Compost and Legionella longbeachae : an emerging infection?

Human disease caused by Legionella species is dominated by Legionella pneumophila, the main causative agent in cases of Legionnaires’ disease. However, other species are known to cause infection, for example, Legionella longbeachae causes an equivalent number of cases of disease as L. pneumophila in Australia and New Zealand. Infection with L. longbeachae is commonly associated with exposure to composts and potting soils, and cases of infection with this organism have been increasing in Europe over the past ten years. The increase in incidence may be linked to factors such as increased awareness of clinical presentation, or due to changing formulation of growing media, although it should be noted that the presence of Legionella species in growing media does not correlate with the number of cases currently seen. This is likely due to the variables associated with infection, for example, host factors such as smoking or underlying health conditions, or difference in growing media storage or climate, especially warm humid conditions, which may affect survival and growth of these organisms in the growing media environment. There are numerous unknowns in this area and collaboration between growing media manufacturers and researchers, as well as more awareness among diagnosing clinicians, laboratory staff and the general public is necessary to reduce risk. More research is needed before definitive conclusions can be drawn: L. pneumophila research currently dominates the field and it is likely that the overreliance on diagnostic techniques such as the urinary antigen test, which is specific for L. pneumophila Sg 1, is detrimental to the diagnosis of L. longbeachae infection

Personal, interpersonal and structural challenges to accessing HIV testing, treatment and care services among female sex workers, men who have sex with men and transgenders in Karnataka state, South India.

BACKGROUND: Despite high HIV prevalence rates among most-at-risk groups, utilisation of HIV testing, treatment and care services was relatively low in Karnataka prior to 2008. The authors aimed to understand the barriers to and identify potential solutions for improving HIV service utilisation. METHODS: Focus group discussions were carried out among homogeneous groups of female sex workers, men who have sex with men and transgenders, and programme peer educators in six districts across Karnataka in March and April 2008. RESULTS: 26 focus group discussions were conducted, involving 302 participants. Participants had good knowledge about HIV and HIV voluntary counselling and testing (VCT) services, but awareness of other HIV services was low. The fear of the psychological impact of a positive HIV test result and the perceived repercussions of being seen accessing HIV services were key personal and interpersonal barriers to HIV service utilisation. Previous experiences of discrimination at government healthcare services, coupled with discriminatory attitudes and behaviours by VCT staff, were key structural barriers to VCT service uptake among those who had not been HIV tested. Among those who had used government-managed prevention of parent to child transmission and antiretroviral treatment services, poor physical facilities, long waiting times, lack of available treatment, the need to give bribes to receive care and discriminatory attitudes of healthcare staff presented additional structural barriers. CONCLUSIONS: Embedding some HIV care services within existing programmes for vulnerable populations, as well as improving service quality at government facilities, are suggested to help overcome the multiple barriers to service utilisation. Increasing the uptake of HIV testing, treatment and care services is key to improving the quality and longevity of the lives of HIV-infected individuals

Relationship between antibiotic- and disinfectant-resistance profiles in bacteria harvested from tap water

Chlorination is commonly used to control levels of bacteria in drinking water; however, viable bacteria may remain due to chlorine resistance. What may be concerning is that surviving bacteria, due to co-selection factors, may also have increased resistance to common antibiotics. This would pose a public health risk as it could link resistant bacteria in the natural environment to human population. Here, we investigated the relationship between chlorine- and antibiotic-resistances by harvesting 148 surviving bacteria from chlorinated drinking-water systems and compared their susceptibilities against chlorine disinfectants and antibiotics. Twenty-two genera were isolated, including members of Paenibacillus, Burkholderia, Escherichia, Sphingomonas and Dermacoccus species. Weak (but significant) correlations were found between chlorine-tolerance and minimum inhibitory concentrations against the antibiotics tetracycline, sulfamethoxazole and amoxicillin, but not against ciprofloxacin; this suggest that chlorine-tolerant bacteria are more likely to also be antibiotic resistant. Further, antibiotic-resistant bacteria survived longer than antibiotic-sensitive organisms when exposed to free chlorine in a contact-time assay; however, there were little differences in susceptibility when exposed to monochloramine. Irrespective of antibiotic-resistance, spore-forming bacteria had higher tolerance against disinfection compounds. The presence of chlorine-resistant bacteria surviving in drinking-water systems may also carry additional risk of antibiotic resistance

The use of minimum selectable concentrations (MSCs) for determining the selection of antimicrobial resistant bacteria

The use of antimicrobial compounds is indispensable in many industries, especially drinking water production, to eradicate microorganisms. However, bacterial growth is not unusual in the presence of disinfectant concentrations that would be typically lethal, as bacterial populations can develop resistance. The common metric of population resistance has been based on the Minimum Inhibitory Concentration (MIC), which is based on bacteria lethality. However, sub-lethal concentrations may also select for resistant bacteria due to the differences in bacterial growth rates. This study determined the Minimal Selective Concentrations (MSCs) of bacterial populations exposed to free chlorine and monochloramine, representing a metric that possibly better reflects the selective pressures occurring at lower disinfectant levels than MIC. Pairs of phylogenetically similar bacteria were challenged to a range of concentrations of disinfectants. The MSCs of free chlorine and monochloramine were found to range between 0.021 and 0.39 mg L-1, which were concentrations 1/250 to 1/5 than the MICs of susceptible bacteria (MICsusc). This study indicates that sub-lethal concentrations of disinfectants could result in the selection of resistant bacterial populations, and MSCs would be a more sensitive indicator of selective pressure, especially in environmental systems

Antibiotic resistant bacteria found in municipal drinking water

Multidrug resistant bacteria in water supply systems have been emerging as a growing public health concern. Many factors affect the source and fate of these bacteria. However, conditions in the distribution systems may contribute in the dispersion of resistance genes among bacterial populations. Through the process of lateral gene transfer, resistance genetic material can be exchanged between species in the microbial population, intensifying the problem of resistance genes. The main aim of this study was to investigate the diversity of microorganisms in tap-water in Glasgow, Scotland, and the occurrence of certain antibiotic resistance genes and gene-transfer mechanisms. Results show that antibiotic resistant bacteria exist at the consumers’ end of the distribution system, some of which also contain integrase genes, which can aid in the dispersion of resistance genes. Presence of such microorganisms indicates that further investigations should be taken to assess the risks to public health

Rapid selection of antimicrobial resistant bacteria in complex water systems by chlorine and pipe materials

Antimicrobial resistance is a major health issue induced by the overuse of antibiotics and disinfection reagents, e.g. chlorine. Resistant bacteria thus occur in water supply systems, and they transfer genes to other microbial populations, including pathogens. Treatment and inactivation of resistant bacteria are difficult in complex systems because the behaviour of resistant bacteria in such systems is poorly known, as most previous investigations are commonly performed in pure media. Therefore, we tested here the effect of 0.5 mg/mL chlorine and pipe materials made of polyvinyl chloride (PVC), copper and cement, on microbial populations in biofilms, during 5 days. Bacterial survival was monitored by viable counts, and resistant genes were analysed by quantitative polymerase chain reaction (qPCR). Results show that, in 56% of the cases, resistant bacteria became immediately enriched into biofilms due to chlorine exposure. Higher proportion of resistant bacteria were found in biofilms on PVC and copper pipes. Our findings imply that resistant microbial strains are very rapidly selected and that the pipe material has an influence on microbial selection

Summary Report of 2-Day Workshop - Developing a Road Map for Health Surveillance Assistant Training

Summary report of sandpit event held in partnership with the Ministry of Health in August to inform the development of a restructured training and qualification programme for HSAs under the Community Health Services Unit

Blood, men and tears: keeping IUDs in place in Bangladesh.

The Intra-Uterine Device (IUD) is an effective method of contraception, but in Bangladesh is associated with high levels of discontinuation within the first year. This study involved data collection from a retrospective cohort of women who had an IUD inserted 12 months earlier. In the cohort, 330 women were interviewed to identify factors associated with discontinuation. Later, 20 women, of the 103 who reported discontinuing because of excessive menstrual bleeding, were interviewed again and in depth about these issues. Of 330 women who had an IUD inserted, 47.3% had discontinued use one year post-insertion. In univariate and multivariate analyses, IUD discontinuation was strongly associated with side-effects (heavier periods; abdominal pain) and spousal factors (not discussing IUD with husband pre-insertion), but not with service delivery factors. In-depth interviews with women who reported excessive blood loss as the main reason for discontinuation found a doubling of both menstrual days and blood loss after IUD insertion. In Bangladesh, women cannot pray, have sexual intercourse, perform household tasks or participate in community activities during menstruation. Thus, women with menstrual side-effects faced serious physical, social and psychological challenges that made continuation difficult. Among those who discontinued, spouses were generally unsupportive and sometimes abusive, particularly when not involved in the decision to use the IUD

Is the HCV-HIV co-infection prevalence amongst injecting drug users a marker for the level of sexual and injection related HIV transmission?

BACKGROUND: Amongst injecting drug users (IDUs), HIV is transmitted sexually and parenterally, but HCV is transmitted primarily parenterally. We assess and model the antibody prevalence of HCV amongst HIV-infected IDUs (denoted as HCV-HIV co-infection prevalence) and consider whether it proxies the degree of sexual HIV transmission amongst IDUs. METHODS: HIV, HCV and HCV-HIV co-infection prevalence data amongst IDU was reviewed. An HIV/HCV transmission model was adapted. Multivariate model uncertainty analyses determined whether the model's ability to replicate observed data trends required the inclusion of sexual HIV transmission. The correlation between the model's HCV-HIV co-infection prevalence and estimated proportion of HIV infections due to injecting was evaluated. RESULTS: The median HCV-HIV co-infection prevalence (prevalence of HCV amongst HIV-infected IDUs) was 90% across 195 estimates from 43 countries. High HCV-HIV co-infection prevalences (>80%) occur in most (75%) settings, but can be lower in settings with low HIV prevalence (0.75). The model without sexual HIV transmission reproduced some data trends but could not reproduce any epidemics with high HIV/HCV prevalence ratios (>0.85) or low HCV-HIV co-infection prevalence (10%. The model with sexual HIV transmission reproduced data trends more closely. The proportion of HIV infections due to injecting correlated with HCV-HIV co-infection prevalence; suggesting that up to 80/60/90%. CONCLUSION: Substantial sexual HIV transmission may occur in many IDU populations; HCV-HIV co-infection prevalence could signify its importance