Terminologies

1. Communicable Disease

• Illness caused by an infectious agent of its toxins

2. Infection

• Implantation and successful replication of an organism within the body causing immunologic response

3. Contact

• the state or condition of physical touching

4. Carrier

• a person or thing that carries or holds something

5. Contagious Disease

• Disease that is easily transmitted

6. Infectious Disease

• Requires direct inoculation through a break on the skin or mucous membrane

7. Host

• where a parasite or commensal organism lives

8. Reservoir

• chronically infested with the causative agent of a disease and can act as a source of further infection

9. Disinfection

• Destruction of pathogens outside the body by physical or chemical mean

10. Concurrent Disinfection

• When patient is still the cause of infection

11. Terminal Disinfection

• Patient is no longer the source of infection

12. Isolation

• Separation of person with communicable disease

13. Reverse Isolation

• Separation of immunocompromised person at risk of communicable disease

14. Quarantine

• Limitation of freedom within the longest incubation period of the disease

Epidemiology

Epidemiologic Triangle

• Agent

• Host

• Environment

Patterns of Occurrence and Distribution

• Endemic - occurring within an area or community

• Sporadic - occurring at irregular intervals or only in a few places; scattered or isolated

• Epidemic - a rapid spread of disease to a specific region or population

• Pandemic - a global outbreak

Agents

• Bacteria

• Viruses

• Fungi

• Protozoa

• Prions

• Helminths

Chain of Infection

• Causative Agent

• Reservoir

• Portal of Entry

• Mode of Transmission

• Portal of Exit

• Susceptible Host

Agent factors

Infectivity

• Ability to invade and replicate

Virulence

• Strength of the agent to cause a disease

Pathogenicity

• Ability to cause a disease

Antigenicity

• Ability to stimulate antibody production

Invasiveness

• Ability to live outside the body

Mode of Transmission

• Direct Contact

• Indirect Contact

• Droplet Spread

• Air-borne Transmission

• Vehicle-borne Transmission

• Vector-borne Transmission

Acquisition

• Community acquired

• Nosocomial

• Iatrogenic

Stages of Infection

Incubation

• Infection - 1st s/sx

Prodromal

• 1st s/sx - Pathognomonic signs (obvious signs)

Illness or Fastigial

• All s/sx

Convalescence or Defervescence

• Subsiding s/sx and recovery

Immunity

Natural Immunity

• Active

• Passive

Artificial Immunity (vaccines)

• Active - injection of dead or weakened pathogen

• Passive - You receive an injection of antibodies that were generated by another person or animal, or artificially in a lab. These antibody-containing preparations are called antisera and are used to treat infections.

  Types of Antigens:

• Inactivated (dead or altered pathogen)

  • Not long lasting

  • Multiple doses

  • Booster needed

    • eg. rabies, hepa a, flu, ipv

• Attenuated (weakened pathogen)

  • Single dose only

  • Long lasting immunity

    • eg. measles, mumps, and rubella (mmr), bcg, opv, influenza,

• Isolation

  • Strict Isolation

  • Contact Isolation

  • Respiratory Isolation

  • Enteric Isolation

  • Drainage/Secretion Precaution

  • Universal Precaution:

  

Integumentary Diseases

1. Chicken Pox

• Agent: HHV3 or Varicella-Zoster Virus

• MOT

  • Airborne

  • Direct Contact

  • Contact with contaminated fomites

• Incubation Period: 11 to 21 Days

• Period of Communicability: 5 days before onset of rash and 5 days after first crop of vesicles

• Signs and Symptoms

  • Itchy maculovesiculopapular lesions

  • Earliest complication: Encephalitis

  • Late complication: Herpes Zoster

• Dx

  • Tszank Smear: A diagnostic test used to identify the presence of viral infections, particularly herpes simplex virus, by examining cells collected from lesions.

  • Lesion: Center to Periphery

• Management

  • Strict Isolation

  • Fever: NO ASPIRIN

  • Pruritus

  • Calamine Lotion

  • Oatmeal bath

  • Cornstarch bath

  • Antihistamine

  • Cut nails or use mittens

• DOC: Acyclovir/Zovirax

2. Rubeola (measles)

• Measles, 1st Disease, English Disease, 7 day rash

• Agent: Paramyxoviridae

• MOT:

  • Airborne

  • Direct Contact

  • Indirect Contact

• Incubation Period: 7-14 days

• Period of Communicability: Just before the prodrome until 4 days after the rash appears

• Koplik’s Spots (ENANTHEM) – pathognomonic sign

• Pre-eruptive Stage

  • Fever

  • Catarrhal symptoms - inflammation

  • Stimson’s line - characterized by transverse line of inflammation along the eyelid margin

• Eruptive Stage

  • Maculo-papular rash (EXANTHEM or widespread rash)

  • High grade fever

  • Anorexia and Irritability

• Convalescence Stage

  • Rashes fade away

  • Fever subsides

  • Desquamation begins

  • Symptoms subsides

• Management

  • Supportive and Symptomatic

    • Fever – Tepid Sponge Bathing

    • Koplik Spots – Gentian violet, water and salt

  • Vitamin A

    • <1 yr – 100,000 IU

    • >1yr – 200,000 IU

    • Pregnant – 10,000 IU

  • Dim light and use Shades

• Complication: Bronchopneumonia

• Prevention: Immunization

  • Anti-measles: 9 months

  • MMR

    • 1st dose at 15 months

    • 2nd dose at 12 years old

• No to ASPIRIN - may lead to reye syndrome which affects brain and liver

3. Rubella

• German measles, 3 Day Rash

• Agent: Togaviridae

• MOT

  • Droplet

  • Direct contact of respiratory secretions

  • Transplacental Transmission

• Incubation period: 2 to 3 days

• Prodromal Period

  • Low grade fever

  • Headache

  • Malaise

  • Mild coryza - inflammation of mucous membranes

  • Conjunctivitis - redness and inflammation of eye

  • Cervical lymphadenopathy

• Eruptive period

  • Forchheimer’s Spot – Pathognomonic (small, red spots that appear on the soft palate of the mouth)

  • Rash – last for 1 to 5 days

  • Orchitis - testicle bumps

  • Transient polyarthritis

• Congenital Rubella

  • IUGR - Intrauterine Growth Restriction

  • IUFD - Intrauterine Fetal Demise

  • Cleft palate

  • Cardiac Defects

  • Eye defects

  • Ear defects

  • Mental retardation

• Prevention

  • MMR: 2 doses

  • Rubella titer <1:8 – Not immune

  • Immune serum globulin within one week after exposure

4. Scabies

• The Itch

• Agent: Sarcoptes scabiei

• MOT

  • Direct inoculation

  • Skin to skin contact

  • Indirect contact with fomites

• IP: 4 to 6 weeks

• Signs and Symptoms

  • Linear burrow

  • Anaphylactic reaction

  • Acropustulosis

    • Pustules

    • Blisters

    • Ulceration

• Management

  • Permethrin (5%) - head to toe and left for 8-14hrs and reapplied a week later

  • Kwell lotion (Gamma benzene hexachloride)

  • Crotamiton (Eurax)

  • DOC: IVERMECTIN: Single dose

• Prevention

  • Good personal hygiene

  • Avoid direct contact with infected persons

  • All members of the household should be treated

Neurologic Diseases

1. Rabies

• Hydrophobia, Lyssa

• Agent: Rhabdovirus

• All warm blooded animals are susceptible

• MOT

  • Bite or scratch of rabid animal

  • Transplant of infected organ

• Incubation Period: 9 days to 7 years

• Signs and Symptoms

  • Numbness at site

  • Salivation

  • Fever

  • Headache

  • Malaise

  • Hydrophobia/Aerophobia

  • Hallucination

  • Confusion or Restlessness

  • Respiratory paralysis

• Dx: Flourescent Antibody Test

  

• Management

  • Wash wound for 5 minutes

  • Observe the dog for 10 to 14 days

  • Do not rub garlic on wound

  • Hospital: assess for

    • Severity

    • Site (Proximity)

    • Numbness

    • Duration

    • Give Tetanus Immunoglobulin

  • Rabies Immunoglobulin

    • Bayrab

    • Verorab

    • Rabipur

    • Imogam

  • Human Diploid Cell vaccine (HDCV)

    • Imovax

  • When symptoms are already present

    • IVF – cover

    • Sedation

    • Restraint

  • Prevention

    • Responsible pet ownership

2. Leprosy

• Lepra, Hansenosis, Hansen’s Disease

• Mycobacterium leprae

• MOT

  • Droplet

  • Skin to skin contact

• Distinct Forms

  • Lepromatous leprosy

  • Tuberculoid leprosy

  • Borderline leprosy

• Lepromatous

  • Multibacillary

  • Lepromin (-)

  • Large amount of bacilli in skin lesion

  • 24-30 months treatment

  • Rifampicin, Dapsone, Lamprene (Clofazimine)

• Tuberculoid

  • Paucibacillary

  • Lepromin (+)

  • Organism rarely isolated on skin lesion

  • 6-9 months treatment

  • Rifampicin, Dapsone

• Early Signs and Symptoms

  • Change in skin color

  • Loss of sensation

  • Decreased/absent sweating and hair growth

  • Thickened or painful nerves

  • Muscle weakness or paralysis

  • Nasal obstruction

  • Pain or redness of eyes

  • Non healing ulcer

• Late Signs and Symptoms

  • Gynecomastia - enlargement of chest in male

  • Madarosis - a condition that causes the loss of eyelashes and/or eyebrows

  • Lagophthalmos - prevents a person from fully closing their eyelids

  • Leonine facies - causes facial features to resemble a lion

  • Contractures

  • Clawing

  • Sinking nose bridge

  • Chronic ulceration

• Dx: Slit Skin Smear

• Prevention

  • Report all cases and suspects of leprosy

  • BCG vaccine

  • Health education

3. Tetanus

• Lock jaw

• Agent: Clostridium tetani

• MOT: Direct Inoculation

• IP: 3 to 21 days

• Signs and Symptoms

  • Hemolysis – Tetanolysin

  • Spasms – Tetanospasmin

  • Opisthostonus - causes a person to arch their back and neck into a rigid

  • Trismus - limits the ability to open the mouth

  • Risus sardonicus - fixed smile

• Management

  • Wash wound area

  • Hospital: Antitetanus Serum (ATS)

  • Spasms

    • Dilantin

    • Diazepam

  • DOC

    • Metronidazole

    • Penicillin (GABA Antagonist)

  • Prevention:

    • Tetanus Toxoid: 5 doses

    • DPT

4. Meningitis

• Agent: Bacteria or Fungi

• common in dorm or prison

• MOT: Droplet

• Signs and Symptoms

  • Increased ICP

  • Brudzinki’s Sign *occipital pain

  • Kernig’s Sign *knee extension

  • Photophobia

• Dx

  • Lumbar Tap - lumbar puncture, also known as a spinal tap, is a medical procedure that involves inserting a needle into the lower back to collect a sample of cerebrospinal fluid (CSF)

  • Bacterial meningitis (worse)

    • Cloudy

    • Yellowish

    • Decreased glucose

    • Increased protein

    • (+) gram stain

  • Viral meningitis

    • Clear

    • Normal glucose

    • (-) gram stain

• Pediatric - High pitched cry and bulging fontanelles

• Management

  • Clue: It’s raining men (meningitis need droplet precaution)

  • Respiratory Isolation

  • N95 mask

  • DOC:

    • Penicillin G

    • Mannitol

    • Steroids – cerebral edema

• Prevention: Avoid contact with infected person

5. Poliomyelitis

• Infantile paralysis, Acute flaccid paralysis (AFP)

• Agent:

  • Poliovirus 1,2,3

  • Legio Debilitans

    • Type I. Brunhilde

    • Type II. Lansing

    • Type III. Leon

• MOT: Fecal-oral transmission

• Signs and Symptoms

  • Poker Spine – destruction of anterior horn cells of spine caused by ankylosing spondylitis (AS)

  • Hoyne’s Sign or Tripod Sign - sign of meningeal irritation

  • Muscle tenderness, weakness, and spasms

  • Asymmetrical Paralysis of the extremities

  • Loss of superficial and deep reflexes

• Dx: Pandy’s Test - normal protein values 0.20 to 0.45 g/liter

• Management

  • Enteric isolation

  • ROM exercises

  • Trochanter rolls and foot board are indicated

  • Physical Therapy

• Prevention

  • SALK: Inactivated Polio Vaccine (IPV)

  • SABIN: Oral Polio Vaccine (OPV)

Vector-Borne Diseases

1. Dengue

• H Fever, Dandy’s Fever, Breakbone fever, Infectious Thrombocytopenic Purpura

• Agents

  • Dengue virus 1,2,3,4

  • Arbovirus

  • Chikungunya virus

• MOT: Vector-borne: Aedes Egypti mosquito

• Grade 1

  • Dengue fever

  • Fever: 39 degrees Celsius

  • Abdominal Pain and vomiting

  • Petechial rash

• Grade 2

  • Dengue hemorrhagic fever

  • Bleeding

• Grade 3

  • Circulatory collapse

• Grade 4

  • Shock, coma, and death

• Dx: Presumptive

  • Tourniquet test, Rumple-lead test, or Capillary fragility test - The presence of 20 or more petechiae per square inch indicates increased capillary fragility,

• Dx: Confirmatory

  • CBC

  • Platelet count (150,000 and 450,000 platelets per microliter of blood)

• Management

  • Supportive and symptomatic

  • Fever: Analgesics, NO ASPIRIN

  • Increase fluid intake

  • Oresol

  • IVF

  • Blood transfusion

• Prevention

  • Sanitation

  • Treated mosquito nets

  • On-stream seeding

  • On-stream clearing

  • Wear covered clothing

  • Planting Neem trees

  • Zooprophylaxis

2. Malaria

• Marsh Fever, Ague

• Agents:

  • Plasmodium falciparum

  • Plasmodium vivax

  • Plasmodium malariae

  • Plasmoidium ovale

• MOT

  • Vector: Anopheles mosquito (female)

  • Blood transfusion

  • Transplacental

• Signs and Symptoms

  • Paroxysms with shaking chills

  • Rapid rising fever with severe headache

  • Profuse sweating

  • Myalgia

  • Splenomegaly

  • Hepatomegaly

• Dx: Malarial Smear

• Management

  • Chemoprophylaxis: Chloroquine

  • DOC

    • Artemether

    • Quinine

    • Primaquine

• Prevention

  • Sanitation

  • Treated mosquito nets

  • On-stream seeding

  • On-stream clearing

  • Wear covered clothing

  • Planting Neem trees

  • Zooprophylaxis

  • Avoid outdoor night activities (9PM to 3AM)

3. Filariasis

• Elephantiasis

• Agent:

  • Wuchereria bancrofti

  • Brugia malayi

  • Brugia timori

• MOT:

  • Vector:

    • Aedes Poecellus

    • Culex quinquefasciatus

    • Anopheles Minimus

• Signs and Symptoms

  Acute

  • Inflammation

  • Lymphadenitis

  • Lympharyngitis

  • Epidydimitis

  Chronic

  • Lymphedema

  • Hydrocele

  • Elephantiasis

• Dx:

  • Nocturnal Blood Smear (8PM above)

  • Immunochromatographic Test

  • Bentonite Flocculation Test

• DOC:

  • DEC (Diethyl Carbamazipine Citrate)

  • Hetrazan/Beltrazan

• Prevention:

  • Fumigation/Fogging

  • Proper garbage disposal

  • Avoid over hanging of clothes

  • Seeding: larva eating fishes

  • Cleaning: exposure to sunlight

  • Zooprophylaxis

  • Plant: Neem Trees (sampaguita)

  • Stock: cover/put salt

Respiratory Diseases

1. Diphtheria

• Agent

  • Klebs-Loeffler Bacillus

  • Corynebacterium Diphtheria

• MOT

  • Droplet

• Signs and Symptoms

  • Nasal – Foul smelling nasal discharge

  • Pharyngeal – Pseudomembrane, bull-neck

  • Laryngeal – Stridor

• Dx:

  • Confirmatory: Nasal and Throat Swab

  • Schick’s Test – Susceptibility

  • Maloney’s Test - Hypersensitivity

• Management

  • Do not remove the pseudomembrane

  • Anti-Diphteria Serum

  • Tracheostomy set at bedside

• DOC:

  • Penicillin

  • Erythromycin

2. Pertussis

• Whooping cough

• Agent:

  • Bordotella pertussis

  • Haemophilus pertussis

  • Bordet-Gengou Bacillus

• MOT:

  • Droplet

  • Direct contact of respiratory discharges

• Signs and Symptoms

  • A. Catarrhal Stage - Highly communicable

    • Cough

    • Sneezing

    • Teary eyes

    • Fever

  • B. Paroxysmal Stage - Frequent coughing ending in inspiratory whoop.

• Dx:

  • Nasal and Throat Swab

• Management

  • DOC: Erythromycin

  • Supportive Therapy

    • Fluid and Electrolytes replacement

    • Adequate nutrition

    • Oxygen therapy

3. Pneumonia

• Figure:

  

• Most common test is impaired gas exchange

• Signs and Symptoms

  • Altered mental status (agitation and restlessness)

  • yellow sputum

  • crackles

  • pleuritic chest pain or pleural friction rub

• Consolidation of the lungs

• Agent:

  • Streptococcus Pneumoniae

• MOT:

  • Droplet

• Signs and Symptoms

  • Rusty Sputum

• DOC:

  • 1st Amoxicillin

  • 2nd Cotrimoxazole (Hepatotoxic)

4. Tuberculosis

• Figure:

  

• Consumption disease/ Poor Man’s Disease/ Phi

• Agent:

  • M. Tuberculosis

  • M. Africanum

  • M. Bovis

• MOT:

  • Airborne

• Incubation period: 6-8 weeks

• Signs and Symptoms

  • Cough for 2 weeks or more

  • Afternoon fever

  • Night sweats

  • Chest pain, back pain

  • Anorexia

  • Weight loss

  • Fatigue

• Dx:

  • Presumptive:

    • Mantoux Test, Tuberculin, or PPD test

    • Incubation period: 48-72

    • Induration:

      • Immunocompromise: >5mm

      • With risk: >10mm

      • Without risk: >15mm

  • DSSM (Direct Sputum Smear Microscopy):

    • Sputum Test

    • AF Bacilli Test

  • Chest X-ray

• Management: DOTS

• Category I

  • New patient

  • DSSM (+)

  • Serious

• Category II

  • Default

  • Relapse

  • Failure

• Category III

  • Children

  • DSSM (-)

  • Less serious

• Category IV

  • Chronic

  • MDR

• Drugs: RIPES

  • Rifampicin

    • Nephrotoxic

    • Discoloration of secretions

  • Isoniazid (INH)

    • Hepatotoxic (SGPT, SGOT, ALT)

    • Peripheral neuritis

  • Pyrazinamide (PZA)

    • Hyperuricemia

    • Gout

  • Ethambutol

    • Opthotoxic (-) 6y/o and below

  • Streptomycin

    • Ototoxic

    • vertigo, deafness

  

• Prevention: BCG vaccination

Gastrointestinal Diseases

1. Schistosomiasis

• Snail fever

• Katayama disease

• Bilhariasis

• Agent:

  • Schistosoma japonicum

  • Schistosoma haematobium

  • Schistosoma mansoni

• Reservoir: Oncomelania quadrasi

• MOT: Direct inocculation

• Signs and Symptoms

  • Fever

  • Hepatosplenomegaly

  • Eosinophilia

  • Cough

• Dx: Katokatz test - diagnostic technique for the detection of helminth eggs in stool using a light microscope

• DOC: Praziquantel

• Prevention:

  • Boots

  • Molluscicides

2. Cholera

• “El Tor”

• MOT: Fecal-oral

• Agent:

  • Vibrio Cholerae

  • Vibrio El Tor

• Signs and Symptoms

  • Rice water stool

  • Washer woman’s hands

  • Vomiting

  • Diarrhea (10-20L)

  • Oliguria

• Management

  • Tetracycline

  • Nalidixic Acid

3. Amoebiasis

• Figure:

  

• Amoebic Dysentery

  • Mucoid

  • Blood

• Agent:

  • Protozoa: Entamoeba Hystolytica (cyst)-resistant to chlorine

• Signs and Symptoms: Bloody mucoidal stool

• DOC: Metronidazole (Flagyl)

4. Leptospirosis

• Figure:

  

• Weil’s disease

• Canicola fever

• Trench fever

• Mild fever

• Canefield fever

• Swineherd’s fever

• Nanukayami disease

• Flood Fever

• Spirochetal Jaudice Disease

• Agent:

  • Spirochete

  • Leptospira interrogans

• MOT:

  • Vector – Rodents

  • Direct contact to skin on open wounds

• Signs and Symptoms

  • GI

  • Fever

  • Jaundice

  • Conjunctival suffusion

  • Renal interstitial tubular necrosis

  • Nausea and vomiting

  • Meningeal irritation

  • Headache

  • Myalgia

• Dx:

  • MAT (Microscopy Agglutination Test)

  • LAT (Leptospira Antigen-Antibody Test)

• DOC: Penicillin

• Prophylaxis: Doxycycline

• Prevention: Eradication of Rodents

5. Typhoid fever

• Enteric Fever

• Agent:

  • Salmonella Typhii

  • Typhoid bacillus

• MOT: Fecal-oral

• Signs and Symptoms

  • Rose spots/Red spots

  • Ladder-like fever

  • Splenomegaly

• Dx:

  • Typhidot

  • Widal test

• DOC: Chloramphenicol

6. Parasitism

• Ascariasis

  • Ascaris lumbrecoides (giant round worm)

• Ancylostomiasis

  • Ancyclostoma duodenale (hookworm)

  • Necator americanus

• Trichuriasis

  • Trichuris trichuria (whipworm)

• Enterobiasis

  • Enterobium vermicularis (pinworm)

• Taeniasis and Cystiscercosis

  • Taenia solium (flat/tapeworm)

  • Taenia saginata

• Trichinosis

  • Trichinosis spiralis

• DOC: Mebendazole

Reproductive Tract Diseases

1. Gonorrhea

• N. gonorrhea

• Purulent discharge

• Penicillin

2. Candidiasis

• Candida albicans

• Cheese-like/curd like secretions

• Mycostatin (Nystatin)

3. Herpes Simplex

• HSV

• Blisters

• Antiviral/not curable

4. Syphilis

• Spirochete: Treponema palidum

• VDRL (Venereal Disease Research Lab Test)

• RPR (Rapid Plasma Reagin)

• Penicillin G

5. Chlamydia

• Chlamydia trachomatis

• Azithromycin

6. Trichomoniasis/Vaginitis

• Trichomonas vaginalis

• Frothy/bubble-like discharge

• Metronidazole

7. Condyloma accuminata lata

• Genital warts

• HPV

• Cauliflower-like lesions

TIP:
-nazole is antifungal

-dazole is for da-gut