International Science and Technology Journal of Namibia

Prevalence and socio-demographic factors associated with lower-extremity peripheral neuropathy among HIV-infected adult patients on antiretroviral therapy.

2025-11-17T16:31:01+02:00

Abstract
This study analysed data from a large cohort of HIV-infected persons to determine the proportion of adult patients who developed peripheral neuropathy (PN) of the lower extremities after initiation of antiretroviral therapy (ART) and further identify the socio-demographic factors associated with the condition. A retrospective cohort study was conducted analysing prospectively and routinely-collected demographic and clinical data of HIV-infected adults initiated on ART at Parirenyatwa Group of Hospital Family Care Center (PGH-FCC). Participants’ data were extracted from an electronic patient management database (ePOC). A total of 1 546 records were eligible for the retrospective analysis. The majority of the data records were from female patients (61.5%), and the age range of patients was between 18 and 81 years. The majority of the data extracted was from HIV-infected patients who were married (53.0%), living in the high-density suburbs (52.0%), had reached secondary school (71.7%), and were employed (67.5%). Of the1 546 patient records analysed, 190 (12.3%) HIV-infected patients on ART had a physician-based diagnosis of PN (95% CI=10.8%-14.0%). The most common symptoms reported by patients with PN were sensations of burning type of pain in the legs/ feet and paraesthesia. Being divorced (OR=1.66; p=0.001), unemployed (OR=2.86; p<0.01), residing in high density suburbs (OR=1.98; p<0.01), no education (OR=8.21; p=0.014) and having attained primary education (OR=1.92; p=0.014 were all associated with reports of PN. The study findings link the occurrence of PN among HIV-infected persons on ART with advancing age, socio-economic and educational status.

Health Risk Assessment of Natural Radioactivity in Wasteland Soils in Helao Nafidi dumpsite, Namibia

2025-03-20T10:45:40+02:00

Humans are exposed to radiation in the soil of wasteland areas because radiation occurs naturally in the environment through cosmic and terrestrial rays. Children and residents from the neighborhood use dumpsites every day to scrounge for food and other items, increasing their exposure to radiation. The aim of the study is to ascertain whether the radioactive compounds found in the Helao Nafidi dumpsite pose a threat to human health. In this work, the activity concentrations of 226Ra, 232Th, and 40K in 19 soil samples were measured using a gamma-ray spectrometer. Several radiological parameters were computed from these actions. The average activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K were 4.83 ±0.58, 4.72 ±0.62 and 51.31±5.41, respectively. The average Ra_eq value from the Wasteland soil was 15.53 Bq/kg. All of the soil samples had Raeq values that were less than the average global value of 370 Bq/kg. The average AEDE value was 0.01 mSv.y-1, less than the 0.48 mSv global recommendation. The Wasteland soil's Annual Gonadal Dose Equivalent (AGDE) value was 50.77 Sv.y-1, which was found to be less than the 298 Sv.y-1 global critical value. The average values of RLI and Hex were found to be 0.11 and 0.04, respectively. These indices were less than the world accepted-limit values. The average value of the excess lifetime cancer risk (ECLR) was found to be 0.03 and lower than world average of 2.9 x . These findings indicate that natural radioactivity in the soil of the Helao Nafidi wasteland area is not now a health risk.

Gravimetric characterization of Pyrite carbothermic reduction in the presence of lime

2025-06-27T14:51:43+02:00

Pyrite carbothermic reduction studies were conducted on pyrite concentrate (40.75 % iron, 48.04 % sulphur, 0.11 % copper) from the Otjihase Mine in the Repubic of Namibia. Additionally, this research included thermal decomposition and ion exchange since they cannot be dissociated from carbo-thermic reduction. The aim was to assess the iron metallization, and the assessement was carried out through mass percent reduction. A factorial research design was adopted, consisting of two factors (time and CaO/C ratio at five levels, and one factor (temperature) at three levels in reducing environment. The analysis of variance (ANOVA) was used for data analysis. At thermal decomposition stage, metallization increased with treatment time, it was flatter at higher temperature but remained consistently higher than at lower temperatures. At ion exchange stage, metallization was random, yet showing much lower magnitude than the metallization at thermal decomposition stage. At carbo-thermic reduction stage, metallization decreased with increased treatment time at 1273K and 1473K for different C/CaO ratio, however the opposite phenomenon occurred at 1373K. In general, higher carbon to calcium oxide ratio triggered more metallization.

Analytical and magnetic characterization of the pyrite Carbothermic reduction in the presence of lime

2025-06-27T15:00:35+02:00

The Otjihase mining and processing design allows the recovery of copper in the first stage of flotation and pyrite in the second. Pyrite production was discontinued in 2001, because of market reasons, since then any pyrite content of the ore, ended at tailings dam. This threatened the financial and operational performances, while compromising environment integrity. An alternative to these challenges, was a value addition to pyrite through iron metallization for industrial applications diversification. Carbothermic reduction of complex sulphides minerals was reported, metallization was effective and sulphur was captured in a solid phase. Therefore this study investigated the iron metallization degree at three stages at: 1273K, 1373K, 1473K and used ANOVA for data analysis focussing on analytical and magnetic results. The study found that sulphur was completely depleted and iron concentration reached 68.59 % at 1473K. At ion exchange sulphur was captured in solid and at carbo-thermic reduction increased C/CaO increased iron concentration but reduces residual sulphur.

Application of portable X-ray fluorescence for exploration of carbonate-hosted sulfide mineralisation, Otavi Mountain Land, Namibia

2025-02-06T12:52:13+02:00

Otavi Mountain Land province forms part of the Damara Orogenic Belt within the Neoproterozoic carbonate platform, which is well-known for its sedimentary-hosted, polymetallic mineralized zones, including the Cu-Pb(-Ag) Kombat deposit. The mineralisation at Kombat is of massive, disseminated, veinlet-controlled and brecciated mineralisation styles it comprises mainly of bornite, chalcopyrite, galena, covellite and chalcocite associated with quartz and calcite as gangue minerals. Mineralized zones are distinctly enriched in chalcophile elements, including Pb, Cu, As and Ag. For the analysis of such rocks, laboratory-based analytical methods, including inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectroscopy (AAS), are well established, in contrast to on-site geochemical analytical methods. This study shows the applicability and limitations of portable X-ray fluorescence (pXRF) in the geochemical exploration of sulfide (Ag, Cu, Fe, Mn, Pb, Zn) ores in carbonate matrix. By using additional ICP-MS/AAS data and certified reference materials, the applicability of such portable tools can be assessed for Kombat-type ores, resulting in pXRF data of excellent or very good precision for elements like Cu, Fe, Mn, Pb and Zn (RSD ≤10%), while other elements (Ag, Sr) show poor precision. The trace element concentrations obtained by pXRF are comparable to ICP-MS results yielding a good correlation (R² ≥0.85) and acceptable accuracy and precision. Portable XRF is identified as a low-cost tool that can be used successfully in the geochemical exploration for a list of elements in carbonate-hosted sulfide ores.

Isolation and identification of selected bacterial pathogens from various markets in Windhoek

2025-07-10T14:28:52+02:00

This study assessed the microbiological quality of fresh fish, specifically focusing on bacterial contamination. Fish samples, including Merluccius species (hake) and Trachurus species (horse mackerel), were collected from wholesalers and retailers in Windhoek, Namibia. The key bacterial pathogens such as Salmonella species, Shigella sonnei, Staphylococcus aureus and Escherichia coli, were isolated and identified through standard microbiological methods. The presence of these pathogens indicates potential health risks, such as foodborne illnesses and underscores the need for stringent quality control in fish handling, processing, and storage. The findings highlight the importance of public health interventions and quality assurance measures to ensure consumer safety and maintain industry reputation.

The Prevalence of depression among inpatients and outpatients and key associated sociodemographic and clinical factors, 2010 - 2022: A systematic review

2025-06-30T13:14:22+02:00

Depression has a higher prevalence than other mood disorders, and the disability it causes is a global burden. Although mental health is an essential component of normal functioning and health, mental disorders such as depression are neglected. The study aimed to summarise the prevalence of depression, gender differences, and associated factors in inpatients and outpatients. A systematic review approach was used, whereby the PubMed, Google Scholar and Scopus electronic databases were searched for studies published between the years 2010 and 2022 to identify observational studies with the above information on different continents. Data characteristics were extracted independently by two investigators. After scanning and evaluation, 52 articles were initially identified. After further screening, 29 articles were reviewed for the study. These 29 cross-sectional studies included a total of 46979 individuals. From the literature reviewed, common factors associated with depression included demographic characteristics, biopsychosocial factors, substance abuse, a history or family history of mental illness, and a history or family history of chronic illness. Women were more prone to depression than men (54.9%). In terms of geographical location, the prevalence of depression was highest in North America at 36.0% and lowest in Europe at 25.0%. Further studies are needed to evaluate the prevalence of depression and associated factors specific to other geographical locations.