The Strongyloides stercoralis-hookworms association as a path to the estimation of the global burden of strongyloidiasis: A systematic review

Soil-transmitted helminths (STH) represent a significant public health problem. However, Strongyloides stercoralis is not yet integrated into the control strategy against STH, given limi- tations to accurately assess its burden. Considering that S. stercoralis shares biological and epidemiological characteristics with hookworms, we describe a new approach for an improved estimation of the burden of infections by S. stercoralis based on the prevalence and burden of hookworms and the relationship between these species. A systematic review of publications reporting prevalence rates for S. stercoralis and hookworms was carried out. The data was classified into two categories: 1) “Community”, with surveys including all age groups, and 2) “SAC”, with surveys limited to school-aged children. The relationship between S. stercoralis and hookworms was characterized in order to estimate the global burden of S. stercoralis infections. The study is registered in PROSPERO (CRD42019131127). Spearman correlation coefficient between S. stercoralis and hookworms was estimated and the global burden of S. stercoralis infections was estimated using a regression model. A total of 119 articles were included, and a significant positive correlation between the burden of S. stercoralis and hook- worms was identified. Spearman’s coefficient for Community surveys was 0.94 and for SAC surveys it was 0.63. Based on the linear model, the global burden of S. stercoralis infections was estimated at 386 million (95%CI 324–449 million) people, including 22 million (95%CI 20–24 million) SAC. The significant relationship between S. stercoralis and hookworms allows an estimation of the global burden of S. stercoralis infections in most epidemiologic settings using hookworm burden and justifies the search of integrated control activities

Effect of Cr(V) on reproductive organ morphology and sperm parameters: An experimental study in mice

BACKGROUND: Cr(V) species are formed during the intracellular reduction of Cr(VI), a ubiquitous environmental pollutant. In this study, the acute toxicity of a physiologically stable Cr(V) compound, [Cr(V)-BT](2- )(BT = bis(hydroxyethyl)aminotris(hydroxymethyl)methane) was investigated in the male reproductive system of sexually mature 60-day-old male ICR-CD1 mice. METHODS: Eight-week-old animals were subcutaneously injected daily with a dose of ca 8 μmol of Cr/mouse, during 5 days. The control group was injected with 0.5 mL of BT buffer. Testis and epididymis morphology was evaluated using light and transmission electron microscopy. Epididymal sperm counts, motility and acrosome integrity were also assayed using standard methods. RESULTS: Seminiferous epithelium abnormalities were detected in the Cr(V)-BT experimental group, including intraepithelial vacuolation, and remarkable degeneration of Sertoli cells, spermatocytes and spermatids. The premature release of germ cells into the tubular lumen was also evident. Histological evaluation of epididymal compartments revealed apparently normal features. However, the epididymal epithelium presented vacuolation. [Cr(V)-BT](2- )induced a reduction in sperm acrosome integrity. However, sperm motility and density were not significantly affected. CONCLUSION: This in vivo study using a Cr(V) compound, provides evidence for the potential reproductive hazards caused on male reproductive system by species containing chromium in intermediate oxidation states

Cobalt-chromium toxic retinopathy case study

Purpose: To report the clinical case of a 65-year-old male who developed retinal dysfunction following cobalt-chromium toxicity. Methods: A review of the clinical, haematological, radiological and electrophysiological investigations into a single patient was performed in order to form a case report. Results: A 65-year-old male presented to his ophthalmologist with a 1-year history of worsening vision on the background of a multisystem illness including motor axonopathy, pericardiomyopathy and bulbar palsy. His medical history included hypertension, hypercholesterolaemia and a metallic hip prosthesis. Ocular examination revealed significantly reduced visual acuity bilaterally along with very poor colour vision. Cornea, fundi and optic discs all appeared normal. Bilateral moderate nuclear sclerosis was noted. Basic investigations including mitochondrial studies, auto-immune screen and MRI of brain were unremarkable. Further investigations showed significantly elevated plasma cobalt and chromium levels. Electrophysiological studies revealed an abnormality in all phases of the ERG including a negative b-waveform, suggestive of inner retinal pathology. Following subsequent revision of the hip, cobalt and chromium levels decreased and the patient's vision improved. Further electrophysiological testing indicates a persistent ERG abnormality despite a significant improvement in both the patient's visual acuity and colour vision. Conclusions: These results suggest that cobalt-chromium toxicity can cause inner retinal dysfunction