assigned to control (n=18) and intervention arms (n=18). The control arm went through a session in which they were provided with standard informed consent information for the microbicide trial. The intervention arm went through a session in which they were provided with a narrative in ChiChewa, the local language, with the assistance of a power point presentation which included pictures as well as discussions on justification and personal implications of the concepts under study. The findings on the efficacy of the intervention suggest that the 3 scientific concepts and their personal implications can be understood by low literacy populations using simple language and everyday local examples. The findings also suggest that the intervention positively impacted on understanding of trial procedures under study, as 13 of the 18 women in the intervention arm, obtained high scores (above 75%) during the post intervention assessment and none of the 18 in the control arm obtained a high score. Using Fischer’s exact test, it was confirmed that the effect of the intervention on understanding of the three procedures was statistically significant (p=0.0001). Potential trial participants can be assisted to understand key clinical trial procedures, their justification and personal implications by using innovative tailored local narratives.

Perceptions of HIV-related health services in Zambia for people with disabilities who are HIV-positive

Abstract: Introduction: Despite the emerging body of literature on increased vulnerability to HIV among people with disabilities (PWDs), there is a dearth of evidence related to experiences of PWDs who have become HIV-positive. This priority was identified by a disability advocacy organization in Lusaka, Zambia, where the prevalence of HIV and of disability is each approximately 15%. The purpose of this study was to explore perceptions and experiences of HIV-related health services for PWDs who are also living with HIV in Lusaka, Zambia. Methods: This qualitative, interpretive study involved in-depth, semi-structured, one-on-one interviews with two groups of participants in Lusaka, Zambia: 21 PWDs who had become HIV-positive, and 11 people working in HIV and/or disability. PWDs had physical, hearing, visual and/or intellectual impairments. Interviews were conducted in English, Nyanja, Bemba or Zambian sign language. Descriptive and thematic analyses were conducted by a multidisciplinary, international research team. Results: Participants described their experiences with HIV-related health services in terms of the challenges they faced. In particular, they encountered three main challenges while seeking care and treatment: (1) disability-related discrimination heightened when seeking HIV services, (2) communication barriers and related concerns with confidentiality, and (3) movement and mobility challenges related to seeking care and collecting antiretroviral therapy. These experiences were further shaped by participants' profound concerns about poverty and unmet basic needs. Discussion: This study demonstrates how PWDs who are HIV-positive have the same HIV care, treatment and support needs as able-bodied counterparts, but face avoidable barriers to care. Many challenges mirror concerns identified with HIV prevention, suggesting that efforts to promote inclusion and reduce stigma could have widespread benefits. Conclusions: Despite the growing body of literature on increased risk of exposure to HIV among HIV-negative PWDs, this is the first published study to examine perceptions of testing, treatment and other HIV services for PWDs who have become HIV- positive. Findings reveal far-reaching opportunities for improving the quality of care for this population.

Gnarled-trunk evolutionary model of influenza A virus hemagglutinin.

Abstract: Human influenza A viruses undergo antigenic changes with gradual accumulation of amino acid substitutions on the hemagglutinin (HA) molecule. A strong antigenic mismatch between vaccine and epidemic strains often requires the replacement of influenza vaccines worldwide. To establish a practical model enabling us to predict the future direction of the influenza virus evolution, relative distances of amino acid sequences among past epidemic strains were analyzed by multidimensional scaling (MDS). We found that human influenza viruses have evolved along a gnarled evolutionary pathway with an approximately constant curvature in the MDS-constructed 3D space. The gnarled pathway indicated that evolution on the trunk favored multiple substitutions at the same amino acid positions on HA. The constant curvature was reasonably explained by assuming that the rate of amino acid substitutions varied from one position to another according to a gamma distribution. Furthermore, we utilized the estimated parameters of the gamma distribution to predict the amino acid substitutions on HA in subsequent years. Retrospective prediction tests for 12 years from 1997 to 2009 showed that 70% of actual amino acid substitutions were correctly predicted, and that 45% of predicted amino acid substitutions have been actually observed. Although it remains unsolved how to predict the exact timing of antigenic changes, the present results suggest that our model may have the potential to recognize emerging epidemic strains.