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- Southern African Journal of Epidemiology and Infection
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- Volume 25, Issue 4, 2010
Southern African Journal of Epidemiology and Infection - Volume 25, Issue 4, 2010
Volume 25, Issue 4, 2010
Source: Southern African Journal of Epidemiology and Infection 25, pp 3 –4 (2010)More Less
Immunisation has been called one of the best buys in health. This success has led to substantial efforts to develop new vaccines against a range of infectious agents responsible for significant childhood morbidity and mortality. As research and development, clinical trials, registration and marketing have become a lengthy, complex and expensive process, so too health authorities and donor organisations have weighed up the cost of a new vaccine in the light of efficacy and effectiveness, perceptions and priorities, and the capacity of a country to deliver and sustain expanded immunisation programmes. It is therefore not surprising that in many developing countries, often the very places where the vaccines are most needed, it can take decades before a new childhood vaccine is introduced.
Source: Southern African Journal of Epidemiology and Infection 25, pp 5 –6 (2010)More Less
Tigecycline, the first of a new class of broad-spectrum antibiotics, the glycylcyclines, has been licensed in South Africa for the parenteral treatment of adult patients with complicated intra-abdominal (cIAI) and complicated skin and soft tissue infections (cSSTI).
This document serves as a summary of the recently published guideline on the appropriate use of tigecycline, a collaborative effort by representatives of the Association of Surgeons of South Africa, the Critical Care Society of Southern Africa, the Federation of Infectious Diseases Societies of Southern Africa, the South African Thoracic Society, and the Trauma Society of South Africa.
The guideline addressed important aspects of the new agent, including details of its metabolism and pharmacokinetics, mode of action, antibacterial spectrum, performance in key clinical trials (including data regarding its safety and tolerability), and also highlighted appropriate use of the drug. Other aspects that were considered included breakpoints for susceptibility testing, in vitro and in vivo data for activity against multi-drug resistant (MDR) pathogens, such as carbapenem-resistant Acinetobacter baumannii, Enterobacteriaceae and Stenotrophomonas maltophilia, and use in bacteraemic patients and Clostridium difficile infections (CDI).
The guideline and summary were written because of concern regarding the widespread misuse of antibiotics. The primary intention of the current publication is to facilitate, through a brief summary published in several professional journals, the heterogeneous use of antibiotics as a component of antibiotic stewardship. The emphasis is on clinical profiles that could potentially benefit from empiric or directed tigecycline therapy.
Source: Southern African Journal of Epidemiology and Infection 25, pp 7 –10 (2010)More Less
Mycoplasma genitalium belongs to the class Mollicutes and is the smallest prokaryote capable of independent replication. It was originally isolated from the urethras of two men with non-gonococcal urethritis (NGU). It has a number of characteristics which are similar to its genetically close relative, Mycoplasma pneumoniae, which is an established pathogen of the respiratory tract. M. genitalium lacks a cell wall and has a characteristic pear / flask shape with a terminal tip organelle. This organelle enables M. genitalium to glide along and adhere to moist / mucous surfaces, including host cells. M. genitalium has minimal metabolism, and when compared to the other genital mycoplasmas, has the ability to metabolise glucose. The organism is the smallest self-replicating prokaryote with a genome of only 580 kb pairs and was the second bacterium to have its genome fully sequenced. Its DNA falls under the low G+C category and thus has a lower melting temperature during denaturation in polymerase chain reaction (PCR) assays. The target genes for PCR assays include MgPa, rRNA and gap. M. genitalium has several virulence factors that are responsible for its pathogenicity. These include the ability to adhere to host epithelial cells using the terminal tip organelle with its adhesins, the release of enzymes and the ability to evade the host immune response by antigenic variation.
Superior detection of pathogens in synovial fluid by the Bactec 9240 Peds Plus/F system compared to the conventional agar-based culture method : original researchSource: Southern African Journal of Epidemiology and Infection 25, pp 11 –14 (2010)More Less
To improve culture yield in cases of possible septic arthritis, we compared culture of joint fluid aspirates on conventional agar-based media to culture in Bactec 9240 Peds/Plus F blood culture bottles with and without the addition of fastidious organism supplement (FOS). Over a period of 21 months, we analysed 123 synovial fluid samples and isolated 20 pathogens. The Bactec methods proved superior by yielding more pathogens than the conventional culture method (p=0.074). However, this method also yielded more contaminants within the first three days of incubation (p=0.027). All contaminants detected after three days of incubation were the result of overgrowth on conventional method agar plates. The Bactec methods provided clinicians with a positive pathogen result one day earlier than the conventional counterpart (p=0.001). Four isolates of Neisseria gonorrhoeae were only cultured with the Bactec method. No significant benefit was demonstrated by supplementing blood culture bottles with FOS. We recommend that whenever infection by fastidious organisms is suspected, synovial fluid aspirates should be cultured using automated blood culture systems to increase the culture yield and to decrease the time to detection.
Bacteriological profile and antibiogram of aerobic burn wound isolates in Mthatha, Eastern Cape, South Africa : original researchSource: Southern African Journal of Epidemiology and Infection 25, pp 16 –19 (2010)More Less
Burn wound colonisation and infection is not only associated with delayed wound healing and scar formation, but may also lead to sepsis-related mortality. A wide variety of microorganisms, like staphylococcus aureus, Pseudomonas aeruginosa, and Enterobacteriaceae-like Klebsiella pneumoniae and Escherichia coli, are involved. Resistance is generally increasing, with reports of multidrug- and pan-resistant isolates. This study was conducted to determine the common aerobic bacterial isolates in our setting and describe their antimicrobial susceptibility. This retrospective, descriptive study was carried out on 243 patients, from whom 312 burn wound specimens were received by the Nelson Mandela Academic Hospital microbiology laboratory of the National Health Laboratory Service, Mthatha. All samples were processed according to standard laboratory protocols; isolates were tabulated according to age and gender of the patients, and their percentage susceptibilities to relevant antibacterials were computed. A total of 229 patient specimens showed growth on culture. The total number of isolates was 629, out of which 269 were Gram-positive cocci and 360 were Gram-negative bacilli. The commonest organism was S. aureus (27.7%), followed by K. pneumoniae (13.4%), Proteus mirabilis (12.4%), Group D streptococcus (9.4%), P. aeruginosa (8.9%) and E. coli (6.2%). A generally high level of resistance was observed in many organisms. Methicillin-resistant S. aureus accounted for 57.5% of the S. aureus. Resistance among the Gram-negative bacilli was, in general, least to imipenem, amikacin and ciprofloxacin. The common organisms causing burn wound infections in our setting include staphylococci, Klebsiella, Proteus and Pseudomonas and there is a high level of resistance against commonly used antimicrobials. Regular surveillance of burn wound organisms and their antimicrobial resistance patterns will help in determining empirical antibiotic therapy for subsequent related septic events.
Source: Southern African Journal of Epidemiology and Infection 25, pp 22 –26 (2010)More Less
Although malaria is a controllable and preventable disease, it remains among the leading causes of mortality and morbidity in southern Malawi. The importance of early diagnosis and prompt treatment with hospital prescribed drugs and effective home management to control malaria is well established; however, these in part depend on how households make their decisions when family members have suffered from malaria. This study examines the behaviour of households with regard to decisions they make in managing malaria illness. Using hierarchically built data from a survey of 1,400 mothers nested within 33 communities, a series of two-level logistic regression models with Bayesian estimation was used to determine predictors of care-seeking behaviour towards malaria when a family member or a child was perceived to have malaria. The results show that most families normally visit or use medication prescribed at health facilities for both adult (80%) and child (86%) members when they are perceived to have malaria. The main obstacle to accessing the nearest health facility was distance and transport costs (73%) and the main problems encountered at health facilities were long waiting time or absence of health workers (73%) and shortage of drugs (35%). Among the main predictor variables for choices of treatment for childhood malaria was the absence of a health surveillance assistant for those that visited hospitals [β=0.56; 95% CI:-0.86, -0.26]; bought medication from open markets [β=0.51; 95% CI:0.20,0.82]; and those that used other traditional methods or did nothing [β=0.70; 95% CI:-0.04,1.44; p=0.06]. The results have an important role to play in the control and prevention of malaria in Malawi. The results reveal the need for increased awareness about the dangers of purchasing drugs from non-medical and/or uncertified private institutions and sources such as those found in open markets. They also show the important role of community health workers in the delivery of health systems. The study recommends empowerment of community health workers through rigorous and relevant health promotion programmes to update both their knowledge and their skills in communication and counselling.
Schistosoma haematobium prevalence in school children in the rural Eastern Cape Province, South Africa : brief reportSource: Southern African Journal of Epidemiology and Infection 25, pp 28 –29 (2010)More Less
The urine of 209 children was examined for haematuria and the presence of schistosome eggs. Comparing the infection rate of 72.3% with existing data suggests an increase in the prevalence over the last decades. Schistosomiasis lacks the attention it deserves in South Africa.
Schistosomiasis and water-related practices in school girls in rural KwaZulu-Natal, South Africa : original researchSource: Southern African Journal of Epidemiology and Infection 25, pp 30 –33 (2010)More Less
There is increasing evidence of an association between female genital Schistosoma haematobium infection and HIV. In KwaZulu-Natal, we aimed to explore girls' water contact practice and to determine whether a study exclusively on girls would be manageable and welcomed. Three primary schools that had participated in a parasite control programme eight years prior were approached. Subject to consent, girls aged 9 to 12 years were interviewed on water-body contact, symptoms and household composition. Urine samples were analysed for S. haematobium infection eggs. Good dialogue was achieved in all schools and 95% consented to participation; 43% had an S. haematobium infection, geometric mean intensity 10.5 ova per 10 ml urine. Only 12% had ever been treated for S. haematobium. Water-body contact was significantly associated with S. haematobium (OR 2.8, 95% CI 1.3-5.9, p= 0.008); however, S. haematobium was also found in 20% of girls who claimed to never have had water-body contact. Sixty-four percent thought they had no choice but to use unprotected water; 21% had no mother in the household, and being an orphan increased the risk of having S. haematobium. The community welcomed the study. Prevalence levels in South Africa are so high that some communities are eligible for WHO-recommended regular mass treatment.
Source: Southern African Journal of Epidemiology and Infection 25, pp 35 –38 (2010)More Less
The study aspired to assess the impact of time of birth on spontaneous onset of labour and delivery. A retrospective descriptive study was conducted from the Empangeni Hospital delivery registry on 9,397 infant births between January to December 2005, weighing more than 1,000 g. Logistic regression, adjusting for birth weight and for gender was used to estimate the relationship between spontaneous birth and timing of birth. A higher proportion of births (59%) occurred between 10h00 and 22h00 of the day. Estimating the hourly births, we found that the daytime peak is 5.3% and occurred at 10h00 while the night-time peak is 4.9% and occurred at 20h00. Maternal age was significantly associated with the timing of spontaneous births (p<0.05). A higher proportion of preterm babies was born during the day (6.4%) and early night (3.4%) compared to late night births (1.6%). There were significant differences between multiple births and low birth weight infants born during the day (1.1%, 6.9%) and night (0.8%, 6.3%). However, low birth weight babies were born mostly during early night rather than late night (4% vs. 2.3%, p<0.05). Adverse pregnancy outcome, measured by estimating the perinatal mortality rate, was the same for day and night and was equally distributed between early and late night. Timing of birth of infants did not influence the negative outcomes of pregnancy among this study population.
The prevalence and health implications of violence in impoverished communities in Johannesburg : original researchSource: Southern African Journal of Epidemiology and Infection 25, pp 41 –46 (2010)More Less
The experience of violent crime can have a significant impact on the physical and psychological well-being of victims and their families. This paper looks at household experience of violence in five impoverished sites in the city of Johannesburg, South Africa. Five sites were purposefully selected to reflect the prevailing housing profiles in settings of relative impoverishment in Johannesburg. A structured questionnaire was used to obtain information on demographic profiles, socioeconomic data, environmental conditions and health status. Bivariate analyses were conducted to assess the relationship between household experience of violence, and potential risk factors and health/social outcomes. Overall, members of 28% of households had been a victim of violence in the year preceding the study. Across sites, experience of violence within households ranged from 21% to 36%. Perceptions of drug abuse (p=0.01) and drug peddling (p=0.03) as being major problems in the neighbourhood, and living in a house of poor quality (p=0.01), were significantly associated with household experience of crime. In households with experience of violence, fear of crime (p=0.03) and depression (p<0.001) were elevated, and levels of exercise in men were decreased (p=0.05). This paper highlights the high prevalence of violence in impoverished urban areas in South Africa, and contributes to existing evidence regarding the associations between experience of violent crime and psychological ill health in affected communities. The high prevalence of violent crime, and the resultant health and social effects, demand a cross-sectoral intervention to reduce violence, with the health and social sectors playing key roles.
Author E. PrenticeSource: Southern African Journal of Epidemiology and Infection 25, pp 47 –48 (2010)More Less
Bacteria, platypuses, Eco and a poem: such is the mind of a poor pre-exam registrar. Madness or method? I prefer to think the latter because all are associated in some way or another with a list. To the non-microbiologist a cursory glance over even the most basic text would lead you to understand my present state of mind which may explain why, when taking a 'break' at the bookshop recently I was stopped dead in my browsing by Umberto Eco's recent book, 'The Infinity of Lists'! Although not displayed in the self help section, this encounter resulted in a very rapid transaction between the bookseller and my bank account as I was secretly and I daresay even desperately hoping for an Oprah-esque "Aha moment" and transformation. Alas this was not to be. However, for me at least, the list will never be the same again.