Selected Communicable Disease Flashcards
Bacterial Diseases
Tuberculosis
Pneumonia
Leptospirosis
Gonorrhea
Viral Diseases
Measles
Hepatitis A (Infectious hepatitis, Epidemic hepatitis, Catarrhal jaundice)
Influenza
Rabies (Hydrophobia, Lyssa)
Dengue Hemorrhagic Fever (H-Fever)
Hepatitis B
Parasitic Diseases
Schistosomiasis (Bilhariasis or snail fever)
Paragonimiasis or Pulmonary Distomiasis
Soil Transmitted Helminthiasis
Filariasis (Elephantiasis)
Malaria
Tuberculosis
Causative Agent
* Mycobacterium tuberculosis / Koch’s bacillus
Mode of Transmission
* Inhalation of infective droplets present in the air
Signs and Symptom
* Cough of 2 weeks or more
* Fever
* Chest pain or back pains not referable to any musculo-skeletal disorders
* Hemoptysis or recurrent blood-streaked in the sputum
* Significant weight loss
* Other sign and symptoms such as sweating, fatigue, body malaise and shortness of breath
Treatment
* Isoniazid, Rifampacin, Pyrazinamide, Ethambutol
Typhoid Fever
Causative Agent
* Salmonella typhi
Source of Infection
* Feces and urine of infected person. Family contacts may be transient carrier. Carrier state is common among person over 40 years of age especially females.
Mode of Transmission
* Direct or indirect contact with patient or carrier. Principal vehicles are food and water. Contamination is usually by hands of carrier. Flies are vectors.
Diagnosis
* Stool culture, Serological tests
Pneumonia
Causative Agent:
* Majority of cases due to Streptococcus pneumoniae (Diplococcus pnemoniae)
* Occasionally Klebsiella pneumoniae
* Viruses
Sign and Symptoms
* Rhinitis/common cold Pain over affected areas
* Rusty sputum Highly colored urine
* Productive cough Severe chill, in young children
* Fast respiration High fever
* Vomiting at times Dilated pupils
* Convulsion may occur
Leptospirosis
Causative Agent
* Leptospira interrogans. There are about 200 serovars with serovar icterohemmorhagiae thought to be more virulent and cause leptospirosis.
Mode of Transmission
* Through contact of the skin, especially open wounds with water, moist soil or vegetation contaminated with urine of infected host.
Sign and Symptoms
1. Leptospiremic phase - leptospires present in blood and CSF. Onset of symptoms are abrupt with fever, headache, myalgia, nausea, vomiting, cough and chest pain
2. Immune phase - correlates with the appearance of circulating IgM
Treatment
* Penicillin and other B-lactam antibiotics, Tetracycline, and Erythromycin.
Gonorrhea
Causative Agent
Neisseria gonorrhoeae bacterium.
Mode of Transmission
* Sexual contact in adult, transmission in neonates (ophthalmia neonatorum) is during birth
Sign and Symptoms
* Genital (penis or cervix), anus throat and eyes can be infected.
* Males - burning urination and pus discharges from infection of urethra
* Females - vaginal discharge
Treatment
* Cefriaxone for uncomplicated cases. If resistant, spectinomycin is used
* PPNG (penicillinase producing N. gonorrheae)
Measles
Causative Agent
* Measles virus (Morbilivirus under Family Paramyxoviridae) (RNA virus)
Source of Infection
* Secretion of nose and the throat of infective person.
Mode of Transmission
* By droplet spread or direct contact with infected persons, or directly through articles freshly soiled with secretions of nose and throat
Incubation Period
* 10 days from exposure to appearance of fever and about 14days until rash appears.
Influenza
Highly communicable disease characterized by abrupt onset with fever which last 1 to 6 days, chilly sensation or chills, aches or pain in the back and limbs with prostrations. Respiratory symptoms include coryza, sore throat and cough
Causative Agent
Influenza Virus A, B, C under Family Orthomyxoviridae (RNA virus)
Source of Infection
* Discharges/Secretions from the mouth and nose of infected person.
Mode of Transmission
By direct contact, through droplet infection, or by articles freshly soiled with discharge of nose and throat of infected person, airborne
Period of Communicability
* Probably limited to 3 days from clinical onset
Hepatitis A
(Infectious hepatitis, Epidemic hepatitis, Catarrhal jaundice)
- A form of hepatitis occurring either sporadically or in epidemics and caused by virus introduced by fecally contaminated water or food
- Young people especially school children are most frequently affected
Causative Agent
* Hepatitis A Virus (HAV) (Under Family Picornaviridae) (RNA virus)
Signs and Symptoms
* Influenza-like symptom like headache
* Malaise and easy fatigability
* Anorexia and abdominal discomfort
* Nausea and vomiting
* Fever
* Lymphadenopathy
* Jaundice
* Bilirubinemia with clay colored stool
Rabies (Hydrophobia, Lyssa)
Acute viral encephalomyelitis caused by the rabies virus, a rhabdovirus of the genus Lyssavirus (RNA virus). It is fatal once the signs and symptoms appear
Mode of Transmission
* Usually by bites of a rabid animal whose saliva has the virus. The virus may also be introduced into a scratch or in fresh breaks in the skin (very rare). Transmission from man to man is possible.
Incubation Period
* The usual incubation period is 2 to 8 weeks
Susceptibility and Resistance
* All warm-blooded mammals are susceptible. Natural Immunity in man is unknown
Signs and Symptoms
* Sense of apprehension
* Headache
* Fever
* Sensory change near the site of animal bite
* Spasm of muscles or deglutition on attempt to swallow (fear of water)
* Paralysis
* Delirium and convulsion
Without medical intervention, the rabies victim would usually last only for 2 to 6 days. Death is often due to respiratory paralysis.
Dengue Hemorrhagic Fever (H-Fever)
Etiologic Agents
* Dengue Virus Types 1, 2, 3, and 4 (Flavivirus, an RNA virus)
Source of Infection
* Immediate source is a vector mosquito, the Aedes aegypti or the common household mosquito.
Mode of Transmission
* Through bite of infected female mosquito.
Signs and Symptoms
* An acute febrile infection of sudden onset with clinical manifestation of 3 stages:
* First 4 days - invasive stage starts abruptly as high fever, abdominal pain and headache
* 4th to 7th days - toxic or hemorrhagic stage - lowering of temperature, severe abdominal pain, vomiting, frequent bleeding. Death may occur
* 7th to 10th day - convalescent or recovery.
Diagnostic Test
* Torniquet test (Rumpel Leads Test)
* Platelet count
* Hematocrit
Supportive and Symptomatic Treatment
* Paracetamol, analgesic for fever, muscle pain or headache. DON’T GIVE ASPIRIN
* Rapid replacement of body fluids.
Hepatitis B
Causative Agent
* Hepatitis B Virus (HBV) under Family Hepadnaviridae (DNA virus)
Mode of Transmission
* Sexual intercourse, also transmitted through blood and during birth.
Signs and Symptoms
a. Loss of appetite
b. Easy fatigability
c. Joint and muscle pain
d. Low grade fever
e. Right sided abdominal pain
f. Jaundice
g. Dark colored urine
Schistosomiasis (Bilhariasis or snail fever)
- Also known as the Bilhariasis or snail fever has a long been one of the important tropical diseases on our country. It is caused by a blood fluke that is transmitted by a tiny snail Oncomelania hupensis quadrasi
Causative Agent
* Schistosoma japonicum
Signs and Symptoms
* Diarrhea
* Bloody stool
* Enlargement of abdomen
* Splenomegaly
* Weakness
* Anemia
* Inflamed liver
Mode of Transmission
* Infection occurs when the skin comes in contact with contaminated fresh water in which certain types of snails that carry Schistosomes are living. It is a free-swimming larval form (cercaria) of the parasite that penetrates the skin. Fresh water becomes contaminated when infected people urinate or defecate in water.
Treatment
* Praziquantel is the drug of choice against all species. Alternatively, drugs are Oxamniquine for S. mansoni and Metrifonate for S. haematobium.
