The document discusses common parasites of military importance, including intestinal parasites like Entamoeba histolytica and Giardia lamblia, malaria parasites such as Plasmodium falciparum, blood flukes like Schistosoma species, and filarial parasites including Wuchereria bancrofti. It describes the lifecycles and military relevance of these parasites, noting how military personnel are at high risk of infection due to environmental exposures during operations and missions. The document aims to increase awareness of parasitic diseases that can impact military operations and public health.
2. CONTENTS
1. Introduction of Parasites
a. Definition of Parasites.
b. Types of Parasites.
c. Classification of Parasites.
d. Lifecycle of Parasites.
e. Groups of Parasites.
2. List of Parasites of Medical Importance.
3. Common Parasites of Military Importance.
a. Pathogenic Intestinal Parasites.
b. Malaria Parasites.
c. Blood flukes.
d. Filarial Parasites
e. Haemoflagelates parasites
f. Arthropods of Military Importance.
4. Activities to Modify Risk of Infection.
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5. Conclusion.
3. DEFINITION OF PARASITES (1)
1. An animal or organism – lives on or in another organism and
derives it nourishments there from.
2. An obligate parasite – A parasite which is completely
dependent upon the host (organism which harbour parasite
and is usually larger than the parasite).
3. A facultative parasite – An organism which is capable of living
both freely and as a parasite.
(Last J.M, 4th Edition A Dictionary of Epidemiology)
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4. DEFINITION OF PARASITES (2)
1. Parasites are organism that live inside humans or
other organisms, who act as hosts.
2. They are dependents on their hosts – unable to
produce food or energy for themselves.
3. Parasites are harmful to humans or other organism
because:
* they consume needed food
* eat away body tissue and cells
* eliminate toxics waste which makes people sick.
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5. TYPES OF PARASITES
1. Endoparasites - A parasites which lives within the
body of the host. Example: Plasmodium vivax,
Enterobuis vermicularis, Brugia malayi.
2. Ectoparasites - A parasites which lives on the
outside of the host. Example: Fleas, Tsetse Flies
and lice.
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6. CLASSIFICATION OF PARASITES
1. Parasites are classified according to the International
Code of Zoological Nomenclature.
2. Major divisions of animal kingdom – Phylum, Class,
Order, Family, Genus and Species.
3. Main criteria – morphology and genetic structure of
parasites.
4. Each parasites is designated under the binomial (two
names) system, genus and species: eg:
Entamoeba histolytica.
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7. LIFECYCLE OF PARASITES
1. A parasite is dependent for its survival on transmissions
from host to host.
2. Lifecycle patterns: simple - involving a single host.
: complex - involving 2 or more
intermediate hosts
3. Importance of lifecycle: diagnostic stage - diagnosis
: infective stage - initiates infection
: control program against parasites
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8. GROUPS OF PARASITES
Parasites can be categorized into:
1. Protozoa. eg: Plamodium vivax, Entamoeba histolytica,
Toxoplasma gondii, and Pneumocystis carinii.
2. Helminths. eg: Wuchereria bancrofti, Trichuris Trichiura,
Enterobius and vermicularis.
3. Arthropods. Fleas, Tsetse Flies and lice.
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11. PATHOGENIC INTESTINAL PARASITE – Introduction (1)
Entamoeba hystolytica
• Worldwide distribution with higher incidence in developing
countries.
• This amoeba is the human intestinal tract parasite.
• Humans are primary host for this pathogen.
• It is spread via the anal to oral route.
• Acquired form contaminated water, or foodstuffs
contaminated by untreated sewage.
Entamoeba
histolytica cyst Entamoeba histolytica
(infective stage) trophozoites
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13. Entamoeba histolytica – The Source of Infection in Military (3)
• In military environment - parasite usually acquired by soldiers
from: drinking water contaminated with fecal material from
infected person (river/lake),
• Food intake, contaminated with cysts of E.histolytica.
• This happen because: when soldiers are tired, not enough
facility to cook, lack of knowledge about hygiene.
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14. Entamoeba histolytica of Military Importance (4)
• The most pathogenic amoeba for humans (soldiers).
• Infectious diseases – can be spread(Waterborne & Food borne Ds).
• Worldwide distribution – military more expose to this parasite (jungle
exercise, UN mission, war).
• E. histolytica causes amoebic dysentery – the trophozoites invade
intestinal wall, leading to formation of amoebic ulcers: characterized
by bloody stools and diarrhea accompanied by abdominal pain.
• Trophozoites penetrate the intestinal wall – spread to blood streams
cause liver abcesses or spread to lungs and brain - resulting in
death.
•
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15. Giardia lamblia -Introduction (1)
• Giardia lamblia is a flagellate of world-wide distribution.
• It is the most common flagellate of the intestinal tract causing
Giardiasis. Giardiasis is an infection of the upper small bowel, which
may cause diarrhoea.
• G. lamblia is transmitted through ingestion of cysts in contaminated
water or food.
• It is a major cause of waterborne intestinal disease.
• Has a high rate of person to person transmission.
• Groups at increased risk - food handlers, travelers to endemic areas
(such as St Petersburg, Russia), hikers and campers who neglect to
adequately purify their water.
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17. Giardia lamblia – The Source of Infection in Military (3)
• The source of infection is from the contaminated water with
cysts of Giardia lamblia which can be ingested from the river, lake,
pond or from the well in rural area.
• The other sources of infection are from food or dirty hands
which contaminated with the cysts of G. lamblia.
• Giardiasis is the waterborne disease – military may expose to this
disease because the attitude of themselves who neglect to
adequately purify their water – lack of hygiene knowledge, shortage
of time in the war, lack of facilities to cook their food or water .
• The military are always expose to the endemic area. Going for
UN mission around the world. Military traveling to other countries
and get infection to this parasite - called travelers disease.
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18. Giardia lamblia of Military Importance (4)
• Why the parasites are importance?
• Parasites can cause many causalities in military. Operations
can’t be execute with diarrhoeal soldiers.
• Humans are the only important reservoir of the infection .
Parasites loves soldiers with attitude of neglect the hygiene
especially in the jungle or rural area.
• G. lamblia has a high rate of person to person transmission.
• The main symptoms of disease are abdominal pain, flatulence, and
episodic diarrhoea with malabsorptive syndrome (steatorrhea) and
periodical soreness in severe cases.
• The parasites can be a disaster to military in the endemic area .
Many soldier get sick and can’t going for war. 18
19. Malarial Parasites -Introduction (1)
• Malarial parasites are known as Plasmodium spp. which
cause the important tropical disease, Malaria. Malaria
CASEVAC/MEDEVAC with 1-3 million deaths per year caused by
is a global problem
via air ambulance
falciparum malaria.
• Plasmodium sp. are sporozoan obligate intracellular
Exercise Planning : 2 Scenarios
1. parasites of liver Burn blood cells - blood parasites.
Scenario 1: and red
• Scenario 2: Appendicitis
2. 4 species which infect both humans and animals:
• Plasmodium falciparum
• Plasmodium vivax
• Plasmodium ovale
• Plasmodium malariae
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21. Malarial Parasites – The source of Infection and
Transmission in Military (3)
• Jungle is the main source of malarial parasites infection- ¾ of
Malaysia covered by jungle.
• The humidity, moderate temperature and clear water in the
tropical rain forests
CASEVAC/MEDEVAC can enhance the survival of the parasites.
via The Anopheles
• air ambulance mosquitoes is the main vector of these parasites.
• Why soldiers are the easiest group
Exercise Planning : 2 Scenariosacquired the infection?
1. working environment ; in the jungle - expose to mosquitoes
- Scenario 1: Burn
2.bites.
Scenario 2: Appendicitis
- lack of facility of battling the malaria - war, jungle exercise.
- lack of knowledge of anti-malaria drugs - chemoprophylaxis.
• The transmission of parasites requires two hosts,
a. Intermediate invertebrate host (vector): Anopheles mosquitoes.
b. Definitive vertebrate host: Humans (soldiers)
Female anopheline mosquito 21
22. Malarial Parasites of Military Importance (4)
• The parasite cause the most important communicable disease
in the field for Malaysian soldier.
• Malarial parasites has resulted in large number of casualties
CASEVAC/MEDEVAC
via air ambulance in
when operating endemic area. Eg; Many causalities in US
Forces when deployments in Vietnam, Africa, Middle East & Korea -
weaken the fighting strength.
Exercise Planning : 2 Scenarios
• 1. Scenario 1: Burn are resistant to anti malarial drug -
Certain parasites species
could be one of the enemy during war! - eg; P.falciparum is
2. Scenario 2: Appendicitis
resistant to chloroquine and other antimalarial drugs.
• Parasites attack still become disaster and psychological
stress in most military troops – no vaccine available to cure & can
cause to death.
• Parasites available for research in term of prevention by military.
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23. Blood Flukes(Schistosoma sp.) – Introduction (1)
• The Schistosoma sp. are blood trematodes.
• There are 5 species of Schistosoma:
• S. mansoni, S. haematobium, S. japonicum, S. mekongi, S.
intercalatum. All with similar life cycle involving freshwater snails.
• Distribution of parasites – S. haematobium (Africa, M/East,
India), S.mansoni (Africa, Brazil, Surinam, Venezuela, Caribbean
islands), S.japonicum (China, Philippines), S. mekongi (Laos,
Cambodia), S.intercalatum (Central Africa).
• Only trematodes that live in the blood stream of warm
blooded hosts.
• Have two hosts definitive host (human) and intermediate
(snail).
• Over 200 million people are infected and over at least 75
countries with 500 million or more exposed to infection.
• The disease caused is called Schistosomiasis or Bilharzia.
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25. Schistosoma sp. – Source of Parasites
infection (3)
How people acquired the
parasites infection – contact
with water in the endemic area
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26. Schistosoma sp. Source of Infection in Military (4)
• Source of infection from the river, lake, valley or any
place
in the jungle with swampy area where snails can be
found.
• Military can easily acquired this parasites infection -
working environment ; always contact with water
during exercise or in war.
• In the PBB mission especially in Africa and middle
East ; endemic area – military can easily acquired
infection.
• The infective stage of parasite is cercaria can
penetrate the military body through skin – results of
contact with water where the snails are present.
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27. Schistosoma sp. of Military Importance (4)
• The parasites has resulted many casualties when operating in
endemic area.
• Parasites attack can become psychological stress in most
military troops.
• Military more expose to the source of infection – river, lake,
swampy area with present of snails.
• Parasites available for research in term of prevention by military.
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28. Filarial Parasites – Introduction (1)
• It is estimated that over 140 million people are infected with one
or more species of filaria.
• Parasites Inhabit a range of locations within the body; lymph glands,
deep connective tissue, subcutaneous tissues or mesenteries. Invasions of
these tissues cause typical symptom of a human filarial infection. In some
cases these result in fleshy deformities known as elephantiasis.
• There are 5 commonly pathogenic species infecting man:
•Wuchereria bancrofti, Brugia malayi, Brugia timori,
Onchocerca volvulus and Loa loa.
ns
•W. bancrofti is distributed throughout the tropical regions of Asia, Africa, China, the Pacific and
isolated locations in the Americas.
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•Endemic range of Brugia malayi is confined to South and South-East Asia from India in the west to
Korea in the east
30. Filarial Parasite – Wuchereria bancrofti (3)
•Wuchereria bancrofti is a nematode causing lymphatic filariasis
throughout the tropics and subtropics.
•Transmitted by the mosquito,Culex quinquefasciatus, Anopheles
gambiae and Anopheles funestus.
•Humans are the only known reservoir host of W. bancrofti.
•Infection rates in some communities in East Africa exceed 30% of
adults causing revolting swellings of the legs or genital system,
known as elephantiasis in man.
•The adult worm occurs in tightly coiled nodular masses in the major
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lymphatic ducts.
31. Filarial Parasite – Brugia malayi (4)
• Brugia malayi is a nematode causing lymphatic filariasis in
South East Asia.
• Two strain of B. malayi:
• 1. Nocturnal periodic strain – Asia, microfilariae highest
concentration between hours 10pm and 2 am.
• 2. Subperiodic strain – Malaysia, Indonesia and Philippines,
microfilariae detected between noon and 8pm.
• Nocturnally periodic Brugian filariasis – transmitted by various
Anopheles sp. and Masonia mosquitoes – bites during night.
• Nocturnal sub-periodic B.malayi – transmitted exclusively by
Mansonia sp.
Mansonoa bonneae are important vectors in Malaysia –
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breeding in swamp forest and bitting by night.
32. Filarial Parasites – The source of infection in military (5)
• Military can acquired this infection from swampy tropics
and subtropics forests. These the major habitats of the
parasites and the their vectors (Anopheles, Culex and
Mansonia mosquitoes).
Eg: Mansonoa bonneae are important vectors in Malaysia –
breeding in swamp forest and bitting by night.
• UN and other military mission to Africa, South-east Asia,
Indonesia, Philippines, Timor Timor, Vietnam are the other
sources of infection that military can acquired of these
parasites.
Eg: During Vietnam war, many American soldiers infected by
the parasites including filarial parasite – soldiers had been
quarantine and not allow to donate their blood.
The same practice also in Malaysia - Soldiers going back from
mission are quarantine.
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33. Filarial Parasites of Military Importance (6)
• The infection of these parasites can cause many causalities in
military. Parasites Inhabit a range of locations within the body; lymph
glands, deep connective tissue, subcutaneous tissues or mesenteries. In
some cases these result in fleshy deformities known as elephantiasis.
• During Viet Nam War thousands of returning US troops carried the
parasites - induced disease. Nearly 54,000 soldiers returning from Operation
Dessert Storm carried parasites disease including this parasite!
• Military are the troops on the move, especially by sending them to
the mission. This means military have great expose to this parasite’s
infection in other countries.
• This parasites can be spread easily by the mosquitoes vector and can
cause disaster and psychological stress to military. Patients are
asymptomatic and the attack are drastic!
• The parasites can be transmitted from one person infected to others
by the mosquitoes vectors. Parasites can be spread and cannot be
controlled easily!
• The parasites are useful to military because it can be used as
experiment organisms for R & D by means of the prevention to parasite
disease.
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34. Haemoflagellates parasites (Leishmania sp.)
Intoduction (1)
•Two genera are medical importance: Leishmania sp. and
Trypanosoma sp.
• Leishmania sp is endemic in many parts of Africa, Asia and
South America. It is transmitted by Phlebotomus species,
Sandfly.
• 7 species infecting human: L.donovani complex, L.major, L.
tropica, L. aethiopica, L. mexicana complex, L. braziliensis
complex, L. peruviana
•Leishmaniasis is a vector-borne parasitic disease endemic in parts of the
tropics, subtropics, and Southern Europe. The World Health Organization
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estimates that 1.5 million cases of CL and 500,000 cases of visceral
leishmaniasis (VL) occur each year.
35. Haemoflagellates parasites (Leishmania sp.)
Intoduction (2)
• They cause diseases collectively known as Leishmaniasis. 3 types of
Leishmaniasis : visceral, cutaneous and mucocutaneous leishmaniasis.
• Visceral leishmaniasis – sometimes known as kala-azar –caused by L.
donovani complex; L.donovani, L.donovani infantum and L. donovani
chagasi.
• Cutaneous leishmaniasis – a vector- borne parasitic disease, is a risk
for military personnel who travel to tropics, subtropics and Southern
Europe where disease is endemic. It caused by L.tropica, L.major and
L. aethiopica, L.mexicana.
• Mucocutaneous leishmania – L. braziliensis.
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37. Haemoflagellates parasites (Trypanosoma sp.)
Introduction (4)
•3 species of haemoflagellates Trypanosoma are responsible
for disease in humans:
• T. rhodesiense & T. gambiense
• Salivarian trypanosomes – parasites complete dev. in salivary
system of vector.
-disease known as Trypanosomiasis. (sleeping sickness in Africa).
- Distribution of parasites – T. rhodesiense(E. Africa), T. gambiense
(W. Africa).
-Transmitted of trypomastigotes by bitting flies of Genus Glossina
(tsetse fly).
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38. Haemoflagellates parasites Trypanosoma sp. – Introduction (5)
Trypanosoma sp.
Two form of trypomastigotes
of T.rhodesiense & T.gambiense
The infective stage is
trypomastigotes which can
invade the lymphatic tissue,
heart, various organs- organs
enlarge. Infection of central
nervous system – leading to
coma and death within several
years.
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39. Haemoflagellates parasites – Introduction (6)
• Trypanosoma cruzi
• Stercorian trypanosomes – complete their dev. in posterior
region of vector, infective forms appear in the insects faeces.
• This the aetiological agent of South and Central America.
• Cause a disease known as Chagas’ disease.
•The vectors are the blood sucking bug of the genera Triatoma,
Panstroglus, Rhodnius.
• Multiplication of T.cruzi at site of infection can produce inflamed
swelling – chagoma. Oedema of upper & lower eyelid may occur
along with conjuctivitis – Ramona’s sign.
•
Insect Triatominae
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T. Cruzi in blood sample Multiplication of T. cruzi in the
muscle – Kissing bug
41. Haemoflagellates parasites -The source of infection in Military (8)
1. Military acquired the infection of these parasites fm the
endemic area in many parts of Africa, Asia and South
America.
2. All forms of infection starts when a female sandfly
(Phlebotomus sp.) takes a blood meal from an infected host.
The countries with dessert eg; (Iraq, Kuwait and Afghanistan)
usually the habitat for the sandfly, is also the main source for
the infection this parasites.
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42. Haemoflagellates parasites of Military Importance (9)
1. The parasites, cause many causalities to the soldiers.
Eg: There are 22 cases of chronic skin lesions of CL in US
military personnel deployed during 2002-2003 to Afghanistan, Iraq
and Kuwait.
2. Parasites are easily transmitted from one infected
soldier to others by sandfly (vector-borne parasitic
disease) - is a risk for military personnel who travel to the
endemic area.
3. The World Health Organization estimates that 1.5 million
cases of CL and 500,000 cases of VL occur each year –
This amount of cases also can give bad impact to military.
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43. Arthropods as an Ectoparasites - Introduction (1)
1. The 2 most important classes of Arthropods are Insecta
and Arachnida.
2. Insecta – mosquitoes, flies, bugs, fleas.
Arachnida – ticks, mites, spiders and scorpions.
3. Arthropods may transmit disease by following methods:
• Mechanical transmission : diseases producing agent does not
multiply in the arthropod. eg: Salmonella trasmission by the
house fly.
• Biological transmission – arthropod is an integral part of the life
cycle of parasites; Wuchereria bancrofti and Plasmodium sp in
mosquitoes.
(Zaman V. and Keong A.L, 3rd Edition Handbook of Medical Parasitology)
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44. Arthropods of Military Importance - (2)
1. Soft Ticks
• Class: Arachnida.
• Genus: Ornithodoros.
• Worldwide distribution: Europe, Africa, Asia and the Americas.
• Life cycles: hemimetabolous, eggs hatching six legged
larvae – moult to eight legged nymphs. Larval instars requiring a
blood meal to proceed for life cycle.
• Disease – the most important disease is tick borne relapsing
fever. Which occurs world wide and is spread by spirochaete
infected Ornithodoros.
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45. Arthropods of Military Importance - (3)
2. Mosquitoes
• Class: Insecta
• Order: Diptera
• Genus: Anopheles, Culex, Aedes, Mansonia.
• Mosquitoes are the blood feeders (ectoparasites).
• Also as vector to certain disease (Vectorborne disease).
• Anopheles sp – vector for malaria parasites.
• Culex sp – vectors for Wuchreraria bancrofti, Japanese
Encephalitis.
• Aedes sp a - vectors of Bancrofti filariasis and arboviruses such
as yellow fever and dengue.
• Mansonia sp – Brugia malayi.
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46. Arthropods of Military Importance - (4)
3. Tsetse Flies
• Class: Insecta
• Order: Diptera
• Genus: Glossina
• Tsetse flies are the blood feeders (ectoparasites) to cows and
humans.
• Also as vector to certain disease (Vectorborne disease).
• Tsetse flies are Vectors for African sleeping sickness (T.
rhodesiense and T.gambiense).
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47. ACTIVITIES TO MODIFY RISK OF INFECTION
1. Foodborne And Water Borne Infection
• Avoid undercooked food, non bottled
beverage sand non pasteurized dairy
products.
• Avoid consuming food sold by street vendors
• Avoid salads and raw seafood
• Peel fruit
• Used bottled water for drinking, making ice
cubes and brushing teeth.
• Wash hands with soap and water or alcohol
and sanitizers before each meal.
• Carbonated beverages are safe.
• Vaccines are available for hepatitis A and
typhoid.
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48. ACTIVITIES TO MODIFY RISK OF INFECTION
2. Vectorborne Infection
• Wear the uniform with the pants tucked into
boots, sleeves worn down and undershirt
tucked into the pants.
• Minimize outdoor exposure during periods of
insect activity.
• Use 33% extended-duration DEET.
• Impregnate uniform with permethrin.
• Used insect netting sprayed with permethrin
• Check for ticks regularly.
• Use malaria chemo prophylaxis if indicated.
• Vaccines are available for Yellow fever and
Japanese B encephalitis.
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49. ACTIVITIES TO MODIFY RISK OF INFECTION
3. Respiratory infection
• Wash hands regularly or use alcohol hand
gel.
• Avoid hand contact to the face.
• Do not share drinking or eating utensils.
• Use appropriate control measures when
dealing with infected or potentially infected
individuals
• Submit to pre-and post deployment tuberculin
skin testing.
• Vaccines are available for measles, mumps,
rubella, diphtheria, pertussis,meningococcus
influenza, varicella, smallpox and anthrax.
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50. ACTIVITIES TO MODIFY RISK OF INFECTION
4. Zoonotic infection
• Do not pet or feed animals (especially dogs).
• Avoid direct contact with animals or animal
products.
• Do not stray animals as pets.
• Use appropriate control measures when
dealing with infected or potentially infected
individuals
• Vaccines is available for rabbies.
• Vaccines are available for measles, mumps,
rubella, diphtheria, pertussis,meningococcus
influenza, varicella, smallpox and anthrax.
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51. ACTIVITIES TO MODIFY RISK OF INFECTION
5. Water exposure
• Avoid swimming in fresh water, especially if it
is stagnant or slowly flowing
• Doxycycline chemo prophylaxis available.
6. Soil exposure
• Water toe covered footwear.
• Avoid sitting in sandy areas with uncovered
skin.
• Avoid ingesting soil.
• Vaccine is available for tetanus.
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52. CONCLUSION
1. Parasites are the organism that derives the
lives on or in another organism and derives it
nourishments from their host.
2. Parasites can cause many casualty in the
military operation.
3. Parasites have their own importance whether
in medical or in military.
4. The effective prevention of parasites infection
can conserve the military fighting strength.
5. Soldiers must practice all the time the
activities to modify the risk of infection.
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