Infectious diseases in brief

1. Infectious Disease
Mug Up
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2. Reservoir of Important Infectious
Disease
Reservoir Disease
Human Epidemic typhus, Dracunculiasis, Ancylostomiasis,
Trench fever, Ascarasis
Rodents Endemic typhus, Indian tick typhus, RMSF, Rickettsial
pox
Non
Living
Soil harbours tetanus, anthrax, coccidiomycosis,
Mycetoma
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3. Types of Host
Disease Primary Secondary
Taperworm (T. saginata) Man Cattle
Taperworm (T. solium) Pig
Guinea worm Cyclopes
Filaria Culex
Sleeping sickness Tse tse fly
Malaria Anopheles Man
Hydatid cyst Dog Sheep, cattle, man
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4. Composition of Reduced Osmolarity
ORS
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5. Zoonoses (less important)
Viral Bacterial Rickettsial Parasitic
Rabies Brucellosis Taeniasis
Yellow fever Leptospirosis Hydatid
disease
JE* Plaque Leishmaniasis*
KFD Human
salmonellosis*
Chikungunya
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6. Diseases Associated with Rodents
(less important)
Bacterial Viral Rickettsial Parasitic Others
Plaque Lassa fever Scrub
typhus
Hymenolep
sis
Rat bite
fever
Tularemia Hemorrhag
ic fever
Murine
typhus
Leishmania
sis
Leptospiros
is
Salmonello
sis
Encephaliti
s
Rickettsial
pox
Amoebiasis Histoplasm
osis
Trichinosis
Chagas
disease
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7. Rickettsial Diseases (v.v.imp)
Diseases Rickettsial Agent Insect vectors Mammalian
reservoirs
Typhus Group
Epidemic R. Prowazakii Louse (by
scratch/
crushing)
Human
Murine R. Typhi Flea Rodents (Rats)
Scrub R. tsutsugamushi Mite* (bite of
larval stage)
Spotted fever
Indian tick R. Conorii Tick* (bite/
scratch/ crush)
Rodents, Dogs
RMSF R. Rickettsii
Rickettsial pox R. akari Mite* (bite) Mouse 7

8. Rickettsial Diseases (contd.)
Diseases Rickettsial
Agent
Insect
vectors
Mammalian
reservoirs
Distribution
Others
Q fever C. Burnetti Nil
(Inhalatio
n, Direct
inoculatio
n)
Cattle, Sheep,
Goats
Worldwide
Trench fever Rochalimaea
quintana
Louse
(faeces)
Human (only) Europe
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•Also serve as arthropod reservoir, by maintaining the rickettsiae through ovarian transmission
• Bite causes an eschar
• Arthropod insect vectors (except Q Fever)

9. Period of Communicability (v.v.imp)
Disease Period of Communicability
Chicken
pox
1- 2 days before to 4- 5 days after appearance of rash
(Patient ceases to be infectious once lesions have crusted)
Measles 4 days before to 5 days after appearance of rash
(Highly infectious during pro dromal stage & during
eruption, period of communicability decreases after rash
appears)
Diptheria 14- 28 days from disease onset
Rubella 1 week before to 1 week after rash onset (Max. When
rash is erupting)
Mumps 4- 6 days before onset of symptoms & a week thereafter
Influenza 1- 2 before & 1- 2 days after onset of symptoms
Whooping
cough
1 week after exposure to 3 weeks after onset of
paroxysmal stage (catarrhal stage) 9

10. Period of Isolation (v.v.imp)
Disease Duration
Chicken Pox 6 days after onset of rash
Measles Onset of catarrhal to 3rd day of rash/
7days after rash onset
German measles None (except in 1st trimester)
Influenza 3 days after onset
TB Until 3 weeks of chemotherapy
Cholera, Diptheria 3 days after tetracycline started till 48
hours of antibiotics
Herpes zoster 6 days after onset of rash
Mumps Until swelling subsides
Pertussis 3 to 4 weeks or until paroxysms cease
Meningococcal meningitis,
Streptococcal pharyngitis
Until 1st 6 hours antibiotics completed
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11. Gastro Intestinal Infections:
Common Features
• Mode of transmission: contaminated water, food &
drinks
• Period of isolation:
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Disease Duration
Cholera, Diptheria 3 days after tetracycline started till 48 hours
of antibiotics (7- 10 days)
Shigella, Salmonella Until 3 consecutive negative stool cultures
Hepatitis A 3 weeks
Polio 2 weeks adults, 6 weeks paediatric

12. Chemoprophylaxis (v.v.imp)
Disease Chemoprophylaxis
Cholera Tetracycline
Bacterial conjunctivitis Erythromycin
Diptheria Erythromycin
Influenza Amantadine
Malaria < 6 weeks (doxycycline, chloroquine),
> 6 weeks (mefloquine)
Meningococcal meningitis Rifampicin
Plaque Tetracycline
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