Frequency of CCR2V64I and CCR5Δ32 host genes and their association with HIV infection among pregnant women from Harare, Zimbabwe

Magister Public Health - MPHAim: To determine and compare the prevalence of CCR5-Δ32 and CCRV64I genes in HIV positive and HIV negative population of pregnant women from Harare, in Zimbabwe. Results: The proportion of pregnant women with the homozygous CCR2V64I gene was 24.38% and this gene was two times more associated with HIV infection than in those without it ( RR= 2.32, 95% CI-1.38-3.92). No CCR5-Δ32 deletion was detected in the studied population. Conclusion: The homozygous CCR2V64I gene and STIs were more prevalent in HIV infected pregnant women than in uninfected pregnant women and no homozygousCCR5-Δ32 gene was detected in this study.South Afric

The STAR-MELT Python package for emission line analysis of YSOs

We introduce the STAR-MELT Python package that we developed to facilitate the analysis of time-resolved emission line spectroscopy of young stellar objects. STAR-MELT automatically extracts, identifies and fits emission lines. We summarise our analysis methods that utilises the time domain of high-resolution stellar spectra to investigate variability in the line profiles and corresponding emitting regions. This allows us to probe the innermost disc and accretion structures of YSOs. Local temperatures and densities can be determined using Boltzmann statistics, the Saha equation, and the Sobolev large velocity gradient approximation. STAR-MELT allows for new results to be obtained from archival data, as well as facilitating timely analysis of new data as it is obtained. We present the results of applying STAR-MELT to three YSOs, using spectra from UVES, XSHOOTER, FEROS, HARPS, and ESPaDOnS. We demonstrate what can be achieved for data with disparate time sampling, for stars with different inclinations and variability types. For EX Lupi, we confirm the presence of a localised and stable stellar-surface hotspot associated with the footprint of the accretion column. For GQ Lupi A, we find that the maximum infall rate from an accretion column is correlated with lines produced in the lowest temperatures. For CVSO109 we investigate the rapid temporal variability of a redshifted emission wing, indicative of rotating and infalling material in the inner disc. Our results show that STAR-MELT is a useful tool for such analysis, as well as other applications for emission lines.<br/

Modelling climate change impact on the spatial distribution of fresh water snails hosting trematodes in Zimbabwe

BACKGROUND: Freshwater snails are intermediate hosts for a number of trematodes of which some are of medical and veterinary importance. The trematodes rely on specific species of snails to complete their life cycle; hence the ecology of the snails is a key element in transmission of the parasites. More than 200 million people are infected with schistosomes of which 95% live in sub-Saharan Africa and many more are living in areas where transmission is on-going. Human infection with the Fasciola parasite, usually considered more of veterinary concern, has recently been recognised as a human health problem. Many countries have implemented health programmes to reduce morbidity and prevalence of schistosomiasis, and control programmes to mitigate food-borne fascioliasis. As these programmes are resource demanding, baseline information on disease prevalence and distribution becomes of great importance. Such information can be made available and put into practice through maps depicting spatial distribution of the intermediate snail hosts. METHODS: A biology driven model for the freshwater snails Bulinus globosus, Biomphalaria pfeifferi and Lymnaea natalensis was used to make predictions of snail habitat suitability by including potential underlying environmental and climatic drivers. The snail observation data originated from a nationwide survey in Zimbabwe and the prediction model was parameterised with a high resolution Regional Climate Model. Georeferenced prevalence data on urinary and intestinal schistosomiasis and fascioliasis was used to calibrate the snail habitat suitability predictions to produce binary maps of snail presence and absence. RESULTS: Predicted snail habitat suitability across Zimbabwe, as well as the spatial distribution of snails, is reported for three time slices representative for present (1980-1999) and future climate (2046-2065 and 2080-2099). CONCLUSIONS: It is shown from the current study that snail habitat suitability is highly variable in Zimbabwe, with distinct high- and low- suitability areas and that temperature may be the main driving factor. It is concluded that future climate change in Zimbabwe may cause a reduced spatial distribution of suitable habitat of host snails with a probable exception of Bi. pfeifferi, the intermediate host for intestinal schistosomiasis that may increase around 2055 before declining towards 2100. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-014-0536-0) contains supplementary material, which is available to authorized users

STAR-MELT:STellar AccRetion-Mapping with Emission Line Tomography

Accretion is a fundamentally important process for pre-main-sequence stars, affecting disk stability and evolution, stellar rotation and activity, and planet formation and migration. The main observational challenge is probing the sub-au scales of the innermost disk, which is not yet possible via interferometry. Such young stars, however, possess a wealth of metallic emission lines that can reveal the nature of these accretion-related processes.Our analysis involves emission line tomography of time-resolved, high-resolution spectra of young stars. This technique uses the time domain to investigate distortions in the stellar emission line profiles and radial velocity signatures. Local temperatures and densities can be determined for the various emission line species. With both temporal and spatial information, we can then infer a tomographic map of the accretion structures, activity spots, and the innermost hot atomic gas; down to scales smaller than those achievable with direct imaging. Our analysis allows for new science results to be obtained from archival data, as well as facilitating timely analysis of new data as it is obtained.In this talk, we will give a demonstration of the STAR-MELT Python package. Directly from the FITS files, the emission lines are automatically extracted and identified, via matching to a compiled reference database of lines. Line profiles are fitted and quantified, allowing for calculations of physical properties across each individual observation. Temporal variations in lines can readily be displayed and quantified. Our STAR-MELT python package would also be useful for different applications of spectral analysis, where emission line identification is required. Standard data formats for spectra are automatically compatible, with user-defined custom formats also available. Any reference database (atomic or molecular) can also be used for line identification.For further details on the emission line tomography results, see the poster by Aurora Sicilia Aguilar....https://zenodo.org/record/4561359#.YMNqwajdth

Modelling spatial distribution of snails transmitting parasitic worms with importance to human and animal health and analysis of distributional changes in relation to climate

The environment, the on-going global climate change and the ecology of animal species determine the localisation of habitats and the geographical distribution of the various species in nature. The aim of this study was to explore the effects of such changes on snail species not only of interest to naturalists but also of importance to human and animal health. The spatial distribution of freshwater snail intermediate hosts involved in the transmission of schistosomiasis, fascioliasis and paramphistomiasis (i.e. Bulinus globosus, Biomphalaria pfeifferi and Lymnaea natalensis) were modelled by the use of a maximum entropy algorithm (Maxent). Two snail observation datasets from Zimbabwe, from 1988 and 2012, were compared in terms of geospatial distribution and potential distributional change over this 24-year period investigated. Climate data, from the two years were identified and used in a species distribution modelling framework to produce maps of predicted suitable snail habitats. Having both climate- and snail observation data spaced 24 years in time represent a unique opportunity to evaluate biological response of snails to changes in climate variables. The study shows that snail habitat suitability is highly variable in Zimbabwe with foci mainly in the central Highveld but also in areas to the South and West. It is further demonstrated that the spatial distribution of suitable habitats changes with variation in the climatic conditions, and that this parallels that of the predicted climate change

High prevalence of molecular markers for resistance to chloroquine and pyrimethamine in Plasmodium falciparum from Zimbabwe

Chloroquine has been the first line drug of treatment for malaria in Zimbabwe until a recent adoption of an interim policy to treat using a combination of chloroquine (CQ) and sulfadoxine/pyrimethamine (SP). We examined the prevalence of parasites with mutations associated with resistance to the drug combination in three areas that have been previously described to differ in malaria endemicity. Our results show that the parasite population from the three areas had a high prevalence of molecular markers of resistance to chloroquine and pyrimethamine. The prevalence of crt (K76T) was 64, 82, and 92% for Chiredzi, Kariba, and Bindura, respectively. On the dhfr locus, the presence of triple mutations (codons 51, 59, and 108) was approximately 50% for all the three locations. On the other hand, the prevalence of dhps mutations (codons 436, 437, and 540) was low accounting for less than 20% in all the areas. Studies reported here demonstrate widespread prevalence of molecular markers associated with chloroquine and pyrimethamine resistance and should be taken into consideration for further refinement of malaria control strategies in Zimbabwe. The design and implementation of successful control strategies would benefit from understanding the prevalence of mutations associated with drug resistance in parasite populations. © 2007 Springer-Verlag