Characterisation of mobile colistin resistance genes (mcr-3 and mcr-5) in river and storm water in regions of the Western Cape of South Africa.

BACKGROUND: Colistin is regarded as a last-resort antimicrobial against multi-drug resistant Gram-negative bacteria (GNB), therefore the dissemination of colistin resistance in the environment is of great concern. Horizontal transfer of mobile colistin resistance (mcr) genes to potential pathogens poses a serious problem. This study aimed to describe the presence of colistin resistant GNB and mcr genes in river and storm water in regions of the Western Cape. METHODS: Water samples were collected from three rivers during May 2019 and January 2020 and two storm water samples were collected in November 2019. Colistin resistant GNB were cultured on MacConkey agar containing colistin and identified by MALDI-TOF. Colistin resistance was confirmed using broth microdilution (BMD). mcr-1-5 genes were detected by PCR performed directly on the water samples and on the colistin resistant isolates. mcr functionality was assessed by BMD after cloning the mcr genes into pET-48b(+) and expression in SHuffle T7 E. coli. RESULTS: mcr-5.1 and various mcr-3 gene variants were detected in the Plankenburg-, Eerste- and Berg rivers and in storm water from Muizenberg, and only mcr-5.1 was detected in storm water from Fish Hoek. Colistin resistant GNB were isolated from all of the water sources. Aeromonas spp. were the most common colistin resistant organisms detected in the water sources; 25% (6/24) of colistin resistant Aeromonas spp. isolated from the Berg river contained novel mcr-3 variants; mcr-3.33 (n = 1), mcr-3.34 (n = 1) mcr-3.35 (n = 1) mcr-3.36 (n = 2) and mcr-3.37 (n = 1), which were confirmed to confer colistin resistance. CONCLUSIONS: The mcr-5.1 and mcr-3 colistin resistance gene variants were present in widely dispersed water sources in regions of the Western Cape. The mcr genes were only detected in water sampled downstream of and alongside communities, suggesting that their presence is driven by human influence/contamination. This is the first documentation of mcr-3 and mcr-5 gene variants in any setting in South Africa. Spill-over of these genes to communities could result in horizontal gene transfer to pathogenic bacteria, exacerbating the challenge of controlling multidrug resistant GNB infections.

Early childhood caries and dental treatment need in low socio-economic communities in Cape Town, South Africa.

BACKGROUND: Early childhood caries (ECC) is a particularly severe problem in low socio-economic communities which impacts the overall health and well-being of children. The extensive waiting lists for general anaesthesia and sedation services at the only tertiary dental care centre in the study area for the treatment of children with ECC were an indication of the extent of the problem. The true extent of the problem in this area was, however, not known. This information is crucial in order to plan and execute remedial measures. AIM: To assess the prevalence of oral and dental problems, especially ECC, in children under six years of age in the study population, and ascertain their need for dental treatment. METHODS: A cross-sectional survey of 659 children from selected schools and clinics in the study area was carried out between 2010 and 2013. RESULTS: A caries prevalence of 71.6% (472/659) was recorded. Of these, 67.5% (445/659) of children were in need of dental treatment. CONCLUSION: Over the last decade, there has been no improvement in the caries status of children in the study population, and no organised measures have been put in place to address this problem. Awareness needs to be raised so that governments, especially in developing countries, can take appropriate measures to alleviate this public health problem. Time and resources have to be invested in the education of all health professionals dealing with children, by raising their awareness of the early stages of the disease so that timeous referrals can be made.

The health status and unmet health needs of old-age pensioners living in selected urban poor communities in Cape Town, South Africa.

Indigent elderly residing in low-income urban communities face many adversities. This study investigated the health status and health needs of the elderly collecting an old-age pension at pay points in impoverished urban communities in the City of Cape Town. The pay-out points were selected to constitute a fair representation of points serving impoverished areas of the city. Data was gathered by means of a structured interview with a formal questionnaire since a large proportion of the participating elderly could not read well. Systematic sampling with random starting points of persons in the pay-out queue was used and 703 pensioners were selected to participate from eight pension points in four urban poor communities. All agreed to do so. The health status of the participants was not good: 82.8% were on chronic medication, 32% had diarrhoea in the previous 2 weeks, 24% had TB in the past and 36% reported a previous heart attack. Their health needs were equally not great: 48% reported that their spectacles need changing while 56% have trouble hearing well and 65% needed dentures, while 66% needed a walking aid. Only 4.7% did not have problems with activities of daily living while many faced added burdens such as custodial child care.

The impact of densification by means of informal shacks in the backyards of low-cost houses on the environment and service delivery in cape town, South Africa.

This paper investigates the state-sponsored low cost housing provided to previously disadvantaged communities in the City of Cape Town. The strain imposed on municipal services by informal densification of unofficial backyard shacks was found to create unintended public health risks. Four subsidized low-cost housing communities were selected within the City of Cape Town in this cross-sectional survey. Data was obtained from 1080 persons with a response rate of 100%. Illegal electrical connections to backyard shacks that are made of flimsy materials posed increased fire risks. A high proportion of main house owners did not pay for water but sold water to backyard dwellers. The design of state-subsidised houses and the unplanned housing in the backyard added enormous pressure on the existing municipal infrastructure and the environment. Municipal water and sewerage systems and solid waste disposal cannot cope with the increased population density and poor sanitation behaviour of the inhabitants of these settlements. The low-cost housing program in South Africa requires improved management and prudent policies to cope with the densification of state-funded low-cost housing settlements.

Contribution of water pollution from inadequate sanitation and housing quality to diarrheal disease in low-cost housing settlements of Cape Town, South Africa.

OBJECTIVES: We investigated the effects of failing sanitation, poor housing conditions, and fecal pollution in runoff water on the health-particularly the incidence of diarrheal disease-of residents of low-cost housing settlements in Cape Town, South Africa. METHODS: In November 2009, we conducted a cross-sectional survey with structured interviews in 4 communities (n = 336 dwellings; 1080 persons). We used Colilert defined-substrate technology to determine Escherichia coli levels in runoff water samples taken from the study communities. RESULTS: Almost 15% of households disposed of soiled products in storm water drains and 6% disposed of soiled products in the street. In only 26% of the dwellings were toilets washed daily. Approximately 59% of dwellings lacked a tap near the toilet for hand washing, and 14% of respondents suffered 1 or more attacks of diarrhea in the 2 weeks preceding their interview. E.coli counts of runoff environmental water samples ranged from 750 to 1 580 000 000 per 100 milliliters. CONCLUSIONS: A holistic and integrated approach is needed to improve housing quality and sanitation among Cape Town's low-income citizens.

Living in low-cost housing settlements in cape town, South Africa-the epidemiological characteristics associated with increased health vulnerability.

The aim of this study was to assess the epidemiological characteristics of a representative sample of subsidized low-cost housing communities in the City of Cape Town in relation to their living conditions and their health status. Four subsidized low-cost housing communities were selected within the City of Cape Town in this cross-sectional survey. Structured interviews were administered in 336 dwellings on 173 plots. Data was obtained from 1,080 persons with a response rate of 100%. Almost all of the state-subsidized houses had one or more shacks in the backyard, increasing the occupation density and putting the municipal sanitation infrastructure under pressure. In 40% of main houses, one or more cases of diarrhea were reported during the two weeks preceding the survey, in contrast to 23% of shacks (p < 0.0007). Of the total group, 1.7% willingly disclosed that they were HIV positive, while 3.5% reported being tuberculosis (TB) positive. One of them reported having multiple drug-resistant TB. None of the HIV positive or TB positive persons was on any treatment. A reported 6.3% of the families admitted regularly eating only one meal per day, whereas 18.5% reported having only two meals per day. The shack dwellers had significantly higher education and employment status (p < 0.01), since they had to pay rent. Improvements in health intended by the rehousing process did not materialize for the recipients of low-cost housing in this study. The health vulnerability of individuals in these communities had considerable implications for the curative health services. Sanitation failures, infectious disease pressure, and environmental pollution in these communities represent a serious public health risk. The densification caused by backyard shacks, in addition, has municipal service implications and needs to be better managed. Urgent intervention is needed to allow the state-funded housing schemes to deliver the improved health that was envisaged at its inception.