ORCID Profile
0000-0003-3533-1515
Current Organisation
James Cook University
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Publisher: Oxford University Press (OUP)
Date: 03-2001
DOI: 10.1016/S0035-9203(01)90175-0
Abstract: Genetic ersity of malaria parasites represents a major issue in understanding several aspects of malaria infection and disease. Genotyping of Plasmodium falciparum infections with polymerase chain reaction (PCR)-based methods has therefore been introduced in epidemiological studies. Polymorphic regions of the msp1, msp2 and glurp genes are the most frequently used markers for genotyping, but methods may differ. A multicentre study was therefore conducted to evaluate the comparability of results from different laboratories when the same s les were analysed. Analyses of laboratory-cloned lines revealed high specificity but varying sensitivity. Detection of low-density clones was h ered in multiclonal infections. Analyses of isolates from Tanzania and Papua New Guinea revealed similar positivity rates with the same allelic types identified. The number of alleles detected per isolate, however, varied systematically between the laboratories especially at high parasite densities. When the analyses were repeated within the laboratories, high agreement was found in getting positive or negative results but with a random variation in the number of alleles detected. The msp2 locus appeared to be the most informative single marker for analyses of multiplicity of infection. Genotyping by PCR is a powerful tool for studies on genetic ersity of P. falciparum but this study has revealed limitations in comparing results on multiplicity of infection derived from different laboratories and emphasizes the need for highly standardized laboratory protocols.
Publisher: Hogrefe Publishing Group
Date: 02-2011
Publisher: MDPI AG
Date: 11-07-2020
DOI: 10.3390/TROPICALMED5030115
Abstract: Tsetse transmitted trypanosomiasis is a fatal disease commonly known as Nagana in cattle and sleeping sickness in humans. The disease threatens food security and has severe economic impact in Africa including most parts of Zambia. The level of effectiveness of commonly used African trypanosomiasis control methods has been reported in several studies. However, there have been no review studies on African trypanosomiasis control and management conducted in the context of One Health. This paper therefore seeks to fill this knowledge gap. A review of studies that have been conducted on African trypanosomiasis in Zambia between 2009 and 2019, with a focus on the control and management of trypanosomiasis was conducted. A total of 2238 articles were screened, with application of the search engines PubMed, PubMed Central and One Search. Out of these articles, 18 matched the required criteria and constituted the basis for the paper. An in-depth analysis of the 18 articles was conducted to identify knowledge gaps and evidence for best practices. Findings from this review provide stakeholders and health workers with a basis for prioritisation of African trypanosomiasis as an important neglected disease in Zambia and for formulation of One Health strategies for better control and/or management of the disease.
Publisher: Oxford University Press (OUP)
Date: 12-2004
DOI: 10.1016/J.TRSTMH.2004.03.010
Abstract: Several studies suggest that in in iduals with substantial previous exposure to malaria, co-infection with multiple clones of Plasmodium falciparum can protect against subsequent clinical malaria attacks. Other studies, mainly of in iduals with little previous exposure, found the converse relationship. To test whether acquisition of such cross-protection tracks the acquisition of clinical immunity in general, 610 Tanzanian children aged 0-6 years were enrolled in a nine-month prospective study of the risk of morbidity in relation to parasitological status and merozoite surface protein 2 genotypes on enrolment. Prevalence of parasitaemia and multiplicity of infection increased with age. In the first year of life, the incidence of clinical malaria was almost three times higher in children with parasites at baseline than in those without. In older children, baseline P. falciparum infections appeared to protect against both parasitaemic and non-parasitaemic fever episodes. In children aged less than three years, baseline multiple infection tended to be associated with higher prospective risk of clinical malaria than single infection while in children aged more than three years the converse was found, but these effects were not statistically significant. These results provide further evidence that relationships between asymptomatic malaria infections and clinical malaria change with cumulative exposure.
Publisher: Public Library of Science (PLoS)
Date: 03-2013
Publisher: Oxford University Press (OUP)
Date: 03-03-2018
DOI: 10.1093/CID/CIY179
Publisher: MDPI AG
Date: 30-04-2021
DOI: 10.3390/TROPICALMED6020068
Abstract: African animal trypanosomiasis (AAT) control programs rely on active case detection through the screening of animals reared in disease endemic areas. This study compared the application of the polymerase chain reaction (PCR) and microscopy in the detection of trypanosomes in cattle blood in Mambwe, a rural district in eastern Zambia. Blood s les were collected from 227 cattle and tested for infection with trypanosomes using microscopy and Ribosomal RNA Internal Transcribed Spacers (ITS)-PCR. Microscopy on the buffy coat detected 17 cases, whilst thin and thick smears detected 26 cases and 28 cases, respectively. In total, microscopy detected 40 cases. ITS-PCR-filter paper (FP) on blood spots stored on FP detected 47 cases, and ITS-PCR-FTA on blood spots stored on Whatman FTA Classic cards detected 83 cases. Using microscopy as the gold standard, ITS-PCR-FTA had a better specificity (SP) and sensitivity (SE) (SP = 72.2% SE = 77.5% kappa = 0.35) than ITS-PCR-FP (SP = 88% SE = 60% kappa = 0.45). The prevalence of Trypanosoma brucei s.l. was higher on ITS-PCR-FTA (19/227) than on ITS-PCR-FP (0/227). Our results illustrate the complexities around trypanosomiasis surveillance in rural Africa and provide evidence of the impact that field conditions and staff training can have on diagnostic results, which in turn impact the success of tsetse and trypanosomiasis control programs in the region.
Publisher: Public Library of Science (PLoS)
Date: 28-04-2016
Publisher: American Society for Microbiology
Date: 16-12-2020
DOI: 10.1128/AAC.01422-20
Abstract: Comorbid type 2 diabetes poses a great challenge to the global control of tuberculosis. Here, we assessed the efficacy of metformin (MET), an antidiabetic drug, in mice infected with a very low dose of Mycobacterium tuberculosis . In contrast to diabetic mice, infected nondiabetic mice that received the same therapeutic concentration of MET presented with significantly higher disease burden. This warrants further studies to investigate the disparate efficacy of MET against tuberculosis in diabetic and nondiabetic in iduals.
Publisher: International Union Against Tuberculosis and Lung Disease
Date: 21-09-2015
DOI: 10.5588/PHA.15.0029
Publisher: MDPI AG
Date: 28-12-2021
DOI: 10.3390/PATHOGENS11010030
Abstract: The capacity to detect, control and manage emerging and re-emerging zoonotic diseases in Africa has been limited by a lack of utilisation of available reporting structures and policies to support programmes at national and local levels. This study explored the impact of the Zambian government policies on animal and human disease reporting and management and on One Health opportunities. An in-depth review and analysis of strengths, weaknesses, opportunities, and threats in the existing policies and reporting structures in the departments responsible for Veterinary Services, Health, and Wildlife, was conducted. According to our findings, sub-optimal implementation of existing policies related to the control of zoonotic diseases was impacting disease reporting, and reporting structures play an important role in effective and sustainable reporting of zoonotic diseases. Further, the study explored capacities and strategies in trypanosomiasis control as a case study that could prompt effective adoption of a One Health approach, and as such, the study suggests measures that could help to assess the performance of a One Health system in the control of African trypanosomiasis and other zoonotic diseases.
Publisher: Springer Science and Business Media LLC
Date: 2001
Abstract: The clinical management of HIV-1 infection has benefited enormously from molecular characterization of drug resistance as well as determination of the viral phenotype in vitro. HIV-1 infected in iduals on HAART are currently monitored for the development of drug resistance variants allowing clinicians to redesign drug regimens. An understanding of the molecular basis of the evolution of drug resistance in vivo allows the improvement of the drugs as well as in vitro evaluation of new antiviral compounds alone or in combination with those currently approved. New findings suggest that viral envelopes could be a target to inhibit infection and replication. Therefore the generation of a recombinant virus assay (RVA) to allow the phenotypic determination of drug resistance against entry inhibitors (EI) is anticipated. We constructed an env-deleted clone of HIV-1 using the molecular clone NL-4.3. PCR lified complete envelope genes (NL-4.3, BaL, primary envelope-genes) were ligated in vitro with a deletion clone (pNL-deltaK) and PM1-cells, supporting the replication of R5- and X4-tropic viruses, were transfected. Determination of co-receptor usage of the harvested recombinant virus-swarm revealed no difference compared to the molecular clones derived in idually from three different patients. These results clearly show that an envelope-based RVA is practicable to monitor HIV-co-receptor usage at a given time point. Furthermore, this assay will allow to monitor resistance development against existing and future entry inhibitors and will aid to improve the management of HIV-therapy.
Publisher: BMJ
Date: 09-2017
DOI: 10.1136/BMJOPEN-2016-014679
Abstract: Tuberculosis (TB) is a leading cause of death among people living with HIV in sub-Saharan Africa. Several factors influence the efficacy of TB treatment by leading to suboptimal drug concentrations and subsequently affecting treatment outcome. The aim of this cohort is to determine the association between anti-TB drug concentrations and TB treatment outcomes. Patients diagnosed with new pulmonary TB at the integrated TB-HIV outpatient clinic in K ala, Uganda, were enrolled into the study and started on first-line anti-TB treatment. Between April 2013 and April 2015, the cohort enrolled 268 patients coinfected with TB/HIV 57.8% are male with a median age of 34 years (IQR 29–40). The median time between the diagnosis of HIV and the diagnosis of TB is 2 months (IQR 0–22.5). The majority of the patients are antiretroviral therapy naive (75.4%). Our population is severely immunosuppressed with a median CD4 cell count at enrolment of 163 cells/µL (IQR 46–298). Ninety-nine per cent of the patients had a diagnosis of pulmonary TB confirmed by sputum microscopy, Xpert/RIF or culture and 203 (75.7%) have completed TB treatment with 5099 aliquots of blood collected for pharmacokinetic analysis. This cohort provides a large database of well-characterised patients coinfected with TB/HIV which will facilitate the description of the association between serum drug concentrations and TB treatment outcomes as well as provide a research platform for future substudies including evaluation of virological outcomes. NCT01782950 Pre-results.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Proceedings of the National Academy of Sciences
Date: 10-08-2020
Abstract: Tuberculosis (TB) susceptibility and disease are significantly exacerbated in people with type 2 diabetes. The underlying mechanisms are incompletely understood, and it is not known if new TB vaccine candidates will be safe and provide protection in the context of diabetes. Using a long-term diet-induced murine model of type 2 diabetes, we demonstrate that increased susceptibility to TB is caused by impaired mycobacterial recognition and killing in the diabetic lung. Importantly, we show that mucosal vaccination of diabetic mice with Bacillus Calmette–Guérin (BCG) strains expressing the ESX-1 secretion system from Mycobacterium tuberculosis can overcome this defect and provide superior immunity against TB. Our data warrant a consideration of ESX-1–containing BCG strains as effective TB vaccines in older in iduals and diabetics.
Publisher: Springer Science and Business Media LLC
Date: 31-01-2015
Publisher: Elsevier BV
Date: 03-1999
DOI: 10.1016/S0001-706X(98)00090-4
Abstract: DNA isolation from blood s les collected in molecular epidemiological studies is crucial for the quality and reproducibility of data. Blood s les from two malaria endemic sites have been prepared by four different DNA isolation methods with subsequent PCR lification of the msp2 locus of Plasmodium falciparum. We tested a rapid boiling method the guanadine isothiocyanate DNA extraction QIAmp blood kit and the ISOCODE STIX PCR template preparation dipstick, and analysed the numbers of concurrent infections/s le. The rapid boiling method and the ISOCODE STIX provided overall the best sensitivity combined with ease of handling. The possibility to store and ship the ISOCODE STIX at ambient temperature adds further advantage to this method.
Publisher: SMW Supporting Association
Date: 23-12-2015
No related grants have been discovered for Lars Henning.