VECTOR BORNE DISEASES

Presentation by;NITESH SINGHALINA KHIMBAJA

Supported by:Dr. S K MADHUP

DEFINITION of vector borneA biological association between an arthropod (insect or arachnid ) and a pathogen acquired by feeding on the blood of the infected vertebrate host

OverviewOn the basis of host we can classify vector borne disease in following class;

1) Mosquitoes borne2)Flies borne3)Lice borne 4)Fleas borne5)tick borne

Disease Causative agents

Vectors Methods of infections

Malaria (commonest)

Plasmodium Anopheles mosquitoes

Bite

Dengue fever Virus Aedes mosquitoes

Bite

Encephalitis Virus Culex mosquitoes

Bite

African sleeping sickness

trypnosomas Tse tse fly Bite

Dysentry (amoebic)

Protozoan Housefly Contamination of food

Dysentery (bacilary)

Bacteriumshigella sp.

Housefly Contamination of food

Cholera Vibrio cholerae Housefly Contamination of food

Vectors and Vector borne disease

Disease Causative agents

Vector Method of infection

Onchocerclosis Parasite worm,onchocerco volvulus

Black flies Bite

Plague Bacterium,pastaurella pestis

Oriental rat flies and other fleas

Bites of contact with infected rodents

Rocky mountain fever

Ricketsia American dog tick

Bite

Typhoid Salmonella typhi

Houseflies Contamination of food

Typhus Ricketsia prowzeki

Human louse flies

Contamination or bite

Yellow fever Viruses Aedes mosquitoes

bite

MOSQUITOES & KEY VBDS Responsible for a great VBD burdens

-Malaria-Parasite-Yelow fever-Virus-Dengue fever/hemorrhagic fever-virus-Other viral fevers West Nile, Rift Valley-Filiariasis-Helminth-Encephalitis-viruses

MALARIA; Causative agent:- a) plasmodium vivax

b) plasmodium falciparumc) plasmodium ovaled) plasmodium malarie

Primary host:man Secondary host: anopheles mosquito

Most prevallent in south african countries, and tarai region of Nepal

Controll measure:1) control of host a)clean the surrounding

b)fishes gambusia 2) mosquito net 3) mosquito coils and other mosquito

repellants

DENGUE FEVER Causative agent: dengue virus•Hosts:1)Primary host:2)Secondary host:•Infective stage:

FILARIASIS

Causative agent: Waucheria bancroftiHost: 1)primary host: 2)secondary host:

INFECTIVE STAGE:

FLIES & VBDS

African sleeping sickness- african trypnosome parasite- tsetse fly bite

Enteric bacteria diseases-housefly- food contamination

-vibrio cholerae(cholera), typhoid fever(salmonella typhi),shigella sp.(Bacterial dysentery)

Onchoceriasis (river blindness)- helminth- black fly bite

LICE & VBDS-TYPHUS FEVER Agent: ricketssia prowazeckii vector:body licePediculus humanus corporis Associated with poor sanitation and lice

infestation(ectoparasite cariage) -Transmitted by louse feces penetratingskin or inhaled

in dust Controlled with insectidial body powder and

improved sanitation Other louse borne diseases-Trench fever- Bartonella quintana-Relapsing fever-borrelia recurrentensis

TRENCH FEVER Caused by: Bartonella quintana Used in world war I Transmitted by Pediculus humanus(Louse)

FLEAS & VBDS – PLAGUE Plague-pastaurella(now Yersinia) pestis(Gr. –ve bacterium) Fleas carried on rats and other rodents

-Zoonosis-Rats bitten by fleas become infected and dies-Rats then hop onto Humans , biting (taking a blood meal) and infecting with P.pestis

Bubonic plague:flea bite-infection- lymph node-swelling called buboes-septicemia-fever bubonic plague-dark patches on skin-called “black death”

Pneumonc plague;secondary spread to lungs can result in pneumonia and ability to spread via respiratory secretion and droplets, resulting in person to person spread as “pneumonic plague”

Concern as a bioterroism agent

YERSINA PESTIS Caused by gram –ve, non sporing,non

motile,short coccobacillus pasturella pestis Plaque Host: Rattus rattus (Rats)

Treatment: antibiotics like aminoglycosides,chloramphenicol,co-trimoxazole,tetracyclin.

CONTROL: Control of the vector:

1)rats can be killed by rat poisons2)Fleas by the libral application of insectisides to run rat3)Construction of rat proof dwelling houses4)fumigation of ships and aircrafts

Yersina/pastaurella plague

Bubonic plague

TICKS & VBDS Rocky mountain spotted fever- Rickettsia-tick bite

-causes systemic infection with fever, nausea,vomiting,muscle pain,lack of appetite,severe headache;later ;rash,abdominal pain,joint pain,diarrhea

Lyme disease-spirochete bacterium- Borrelia burgdorferi-tick bite leads systemic disease with fever,headache,fatigue and a characteristic skin rashn called “Erythema migrans”-Untreated, infection can spread to joints,the heart and the nervous system; Neurological sequelae

Erlichiosis-Ehrlichis chaffeenis- a bacterium-Infection causes systemic illness with fever,headache,fatigue and muscle aches-also nausea,vomitting,cough,joint pains, confusion and ocassionally rash.

Q fever :coxiella burnetti-zoonotic

REFRENCES Journals Internet

- www.cdc.gov- www.who.int

library