Tick-Bourne Pathogens of Potential Zoonotic Importance in the Southern African Region

The aim of this communication is to provide preliminary information on the tick-borne pathogens of potential zoonotic importance present in southern Africa, mainly focusing on their geographical distribution and host range, and to identify research gaps. The following tick-borne zoonoses have been reported to occur in southern Africa based mainly on case reports: Crimean–Congo haemorrhagic fever caused by Crimean–Congo haemorrhagic fever virus; ehrlichiosis caused by Ehrlichia ruminantium, Ehrlichia canis and Anaplasma phagocytophilum; babesiosis caused by Babesia microti; relapsing fever caused by Borrelia duttonii and rickettsioses caused by Rickettsia africae, Rickettsia aeschlimannii and Rickettsia conorii. The epidemiological factors influencing their occurrence are briefly reviewed

Internalisation of the research supervisor : experiences and perceptions of psychology masters students at a historically disadvantaged university

Magister Artium (Psychology) - MA(Psych)Knowledge-based competition within a globalising economy is prompting a fresh consideration of the role of higher education in development and growth. Previously, it was often viewed as an expensive and inefficient public service that largely benefited the wealthy and privileged. It is now understood to make a necessary contribution to the success of national efforts to boost productivity, competitiveness and economic growth. Several governments see universities as engines for change and expansion of prosperity. There is also an increasing recognition that Higher Education has become dominated by a market-driven, consumerist service ethic and that this may have an impact on the style of research output and research supervision that academics adopt for a new knowledge economy. Research education or training, as it is often termed, is attracting greater scrutiny as research itself is seen of greater importance in the global knowledge economy. Students in post-graduation degree programmes across the world conduct research projects as a requirement to complete degrees A thesis or dissertation develops the ability to work independently and critically, the ability to develop arguments, and awareness and use of advanced methodological designs that pertain to the student's discipline of study. Thus such learning is argued to be facilitated in the context of research advisement or supervision. Through this process the student might adopt or internalise values and attitudes of the supervisor regarding research. This process is referred to as internalisation of the research supervisor, thereby contributing to the development of the student researchers. The theoretical framework chosen for this study was social constructionism. The aim of this present study was to explore the perceptions and experiences of students in relation to the internalisation of the supervisor that may take place during research supervision. The study utilised in-depth semi-structured interviews to collect data. Eleven participants from various supervisors consented to be part of the study. These were recruited using purposive sampling. The ethics considerations of the study adhered to the guidelines stipulated by Ethics committee of the University. Data was transcribed, and analysed using thematic analysis. The findings of this study indicate factors contributing to internalisation vary depending on aspects such as personalities of both the supervisor and the student, perceived quality of supervision and the supervision process itself. Findings also suggest that internalisation, whether positive or negative, of the research supervisor took place among the participants

Functional expression of TcoAT1 reveals it to be a P1-type nucleoside transporter with no capacity for diminazene uptake

It has long been established that the Trypanosoma brucei TbAT1/P2 aminopurine transporter is involved in the uptake of diamidine and arsenical drugs including pentamidine, diminazene aceturate and melarsoprol. Accordingly, it was proposed that the closest Trypanosoma congolense paralogue, TcoAT1, might perform the same function in this parasite, and an apparent correlation between a Single Nucleotide Polymorphism (SNP) in that gene and diminazene tolerance was reported for the strains examined. Here, we report the functional cloning and expression of TcoAT1 and show that in fact it is the syntenic homologue of another T. brucei gene of the same Equilibrative Nucleoside Transporter (ENT) family: TbNT10. The T. congolense genome does not seem to contain a syntenic equivalent to TbAT1. Two TcoAT1 alleles, differentiated by three independent SNPs, were expressed in the T. brucei clone B48, a TbAT1-null strain that further lacks the High Affinity Pentamidine Transporter (HAPT1); TbAT1 was also expressed as a control. The TbAT1 and TcoAT1 transporters were functional and increased sensitivity to cytotoxic nucleoside analogues. However, only TbAT1 increased sensitivity to diamidines and to cymelarsan. Uptake of [3H]-diminazene was detectable only in the B48 cells expressing TbAT1 but not TcoAT1, whereas uptake of [3H]-inosine was increased by both TcoAT1 alleles but not by TbAT1. Uptake of [3H]-adenosine was increased by all three ENT genes. We conclude that TcoAT1 is a P1-type purine nucleoside transporter and the syntenic equivalent to the previously characterised TbNT10; it does not mediate diminazene uptake and is therefore unlikely to play a role in diminazene resistance in T. congolense

Genetic characterisation of African swine fever virus from 2017 outbreaks in Zambia: Identification of p72 genotype II variants in domestic pigs

African swine fever (ASF) is a contagious haemorrhagic disease associated with causing heavy economic losses to the swine industry in many African countries. In 2017, Zambia experienced ASF outbreaks in Mbala District (Northern province) and for the first time in Isoka and Chinsali districts (Muchinga province). Meanwhile, another outbreak was observed in Chipata District (Eastern province). Genetic analysis of part of the B646L gene, E183L gene, CP204L gene and the central variable region of the B602L gene of ASF virus (ASFV) associated with the outbreaks in Mbala and Chipata districts was conducted. The results revealed that the ASFV detected in Mbala District was highly similar to that of the Georgia 2007/1 isolate across all the genome regions analysed. In contrast, while showing close relationship with the Georgia 2007/1 virus in the B646L gene, the ASFV detected in Chipata District showed remarkable genetic variation in the rest of the genes analysed. These results suggest that the Georgia 2007/1-like virus could be more diverse than what was previously thought, underscoring the need of continued surveillance and monitoring of ASFVs within the south-eastern African region to better understand their epidemiology and the relationships between outbreaks and their possible origin

First COVID-19 Case in Zambia - Comparative phylogenomic analyses of SARS-CoV-2 detected in African countries

Since its first discovery in December 2019 in Wuhan, China, COVID-19, caused by the novel coronavirus SARS-CoV-2, has spread rapidly worldwide. Whilst African countries were relatively spared initially, the initial low incidence of COVID-19 cases was not sustained for long due to continuing travel links between China, Europe and Africa.. In preparation, Zambia had applied a multisectoral national epidemic disease surveillance and response system resulting in the identification of the first case within 48 hours of the individual entering the country by air travel from a trip to France. Contact tracing showed that SARS-CoV-2 infection was contained within the patient's household, with no further spread to attending health care workers or community members. Phylogenomic analysis of the patient's SARS-CoV-2 strain showed it belonged to lineage B.1.1., sharing the last common ancestor with SARS-CoV-2 strains recovered from South Africa. At the African continental level, our analysis showed that lineage B.1 and B.1.1 lineages appear to be predominant in Africa. Whole genome sequence analysis should be part of all surveillance and case detection activities in order to monitor the origin and evolution of SARS-CoV-2 lineages across Africa

High Prevalence of Drug Resistance in Animal Trypanosomes without a History of Drug Exposure

Trypanosomosis is responsible for the death of 3 million heads of cattle yearly, with 50 million animals at risk in sub-Saharan Africa. DA, a commonly used drug against the disease, was marketed decades ago. Drug resistance is reported in 21 African countries. A common argument about the origin of drug resistance is the selection by the drug of rare individuals that are naturally resistant and the propagation of those individuals in the population because of the competitive advantage they have when exposed to drug. When the drug pressure decreases, the wild-type individuals regain their supremacy. The principal objective of this study was thus to estimate the prevalence of trypanosomes resistant to DA in a population that was never exposed to the drug. Our results showing a high prevalence of drug resistance in environments free of any drug pressure is thought provoking and suggests that ceasing the use of DA will not allow for a return to a DA-sensitive population of trypanosomes. Drug resistance in animal trypanosomes thus present a pattern different from what is observed with Plasmodium sp. (causative agent of malaria) where a complete stoppage in the use of the chloroquine allows for a return to drug sensitivity

West Nile Virus in Farmed Crocodiles, Zambia, 2019

We detected West Nile virus (WNV) nucleic acid in crocodiles (Crocodylus niloticus) in Zambia. Phylogenetically, the virus belonged to lineage 1a, which is predominant in the Northern Hemisphere. These data provide evidence that WNV is circulating in crocodiles in Africa and increases the risk for animal and human transmission

Luna Virus and Helminths in Wild Mastomys natalensis in Two Contrasting Habitats in Zambia: Risk Factors and Evidence of Virus Dissemination in Semen

Transmission dynamics and the maintenance of mammarenaviruses in nature are poorly understood. Using metagenomic next-generation sequencing (mNGS) and RT-PCR, we investigated the presence of mammarenaviruses and co-infecting helminths in various tissues of 182 Mastomys natalensis rodents and 68 other small mammals in riverine and non-riverine habitats in Zambia. The Luna virus (LUAV) genome was the only mammarenavirus detected (7.7%; 14/182) from M. natalensis. Only one rodent from the non-riverine habitat was positive, while all six foetuses from one pregnant rodent carried LUAV. LUAV-specific mNGS reads were 24-fold higher in semen than in other tissues from males. Phylogenetically, the viruses were closely related to each other within the LUAV clade. Helminth infections were found in 11.5% (21/182) of M. natalensis. LUAV-helminth co-infections were observed in 50% (7/14) of virus-positive rodents. Juvenility (OR = 9.4; p = 0.018; 95% CI: 1.47-59.84), nematodes (OR = 15.5; p = 0.001; 95% CI: 3.11-76.70), cestodes (OR = 10.8; p = 0.025; 95% CI: 1.35-86.77), and being male (OR = 4.6; p = 0.036; 95% CI: 1.10-18.90) were associated with increased odds of LUAV RNA detection. The role of possible sexual and/or congenital transmission in the epidemiology of LUAV infections in rodents requires further study, along with the implications of possible helminth co-infection

African Trypanosomiasis-associated anemia : the contribution of the interplay between parasites and the mononuclear phagocyte system

African trypanosomosis (AT) is a chronically debilitating parasitic disease of medical and economic importance for the development of sub-Saharan Africa. The trypanosomes that cause this disease are extracellular protozoan parasites that have developed efficient immune escape mechanisms to manipulate the entire host immune response to allow parasite survival and transmission. During the early stage of infection, a profound pro-inflammatory type 1 activation of the mononuclear phagocyte system (MPS), involving classically activated macrophages (i.e., M1), is required for initial parasite control. Yet, the persistence of this M1-type MPS activation in trypanosusceptible animals causes immunopathology with anemia as the most prominent pathological feature. By contrast, in trypanotolerant animals, there is an induction of IL-10 that promotes the induction of alternatively activated macrophages (M2) and collectively dampens tissue damage. A comparative gene expression analysis between M1 and M2 cells identified galectin-3 (Gal-3) and macrophage migration inhibitory factor (MIF) as novel M1-promoting factors, possibly acting synergistically and in concert with TNF-alpha during anemia development. While Gal-3 enhances erythrophagocytosis, MIF promotes both myeloid cell recruitment and iron retention within the MPS, thereby depriving iron for erythropoiesis. Hence, the enhanced erythrophagocytosis and suppressed erythropoiesis lead to anemia. Moreover, a thorough investigation using MIF-deficient mice revealed that the underlying mechanisms in AT-associated anemia development in trypanosusceptible and tolerant animals are quite distinct. In trypanosusceptible animals, anemia resembles anemia of inflammation, while in trypanotolerant animals' hemodilution, mainly caused by hepatosplenomegaly, is an additional factor contributing to anemia. In this review, we give an overview of how trypanosome-and host-derived factors can contribute to trypanosomosis-associated anemia development with a focus on the MPS system. Finally, we will discuss potential intervention strategies to alleviate AT-associated anemia that might also have therapeutic potential

Mosquito-Borne Viral Pathogens Detected in Zambia: A Systematic Review

Emerging and re-emerging mosquito-borne viral diseases are a threat to global health. This systematic review aimed to investigate the available evidence of mosquito-borne viral pathogens reported in Zambia. A search of literature was conducted in PubMed and Google Scholar for articles published from 1 January 1930 to 30 June 2020 using a combination of keywords. Eight mosquito-borne viruses belonging to three families, Togaviridae, Flaviviridae and Phenuiviridae were reported. Three viruses (Chikungunya virus, Mayaro virus, Mwinilunga virus) were reported among the togaviruses whilst four (dengue virus, West Nile virus, yellow fever virus, Zika virus) were among the flavivirus and only one virus, Rift Valley fever virus, was reported in the Phenuiviridae family. The majority of these mosquito-borne viruses were reported in Western and North-Western provinces. Aedes and Culex species were the main mosquito-borne viral vectors reported. Farming, fishing, movement of people and rain patterns were among factors associated with mosquito-borne viral infection in Zambia. Better diagnostic methods, such as the use of molecular tools, to detect the viruses in potential vectors, humans, and animals, including the recognition of arboviral risk zones and how the viruses circulate, are important for improved surveillance and design of effective prevention and control measures