BACTERIA OF KEY PUBLIC HEALTH IMPORTANCE Flashcards
WHAT DOES IT MEAN IF AN ORGANISM IS ‘FACULTATIVE ANAEROBIC’?
THAT IT CAN FUNCTION WITH OR WITHOUT OXYGEN
HOW ARE BACTERIA COMMONLY GROUPED BASED ON THEIR ABILITY TO CAUSE DISEASE?
TO PATHOGENIC (CAUSES DISEASE) AND COMMENSAL (LIVES ON HOST WITHOUT CAUSING HARM)
WHAT ARE COMMENSAL BACTERIA?
BACTERIA WHO LIVE ON A HOST BUT DON’T CAUSE ANY HARM
BASED ON WHICH FEATURES DO WE USUALLY DESCRIBE BACTERIA?
GRAM STAIN, SHAPE, O2 USE, DRUG RESISTANCE, TOXINS, POTENTIAL TO CAUSE DISEASE
WHAT IS THE DIFFERENCE BETWEEN GRAM POSITIVE AND GRAM NEGATIVE BACTERIA?
Gram-negative bacteria are surrounded by a thin peptidoglycan cell wall, which itself is surrounded by an outer membrane containing lipopolysaccharide. Gram-positive bacteria lack an outer membrane but are surrounded by layers of peptidoglycan many times thicker than is found in the Gram-negatives.
WHAT IS GRAM STAINING?
Gram stain or Gram staining, also called Gram’s method, is a method of staining used to classify bacterial species into two large groups: gram-positive bacteria and gram-negative bacteria.
Gram staining differentiates bacteria by the chemical and physical properties of their cell walls. Gram-positive cells have a thick layer of peptidoglycan in the cell wall that retains the primary stain, crystal violet. Gram-negative cells have a thinner peptidoglycan layer that allows the crystal violet to wash out on addition of ethanol. They are stained pink or red
COLOUR OF GRAM POSITIVE VS GRAM NEGATIVE BACTERIA UPON STAINING?
POSITIVE: VIOLET
NEGATIVE: RED OR PINK
WHAT IS A NATURAL HISTORY OF A DISEASE?
IT DESCRIBES THE DISEASE’S EXPECTED PROGRESSION OVER TIME, FROM WHEN A PERSON IS FIRST INFECTED ONWARDS; THIS WOULD INCLUDE WHICH SYMPTOMS TYPICALLY APPEAR AND IN WHAT ORDER
WHAT IS THE INCUBATION PERIOD?
THE TIME BETWEEN A PERSON BEING INFECTED AND WHEN THEY START TO SHOW SYMTPOMS
WHAT IS THE LATENT PERIOD?
THE TIME BETWEEN A PERSON BEING INFECTED AND WHEN THEY START BEING INFECTIOUS TO OTHERS
WHAT IS THE INFECTIOUS PERIOD?
THE PERIOD OF TIME A PERSON IS INFECTIOUS
EXPLAIN THE COMMON EPIDEMIOLOGICAL FRAMEWORK FOR DESCRIBING PATTERNS OF DISEASE?
TIME-PLACE-PERSON
TIME: IS THE DISEASE SEASONAL?, HAS THE PATTERN OF DISEASE BEEN CHANGING OVER TIME?
PLACE: DOES THE PATTERN OF DISEASE VARY BY PLACE?
PERSON: WHO IS AT RISK? WHO IS AT RISK OF SEVERE DISEASE?
TYPES OF PREVENTION STRATEGIES; EXPLAIN:
PRIMARY: AIMS TO PREVENT A CONDITION FROM OCCURRING
SECONDARY: AIMS TO LIMIT DISEASE PROGRESSION AND MODIFY THE DISEASE BY EARLY INTERVENTION ONCE IT HAS ALREADY OCCURRED
TERTIARY: AIMS TO PREVENT COMPLICATIONS OF THE DISEASE
EXAMPLES OF PRIMARY, SECONDARY AND TERTIARY PREVENTION?
PRIMARY: VACCINATION, HAND WASHING, PROGRAMMES ENCOURAGING HEALTHY LIFESTYLES
SECONDARY: BREAST CANCER SCREENING
TERTIARY: DIABETIC EYE SCREENING
DESCRIBE THE NEISSERIA MENINGITIDIS PATHOGEN?
- GRAM NEGATIVE
- AEROBIC
- DIPLOCOCCAL BACTERIUM (OCCURS AS PAIRS OF COCCI, CIRCULAR)
SOME NEISSERIA SPECIES EXCEPT FOR N. MENINGITIDIS?
N. GONORRHOEAE (CAUSES THE STI GONORRHOEA)
N. LACTAMICA (COMMENSAL)
1 IN HOW MANY PEOPLE HAVE N. MENINGITIDIS LIVING HARMLESSLY IN THEIR THROATS AND NOSES?
1/10
UP TO 1/4 IN ADOLESCENTS
WHAT DOES THE TERM MENINGOCOCCAL DISEASE OR INVASIVE MENINGOCOCCAL DISEASE (IMD) REFER TO?
DISEASES CAUSED BY N. MENINGITIDIS;
A) MENINGITIS
B) SEPTICAEMIA
WHAT IS MENINGITIS?
INFLAMMATION OF THE MENINGES - THE MEMBRANES COVERING THE BRAIN AND SPINAL CORD
WHAT IS SEPTICAEMIA?
BLOODSTREAM INFECTION
HOW MANY SEROGROUPS DOES N. MENINGITIDIS HAVE? WHICH ONES ACCOUNT FOR MOST CASES OF INVASIVE DISEASE?
13 SEROGROUPS
6 ACCOUNT FOR MOST CASES OF INVASIVE DISEASE:
A, B, C, W-135, X, Y
WHAT ARE THE 2 MAIN STRAINS OF N. MENINGITIDIS?
ENCAPSULATED AND UNENCAPSULATED
FEATURES OF N. MENINGITIDIS THAT MAKE IT MORE DIFFICULT FOR THE IMMUNE SYSTEM TO FIGHT IT?
THE CAPSULES (IN THE CAPSULATED FORMS WHICH MORE COMMONLY CAUSE INVASIVE DISEASE) CONTAIN A TYPE OF SIALIC ACID THAT IS SIMILAR TO THOSE FOUND IN THE HUMAN BODY, AND THIS ACTS AS A PARTIAL CAMOUFLAGE TO THE IMMUNE RESPONSE
N. MENINGITIDIS ALSO CONTAINS PILI (HAIR LIKE STRANDS) WHICH HELP THE BACTERIA STICK TO THE CELLS ON THE INSIDE OF THE THROAT/NOSE
WHICH CAPSULATED GROUP OF N. MENINGITIDIS DOES NOT CONTAIN SIALIC ACID?
GROUP A
WHAT IS LESS SEVERE, VIRAL OR BACTERIAL MENINGITIS?
VIRAL
OTHER CAUSES OF MENINGITIS APART FROM N. MENINGITIDIS?
VIRUSES
FUNGAL OR PARASITIC MENINGITIS IS POSSIBLE BUT RARE
OTHER BACTERIA (TUBERCULOSIS, HAEMOPHILUS INFLUENZAE AND STREPTOCOCCUS AGALACTIAE)
MOD OF TRANSMISSION FOR N. MENINGITIDIS?
PERSON-TO-PERSON
ESPECIALLY WHERE INDIVIDUALS ARE LIKELY TO COME INTO CLOSE CONTACT WITH THE NASO-PHARYNGEAL SECRETIONS OR RESPIRATORY DROPLETS OF OTHERS (E.G. HOUSEHOLD CONTACTS OR KISSING CONTACTS)
!!!! HOWEVER, EVEN IN A HOUSEHOLD SETTING, THE RISK OF A SECOND CASE OF MENINGOCOCCAL DISEASE IS LOW !!!!!
FATALITY RATE OF MENINGOCOCCAL DISEASE?
CCA 10%
ARE SURVIVAL RATES HIGHER IN PATIENTS WITH MENINGITIS OR SEPTICAEMIA?
MENINGITIS
INCUBATION PERIOD FOR N. MENINGITIDIS?
3-5 DAYS
SYMPTOMS OF MENINGITIS?
Sudden high fever Stiff neck Severe headache that seems different from normal Headache with nausea or vomiting Confusion or difficulty concentrating Seizures Sleepiness or difficulty waking Sensitivity to light No appetite or thirst Skin rash (sometimes, such as in meningococcal meningitis)
PERMANENT COMPLICATIONS ARE PRESENT IN WHAT PERCENTAGE OF PEOPLE WHO SURVIVE MENINGOCOCCAL DISEASE, AND WHAT DO THEY INCLUDE?
15%
LOSS OF LIMBS, HEARING LOSS, SEIZURES AND COGNITIVE IMPAIRMENTS
WHEN WAS MENC VACCINE INTRODUCED IN ENGLAND?
1999
WHEN IS MENINGOCOCCAL DISEASE MORE COMMON?
IT IS SEASONAL AND MORE COMMON IN WINTER
WHEN WAS MENB VACCINE INTRODUCED IN ENGLAND? DID THE DECLINE IN INCIDENCE OCCUR BEFORE OR AFTER THIS?
2015
BEFORE
EPIDEMIOLOGICAL YEARS IN CASE OF MENINGOCOCCAL DISEASE RUN DURING WHICH PERIOD?
JULY TO JUNE TO ENSURE THE ENTIRE WINTER PERIOD IS CAPTURED WITHIN ONE YEAR
WHAT IS THE ‘MENINGITIS BELT’?
AREA OF HIGHER INCIDENCE OF MENINGOCOCCAL DISEASE; A GROUP OF COUNTRIES SPANNING THE WIDEST PART OF AFRICA
SOME RISK FACTORS FOR DEVELOPING INVASIVE MENINGOCOCCAL DISEASE?
BEING AROUND OTHERS WHO SMOKE, OVERCROWDING, HAVING RECENTLY HAD THE FLU, HAVING SOME CONDITIONS AFFECTING IMMUNITY (E.G. NO SPLEEN)
THE AGE GROUP WITH THE HIGHEST INCIDENCE OF MENINGOCOCCAL DISEASE?
INFANTS
WHICH GROUP OF N. MENINGITIDIS IS THE MOST COMMON IN THOSE UNDER 25 AND WHICH IS MORE COMMON IN OLDER PEOPLE WITH COMORBIDITIES?
UNDER 25: MENB
ELDERLY: GROUP Y
AGE GROUPS WITH THE HIGHEST RISK OF MENINGOCOCCAL DISEASE?
INFANTS HAVE THE HIGHEST RISK, THEN AGES 1-5, THEN TEENAGERS
WHY IS THE ABSOLUTE NUMBER OF CASES OF MENINGOCOCCAL DISEASE HIGHER IN ADULTS ALTHOUGH THE RISK IS LOWER?
BECAUSE THE ADULT POPULATION IS LARGER
VACCINES AGAINST MENINGOCOCCAL DISEASE ARE AVAILABLE FOR WHICH SUBGROUPS?
A, B, C, W, Y
WHEN SHOULD CHILDREN IN THE UK RECEIVE THE VACCINES MENB, MENC AND MENACWY?
MENB: 16 WEEKS AND 12 MONTHS
MENC: 12 MONTHS
MENACWY: 14 YEARS
INTRODUCTION OF MENC VACCINE REDUCED THE INCIDENCE OF MENINGOCOCCAL DISEASE GROUP C CASES BY HOW MUCH?
96%
AWARENESS CAMPAIGNS REGARDING MENINGITIS ARE OFTEN CARRIED OUT AT WHICH PLACE AND WHY? WHAT KIND OF PREVENTION IS THIS?
AT UNIVERSITIES, AS YOUNG PEOPLE ARE A RISK GROUP AND MANY OF THEM ARE LIVING AWAY FROM THEIR FAMILIES FOR THE FIRST TIME AND IN COMMUNITY SETTINGS
ROLE IS TO ENSURE STUDENTS KNOW THE SYMPTOMS, KEEP AN EYE ON THEIR FRIENDS AND SEEK HELP IF MENINGITIS IS SUSPECTED
TYPE OF SECONDARY PREVENTION
TERTIARY PREVENTION/TREATMENT FOR N. MENINGITIDIS?
ANTIBIOTICS ARE EFFECTIVE
IN CASES OF INVASIVE MENINGOCOCCAL DISEASE, INTRAMUSCULAR OR INTRAVENOUS BENZYLPENICILIN SHOULD BE GIVEN ASAP
SPECIFIC DEFINITION USED FOR CLOSE CONTACT OF CASES OF N. MENINGITIDIS:
A PROLONGED CLOSE CONTACT WITH THE CASE IN A HOUSEHOLD TYPE SETTING DURING THE SEVEN DAYS BEFORE THE ONSET OF ILLNESS.
EXAMPLES OF SUCH CONTACTS WOULD BE: THOSE LIVING OR SLEEPING IN THE SAME HOUSEHOLD, PUPILS IN THE SAME DORMITORY, BF OR GF, UNIVERSITY STUDENTS SHARING A KITCHEN..
WHAT IS GUIDANCE FOR PEOPLE WHO HAVE CASES OF N. MENINGITIDIS BEEN IN CLOSE CONTACT WITH IN THE LAST 7 DAYS?
THEY WILL BE OFFERED CHEMOPROPHYLAXIS; ANTIBIOTICS TO PREVENT THEM FROM PASSING THE BACTERIA ONTO OTHERS
IF THEY HAVEN’T RECEIVED IT IN THE LAST YEAR, THEY WILL ALSO BE OFFERED THE MENACWY VACCINE
WHAT IS CONSIDERED A CLUSTER WHEN IT COMES TO N. MENINGITIDIS?
2 OR MORE CASES WITHIN 28 DAYS IN THE SAME HOUSEHOLD OR EDUCATIONAL/RESIDENTIAL SETTING
WHAT IS THE GUIDANCE WHEN IT COMES TO N. MENINGITIDIS CLUSTERS?
- THE CASE AND CLOSE CONTACTS ARE ADVISED TO HAVE THE RELEVANT VACCINE (MENB/MENACWY) UNLESS THEY HAVE ALREADY BEEN VACCINATED IN THE LAST YEAR
- THEY SHOULD ALSO BE OFFERED CHEMOPROPHYLAXIS, WITH A DIFFERENT ANTIBIOTIC TO THE ONE THEY HAD BEFORE IF THEY HAD CHEMOPROPHYLAXIS IN THE LAST 28 DAYS
WHICH VACCINE IS ADVISED FOR CONTACTS IF THERE IS A CLUSTER OF N. MENINGITIDIS, BUT NOT IF IT IS JUST A SINGULAR CASE?
MENB
IS CHLAMYDIA TRACHOMATIS GRAM POSITIVE OR GRAM NEGATIVE?
IT IS A GRAM NEGATIVE BACTERIUM
NAME SOME SPECIES WITHIN THE CHLAMYDIA GENUS (APART FROM CHLAMYDIA TRACHOMATIS) AND WHAT DO THEY CAUSE?
C. PNEUMONIAE (CAN CAUSE PNEUMONIA IN HUMANS)
C. PSITTACI (AFFECTS BIRDS, BUT CAN BE PASSED ON TO HUMANS)
WHICH TYPE OF CHLAMYDIA AFFECTS BIRDS BUT CAN BE PASSED ON TO HUMANS?
C. PSITTACI
C. TRACHOMATIS IS AN OBLIGATE INTRACELLULAR BACTERIUM. WHAT DOES THAT MEAN?
IT CAN ONLY REPRODUCE WITHIN ITS HOST’S CELLS
HOW IS C. TRACHOMATIS SUBDIVIDED?
IT IS SUBDIVIDED INTO 3 BIOVARS BASED ON THE DISEASE THEY CAUSE: TRACHOMA, CHLAMYDIA OR LYMPHOGRANULOMA VENEREUM (LGV)
WHAT IS A SEROVAR/SEROTYPE?
A serotype or serovar is a distinct variation within a species of bacteria or virus
WHAT IS A SEROGROUP?
A group of serovars with common antigens is called a serogroup or sometimes serocomplex. Serotyping often plays an essential role in determining species and subspecies.
HOW CAN CHLAMYDIA BE TRANSMITTED?
- UNPROTECTED VAGINAL, ANAL OR ORAL SEX
- SHARING SEX TOYS WHICH AREN’T WASHED/ COVERED BY CONDOM
- PEOPLE’S GENITALS COMING INTO DIRECT CONTACT (EVEN IF THERE IS NO ORGASM, EJACULATION OR PENETRATION)
- INFECTED SEMEN OR VAGINAL FLUID GETTING INTO ONE’S EYE
- CAN BE PASSED BY A PREGNANT WOMEN TO HER BABY
CANNOT BE PASSED THROUGH CASUAL CONTACT (E.G. KISSING, HUGGING, SHARING BATHS, TOWELS, CUTLERY…)
CHILDREN BORN TO MOTHERS WITH CHLAMYDIA ARE AT RISK OF WHICH MEDICAL COMPLICATION?
NEONATAL CONJUCTIVITIS
WHAT IS TRACHOMA?
EYE INFECTION THAT CAN LEAD TO BLINDNESS, CAUSED BY C. TRACHOMATIS
WHAT IS LYMPHOGRANULOMA VENEREUM?
AN STI WHICH USUALLY CAUSES INFECTION IN THE RECTUM, CAUSED BY C. TRACHOMATIS
WHY DO WE CONSIDER ‘DETECTION RATE’ (RATE OF NEW CASES DETECTED) INSTEAD OF ‘INCIDENCE RATE’ (RATE OF NEW CASES) WHEN IT COMES TO CHLAMYDIA?
BECAUSE MANY PEOPLE DO NOT HAVE SYMPTOMS OR DO NOT GET TESTED (ACTUAL INFECTION RATE MOST LIKELY HIGHER THAN NUMBER OF KNOWN CASES)
IN 2020, DETECTION RATE FOR CHLAMYDIA IN YOUNG PEOPLE INCREASED OR DECREASED?
DECREASED
TARGET DETECTION RATE FOR CHLAMYDIA?
2 300 PER 100 000 CASES
DO VACCINES AGAINST CHLAMYDIA/TRACHOMA EXIST?
NO
WHAT IS THE NATIONAL CHLAMYDIA SCREENING PROGRAMME?
- OPPORTUNISTIC SCREENING PROGRAMME FOR ASYMPTOMATIC CHLAMYDIA
- FOCUSES ON WOMEN (TO PREVENT HARM TO WOMEN LIKE PELVIC INFLAMMATORY DISEASE AND ECTOPIC PREGNANCY)
WHAT ARE NOTIFIABLE DISEASES?
DISEASES FOR WHICH, WHEN A CASE IS SUSPECTED, THE REGISTERED MEDICAL PROFESSIONALS HAVE TO NOTIFY THE PUBLIC HEALTH AUTHORITIES
IS CHALMYDIA A NOTIFIABLE DISEASE?
NO
HOW IS CHLAMYDIA MANAGED?
THE CASE IS GIVEN ANTIBIOTICS AND IS ADVISED TO ASK THEIR SEXUAL PARTNERS TO GET TESTED
VERTICAL TRANSMISSION?
GENERATIONAL TRANSMITION OF BACTERIA/VIRUSES FROM PARENTS TO OFFSPRING
HOW OFTEN IS CHLAMYDIA ASYMPTOMATIC?
WOMEN: 7/10 CASES
MEN: 5/10 CASES
CAN CHLAMYDIA GO AWAY ON ITS OWN?
YES
INCUBATION PERIOD FOR CHLAMYDIA?
1-3 WEEKS
CHLAMYDIA SYMPTOMS IN MEN?
- PAIN WHEN URINATING
- WHITE, CLOUDY OR WATERY DISCHARGE FROM THE TIP OF THE PENIS
- BURNING OR ITCHING IN THE URETHRA
- PAIN IN THE TESTICLES
CHLAMYDIA SYMPTOMS IN WOMEN?
- PAIN WHEN URINATING
- UNUSUAL VAGINAL DISCHARGE
- PAIN IN THE STOMACH OR PELVIS
- PAIN DURING SEX
- BLEEDING AFTER SEX
- BLEEDING BETWEEN PERIODS
EFFECTS OF CHLAMYDIA AFFECTING ORGANS APART FROM GENITAL ORGANS?
EYES: RED, ITCHY EYES, DISCHARGE
RECTUM: DISCHARGE, DISCOMFORT
THROAT: GENERALLY ASYMTPOMATIC
PELVIC INFLAMMATORY DISEASE (PID, CAN BE A COMPLICATION OF CHLAMYDIA IN WOMEN) LEADS TO INFERTILITY IN 1 IN HOW MANY WOMEN?
1/6
CHLAMYDIA IN PREGNANCY; ASSOCIATED RISKS?
- HIGHER RISK OF PRETERM BIRTH
- HIGHER RISK OF LOW BIRTH WEIGHT
- RISK OF CONJUNCTIVITIS AND PNEUMONIA IN THE NEWBORN
- MOTHER CAN PASS CHLAMYDIA ONTO THE OFFSPRING
SEXUALLY ACQUIRED REACTIVE ARTHRITIS (SARA)?
- CAN BE CAUSED BY CHLAMYDIA
- CAUSES INFLAMMATION IN JOINTS (CAN ALSO AFFECT THE EYES OR URETHRA)
- MORE COMMON IN MEN
THE KEY RISK FACTOR FOR CHLAMYDIA INFECTION?
AGE: SEXUALLY ACTIVE YOUNG PEOPLE, I.E. UNDER 25
CHLAMYDIA DETECTION RATES IN ENGLAND ARE HIGHER IN MORE DEPRIVED OR LEAST DEPRIVED AREAS?
MORE DEPRIVED
HAVING 2 OR MORE SEXUAL PARTNERS WITHOUT USING A CONDOM IN THE PREVIOUS YEAR INCREASES ODDS OF HAVING CHLAMYDIA BY HOW MUCH?
ODDS 3 TIMES HIGHER FOR WOMEN
ODDS 22 TIMES HIGHER FOR MEN
GUIDANCE FOR CHLAMYDIA TESTING IN ENGLAND?
- SEXUALLY ACTIVE WOMEN UNDER 25: RECOMMENDED TO HAVE CHLAMYDIA TEST ONCE A YEAR, AND WHEN HAVING SEX WITH NEW OR CASUAL PARTNERS
- SEXUALLY ACTIVE MEN UNDER 25: RECOMMENDED TO GET TESTED ONCE A YEAR IF NOT USING CONDOMS WITH NEW OR CASUAL PARTNERS
- IF SOMEONE HAD CHLAMYDIA, THEY MIGHT BE OFFERED ANOTHER TEST 3-6 MONTHS AFTER BEING TREATED
LEGIONELLA PNEUMOPHILA; WHAT KIND OF BACTERIA IS IT?
GRAM-NEGATIVE, ROD-SHAPED BACTERIUM
THE DISEASE ASSOCIATED WITH L. PNEUMOPHILA?
LEGIONNAIRES’ DISEASE
HOW DID L. PNEUMOPHILA AND LEGIONNAIRES’ DISEASE GET THEIR NAMES?
THEY GOT THEIR NAME FROM THE OUTBREAK WHERE THE BACTERIUM WAS FIRST IDENTIFIED; A CONFERENCE OF THE AMERICAN LEGION IN PHILADELPHIA IN 1976
HOW MANY SEROGROUPS DOES L. PNEUMOPHILA HAVE?
15
HOW MANY SPECIES OF LEGIONELLA ARE THERE?
39
WHERE DOES L. PNEUMOPHILA RESIDE AND HOW DOES IT AFFECT HUMANS?
IT LIVES IN WATER SOURCES, BUT CAN INFECT HUMANS WHEN THE WATER THAT CONTAINS THEM IS AEROSOLISED (TURNED INTO FINE PARTICLES) AND BREATHED IN
L. PNEUMOPHILA IS A FACULTATIVE INTRACELLULAR PARASITE, EXPLAIN WHAT THAT MEANS?
- IN THE ENVIRONMENT, IT INFECTS AMOEBAE AND CAN USE THEM TO MULTIPLY
- IN HUMANS, IT IS ABLE TO MULTIPLY IN MACROPHAGES
WHAT ARE FACULTATIVE INTRACELLULAR PATHOGENS?
characterized by the ability to have an intracellular phase in the host, which is required for pathogenicity, while capable of extracellular growth in vitro
WHAT DISEASES CAN L. PNEUMOPHILA CAUSE?
LEGIONNAIRES' DISEASE PONTIAC FEVER (A MILDER FORM, WITHOUT PNEUMONIA)
HOW CAN PEOPLE GET LEGIONNAIRES’ DISEASE?
- THROUGH THE INHALATION OF BACTERIA VIA AEROSOLS FROM ENVIRONMENTAL SOURCES (E.G. POORLY MAINTAINED COOLING TOWERS OR JACUZZIS)
- ENTRY OF THE BACTERIA TO THE BODY VIA WOUNDS ALSO POSSIBLE, BUT RARE
INCUBATION PERIOD FOR LEGIONNAIRES’ DISEASE?
2-10 DAYS (MEDIAN CCA 6-7 DAYS), BUT EVEN LONGER INCUBATION PERIODS HAVE BEEN REPORTED
LEGIONNAIRES’ DISEASE INFECTIOUS PERIOD?
THERE IS NO INFECTIOUS PERIOD AS IT IS NOT TRANSMITTED FROM PERSON TO PERSON (ONE POTENTIAL CASE REPORTED, OTHERWISE NO)
WHAT IS THE DEFINING CLINICAL CHARACTERISTIC OF LEGIONNAIRE’S DISEASE?
PNEUMONIA
SYMPTOMS OF LEGIONNAIRE’S DISEASE APART FROM PNEUMONIA?
FEVER UNPRODUCTIVE COUGH FATIGUE HEADACHES MUSCLE ACHES
LEGIONNAIRES’ DISEASE: FATALITY RATE IN EUROPE?
CCA 10%
WHAT KIND OF SEASONALITY DOES LEGIONNAIRES’ DISEASE SHOW?
IT IS MORE COMMON IN SUMMER AND EARLY AUTUMN
THE HIGHEST NUMBER AND THE HIGHEST RATE OF LEGIONNAIRES’ DISEASE ASSOCIATED WITH TRAVEL ABROAD WERE RELATED TO WHICH COUNTRIES?
NUMBER - SPAIN
RATE- UAE
MOST CASES OF LEGIONNAIRES’ DISEASE IN ENGLAND ARE ASSOCIATED WITH?
TRAVEL ABROAD (40%)
% OF HEALTHCARE ASSOCIATED LEGIONNAIRES DISEASE?
2%
RISK FACTORS FOR LEGIONNAIRES DISEASE?
- OLDER AGE (61% OF CASES)
- MALE SEX (70% OF CASES)
- RECENT TRAVEL
- SMOKING (32% OF THE CASES)
- CVD
- RESPIRATORY DISEASE
- DIABETES
- BEING IMMUNOSUPPRESSED
75% OF CASES HAVE ONE OR MORE HEALTH RISK FACTOR OR CO-MORBIDITY
GENERAL CLASSIFICATION OF LEGIONNAIRES DISEASE?
COMMUNITY ASSOCIATED
HEALTHCARE ASSOCIATED
TRAVEL ASSOCIATED
GENERAL CLASSIFICATION OF LEGIONNAIRES DISEASE?
COMMUNITY ASSOCIATED
HEALTHCARE ASSOCIATED
TRAVEL ASSOCIATED
PUBLIC HEALTH MANAGEMENT OF LEGIONNAIRES DISEASE?
- THE DISEASE IS NOT TRANSMITTED FROM ONE PERSON TO ANOTHER SO THE CASE IS NOT A RISK TO OTHERS
- THE SOURCE OF THE INFECTION MIGHT STILL BE A RISK TO OTHERS SO IT IS THE FOCUS OF PUBLIC HEALTH MANAGEMENTS
- LEGIONNAIRES DISEASE CAN BE DIAGNOSED FROM A URINARY ANTIGEN TEST, BUT FOR THE PURPOSES OF THE PUBLIC HEALTH INVESTIGATION, ENSURING THAT A LOWER RESPIRATORY TRACT SAMPLE IS TAKEN FOR CULTURE IS IMPORTANT; THIS IS BECAUSE, WHERE SUCCESSFULLY CULTURED, THE ISOLATE CAN BE ANALYSED TO ASSESS MICROBIOLOGICAL LINKS BETWEEN THE CASE AND ANY ENVIRONMENTAL SAMPLES (OR OTHER CASES)
- IN ORDER TO ASSESS THE POSSIBLE SOURCES OF THE DISEASE, PUBLIC HEALTH SPECIALISTS WILL COMPLETE AN ENHANCED SURVEILLANCE QUESTIONNAIRE (ESQ) WITH THE CASE (OR RELATIVE, OR THE CASE IS NOT WELL ENOUGH)
- THE ESQ COLLECTS INFO ABOUT THEIR MOVEMENTS AND ACTIVITIES IN THE 10 DAYS BEFORE THEY BECAME UNWELL (BECAUSE THE INCUBATION PERIOD IS 2-10 DAYS)
- CONTROL MEASURES TAKEN WHEN NEEDED
WHY IS LOWER RESPIRATORY TRACT SAMPLE TAKEN FOR CULTURE IN LEGIONNAIRES DISEASE TAKEN AND WHY CAN IT BE DIFFICULT TO GET DONE?
IT IS DONE BECAUSE SUCCESSFULLY CULTURED ISOLATE CAN BE ANALYSED TO ASSESS MICROBIOLOGICAL LINKS BETWEEN THE CASE AND ANY ENVIRONMENTAL SAMPLES (OR OTHER CAUSES)
IT CAN BE DIFFICULT BECAUSE THE DISEASE GENERALLY HAS A DRY COUGH - I.E. WITHOUT SEPTUM
WHAT IS THE ROLE OF ENHANCED SURVEILLANCE QUESTIONNAIRE (ESQ) IN LEGIONNAIRES DISEASE?
IT IS USED TO ASSESS THE POSSIBLE SOURCES OF THE DISEASE, COLLECTS INFO ABOUT THE CASES MOVEMENTS AND ACTIVITIES IN THE 10 DAYS BEFORE BECOMING UNWELL AND IT CONTAINS QUESTIONS AROUND HEALTHCARE FACILITIES AND TRAVEL
WHAT IS THE ROLE OF ENHANCED SURVEILLANCE QUESTIONNAIRE (ESQ) IN LEGIONNAIRES DISEASE?
IT IS USED TO ASSESS THE POSSIBLE SOURCES OF THE DISEASE, COLLECTS INFO ABOUT THE CASES MOVEMENTS AND ACTIVITIES IN THE 10 DAYS BEFORE BECOMING UNWELL AND IT CONTAINS QUESTIONS AROUND HEALTHCARE FACILITIES AND TRAVEL
PREVENTION OF LEGIONNAIRES DISEASE?
AS L. PNEMUOPHILA ONLY LIVES IN THE ENVIRONMENT (AS OPPOSED TO HUMAN OR ANIMAL RESERVOIRS) PREVENTION OF LEGIONNAIRES DISEASE IS AROUND ENSURING HIGH QUALITY WATER MANAGEMENT PROCESSES
WHAT ARE BIOFILMS?
GROUPS OF MICRO-ORGANISMS (SOMETIMES LOOKING LIKE ‘DARK SLIME’) WHICH CAN PROTECT BACTERIA FROM MEASURES TO REMOVE IT
WHAT TEMPERATURE RANGE DO LEGIONELLA BACTERIA PREFER?
25-42 DEGREES CELSIUS
WHAT MAKES COOLING TOWERS A PARTICULAR RISK FOR LEGIONNAIRE’S DISEASE?
- THEY CAN DISTRIBUTE LEGIONELLA BACTERIA OVER A LARGE DISTANCE
- THEY OPERATE AT TEMPERATURES SUITABLE FOR LEGIONELLA
- THEY CAN BECOME CONTAMINATED WITH BIOLOGICAL MATTER THAT HAS NUTRIENTS LEGIONELLA CAN USE
- IF THEY AREN’T USED CONTINUOUSLY, THE WATER CAN BECOME STAGNANT, WHICH ALSO HELPS LEGIONELLA BACTERIA GROW
IS ESCHERICHIA COLI GRAM NEGATIVE OR GRAM POSITIVE BACTERIUM?
GRAM NEGATIVE
RESERVOIR FOR STEC?
DIGESTIVE TRACT OF RUMINANTS (GRAZING ANIMALS WITH A FOUR PART STOMACH, LIKE COWS, SHEEP AND GOATS)
MOST TYPES OF E. COLI DO NOT CAUSE DISEASE, BUT WHICH SUBSET CAN CAUSE SEVERE DISEASE?
SHIGA TOXIN PRODUCING E. COLI (STEC) AKA VEROCYTOTOXIN-PRODUCING E. COLI (VTEC)
THE OTHER NAME FOR STEC?
VEROCYTOTOXIN-PRODUCING E. COLI
HOW ARE E. COLI BACTERIA GROUPED?
BASED ON A TYPE OF ANTIGEN KNOWN AS AN ‘O’ ANTIGEN
MOST WELL KNOWN STEC STRAIN?
E. COLI O157
E. COLI BACTERIA ARE GROUPED BASED ON THE O ANTIGEN, AND CAN THEN BE FURTHER SUBDIVIDED BY?
H ANTIGEN TYPE (E.G. O157:H7)
STEC (CAUSES GASTROINTESTINAL ILLNESS) MODE OF TRANSMISSION:
- FOOD OR WATER BORNE (WHERE THESE ARE CONTAMINATED WITH ANIMAL FECES)
- COMING INTO CONTACT WITH ANIMAL FAECES AND THIS BEING TRANSMITTED INTO THE BODY VIA INFECTED HANDS
- FAECAL-ORAL ROUTE FROM INFECTED HUMANS
KEY RISKS FOR GETTING STEC?
- SALAD VEGETABLES OR FRUITS THAT ARE NOT COOKED OR PEELED BEFORE EATING
- UNCOOKED MEAT
- UNPASTEURISED MILK
- WATER-BASED ACTIVITIES (E.G. SWIMMING IN A RIVER)
- FARM VISITS (ESP BY CHILDREN)
STEC INCUBATION PERIOD?
2-4 DAYS (FOR THE O157 TYPE)
SYMPTOMS OF STEC?
DIARRHOEA (BLOODY IF DISEASE IS MORE SEVERE), ABDOMINAL CRAMPS/PAIN AND VOMITTING
COMPLICATION OF STEC?
HAEMOLYTIC URAEMIC SYNDROME (HUS); PRODUCED BY STEC KILLING RBCs; CAN MAKE PATIENTS ANEMIC AND THE DEAD CELLS CAN CAUSE BLOCKAGES IN THE KIDNEYS
— CAN LEAD TO LONG TERM KIDNEY DAMAGE OR BE FATAL
GREATEST RISK FACTOR FOR DEVELOPING HUS FROM STEC?
BEING YOUNGER THAN 5
% OF STEC PATIENTS WHO DEVELOP HUS?
10%
WHEN WAS THE LAST LARGE NATIONAL OUTBREAK OF E. COLI IN ENGLAND?
2016
IS THERE MORE CASES OF E. COLI O157 IN WINTER OR SUMMER?
SUMMER
% OF E. COLI CASES IN ENGLAND AFFECTING WOMEN?
58%
EXAMPLES OF PRIMARY PREVENTION OF STEC?
- APPROPRIATE WATER MANAGEMENT AND TREATMENT
- HAND WASHING AFTER CONTACT WITH FARM ANIMALS OR THEIR FAECES, ESP BEFORE EATING
- FOOD HYGIENE MEASURES (E.G. ENSURING MEET IS COOKED PROPERLY)
- ENSURE THOSE INFECTED WITH STEC (OR THOSE CARING FOR THEM) WASH THEIR HANDS AFTER USING THE TOILET AND DO NOT ATTEND SCHOOL/WORK UNTIL THEY’RE FREE OF SYMPTOMS FOR 48 HRS
AN OUTBREAK OF A CERTAIN INFECTION CAN BE?
POSSIBLE
PROBABLE
CONFIRMED
AN OUTBREAK OF A CERTAIN INFECTION CAN BE?
POSSIBLE
PROBABLE
CONFIRMED
ENGLAND REGIONS WITH THE HIGHEST AND LOWEST INCIDENCE OF E. COLI:
HIGHEST: THE NORTH EAST
LOWEST: LONDON
E. COLI TREATMENT?
- TREATMENT IS SUPPORTIVE (E.G. REPLACING FLUIDS)
- GIVING ANTIBIOTICS OR DRUGS TO STOP THE DIARRHOEA IS USUALLY NOT RECOMMENDED
PUBLIC HEALTH MANAGEMENT FOR STEC?
- CARRYING OUT ENHANCED SURVEILLANCE QUESTIONNAIRE
- DOING A RISK ASSESSMENT
- PUTTING CONTROL MEASURES IN PLACE
- – REFERRING TO AN ALGORITHM THAT HAS BEEN PUBLISHED TO GUIDE PH TEAMS ON ACTIONS TO TAKE IS NEEDED (BASED ON THE TEST RESULTS RECEIVED SO FAR, THE CLINICAL PICTURE, WHETHER THERE IS AN EPIDEMIOLOGICAL LINK TO KNOWN CASES, WHETHER THE CASE HAS BEEN HOSPITALIZED FOR DIARRHEA, THE AGE OF THE PATIENTS ETC.)
WHAT KIND OF QUESTIONS DOES AN ENHANCED SURVEILLANCE QUESTIONNAIRE FOR E. COLI INCLUDE?
- SYMPTOMS?
- TRAVEL?
- FOOD OUTLETS/FOOD HANDLED AND CONSUMED?
- WATER CONSUMED AND EXPOSURE TO WATER?
- CONTACT WITH ANIMALS?
- CONTACT WITH POTENTIAL ENVIRONMENTAL SOURCES?
- INFO ABOUT CONTACTS?
- AGE?
- RISK GROUP?
RISK GROUPS FOR GASTROINTESTINAL INFECTIONS WHICH ARE USED FOR STEC; WHAT ARE THEY AND WHAT IS THE ROLE?
THEY ARE ABOUT THE RISK OF TRANSMISSION TO OTHERS FROM INFECTIONS SPREAD VIA THE FECAL-ORAL ROUTE, ESP THE RISK TO VULNERABLE PEOPLE (RISK GROUPS FOR FURTHER TRANSMISSION)
4 GROUPS: A, B, C, D
GROUP A: ANY PERSON UNABLE TO PERFORM ADEQUATE PERSONAL HYGIENE FOR ANY REASON
GROUP B: ALL CHILDREN YOUNGER THAN 5 WHO ATTEND ANY CHILD CAR FACILITY
GROUP C: PEOPLE WHOSE WORK INVOLVES PREPARING OR SERVING UNWRAPPED READY TO EAT
GROUP D: CLINICAL, SOCIAL CARE OR NURSERY STAFF WHO WORK WITH CHILDREN, ELDERLY OR VULNERABLE GROUPS
HOW LONG SHOULD PEOPLE WITH STEC STAY OFF NURSERY/SCHOOL/WORK?
UNTIL 48 HRS AFTER SYMPTOMS HAVE RESOLVED
WHAT KIND OF BACTERIUM IS CLOSTRIDIOIDES DIFFICILE?
GRAM POSITIVE, ANAEROBIC, ROD SHAPED BACTERIUM
WHAT WAS THE NAME OF CLOSTRIDIOIDES DIFFICILE BEFORE 2016?
CLOSTRIDIUM DIFFICILE
WHAT ALLOWS C. DIFFICILE BACTERIA TO SURVIVE IN CONDITIONS WHERE USUAL CELLS WOULDN’T?
THE ABILITY TO FORM SPORES TO DEFEND ITSELF (E.G. IN THE ENVIRONMENT, WHERE THE O2 WHICH IS PRESENT IS TOXIC TO THEM)
SPORES CAN GERMINATE IN SUITABLE CONDITIONS (E.G. WHEN SOMEONE INGESTED THEM)
WHAT DOES ‘-OIDES’ MEAN IN THE NAME CLOSTRIDIOIDES DIFFICILE?
‘LIKE’
WHAT ARE THE 5 BACTERIA OF KEY PUBLIC HEALTH IMPORTANCE?
ESCHERICHIA COLI NEISSERIA MENINGITIDIS CLOSTRIDIOIDES DIFFICILE CHLAMYDIA TRACHOMATIS LEGIONELLA PNEUMOPHILA
WHICH DISEASE DOES C. DIFFICILE CAUSE?
DIARRHOEAL ILLNESS CALLED C. DIFF INFECTION
C. DIFFICILE MODE OF TRANSMISSION?
FECAL-ORAL ROUTE (INCLUDING INDIRECTLY VIA THE INGESTION OF SPORES THAT CAN CONTAMINATE THE ENVIRONMENT)
HOW MANY PEOPLE HAVE C. DIFFICILE LIVING INSIDE OF THEM WITHOUT CAUSING ANY PROBLEMS?
3% OF ADULTS AND 2/3 OF BABIES
FATALITY RATE FOR C. DIFFICILE INFECTION?
13.5%
SINCE WHEN HAVE C. DIFFICILE INFECTIONS BEEN MONITORED IN ENGLAND?
2004
EXPLAIN THE KEY RISK FACTOR FOR C. DIFFICILE INFECTION?
ANTIBIOTIC USE
C. DIFF CAN LIVE IN THE GI TRACT WITHOUT PROBLEMS, BUT WHEN SOME PEOPLE ARE GIVEN ANTIBIOTICS, THIS KILLS OFF OTHER BACTERIA IN THE GI TRACT ALLOWING C. DIFFICILE TO PROLIFERATE AND PRODUCE HIGH LEVELS OF ITS TOXIN
AGE GROUP AT A HIGHER RISK OF C. DIFF INFECTION?
65+
MORE CASES OF C. DIFF ARE SEEN IN WOMEN, BUT SEX IS NOT CONSIDERED A RISK FACTOR, WHY?
BECAUSE THE ACTUAL RISK FACTOR IS OLDER AGE, AND THE OLDER POPULATION IS PREDOMINANTLY FEMALE
TREATMENT OF C. DIFF INFECTION?
- IF POSSIBLE, THE ANTIBIOTICS THAT MAY HAVE LED TO C DIFF SHOULD BE STOPPED
- USE OF PROTON PUMP INHIBITORS SHOULD BE REVIEWED
- ANTIBIOTICS SHOULD BE GIVEN AS WELL AS SUPPORTIVE CARE (E.G. AVOID DEHYDRATION)
PUBLIC HEALTH MANAGEMENT FOR C. DIFF INFECTION?
MAIN PUBLIC HEALTH IMPLICATIONS ARE IN PREVENTING PERSON-TO-PERSON SPREAD OF C. DIFF AMONG VULNERABLE PEOPLE, SUCH THOSE IN HOSPITALS
!!!!! KEY MANAGEMENT MEASURES RELATE TO INFECTION CONTROL
ACRONYM FOR INFECTION CONTROL FOR C. DIFF, EXPLAIN:
‘SIGHT’
S: SUSPECT THAT A CASE MAY BE INFECTIVE WHERE THERE IS NO CLEAR ALTERNATIVE CAUSE FOR DIARRHOEA
I: ISOLATE THE PATIENTS AND CONSULT WITH THE INFECTION CONTROL TEAM WHILE DETERMINING THE CAUSE OF DIARRHOEA
G: GLOVES AND APRONS NEED TO BE USED FOR ALL CONTACTS WITH THE PATIENT AND THEIR ENVIRONMENT
H: HAND WASHING WITH SOAP SHOULD BE CARRIED OUT BEFORE AND AFTER EACH CONTACT WITH THE PATIENT AND THEIR ENVIRONMENT
T: TEST THE STOOL FOR TOXIN; BY SENDING A SPECIMEN IMMEDIATELY
C. DIFF INFECTION SYMPTOMS?
DIARRHOEA SEVERAL TIMES A DAY FEVER LOSS OF APPETITE FEELING SICK STOMACH PAIN
COMPLICATIONS IN SEVERE CASES OF C. DIFF INFECTION?
PSEUDOMEMBRANOUS COLITIS (INFLAMMATION OF THE LARGE INTESTINE)
CLASSIFICATION OF LEGIONELLA CASES IN ENGLAND (2019):
48 %community associated
2% healthcare associated
40% were classed as ‘travel abroad’
10% were classed as ‘travel UK’
