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1. Definition
Anthrax is an acute disease, caused by
Bacillus anthracis. It affects both humans
and animals. The name 'anthrax' comes
from anthrax [άνθραξ], the Greek word for
'coal', because of the black skin lesions
developed by victims with a cutaneous
anthrax infection.

2. Etiology
Bacillus anthracis is a
rod-shaped, Gram-
positive, aerobic
bacterium, about 1 by
9 micrometers in size
and is usually straight
but may be slightly
curved. The ends of
Gram-positive anthrax bacteria the bacilli are
(purple rods) in cerebrospinal
fluid sample. If present, a Gram- truncated, not
negative bacterial species would rounded.
appear pink. (The other cells are
white blood cells).

3. Etiology
Anthrax bacilli tend to
form into long chains.
B. anthracis produces
a capsule that is
easily visualized using
a methylene blue.
Polychrome methylene blue stain
of Bacillus anthracis. Image
courtesy of Anthrax Vaccine
Immunization Program Agency,
Office of the Army Surgeon
General, United States.

4. Lyme Disease
Lyme disease, or lyme borreliosis, is the tick-
borne infectious disease caused by Borrelia
burgdorferi and characterized by fever,
headache, fatigue, depression, and a
characteristic circular skin rash called erythema
migrans. The disease is named after the town of
Lyme, Connecticut, USA, where a number of
cases were identified in 1975.

5. Etiology
Lyme disease is
caused by Borrelia
burgdorferi from the
genus Borrelia. It is
gram-negative
spirochetal bacteria.
Borrelia bacteria, the causative
agent of Lyme disease. Magnified
400 times.

6. Epidemiology
Lyme disease is classified
as a zoonosis, as it is
transmitted to humans
from a natural reservoir
among rodents by ticks
that feed on both sets of
hosts. Hard-bodied ticks
of the genus Ixodes are
the main vectors of Lyme
disease.
Ixodes scapularis, the vector of
Lyme disease

7. Epidemiology
A tick must be
attached to a person
for 2-3 days to result
in infection. This is
due to the life cycle of
B. burgdorferi in ticks.
Normal and engorged Ixodes
ticks.

8. Physical exam
The manifestations of
Lyme disease have
been divided into 3
stages: localized,
disseminated, and
persistent. The first 2
stages are part of the
early infection, while
persistent disease is
considered late
infection. The primary
Common bullseye rash pattern symptoms of stage 1
associated with Lyme disease are erythema
migrans.

9. Physical exam
Erythema migrans, the characteristic rash of early Lyme disease.

10. Lyme Disease
Avoidance of ticks and areas associated with ticks
The highest concentration of ticks is found in
wooded areas.
Individuals should try to prevent ticks from
getting onto skin and crawling to preferred
areas.
Long hair should be worn under a hat.
Wearing long-sleeved shirts and tucking long
pants into socks is recommended.

11. Lyme Disease
Inspection
Because the above recommendations are not
always practical, particularly for children and
during the summer, and because ticks do not
appear to transmit Lyme disease until they
have been attached for several days, close
inspection for ticks should be performed each
time one has been outdoors.
The groin, axilla, and hairline should be
inspected particularly well.

12. Malaria
Malaria is a mosquito-borne infectious disease
caused by plasmodium parasite. It is widespread
in tropical and subtropical regions, including
parts of the Americas (22 countries), Asia, and
Africa. Each year, there are approximately 350–
500 million cases of malaria, killing between one
and three million people

13. Etiology
The four Plasmodium species known to cause
malaria include:
Plasmodium falciparum
Plasmodium vivax
Plasmodium ovale
Plasmodium malariae.

14. Etiology
Plasmodium vivax Plasmodium ovale
Plasmodium falciparum Plasmodium malariae

15. Epidemiplogy
Malaria is naturally
transmitted by the
bite of a female
Anopheles mosquito.
Anopheles albimanus mosquito
feeding on a human arm. This
mosquito is a vector of malaria
and mosquito control is a very
effective way of reducing the
incidence of malaria.

16. Epidemiplogy
Malaria causes
about 250 million
cases of fever and
approximately one
million deaths
annually. The vast
majority of cases
Countries which have regions where malaria
is endemic as of 2003 (coloured yellow). occur in children
Countries in green are free of indigenous under 5 years old;
cases of malaria in all areas.
pregnant women
are also especially
vulnerable

17. Epidemiplogy
Frequency of malaria cases in 1996