Question

Seek and Find

Choose and research four (4) infectious diseases. Try to achieve a variety in your own selections as well as diseases unique from what your classmates have already posted. For your research please use only well-known, reputable sources.

In one discussion post that has four sections, create a brief description or summary of each of your four diseases. The word count for each disease should be approximately 100 words. The content of your summaries should include the etiology, mode of transmission, target host, or any other pertinent details about each disease that makes them unique. The summaries may be short, but they should be complete and include any essential or notable facts about the diseases.

At the end of each summary include a question about the disease that would prompt your colleagues to visit your references and find the answer. They will have the opportunity to go into more detail about the topics in their discussion replies.

In your replies to this discussion, answer at least one of the four questions posed by your classmate in their initial discussion post. You will visit the resources listed in their reference list to answer and expand on that aspect of the pathogen or the disease it causes.

Resources to get you started

National Institute of Allergy and Infectious Diseases
https://www.niaid.nih.gov/

CDC MMWR Index
http://www.cdc.gov/mmwr/index2015.html

CDC Emerging Infectious Diseases Journal
http://wwwnc.cdc.gov/eid/

Center for Infectious Disease Research and Policy
http://www.cidrap.umn.edu/

Food Poisoning Related Diseases & Conditions
http://www.medicinenet.com/food_poisoning/related-conditions/index.htm

Answer 1

Infectious diseases can be caused by bacteria, virus, fungus etc

1) cholera

• Cholera is an acute diarrhoeal disease caused by vibrio cholera.
• It is characterized by the sudden onset of profuse, effortless watery diarrhea followed by vomiting, rapid dehydration, muscular cramps and suppression of urine.
• Resistance:- v.cholerae killed within 30 minutes by heating at 56 deg C or by boiling. Bleaching powder is also effective
• Toxin production:- it multiply in lumen of small intestine and produce an exotoxin ( enterotoxin). It produces diarrhea
• Reservoir :- human being
• Infective material:- stools and vomit of cases and carriers
• Period of communicability:- 7-10 days. Convalescent carriers- 2+3 weeks
• Host factors:- age,sex,gastric acidity(pH 5 or low), population mobility, economic status, immunity
• Mode of transmission:-man to man. Fecally contaminated water, contaminated food and drinks or by direct contact
• Clinical features:-
  • Stage of evacuation-diarrhea, vomiting, frequency 40 stools per day ( rice watery type)
  • Stage of collapse:- dehydration,sunken eyes, hollow cheeks, scaphoid abdomen, absent pulse, loss of skin elasticity, shallow respiration, decrease urine output, even death may occur
  • Stage of recovery:- temperature to normal, increase BP
• Diagnosis:- stool routine and culture, rectal swab, vomitus, water, food samples
• Treatment:- verified of diagnosis, early case finding, rehydration therapy, antibiotics are fluoroquinolones, tetracycline, azithromycin, ampicillin & trimethroprim TMP- sulfamethoxazole, sanitation methods, chemoprophylaxis, vaccination, health education

2) Thphoid

• It is the result of systemic infection mainly by salmonella typhi found in man
• It is characterized by a typical continuous fever for 3-4 weeks, relative bradycardia with involvement of lymphoid tissues and considerable constitutional symptoms.
• Reservoir of infection:- man
• Source of infection:- primary sources are feces and urine of cases and carriers. Secondary sources are contaminated food and water
• Host factors:- age, sex, immunity
• Incubation period:- 10-14 days
• Mode of transmission :- feco-oral route or urine-oral route
• Clinical features:- high fever with chills, malaise, headache, cough, sorethroat, abdominal pain and constipation, relative bradycardia, dicrotic pulse, rash ( rose spots) etc
• Diagnosis:- microbiological tests, serological tests, widal test, blood culture
• Control of typhoid:-
  • Control of reservoirs
  • Control of sanitation
  • Immunization

3) Malaria

• It is a protozoal disease caused by infection with parasites of the genus plasmodium and transmitted to man by certain specific species of infected female anopheline mosquito.
• Agent :- plasmodium vivax, P.falciparum, P. Malaria, P.ovale
• Stages and clinical features
  • Cold stage (lassitude, headache, chilly sensation, temperature 39-41°C, skin feel cold)
  • Hot stage ( burning hot, dry skin, headache, full and rapid respiration)
  • Sweating stage( fever with profuse sweating, slow pulse)
• Life history
  • Asexual cycle:- starts when infected mosquito bites a person and injects sporozoites. It converts to merozoites and then to trophozoites. Then it becomes gametes which is injested by mosquito then the sexual cycle starts
  • Sexual cycle:- Gametes enter into mosquito unites to form zygote.then to ookinete which forms oocyst and it grows and forms sporozoites. Again it enter in human host.
• Reservoir:- Human being
• Host factors:- age, sex, race, pregnancy, socio-economic development, housing, population mobility, occupation, human habits, immunity
• Incubation period:- usually not less than 10 days
• Diagnosis:- microscopy, serological tests, rapid diagnostic test
• Control
  • Surveillance and case management
  • Vector management
  • Supportive intervention s
  • Mass drug administration