Community health Nursing. Zoonotic diseases.

1. Prepared By:
Mrs. Namita Batra Guin
Associate Professor
Department of Community Health Nursing
Namita Batra Guin

2. Introduction
— Covers complex group of food borne infections.
— Food poisoning is commonly applied to salmonellosis.
— A global problem- 60-80% cases reported annually.
— Disease can occur sporadically or in small outbreak,
usually food contaminated at its source.
Namita Batra Guin

3. Epidemiological determinants
— Agent factors: salmonellae comprising more than 2500
serotypes capable of infecting humans.
— Salmonellae can be classified into 3 main groups:
— Those infect man only- S. typhi, S. paratyphi A and C
— Those that are host adapted for particular species of
animals. E.g. S. cholera- suis in swine, S. dublin- in cattle
— Those with no particular host preference and can infect
both man and animals- S. typhimurium, S. enteritidis.
S. typhimurium is responsible for up to 50% or more of all
human salmonella infections all over the world.
Namita Batra Guin

4. Epidemiological determinants
— Reservoir and sources of infection: intestinal tract of
man and animals. Source is contaminated food,
animals, man or environment.
— Food: food of animal origin considered as primary
source of salmonellosis. Cross contamination of
cooked food from raw ingredients, kitchen utensils or
surface can be cause of contamination.
— Animals: cattles, swine, rodents and fowl are naturally
infected with variety of salmonellae. Carriers occur
among both man and animals.
— Environment: widely distributed in environment-
dusts, manure, water, vegetables, insects etc.
Namita Batra Guin

5. Epidemiological determinants
— Mode of transmission: by ingestion of contaminated
food or drink. By direct contact with domestic animals
especially dogs, pigeons, rats etc.
— Man may spread the infection to others by fecal-oral
route.
— Transmission is facilitated by food handling methods,
local customs, cooking and food habits, food
processing, storage and distribution methods.
— Incubation period: 6 to 72 hrs
Namita Batra Guin

6. Clinical features
— Disease may be manifested as any of the three
syndromes:
— Enteric fever:
— malaise, cough, headache, and sore throat.
— Pt. looks toxic, exhausted and often prostrated after 7 to
10 days.
— Fever ascends like step ladder.
— marked abdominal distension and “pea soup” diarrhea.
— Blood, urine and stool culture positive.
Namita Batra Guin

7. Clinical features
— Salmonella entero-colitis (gastroenteritis):
— After 6 to 48 hrs- nausea ,vomiting, headache and
diarrhea.
— Low grade fever.
— Dehydration
— Blood culture negative. Stool culture positive.
— Death is rare.
Namita Batra Guin

8. Clinical features
— Septicemia with focal lesions:
— Non-typhoid salmonellae invade blood stream.
— Generalised or localised infection presenting as pyrexia
of unknown origin.
— Osteomyelitis, cholecystitis, meningitis, pyelonephritis
and arthritis.
— Stool culture negative. Blood culture positive.
Namita Batra Guin

9. Prevention and control
— Immunization of farm animals against salmonellosis.
— Use of hygenic animal feeds.
— Ensuring sanitary environment for the animals.
— Pasteurization of milk and milk products.
— Proper disposal of wastes.
— Health education and training.
Namita Batra Guin

10. Namita Batra Guin

11. — Causes communicable diseases.
— Transmitted to man by arthropod vectors except Q
fever.
— Contribute substantially to acute fever burden.
— Causative organism- rickettsiae
— Charaterised by malaise, prostration, skin rash,
spleenomegaly, fever, headache and liver enlargement.
— Tetracycline – drug of choice
— Long acting antibiotics- doxycycline.
Namita Batra Guin

12. Namita Batra Guin

13. — Caused by rickettsiae.
— Most widespread.
— Occurs as zoonoses between trombiculid mites and
their small mammals e.g rats, shrews.
— Active over area bound by Japan .
— During decade, 1970-80, scrub typhus was reported in
China, Thialand,Japan, India, Indonesia,Malaysia and
Vietnam.
Namita Batra Guin

14. Epidemiological determinants
— Agent:- rickettsia tsutsugamushi.
— Reservoir: tromboculid mite. Infection remains in
nature transovarially. Larva (chigger) feeds on
vertebrae host. Larva stage serves as reservoir and
vector
— Mode of transmission: bite of infected larval mites.
Mite à Rats and mice à Mite à Rats and mice
Man
— Incubation period – 10 -12 days
Namita Batra Guin

15. Clinical features
— Onset is acute with chills and fever.
— Other manifestations are: headache, malaise,
prostration and macular rash appearing around the 5th
day of illness.
— Generalised lymphadenopathy and lymphocytosis.
— Typical feature- punched out ulcer covered with
blackened scab(eschar) indicating location of mite
bite.
— Pyrexia falls in 3rd week.
Namita Batra Guin

16. Control measures
— Treatment: tetracycline.
— Vector control: insecticides such as lindane for mite
control.
— Personal prophylaxis: impregnating clothes and
blankets with mitical chemicals, mite repellants
— No vaccine exists
Namita Batra Guin

17. Namita Batra Guin

18. — Zoonoses.
— Prevalent in south-east Asian and Western Pacific
region.
— Focal infection associated with docks and shipping
places where rats abound.
Namita Batra Guin

19. Epidemiological determinants
— Agent: rickettsia typhi
— Reservoir: rats (Rattus rattus and Rattus norvegicus)
— Infection in rats is inapparent, long lasting and non-
fatal.
— Mode of transmission:
— Infection spreads from rat to rat and often to rat fleas.
— Transmission occurs through:
— Inoculation into skin.
— Inhalation of dried infective faeces.
— No direct man to man transmission.
Namita Batra Guin

20. Epidemiological determinants
— Transmission cycle:
Rat à Rat flea à Rat à Rat flea à Rat
Man
— Incubation period: 1 to 2 weeks
Namita Batra Guin

21. Epidemiological determinants
— Resembles louse borne typhus but milder
— Rarely fatal
— Weil Felix reaction with Proteus OX-19 becomes
positive in 2nd week.
Namita Batra Guin

22. Control measures
— Treatment: tetracycline.
— Control of fleas: residual insecticides, rodent measures
— No vaccine available.
Namita Batra Guin

23. Namita Batra Guin

24. — Was diagnosed as Rocky mountain spotted fever until
the distinct entity of tick typhus was found to exist in
India.
— It is wide spread in India.
Namita Batra Guin

25. Epidemiological determinants
— Agent: Rickettsia conorii.
— Reservoir: ticks. Infective at all stages of life cycle and
remain infected for life
— Rickettsia can be transmitted to dogs, various rodents
and other animals which assist in maintaining the
disease cycle.
— Mode of transmission: man is accidental host. Direct
contact and tick bite are modes. Cycle:
Tick à Tick à Tick à Tick
Dog Man
Tick Man
Namita Batra Guin

26. Clinical features
— eschar or lesion at site of bite.
— After 3 to 7 days- fever, malaise and headache.
— Maculopapular rash appears on 3rd day.
— Rash appears first on extremities moves centripetally
and involves rest of the body.
— Clinical symptoms may be confused with atypical
measles.
Namita Batra Guin

27. Control measures
— Treatment: broad spectrum antibiotics.
— Personal prophylaxis: known tick infested areas should
be avoided. Disinfection of dogs.
— Health education
Namita Batra Guin

28. Namita Batra Guin

29. — Highly infectious zoonotic disease.
— Occurs in people associated with sheep, goats, cattle or
other domestic animals.
— According to serological surveys: Q fever is present in
animals and human population in Haryana, Punjab,
Delhi, Rajasthan and various other parts.
Namita Batra Guin

30. Epidemiological determinants
— Agent: Coxiella burnetii
— Animal host: cattles, sheep, goats, ticks and some wild
animals.
— Infected animals shed agent in feces and urine.
Placenta of infected animals is also infected.
— Mode of transmission: no arthropod involved.
— Inhalation of infected dust.
— Entry through skin abrasions, conjunctiva or ingestion
of contaminated food.
Incubation period: 2 to 3 weeks.
Namita Batra Guin

31. Clinical features
— Acute onset
— Fever, chills, malaise and headache.
— No rash or lesion.
— Infection can cause pneumonia, hepatitis, encephalitis
and endocarditis.
Namita Batra Guin

32. Control measures
— Treatment: tetracycline orally for 5days.
— Pasteurization, sanitary measures.
— Adequate disinfection and disposal of products.
— Vaccines under development.
Namita Batra Guin