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- Volume 20, Issue 4, 2005
Southern African Journal of Epidemiology and Infection - Volume 20, Issue 4, 2005
Volume 20, Issue 4, 2005
Author Richard MatzopoulosSource: Southern African Journal of Epidemiology and Infection 20, pp 114 –115 (2005)More Less
Injuries, alongside infectious diseases and chronic health conditions, are significant contributors to Africa's burden of disease with injury death rates currently 60% higher than global averages. As increased motorisation exposes more Africans to the risk of collisions and conflicts continue unabated, the WHO estimates that injuries will increase to rank as the second major contributor to African mortality by 2020. The situation in South Africa is even worse : road traffic mortality rates are more than 50% higher than global averages and the homicide rate approximately four times higher.
Source: Southern African Journal of Epidemiology and Infection 20, pp 116 –118 (2005)More Less
In the United Kingdom (UK), as late as 1850, almost unbelievably, the average expectation of life among the numerous poor, namely the 'mechanics, servants and labourers', was only 16 years; it was 26 years for 'tradesmen', but was 45 years for 'gentlemen'. At present, in tremendous contrast, average survival times of populations in many developed countries are very high, the longest ever. Thus, in the UK, mean survival times are approximately 74 years for males and 79 years for females. The enormous increases are largely attributable to the now very low mortality rates among the young, and to the excellent remedial treatments available for adults when ill, particularly for patients suffering from cardiovascular diseases and cancer.
Source: Southern African Journal of Epidemiology and Infection 20, pp 119 –120 (2005)More Less
A study was conducted to determine the relative susceptibilities of Bacillus anthracis to ciprofloxacin compared to moxifloxacin, an agent with enhanced potency against other Gram-positive pathogens. The minimum inhibitory concentrations (MICs) of 51 isolates of B. anthracis from southern African countries, as well as the Sterne vaccine strain, were determined by broth microdilution. All isolates were susceptible to the two quinolones, but ciprofloxacin was slightly more active than moxifloxacin. All isolates were susceptible to doxycycline. Moxifloxacin offers no MIC advantage over ciprofloxacin for the management of wild type infections caused by B. anthracis.
Author C.S. ToiSource: Southern African Journal of Epidemiology and Infection 20, pp 121 –126 (2005)More Less
Bacterial communities are characteristic for distinctive ecological niches. Yet, some indigenous bacteria have the potential to express virulence characteristics when a change in the environment disturbs natural stability, producing a condition of disease. An example of such a system is the human mouth where dental caries can result from the complex interaction of diet, the normal bacterial flora and the host. The mutans streptococci species are most implicated in the cause of this disease. They constitute part of the natural oral flora but express virulence when exposed to increased dietary carbohydrate, especially sucrose. Yet, dental caries is also a transmissible disease, with mutans streptococci acquired and spread through contact from various sources. Modern molecular biology methods have been used to trace the spread of infection and now provide the strongest evidence of the source of transmission of infection in dental caries. These methods also provide insight into change in virulence gene expression and that different levels of virulence are associated with genetic differences between mutans streptococci strains. Surveillance of this complex pathogen in South Africa is reviewed herein.
Detection of Staphylococcus aureus with reduced susceptibility to vancomycin in a South African teaching hospitalSource: Southern African Journal of Epidemiology and Infection 20, pp 127 –129 (2005)More Less
Fifty-six methicillin-resistant Staphylococcus aureus clinical isolates were collected over a two-month period from a large teaching hospital in Pretoria, South Africa. Isolates were subjected to screening and confirmatory testing for vancomycin hetero-resistance. Thirty-three isolates were identified with the macro-method Etest as possibly being hetero-resistant to vancomycin. Twenty randomly selected hetero-resistant isolates were subjected to population analysis profile, area under the curve ratio methodology, of which 18 were confirmed to be vancomycin hetero-resistant. As a screening test, the macro-method Etest thus exhibited high sensitivity and specificity, for detecting hetero-resistant S. aureus at this institution.
Clinical and radiological features of pulmonary disease due to culture-positive M. tuberculosis or nontuberculous mycobacteria in South African gold minersSource: Southern African Journal of Epidemiology and Infection 20, pp 130 –135 (2005)More Less
Distinguishing whether pulmonary mycobacterial disease is due to Mycobacterium tuberculosis or nontuberculous mycobacteria (NTM) has important clinical and public health implications. There are limited data comparing these groups of patients, particularly from developing countries in the era of HIV infection. South African mineworkers have high rates of tuberculosis (TB), NTM disease and HIV infection. The study took place in a hospital serving four gold mines. All men with a positive sputum mycobacterial culture in 1995 were enrolled. Patients were interviewed, sputum and blood samples obtained and a chest radiograph taken. We compared clinical, laboratory and radiological features in those with TB with those with NTM disease (mainly Mycobacterium kansasii). Treatment outcomes are reported for those with pulmonary disease due to M. kansasii. The 425 patients with TB and 51 with NTM disease showed no significant difference in HIV status. Of patients with a positive smear, 91.3% (314/344) cultured M. tuberculosis. Patients with TB weighed less (p=0.03) and had lower haemoglobin levels (p<0.001). Those with NTM were less likely to have extensive radiographic changes (OR 0.27) than those with TB. Those with NTM were more likely to have silicosis (OR 9.7). Fourteen of the 36 patients with M. kansasii pulmonary disease had a positive culture at six months and a further 11 had a positive culture in the follow-up period. Patients with TB had features of more aggressive disease. The current practice of treating smear-positive patients as TB seems reasonable. Treatment failure and relapse were common in those with disease due to M. Kansasii.
Smokeless tobacco products on the South African market do not inhibit oral bacterial flora : a pilot studySource: Southern African Journal of Epidemiology and Infection 20, pp 136 –139 (2005)More Less
Smokeless tobacco (ST) is commonly used by black South African women because of its perceived medicinal properties. This pilot study sought to evaluate the antibacterial effect of the local ST products on salivary microflora, using a growth medium. The five ST products tested included three traditional mixtures (brands A, B, C) and two popular industrially manufactured brands (Taxi and Ntsu). The following dilutions of supernatant solution of aqueous extracts of ST were prepared : 'pure' extract (100%), 75%, 50% and 25%. 50 µl of each ST extract of varying dilution was aseptically placed on sterilised grade 1 filter paper discs of diameter 2.5 cm, which was then placed on the saliva suspension in blood agar plates (BAPs) and incubated at 37°C aerobically and anaerobically for 72 hours. All BAPs, in duplicate, were then visually examined for inhibition zones after 24-, 48- and 72 hours. No bacterial inhibition zone was observed under aerobic or anaerobic conditions with any of the ST products tested, independent of time or the concentration of the ST suspension. However, a striking observation associated with both industrially manufactured brands and two traditional mixtures tested (A & B), was the presence of a zone of haemolysis within which bacterial colonies, identified as Gram-positive Bacillus species, was observed. This was only observed under aerobic conditions with and without saliva inoculums, and with 100% and 75% extract dilutions at 72 hour post-incubation. This preliminary finding of the presence of Bacillus spp with potential health implications, suggests the need for further investigations of bacterial activity in ST.