Arthropods:
Mosquitoes, housefly, sand fly, human
louse, rat fleas, rodents, ticks etc.
Control measures
🌟 Define arthropods responsible for causing disease:
Definition:
Arthropods are a large phylum of invertebrates. They have a number of segments.
The study of arthropods is known as entomology in medicine.
5% of deaths in India are due to arthropod-borne diseases.
Arthropods responsible for causing disease in man are of medical importance as follows:
Mosquito
House fly
Sand flies
Human louse
Rat fleas
Ticks
Mites
Cyclopes
:🌟 State method of transmission of disease:
Transmission:
Direct method:
a. Itch mite-
Cause – Scabies
It is spread by direct contact.
b. Mechanical transmission-
Caring of infection on their body, diarrhea, dysentery
C. Biological transmission-
When the disease agents multiply in the insect host it is known as biological transmission like malaria, filaria.
🌟 Explain mosquito, types and life cycle:
Mosquito:
A mosquito’s body consists of three parts,
Head
thorax
Abdomen
The head has a long needle-like structure called a probe with which the mosquito bites.
The thorax has a pair of wings and three pairs of legs, ventrally. The abdomen is long, narrow and has 10 segments.
Types:
Anipheles
Culex
Ades
🌟 Life Cycle:
There are 4 stages in life of mosquito-
Egg-1-2 days
Larvae-5-7 days
Puepa-1-2 days
Adult – about 2 weeks
🌟 Discuss house fly, sand human fly, louse and their transmission of diseases:
house fly:
Mechanical transmission: through body and sticky hair on body and legs
Vomit drop- If the infected food is eaten, due to the diffusion of the vomit drops into the food.
Disinfection:
Constant defecation by flies on food spreads diseases.
Common diseases spread by houseflies include:
Diarrhea
Typhoid
Cholera
Dysentery
Conjunctivitis
Amoebiasis
Trachoma
Mosquito borne diseases:
Anopheles- malaria
Culex-filarial, encephalitis
Aedes-yellow fever, dengue fever, and hemorrhagic fever
Sand Fly:
Kala azar
Sand fly fever
Oriental sore
Types of lice:
Types of Lice-
Head louse
Body lice
Pubic louse
Transmission Of Diseases-
By biting and their infectious faces
Diseases of louse-
Epidemic typhus
Relapsing fever
Trench fever
Dermatitis
🪄 Topic:
Introduction – rats, fleas, rodents, ticks, etc
🌟 To enlist types of common fleas and it’s life cycle:
Types of fleas
1.
Xenopsylacheopis
3.
Xenopsyllabrazilenis
–Life cycle of fleas:-
Egg 1 week
Larva 2 weeks
Pupa 1-2 weeks
Adult about 2 months
🌟 To describe the flea indices:
State the density of fleas in a given area
Total fleas index- is the average number of fleas per mouse
Cheopis per mouse is the number of Xenopsylavheopis per mouse.
If the cheopis index is below 1, there is no danger of plague spreading
🌟 To describe mode of transmission and disease transmitted by flea:
By bitting- Inject flea plague into the block when plague bacilli are produced by biting the bite of a hungry blocked flea.
multiply in his gullet and block the passage of food
Flea-Borne Disease:
Bubonic plague
Endemic typhus
To describe about ticks and itch, mite, types of ticks and life cycle of ticks and itch mite:
Definition-
Ticks are ectoparytes of vertebrates, oval in shape.
Types of ticks:
Hard and soft ticks
Hard ticks are called hard ticks because of the presence of a hard shield on the dorsum of the tick.
Soft ticks lack shields and have four pairs of legs.
Male is smaller than female
Both males and females bite and suck blood.
Diseases transmitted by ticks:
Hard tick:
Tick typhus
Viral encephalitis
Soft tick:
Relapsing fever
Description about itch mite:
Definition:
An extremely small arthropod, visible only to the naked eye and about 0.4 mm in size, it is an ectoparasite of man and causes scabies disease.
The body of the itch mite is turtle-shaped and rounded at the top and flattened at the bottom.
The life cycle of itch mite:
Egg: 3-4 days
Larva: 3 days
Nymph: 6-8 days
Adult: 1-2 months
To describe disease transmitted by itch mite:
Itching is a skin disease spread by ticks
The worst scabies mites especially affect the hands and wrists and can affect other parts such as axillas, elbows, buttocks, lower abdomen, legs and ankles.
-Treatment of scabies
Scrub with soap and water and apply 25% benzyl benzoate
Apply ointment or sulfur ointment 2-10% or benzene hex 0.5% chloride mixed with coconut oil.
🌟 To describe about rodents, types of rodents and diseases caused by rodents :
Description about rodents:
Rodents are part of man’s environment—causing economic losses and reservoirs of some important infectious diseases to man, such as the plague.
Types of rodents:
Domestic
Wild rodents
domestic: House rat and sever rat
Wild rodents
Diseases caused by rodents:
Plague
Leptospirosis
Murine typhus
Amoebiasis
🪄 Topic:
Control measures
Various mosquito control measures are classified as-
Anti larval measure
Anti-adult measure
Personal protection measures
A. Anti viral control measures :
To eliminate the breeding place.
Application of oil
Peris green
Synthetic insecticide
Biological control
B. Anti adult mosquito control measures:
Spray Malathine, DDT, BHC, LINDANE, OMS 33.
To describe the measure to control house fly and sand fly:
Improve environmental sanitation
Use of insecticides
Fly paper
Use of screening
Health education to get rid of fleas
Spray of malathion, DDT, BHC, LINDANE, OMS 33,
To describe the control of lice:
Head lice- It can be controlled by DDT or medicated drug.
Body lice- 10% DDT
: To describe control of flea:
Can be controlled by 10% DDT or 5% malathine dust.
To describe the control of ticks:
Use of insecticides:
Spray malathine, DDT, BHC, LINDANE, OMS 33 in tick infected area.
Sanitation:
Cracks and fissures in the ground especially adjacent buildings should be filled.
Protection of workers:
Wear protective cloth and remove ticks if found on clothing.
🌟 To describe control of scabies caused by itch mite:
First the patient is scrubbed thoroughly with soap and water and then benzyl benzoate 25% emulsion in coconut oil or sulfur ointment 2-10% or benzene hexachloride 0.5% is applied.
🌟 To describe the control of rodents:
Trapping- Using ancient Danes to capture and destroy.
Using rat poison or rodenticide.
Fumigation of rat burrows with cyanogas. It is used to apply about 2 ounces of its chemical to each rat’s burrow with a special foot pump
By improving hygiene.
Environmental sanitation is essential for permanent control of mice and rats.
a. By proper storage of foodstuffs.
b. By constructing rat proof buildings.
c. By proper collection and disposal of waste.