SPECIAL INFECTION CONTROL CONSIDERATIONS FOR PATHOGENS OF INTEREST – CHOLERA

SPECIAL INFECTION CONTROL CONSIDERATIONS FOR PATHOGENS OF INTEREST – CHOLERA

What is Cholera?

• An acute and severe diarrhoeal disease of Public health importance
• Primarily transmitted within the community
• Caused by consuming food and water contaminated with the bacterium Vibrio cholerae.

• Affects both Adults and Children.

• Incubation Period : 12hrs to 5 days after exposure
• Can kill within hours from dehydration and electrolyte imbalance without treatment

Azman AS, Rudolph KE, Cummings DA, Lessler J. J Infect. 2013;66(5):432-8. doi: 10.1016/j.jinf.2012.11.013.

WHO Fact sheet

Outbreaks continue to occur in Africa

What is Vibrio Cholerae?

• Gram-negative curved bacilli
• Disease caused by bacterial toxin that leads to rapid expulsion of water from the intestinal tract
• There are many serogroups of cholerae,
• Only two – O1 and O139 – cause outbreaks.
  • cholerae O1 – caused all recent outbreaks.
  • cholerae O139 – first identified in Bangladesh in 1992

– has never been identified outside Asia.

• No difference in the clinical presentation of the two sero-groups.

WHO Fact sheet

Epidemiology of Cholera

• Globally there are 3 to 4.0 million cases annually
• 21,000 to 143,000 deaths worldwide due to cholera
• Can be endemic or epidemic
• Endemic: defined as confirmed cholera cases were detected during the last 3 years with evidence of local transmission
• Epidemic:
  • In cholera endemic countries an outbreak represents a greater than expected number of cases.
• In a non-endemic country an outbreak is defined as the occurrence of at least 1 confirmed case of cholera with evidence of local transmission in an area where there is not usually cholera.

Ali M, Nelson AR, Lopez AL, Sack D. (2015). PLoS Negl Trop Dis 9(6): e0003832. doi:10.1371/journal.pntd.0003832.

Clinical Presentation

• Watery Colorless stool (rice water)
• Vomiting,
• Leading to moderate to severe dehydration
• Less than 10% of total cholera cases develop into severe cases of dehydration
• Without any treatment, deaths may reach as high as 50% during outbreaks

WHO Fact sheet

Transmission

• Linked to inadequate access to clean water and sanitation services
• Main reservoirs are people and warm salty water as will be found in coastal areas and estuaries
• Drinking contaminated water
• Eating contaminated food
• Direct Person to person uncommon in the community
• About 75% of people infected with cholera do not develop any symptoms and remain carriers
• Pathogens persist in faeces for 1 to 10 days and are shed into the environment

WHO Fact sheet

Factors that Aid Transmission

• Pathogen factors:
  • Persistence of bacteria in the
  • Presence of a potent exotoxin.
• Reservoir and carrier state:
  • Man is the only known reservoir
  • convalescent carrier may be infectious for 2-3weeks
  • chronic carriers can remain infectious for a month, up till 10 years.
• Host factors:
  • Overcowding
  • Cholera incidence higher among lower socio economic groups which may be attributable to poor E.g in slums
• Environmental factors:
  • poor environmental sanitation; drought, this results in contamination of food and water.

Diagnosis/Testing

• Stool or anal swab samples should be collected once at presentation before administering antibiotics.
• Rapid diagnostic test (RDT) can be used for screening before confirmation in the laboratory.

Case Definition

• Suspect Case
  • Any person 5 years of age or more with copious amounts of watery stool with or without vomiting or with acute watery diarrhoea in an area where there is an acute outbreak of cholera or any person who dies from acute watery diarrhea.
• Confirmed Case
  • Any patient with stooling and diarrhoea from who Vibrio cholerae O1 or O139 is isolated with diarrhoea.

ncdc diseases factsheet

Breaking the Chain of Transmission in Healthcare

• Patients are admitted with vomiting and Diarrhoea
• Risk of faecal contamination of the hands and environment
• Contact and standard precautions should be applied
• Treatment of patient: supportive and antibiotics
• Chemoprophylaxis with antibiotics is not indicated for healthcare providers.

Contact Precautions

• Patient placement
• Hand Hygiene
• Personal protective Equipment
• Environmental care
  • Disposal of faeces and faecal contaminated materials
  • Cleaning and disinfection of soiled linen
  • Cleaning of contaminated environment (spills and vomit)
• Signages

Patient Placement

• Place together in the same room patients who are infected with the same pathogen
• Ensure that patients are physically separated (i.e., >3 feet apart) from each other
• Perform hand hygiene and change PPE between contact with patients in the same room, regardless of whether one or both patients are on Contact Precautions

Personal Protective Equipment (PPE) and Hand Hygiene

• Perform Hand hygiene with soap and water or an alcohol- based hand rub;
• Wear a clean, non-sterile, long-sleeved gown
• Clean gloves which should cover the cuffs of the gown
• Remove gown and gloves before exiting the room/patient care area
• Drop into discard bin
• Perform Hand hygiene before leaving the room/patient-care environment

Patient-Care Equipment and Instruments/Devices

• Use separate equipment for each patient where possible
• For shared equipment (thermometers, stethoscope, sphygmomanometer etc) clean and disinfect between patients
• Disinfectant
  • at least 70% ethanol solution – preferred
  • 1% hypochlorite solution -(Not on metal)

Disposal of Waste

• Ensure Puncture resistant waste containers for sharps are at the point of use (within an arms length)
• Do not recap bend or break contaminated needles

Environmental Control

• Clean and decontaminate spills of vomit, stools or other potentially infectious materials.
• Use protective gloves and other PPE appropriate for this task.
• Clean and disinfect frequently touched surfaces and floor in patient zone regularly with 1% bleach a least twice a day.
• Concentrations for use in the hospital area: (always clean before disinfecting)
  • 10,000 ppm = 1% = Disinfection of spills
  • 1,000 ppm = 1% = Disinfection of critical areas

Soiled laundry

• Handle carefully
• Do not shake to prevent aerosolisation of the infectious agent.
• Wear gloves and apron to handle soiled linen
• Place soiled linen in a laundry bag or designated bin.

Family Members or Visitors

• Family members or visitors who are providing care or having very close patient contact (e.g., feeding, holding) should use PPE correctly.
• Wear gloves whenever touching the patient’s intact skin or surfaces and articles in close proximity to the patient (e.g., medical equipment, bed rails).
• Use gown upon entry into the room or cubicle.
• Remove gown and gloves and observe hand hygiene before leaving the patient-care environment.
• Change personal clothes every day.

Ambulatory Care: Oral Rehydration Points

• Hand hygiene
• Alcohol hand rub, 01% hypochlorite solution or hand washing with soap and water
• Ensure availability of hand-washing facilities with clean running water
• Ensure availability of hand hygiene products (clean water, soap, single use clean towels, alcohol-based hand rub)
• Alcohol-based hand rubs should be available at the point of care.

Management of Corpses

• People who wash and prepare the dead body must:
• Wear gloves, apron and mask.
• Clean the body with 1% chlorine solution.
• Plug the mouth and anus with cotton wool soaked with chlorine solution.
• Bandage the head to maintain the mouth shut.
• Must not empty the bowels.

Management of Patients eating Utensils

• Do not share eating utensils
• Disposable plates and spoons may be used
• Spoon and plates should be washed with soap and water.

Managing a Cholera Outbreak in the Community

Cholera treatment centre

KEY:

1. Entrance and disinfection area.
2. Observation tents
3. Staff Area (Kitchen, Laundry, Supplies, etc )
4. Acute hospitalisation tents
5. Recovery tents
6. Exit and disinfection.
7. Mortuary
8. Waste disposal.
9. Disinfection area.

Areas at where patients may be attended

Cholera Treatment Centre Video Setting up a CTC

CASE STUDY

• A 25-year-old man presents to his local clinic with a short history of profuse, watery diarrhoea and severe dehydration.
• He lives in a shack with no access to running water or toilet facilities.
• He is referred to hospital for intravenous rehydration.
• Over the following week, several more adults and children from the same informal settlement present to the local clinic with watery diarrhoea and dehydration.
• Stool specimens confirm that the cause of this diarrhoeal outbreak is Vibrio cholera.

Questions

• What is the route of transmission for this gastrointestinal pathogen?
• How will you prevent transmission of this diarrhoeal disease in hospital?
• How will you prevent transmission of this diarrhoeal disease in the community?

Answers

• What is the route of transmission for this gastrointestinal pathogen?
  • Vibrio cholera is transmitted by the faeco-oral route
  • direct or indirect contact with
• contaminated water or an
• infected person’s body fluids (stool or vomitus).
  • How will you prevent transmission of this diarrhoeal disease in hospital?
    • Contact precautions should be implemented, ideally in a single room with en suite toilet facilities.
    • Cohorting of affected patients,
    • Ensure easy access to personal protective equipment (gloves, aprons) for staff caring for these patients.
    • Make sure linen and waste from these patients are handled as potentially infectious.
  • How will you prevent transmission of this diarrhoeal disease in the community?
    • A clean water source will have to be supplied (if the water is cholera-contaminated) or
    • health education of the community on how decontaminate water by boiling or
    • Community members with gastrointestinal symptoms should be sent to a healthcare facility for management.
    • Education regarding the importance of hand hygiene and clean water sources.

Key Facts

• Cholera is an acute diarrhoeal disease that can kill within hours if left untreated.
• Researchers have estimated that each year there are 3 to 4.0 million cases of cholera, and 21 000 to 143 000 deaths worldwide due to cholera1.
• Most of those infected will have no or mild symptoms, and can be successfully treated with oral rehydration solution.
• Severe cases will need rapid treatment with intravenous fluids and antibiotics.
• Provision of safe water and sanitation is critical to control the transmission of cholera and other waterborne diseases.
• Oral cholera vaccines are an additional way to control cholera, but should not replace conventional control measures.
• Safe oral cholera vaccines should be used in conjunction with improvements in water and sanitation to control cholera outbreaks and for prevention in areas known to be high risk for cholera.

WHO Cholera Fact sheet. Updated October 2016.

Key Messages

• Cholera is transmitted through contaminated water or food.
• Prevention and preparedness of cholera require a coordinated multidisciplinary approach.
• Cholera can rapidly lead to severe dehydration and death if left untreated.
• Provision of safe water, proper sanitation, and food safety are critical for preventing occurrence of cholera.
• Health education aims at communities adopting preventive behaviour for averting contamination.
• In the healthcare setting, Contact precaution, Hand-hygiene, waste and Environmental management form the bedrock of Infection control.