Occupational lung disease among Basotho ex-miners in a large outreach medical assessment programme

Background: Current initiatives in southern Africa to medically assess former migrant miners for silicosis and tuberculosis, including statutory and lawsuit derived compensation programmes, require burden of disease information. nObjective: To use clinical information collected on ex-miners examined at the Occupational Health Service Centre (OHSC) in Lesotho, operated under the Tuberculosis in Mining Sector in Southern Africa (TIMS) project, to measure the burden of lung disease and respiratory impairment. Methods: Demographic, occupational and medical history information, chest radiology, spirometry, GeneXpert testing for tuberculosis, and pulse oximetry outcomes were analysed, and descriptive summary measures calculated, in a group of ex-miners examined in 2017 and 2018. Results: The study sample comprised 2 758 Basotho former underground miners, with median age of 62 years and median length of service of 28 years. Among ex-gold miners (n = 2 678), disease prevalence was high: radiological tuberculosis (consistent with previous or current disease) 60.9%, silicosis 42.5%, HIV 30.7%, silicotuberculosis 25.7%, and current active tuberculosis 6.8%. Of those with tuberculosis diagnosed microbiologically, 6.7% had no radiological evidence of tuberculosis and 54.1% did not report cough. Conclusion: The findings have public health and compensation implications. There are large numbers of ex-miners with potentially compensable disease under both the statutory system and a settlement trust set up following litigation. This overlaps with a tuberculosis-HIV co-epidemic which requires screening and treatment for tuberculosis and HIV, and managing a considerable disability and care burden on families and the Lesotho health system. Coordinated planning and substantial resources are needed for these programmes to do justice to their mandates

Modelling the distribution of Rhipicephalus microplus and R. decoloratus in Zimbabwe.

Species distribution modelling is a very useful tool in vector management. Ticks are vectors of various pathogens which cause serious problems in livestock production in tropical countries. They have a high dispersal potential which is mainly facilitated by the movement of animals from one area to another. In light of the observed geographic expansion of Rhipicephalus microplus in Zimbabwe, we used species distribution modelling techniques to identify areas which may provide suitable habitats for the occurrence of this invasive tick species as well as the autochthonous Rhipicephalus decoloratus. Our results suggest that, despite the geographic expansion of R. microplus, climate will continue to be a limiting factor for the further expansion of this tick species. We expect its distribution to be restricted to the most favourable areas in the eastern and northern parts. The greater part of Zimbabwe is suitable for R. decoloratus, although in areas where R. microplus occurs, displacement of the former by the latter will be expected to occur. A heterogeneous climate, unregulated movement of cattle and episodic droughts are suggested to be possible factors for the continued existence of R. microplus and R. decoloratus in Zimbabwe and the partial displacement.

Shifts in the distribution of ixodid ticks parasitizing cattle in Zimbabwe.

In an attempt to update information on the ecological distribution of ixodid ticks (Ixodida: Ixodidae) in Zimbabwe, a cross-sectional survey was carried out between September 2013 and May 2015 at 322 dip tanks. A total of 15 tick species were collected, namely: Amblyomma hebraeum Koch (65.2%, n = 210/322), Amblyomma variegatum Fabricius (14.9%, n = 48/322), Hyalomma rufipes Koch (62.4%, n = 201/322), Hyalomma truncatum Koch (37.9%, n = 122/322), Rhipicephalus appendiculatus Neumann (60.6%, n = 195/322), Rhipicephalus compositus Neumann (0.3%, n = 1/322,), Rhipicephalus decoloratus Koch (61.8%, n = 199/322), Rhipicephalus evertsi evertsi Neumann (65.2%, n = 210/322), Rhipicephalus lunulatus Neumann (4%, n = 13/322), Rhipicephalus microplus Canestrini (32%, n = 103/322), Rhipicephalus near punctatus Walker and Horak (7.1%, n = 23/322), Rhipicephalus simus Koch (5.6%, n = 18/322) and Rhipicephalus cf. turanicus Pomerantsev (3.4%, n = 11/322). Compared with previous surveys, changes in the distribution of A. hebraeum, A. variegatum and R. microplus were recorded. The distributions of other tick species have largely remained unchanged. Factors which might have influenced these changes and the possible impacts on the epidemiology of tick-borne diseases are discussed.

Effect of dietary Ximenia caffra kernel meal on blood and liver metabolic substrate content and the general clinical biochemistry of Sprague Dawley rats.

We investigated (at the University of the Witwatersrand: GPS coordinates 26°10' 52.96″S; 28°2' 33.61″E) the effects of substituting soya bean meal (SBM) with Ximenia caffra kernel meal (XCKM) as a dietary protein source on blood and liver metabolic substrates content, serum markers of liver and kidney function and the general clinical biochemistry of Sprague Dawley (SD) rats. Five diets with similar energy and protein content were formulated (D1-D5) where XCKM replaced SBM on a crude protein basis at 0, 25, 50, 75 and 100%. Forty weanling male SD rats were randomly assigned to diets D1-D5, fed for 37 days and weighed twice weekly. The rats were then fasted overnight, and fasting blood glucose and triglyceride concentrations were determined from tail-vein-drawn blood. Immediately thereafter, the rats were euthanised and blood was collected via cardiac puncture. Serum was used to assay for markers of the general health profile. Livers were removed and weighed, and samples were used to determine lipid and glycogen content. Rats fed D4 (75% substitution level) had significantly lower (p < 0.05) blood triglyceride content compared with rats fed D2 (25% level of substitution). The substitution of SBM with XCKM did not affect (p > 0.05) fasting blood glucose and cholesterol concentrations, liver glycogen and lipid content. Additionally, it had no effect (p > 0.05) on serum activity/concentration of surrogate markers of liver (alanine aminotransferase and alkaline phosphatase activity and urea, total bilirubin, globulin and albumin concentrations) and kidney (phosphorus, calcium and creatinine concentrations) function and the general clinical biochemistry of the rats. Defatted XCKM could substitute SBM in rat diets without compromising blood glucose and cholesterol homeostasis, liver and kidney function and the general clinical biochemistry of growing male Sprague Dawley rats.

Cohort study of diabetes in HIV-infected adult patients: evaluating the effect of diabetes mellitus on immune reconstitution.

We conducted a retrospective cohort study assessing the association between diabetes mellitus (DM) and immune recovery in HIV-infected adults. Immune reconstitution after initiating antiretroviral therapy was more rapid in DM patients (120.4 cells/year) compared to non-DM patients (94.2 cells/year, p<0.023). Metformin use was associated with improved CD4 recovery (p=0.034).

Diabetes mellitus in HIV-infected patients receiving antiretroviral therapy.

BACKGROUND: There is little in the literature on HIV and diabetes mellitus (DM) in sub-Saharan Africa. OBJECTIVE: To assess the characteristics of HIV and DM in patients receiving antiretroviral therapy (ART) in Botswana. METHODS: A retrospective case-control study was conducted at 4 sites. Each HIV-infected patient with DM (n=48) was matched with 2 HIV-infected controls (n=108) by age (±2 years) and sex. Primary analysis was conditional logistic regression to estimate univariate odds and 95% confidence intervals (CIs) for each characteristic. RESULTS: There was no significant association between co-morbid diseases, tuberculosis, hypertension or cancer and risk of diabetes. DM patients were more likely to have higher pre-ART weight (odds ratio (OR) 1.09; 95% CI 1.04 - 1.14). HIV-infected adults >70 kg were significantly more likely to have DM (OR 12.30; 95% CI 1.40 - 107.98). Participants receiving efavirenz (OR 4.58; 95% CI 1.44 - 14.57) or protease inhibitor therapy (OR 20.7; 95% CI 1.79 - 240.02) were more likely to have DM. Neither mean pre-ART CD4 cell count (OR 1.0; 95% CI 0.99 - 1.01) nor pre-ART viral load >100 000 copies/ml (OR 0.71; 95% CI 0.21 - 2.43) were associated with a significant risk of diabetes. CONCLUSIONS: These findings suggest a complex interrelation among traditional host factors and treatment-related metabolic changes in the pathogenesis of DM inpatients receiving ART. Notably, pre-ART weight, particularly if >70 kg, is associated with the diagnosis of diabetes in HIV-infected patients in Botswana.

[Epidemiology of obesity in the work milieu, Douala, Cameroon]. / Epidémiologie de l'obésité en milieu du travail à Douala, Cameroun.

Obesity is a worldwide public health problem, and its burden has been poorly explored in Cameroon, especially in work place. We therefore carried out in April 2010, an analytic cross-sectional study aiming to determine the prevalence of obesity, associated risk factors and health risk in six randomly selected enterprises based in Douala. Among the 552 participants, 383 (69.4%) were males. Most of the workers (55.4%) were aged less than 35 years old. There was 191 (34.60%) office staff as against 361 (65.40%) labourers. In each participant, blood pressures, and fasting blood glucose were recorded, as well as obesity indexes comprising body mass index and waist circumference. They were calculated and data analyzed using SPSS 16 and Win Pepi 11.8. The prevalence of obesity in workers was 23.4%, and was more pronounced in women than in men (36.1% vs 17.8%; P < 0.005). The workers aged > or = 45 years old exhibited highest obesity rate than other age group (P = 0.03). Importantly, the prevalence of hypertension was two fold greater in obese workers than non obese (P < 0.005; RR = 2.1; IC 95%: 1.57-2.83). 271 (49.1%) of the workers were overweight. Among the obese subjects, those with visceral obesity: 56 (43.4%) females with a waist circumference > 88 cm and 41 (31.8%) men with a waist circumference > 102 cm were at very high health risk. Obesity was significantly associated with excessive alcohol consumption (P = 0.013) and high salt diet (P = 0.022). This study reveals a high burden of obesity in the work place in Douala and outlines the urgent needs of implementation of prevention programme in that milieu.

The effect of treatment with a 1% injectable formulation of moxidectin during the rainy season and at the beginning of the dry season on gastrointestinal nematodes in cattle from communal areas in Zimbabwe.

The effect of 1% moxidectin/cydectin at 0.2 mg/kg live weight on gastrointestinal nematodes and on the growth of calves, weaners and cows was investigated in five communal areas on the highveld of Zimbabwe. Three field experiments were carried out between March 1996 and June 1997. In experiment 1, treatment was administered in all five areas at the end of the rainy season in March 1996, followed by a further treatment at the beginning of the dry season in May/June 1996. In experiment 2, the treatment was administered in three areas at the end of the rainy season in March 1997. In experiment 3, treatment was administcred in one area at the beginning of the dry season in April 1997. Large numbers of eggs were present in the faeces of calves and weaners at the start of experiments 1 and 2. Epg values were lower in cows and in all age categories in experiment 3. There was a statistically significant reduction in epg values in calves, weaners and cows following treatment with a reduction of 90-99% in all cases except in cows in experiment 3, where no meaningful assessment was possible owing to the low egg counts in both the treated and control cows. The dominating larval types in faecal cultures were Cooperia and Haemonchus. Trichostrongylus, Oesophagostomum and Bunostomum were also found. Following treatment, Haemonchus was suppressed far more than Cooperia. This may be related to a longer residual effect against abomasal parasites like Haemonchus in comparison to small intestinal worms like Cooperia. Anthelmintic treatment conferred significant weight gain advantages (p < 0.05) on treated calves. weaners and cows. The weight gains are discussed in relation to disease and nutrition.

The epidemiology of gastrointestinal nematode infections in communal cattle and commercial beef cattle on the highveld of Zimbabwe.

An epidemiological study of gastrointestinal nematode infections of cattle was conducted on the highveld of Zimbabwe from June 1993 to May 1995. The study was carried out in two communal areas, two conventional beef farms and two commercial beef farms with irrigated pastures. On all farms/areas, faecal egg counts were low (< 500 eggs per g faeces) during the dry season. During the rainy season faecal egg counts were highest in communal areas and lowest in conventional beef farms. Those of irrigated farms had intermediate values. During the dry season pasture larval counts were low in irrigated pastures and conventional beef farms and virtually zero in communal areas. They increased and peaked during the rainy season, coinciding with the egg count peaks. Worm burdens of necropsied cattle indicated that 100% of the animals were infected with nematodes. The important species were Cooperia pectinata, C. punctata, Haemonchus placei, Trichostrongylus axei and Oesophagostomum radiatum in all farms/areas and Ostertagia ostertagi in a beef farm with irrigated pastures. Haemonchus survived the dry season as inhibited early fourth stage larvae whereas Cooperia and Trichostrongylus survived as adults.

Bovine humoral immune responses to Haemonchus placei excretory secretory antigens.

The immune response of calves against excretory secretory (ES) products of adult Haemonchus placei was studied. The ES products of adult H. placei comprise at least ten polypeptides with molecular weights ranging from 10 to over 100 kDa. A primary infection of calves with H. placei did not result in a marked elevation of IgG serum antibodies reactive to ES antigens as demonstrated by ELISA. Immunoblotting experiments revealed that sera of primary infected calves recognised a 50 kDa antigen in most cases. An increase in the level of serum IgG antibodies was observed after trickle infections. The secondary immune response coincided with the recognition of a group of three ES antigens of around 50-55 kDa and one protein with a molecular weight of 24 kDa.

Detection of bovine-virus-diarrhoea-virus antibodies in cattle with an enzyme-linked immunosorbent assay.

The serum-neutralization (SN) and the indirect-immunofluorescence (IIF) assays have invariably been used for detecting antibodies against bovine virus diarrhoea virus (BVDV) in cattle sera. An enzyme-linked immunosorbent assay (ELISA) was applied which has a sensitivity comparable with the SN and IIF in detecting antibody to BVDV. A total of 472 bovine sera were assayed and a high prevalence of 79.2% was recorded. Positive correlations between the ELISA and the SN were found when certain sera were assayed, implying that the former test could then be used for routine diagnosis of BVDV.