Zoonosis 1

Anthroponosis

Infection of animals from humans

What % of known human infectious diseases have their source in animals (whether domestic or wild)

60%

What % of emerging human diseases are zoonotic

75%

Lyme Disease is caused by ______ transmitted by _______

Lyme Disease is caused by Borrelia burgdorferi transmitted by Ixodes ticks

Features of Early Lyme Disease

Proliferation in the skin associated with skin lesion (may not happen or may go unnoticed)

• Many people do not recall tick bites

• B. burgdorferi disseminates from skin

• Early systemic features include fever & lymphadenopathy (many people do not have or do not recall)

Features of Late Lyme Disease

Disease of central nervous system, joints, cardiovascular system

What is the use of 2 tests we do for lyme disease

Category 1: Test for the organism (whole organism or parts of). Detection of organism is generally more definitive (but may not differentiate between infection and colonization)

Category 2: Test for the host immune response. Detection of host immune response can be complex but usually indicates infection (but often does not differentiate between current and previous infection and infection does not equal disease)

Which of the 2 testing methods is the main one for Lyme disease

Detection of host immune response is the main method of testing

2 tests used in Detection of host immune response

Enzyme Immuno Assay (EIA) initial test

Line Immuno Assay (LIA) follow on testing

What antibodies & immunoglobulins would you expect to be positive in Lyme Disease

• Serology – Antibody to B. burgdorferi

• Antibody Positive on EIA

• IgG Immunoblot – positive

• IgM Immunoblot - positive

Treatment for Lyme Disease

Cefotaxime

General cycle of B. burgdorferi (which organisms are involved)

Ticks – Small Rodents- Larger Mammals (Deer)

Humans Incidental & Probably Dead end Host

Where are Campylobacter and Salmonella found & how do we avoid the infection

• Common In The GIT Of Animals

• May Contaminate Meat

• Killed By Cooking

Camplybacteriosis symptoms

Abdominal pain and blood in faeces.

Guillian-Barre syndrome - causes paralysis

How is Camplybacteriosis diagnosed

Lab Diagnosis By Culturing + PCR

Name 2 species of Salmonellosis

• Salmonella Typhimurium (Not Salmonella Typhi which → typhoid)

• Salmonella Enteritidis

Most common symptom of salmonellosis

Self Limiting Diarrhoea

What’s another name for Shiga toxin producing E. Coli (STEC)

Vero-Toxigenic E. coli (VTEC)

True/False Vero-Toxigenic E. coli (VTEC) is part of our normal GIT flora

False - But normal part of sheep GIT flora

Shiga toxin producing E. coli has a low/high infectious dose

Low

Range of illness for Shiga toxin producing E. coli (STEC/VTEC)

• Can be asymptomatic

• Mild diarrhoea,

• haemorrhagic colitis (abdominal cramping, bloody diarrhoea, no/low grade fever)

• haemolytic uraemic syndrome (HUS) (haemolytic anaemia, thromocytopenia, acute renal failure)

• Death

Ages at risk of VTEC

Take with grain of salt - it would affect older/younger more as they are more vulnerable but middle aged might fight it and not really notice

What animal(s) does STEC/VTEC come from

Ruminant animals

• Goats

• Sheep

• Cattle

When we say STEC/VTEC has a low infectious dose, what CFU/ml is required for infection

<10CFU/ml

Name 3 specific serotypes (serovars) of E. coli that can produce Shiga toxin.

serovars O157, O26, O104

Which serogroup was associated with an E.coli outbreak in Northern Germany

0104

What was the result of the E.coli 0104 outbreak

Why is there a higher risk of VTEC/STEC in burgers vs steak

Once streak is seared the bacteria on the outside (which is where they stay) is killed

Undercooked burgers are all mixed up meat so need to be cooked through

How is VTEC diagnosed

Culture Of Faeces

Detection Of Virulence Factors e.g. Serosep Gastro panels….Real-time PCR

What type of organism is Cryptosporidium parvum

Protozoan parasite

Where is Cryptosporidium parvum found

Lives in the intestines of infected humans and animals.

Can be shed in faeces and contaminate water

Cryptosporidium parvum symptoms

watery diarrhoea, stomach cramps, bloating, vomiting and fever.

May be fatal in those with impaired immune system

How is Cryptosporidium parvum eliminated form water

Filters

(Resistant to Chlorine)

What year & where was the last big Cryptosporidium parvum outbreak

How is Cryptosporidium diagnosed

MICROSCOPY + PCR

(NOT CULTURE)

What type of organism is Giardia lamblia

Protozoan Parasite

Giardia lamblia exists in what form

Survives as Cyst

Sx of Giardia lamblia

Acute Or Chronic Diarrhoea

How is Giardia lamblia gotten rid of

Not sure but it is Chlorine Resistant so not chlorine

Method for Diagnosis Of Giardiasis

MICROSCOPY + PCR

(NOT CULTURE)

Through what zoonotic transmission is Giardiasis generally spread to humans

Through dogs

Which of these are not zoonoses:

Leptospirosis

Nipah Virus

Cat Scratch Disease

Yersinia pestis

Avian Flu (HPAI(H5N1))

Trick - they are all zoonoses

M pox discovered in ___ when 2 outbreaks of a pox-like disease occurred in colonies of what animal

M pox discovered in 1958 when 2 outbreaks of a pox-like disease occurred in colonies of monkeys kept for research

First human case of Mpox was recorded where? when?

Democratic Republic of Congo, 1970

There are 2 clades of Mpox. Name them & where they are found

• Clade I – responsible for rise in cases in Central and Eastern Africa

• Clade II – global outbreak that began in 2022

How can Mpox be prevented

vaccines

Name the animals associated with these:

· Rabies

· Avian Flu

. MERS-CoV

· Hepatitis E Vir

SARS-CoV-2 thought to have originated in what animals

Bats

SARS-CoV-2 may have passed through an intermediary host to humans - which animal

pangolin

What test can be used to provide valuable information on potential sources and changes within host.

Genome analysis

Risk Groups for Zoonoses

Occupational Exposure

• Agricultural Workers

• Sewer Workers

• Veterinarians

Recreational Exposure

• Outdoor Activities

• Hill Walking, Orienteering, Fresh Water Sports

• Visits to Open Farms

What type of organisms pass on zoonotic diseases easier to humans

Transmission from Birds, Reptiles Does Occur but Organisms From Mammals may be more Transmissible than those from reptiles

Bacteria and Parasites May be more Transmissible than Animal Virus