B5-BIOLOGICAL AGENTS Flashcards

Question

A company that operates hotels and health spas recognises the risks associated with the legionella bacteria. (b) Outline the control measures that this company should implement to minimise exposure to legionella bacteria. (15)

Answer 1

identification of a responsible person to manage legionella control; regular disinfection of hot water systems with biocides; annual cleaning and disinfection of calorifiers; inspection and cleaning of water storage tanks; avoiding ‘dead legs’ in transfer pipe work; maintaining hot water storage temperatures at temperatures greater than 60 degrees C and cold water below 20 degrees C; keeping shower heads and taps clean and free from scale and running showers and taps for several minutes each week in unoccupied rooms; running showers and taps immediately prior to occupation of a room; treating spa pools continuously with chlorine or biocides and cleaning them on a regular basis; avoiding the use in systems of susceptible materials such as wood or rubber; training all relevant employees in risk factors and controls such as monitoring, dosing and flushing through; minimising biofilm formation, for example by covering water tanks and the use of chemicals, replacing wet air conditioning systems with dry air systems or ensuring their maintenance on a regular basis; undertaking regular monitoring of temperature and chlorine or biocide levels and periodically sending water samples for analysis.

Answer 2

These are set out in Schedule 3 of COSHH 2002 and in ascending order consider the likelihood that the agent will cause human disease; that it may cause a hazard to employees but is unlikely to spread to the community; the severity of the human disease and the possibility of it spreading to the community; and the possibilities available for effective prophylaxis or treatment

Answer 3

the separation of the laboratory from other activities in the same building with access restricted to authorised personnel by means of an airlock; the filtering of input and output air using HEPA with double filtering of output air; the laboratory to be under negative air pressure and to be sealable to permit fumigation; all surfaces in the laboratory to be impervious to water and easy to clean and to be resistant to acids, alkalis, solvents and disinfectants; an observation window to be provided so that occupants may be seen at all times or other means of indicating occupation such as an ‘outside’ light; the presence of secure storage facilities for the biological agent; and the provision of a safety cabinet or isolator for handling infected material and an incinerator or autoclave for the disposal of waste.

Answer 4

where employees are exposed to a substance and engaged in a process which are both listed in Schedule 6 of the Regulations; when there is an identifiable disease or health effect associated with exposure to a hazardous substance and a reasonable likelihood that the disease will occur and when there are valid techniques for detecting indications of the disease or health effect which are of low risk to the employee.

Answer 5

the appointment of a responsible person to oversee health surveillance; undertaking regular skin inspections of the employees and at the same time monitoring any breathing problems they might be experiencing; referring those with breathing problems to occupational health staff for medical assessment; training employees to undertake their own skin inspections and advising them to report any problems they might have with skin irritation or breathing; organising and administering the completion of confidential questionnaires for skin and breathing issues and introducing a record keeping system for health surveillance information and carrying out a regular analysis both of this information and of sickness absence data.

Answer 6

the separation of the laboratory from other activities in the same building; passing extracted air through a HEPA (high efficiency particulate air) filter; the provision of engineered access to be restricted to authorised persons by means of a security pass or swipe card; the workplace to be sealable to permit disinfection and to be maintained at an air pressure negative to atmosphere; all surfaces to be impervious to water, easy to clean and impervious to acids, alkalis, solvents and disinfectants; the provision of secure storage for the biological agents; an observation window to be fitted so that the occupants can be seen at all times; ``` using a class 111 microbiological safety cabinet with sealed front and glove port access to carry out the work; ``` a facility such as an autoclave to be provided for rendering waste safe and finally the provision of appropriate and adequate washing and toilet facilities.

Answer 7

water storage and transfer systems (including showers and taps) where the temperature is between 20 and 45 degrees; spa baths, saunas, steam rooms and pools; water features such as fountains and cascades; fire and lawn sprinkler systems; laundry rooms; pipe work where dead legs exist and stagnation may occur and wet or condenser air conditioning equipment.

Answer 8

measures which should have been described (and which are explained in ACOP L8) included identification of a competent person for overseeing Legionella control; regular disinfection of hot water systems with biocides; annual cleaning and disinfection of calorifiers; inspection and cleaning of water storage tanks; avoiding ‘dead legs’ in transfer pipe work; maintaining hot water storage temperatures at temperatures greater than 60 degrees C and cold water below 20 degrees C; keeping shower heads and taps clean and free from scale and running showers and taps for several minutes each week in unoccupied rooms; running showers and taps immediately prior to occupation of a room; treating spa pools continuously with chlorine or biocides and cleaning them on a regular basis; avoiding the use in systems of susceptible materials such as wood or rubber; training all relevant employees in risk factors and controls; minimising biofilm formation, for example by covering water tanks and the use of chemicals, and introducing regular monitoring procedures and record keeping.

Answer 9

the use of litter picking sticks to minimise the risk of puncture wounds; the prohibition of eating and drinking during normal periods of work; the use of personal protective equipment such as goggles, gloves and footwear; covering up wounds with waterproof dressings; the safe disposal of sharps in a suitable container and frequent hand washing. In addition to these practical controls, candidates could have mentioned the need to provide information and training to the employees on the nature of the risk and the precautions to be taken together with the introduction of procedures for the collection of contaminated waste such as body fluids, blood and contaminated clothing; for cleaning up body fluids and blood and for the action to be taken following a needle stick injury such as the encouragement of bleeding and rinsing the wound under warm water before covering it with a dressing.

Answer 10

In most cases the infection causes a flu-like illness with severe headaches and myalgia (lower back, and legs). Other symptoms include fever, vomiting, abdominal pain, skin rashes, conjunctival haemorrhage, uveitis, and Leptospirosis may present as aseptic meningitis.

Answer 11

The bacteria can then enter the | windsurfers’ bodies via cuts to the skin, nose, mouth or other mucous membranes.

Answer 12

wearing protective footwear and minimising skin contact by wearing full-body wet suit; protecting all existing cuts and abrasions with waterproof dressings; seeking medical advice and treatment for any cuts or bites received whilst in the water (advising their GP of their occupation to aid in early diagnosis); washing down equipment and wet suits and reporting any sighting of rats to ensure effective rodent control in and around the water. showering after being in water and washing hands thoroughly before eating; avoid swallowing water;

Answer 13

reference to COSHH Regulations and ACOP, HSG173 (Monitoring strategies for toxic substances), material safety data sheets; background information on solvents (types, health effects, target organs, synergistic/additive effects, etc); working practices, exposure patterns, efficiency of existing controls; need for monitoring (eg deterioration of controls) and health surveillance; current exposure limits (EH40); route/s of entry (inhalation / skin absorption) relevant to how the substance is used and who is exposed (including any vulnerable groups). The better responses considered atmospheric and biological monitoring within their answers and referred to the three-stage approach in HSG 173.

Answer 14

Suitable monitoring strategies included consideration of: personal versus static monitoring; biological monitoring (total body burden v inhalation); who to monitor, for how long and when; how to monitor: grab sampling — stain tubes versus integrated sampling (pump, passive, adsorption tubes etc); examples of analytical methods; and reference to appropriate MDHS’s.

Answer 15

measurements obtained versus work practices (representative, cyclical, etc); comparisons with exposure standards: calculations for mixtures, taking into account synergistic/additive effects, etc; comparisons with biological standards; comparisons with previous results; measurements reviewed against LEV performance tests, or PPE selection and usage, or results of health surveillance.

Answer 16

in soil or faeces. With that understood, there should have been no difficulty either in suggesting how children on a visit to an open farm might be exposed to the bacteria or in explaining control measures that should be put in place. The children’s hands could be contaminated by touching animals, touching surfaces contaminated by faeces such as gates and fences and coming into contact with contaminated footwear during its removal. The transfer of the bacteria to the mouth could take place during eating or drinking before hands had been thoroughly washed or from putting fingers near or in the mouth for any other purpose (as young children often do).

Answer 17

It would be important before the visit took place to brief schools of the precautions to be observed so that the children could be advised of what they should and should not do once they arrived at the farm. On the farm, contact with animals should be restricted to specified areas and arrangements put in place to clean, disinfect and remove faeces from these areas on a regular basis. Hand washing facilities should be provided, ideally placed at the exits from contact areas and before entrance to areas set aside for taking refreshment and it would be sensible for children to be advised on thorough hand washing techniques at the start of the visit. The animal areas should be segregated from areas set aside for eating and signs warning of the risks of contamination and the precautions to be taken placed in strategic positions. Finally the farm management should ensure that there is an adequate number of staff on duty to supervise and advise visitors in the contact areas.

Answer 18

Leptospirosis causes a flu-like illness with severe headaches and myalgia in the lower back and legs. Other possible ill-health effects include fever, vomiting, abdominal pain, skin rashes and conjunctival haemorrhage. The more severe form of the disease causes jaundice and liver damage which may end in death.

Answer 19

Leptospirosis causes a flu-like illness with severe headaches and myalgia in the lower back and legs. Other possible ill-health effects include fever, vomiting, abdominal pain, skin rashes and conjunctival haemorrhage. The more severe form of the disease causes jaundice and liver damage which may end in death.

Answer 20

The bacteria can then enter the windsurfers’ bodies through cuts or abrasions to the skin and through mucous membranes, and particularly if water is swallowed.

Answer 21

Practical steps which the windsurfers should take must be aimed at preventing water entering the body. They include measures such as maximising dry training to limit the potential contact time; showering after being in water and washing hands thoroughly before eating; taking care not to swallow water; wearing protective footwear and minimising skin contact by wearing a full-body dry suit; protecting all existing cuts and abrasions with waterproof dressings; seeking medical advice and treatment for any cuts or bites received whilst in the water; washing down equipment and dry suits and reporting any sighting of rats to ensure effective rodent control in and around water.

Answer 22

SA is widespread in human population - MRSA in approx 30% of healthy people (asymptomatic = colonisation). Symptoms: local skin infection, boils, serious wound infections (necrotising faciitis), high temperature, pain and body aches.

Answer 23

taking swabs on admission - laboratory analysis to identify carriers; treating with antibiotics prior to admission; cleaning clinical areas and equipment; hand washing - soap, water, alcohol hand gel (staff and visitors); protective gloves, aprons