Exam material
Below we have provided the list as copied from the introduction lecture. We do not expect you to know all the details of the selected infectious diseases,
but you do need to know the relevant disease aspects in relation to the containment/control strategies, such as:
What is it (virus, bacterium, parasite, worm);
What does it cause – disease with clinical features such as fatality, morbidity, common symptoms;
Diagnosis – only when very important in control, and when it is very easy or just very difficult;
Transmission – important routes of transmission between people (e.g. airborne, waterborne, vector borne, etc);
Incubation period and period of communicability – only in general terms, and in relation to control (e.g. infectious when no symptoms? Direct
transmission between people or only through vector? Very long incubation period?);
Occurrence and distribution – where in the world? Widely spread? Prevalence? Endemic or epidemic?;
Prevention and control – understand the most important elements;
Treatment – are treatments available, which and how? Are vaccines available and useful?
Surveillance – feasible, in relation to control?
,Transmission routes
Diseases of poor hygiene:
Direct contact of the skin, conjunctiva or mucous membranes.
Organisms from the skin or in conjunctival secretions can be transported by an intermediate vehicle.
Fecal-oral Diseases:
Direct person-to-person contact (poor personal hygiene).
Indirect by contamination of food or water -> by flies or poor sewage systems.
Food-borne Diseases:
These diseases can only be transmitted through food.
The method of infection is very specific, so also its method of control, which is through food hygiene, proper cooking and sanitary methods to
prevent the food from being contaminated.
Diseases of soil contact:
Transmission can either occur by direct contact with contaminated soil, for instance by swallowing nematode eggs, or from larval penetration of the
skin.
Promotion of personal hygiene and preventing contamination of soil through sanitation are the main methods of control.
Diseases of water contact:
Transmission by contact with water where the intermediate stage of parasite is free living.
Skin infections:
Infection is often transmitted from person-to-person by direct skin contact or by the airborne route.
Avoidance of contact is the main method of control.
Arbovirus diseases also often present skin rash, however the method of transmission is by a vector.
Respiratory Diseases and other Airborne-transmitted Diseases:
These infections are mainly transmitted by direct contact during coughing and sneezing. The closer the contact, the greater the chance of spread.
Droplets can also be sprayed on to surfaces and contact with these by hands is also a method of infection.
Control is difficult to the human contact.
Infective dose and the host response determine whether infection will occur.
, Most of the skin infection are also transmittable by the airborne route.
Diseases transmitted via body fluids:
Diseases of very close contact -> Direct from person-to-person.
o Sexual intercourse accounts for the largest number of infections.
o Contact with blood, serum, saliva, seminal fluid, etc.
Insect-borne Diseases:
A vector carries the pathogen to a new host and introduces it directly into them.
Often a development stage takes place in the vector.
Transmission depends on the vector being able to find a new host within a limited time period.
o This is a vulnerable step in the life cycle and one where control methods are most likely to succeed.
Ectoparasite zoonoses:
Ectoparasites are non-flying vectors of disease, such as fleas, lice and ticks, which live on animals but can spill-over to humans and cause disease in
humans.
Humans are often accidental victims.
Domestic and Synanthropic Zoonoses:
Not a vector included.
Infections are caused by close contact between humans and their domestic animals.
Synanthropic zoonoses are caused by close contact with animals that are not welcomed.
, Pathogen Clinical features Diagnosis Transmission Incubation period Occurrence Prevention & control Treatment Surveillance
Diseases of poor hygiene
Trachoma: Conjunctival Clinical assessment of Direct (by hand) or 5-12 days. Dry regions of the Control: Mass drug A single dose of Evaluating the impact
caused by inflammation, symptoms. indirect contact (with world. Parts of Africa, administration, facial Azithromycin. of control measures.
bacterium scarring, eyelid wipes, towels or As long as lesions are Asia, central and cleanliness,
Chlamydia changes and if left Can be confirmed in clothing) with infected present, you’re South America, the environmental Surgery to prevent
trachomatis untreated, blindness. the lab by taking eye or nasal infectious. Treatment Middle-East and areas improvement (against blindness.
swabs of the secretions. can cease infectivity of Australia. flies) and surgery for
conjunctiva. within 2-3 days, but advanced cases to
Flies can also spread clinical disease It's endemic. prevent blindness.
the discharge that are persists.
around the eyes. Prevention:
Promoting good
hygiene, access to
clean water and face-
washing practices.
Faecal-Oral Diseases
Gastroenteritis Diarrhea, vomiting, Made on clinical Ingestion of 12-72 hours. Throughout the Control: Outbreak Managing symptoms: Monitoring weather
(can be caused abdominal cramps, criteria. contaminated food or world. response, maintaining Replacing fluid and changes.
by bacteria or nausea and water. Communicable good hygiene. electrolytes using
viruses such as sometimes fever. Stool samples are before, during and up Seasonal outbreaks in ORS.
E. coli or used to identify the Direct person-to- to 8-10 days after developed countries Prevention:
rotavirus) Dehydration in severe causative agent. person contact. clinical recovery. due to weather Vaccination
cases. changes (rainfall). (rotavirus), proper
sanitation,
Areas with poor maintaining good
sanitation. personal hygiene,
ensuring food and
water safety.
Cholera: caused Rice-water stools and Based on diarrheal Epidemic cholera is 1-5 days. Classical cholera in Control is aimed at Oral rehydration or Any outbreak should
by bacterium sometimes vomiting. discharge. transmitted by water South-Asia. the cause: foods are intravenous infusion be reported to the
Vibrio cholerae (El Tor can survive During symptoms and banned/water in case of severe WHO. Cases should be
El Tor biotype can Rectal swabs: longer in water than ca. 5 days after El Tor in Asia, Africa, supplies sterilized by dehydration. reported using the
cause a carrier state, vibration under the classical cholera). recovery. Europe and South- super-chlorination, case definition and
resulting in spreading microscope. America. vaccination given and Tetracycline to not just laboratory-
of epidemics. Endemic cholera is quarantine instigated. shorten duration of confirmed cases. A
transmitted by food. illness. warning system can
Confirmation by In endemic areas
Vaccination gives be implemented.
culturing on TCBS children are
agar. susceptible. Here, about 50% protection
there is often poor and lasts for 6
