Lecture 14 Vector-Borne Diseases with Focus on Malaria

vivax/ovale: Less than ___ % of Parasitemias affect humans.

1%; 20,000-50,000

How long is the incubation period?

1-4 weeks

What are three ways that pregnant women in high risk zones for malaria can protect themselves?

1. Insecticide treated nets 2. Intermittent Preventative treatment 3. Effective and prompt case management of malarial illness.

falciparum: Between _ and _ % of Parasitemias affect uphumans.

10-15%

Malaria causes ___ to ____ million cases per year worldwide.

300- 500 million

At least ____ of the world's population lives in endemic areas.

40%

What is Chemoprophylaxis?

A medication taken at regular intervals to kill one or more of the morphological forms (life stages) of the malaria parasite and therefor prevent the onset of clinical illness.

What are the "three big" killers worldwide?

AIDS, Malaria, TB

Prodromal Symptom

An early symptom that might indicate the start of a disease before specific symptoms occur.

Define Reservoir:

An organism or a population that directly or indirectly transmits a pathogen while being virtually immune to its effects.

The malaria infected ____ mosquito introduces sporozoites into a human host.

Anopheles (the female)

Pathogen for Lyme Disease

Bacteria

An example of Chemoprophylaxis:

Chloroquine for trophozoites and RBC schizonts

Does control increase or lower the number of cases? Is transmission increased or reduced?

Control lowers the number of cases; transmission is reduced.

Pandemic

Epidemic has gone international.

Clinical Cure

Eradication of RBC trophozoites and schizonts

Pathogen for river blindness

Helminths (worms)

Vectors: Mosquito and blackfly Pathogen:

Helminths - worms

What is the dormant stage of P. vivax called?

Hypnozoites

Where can the dormant stage of P. vivax and P. ovale persist?

In the liver

ITN stands for...

Insecticide treated bed net

Endemic

Large number of cases all or most of the time with a particular group of people or in a particular area.

Epidemic

Large number of cases in a population over a short period of time.

______ infect red blood cells.

Merozoites

What are the four classifications for Vector-Borne Diseases?

Mosquito-borne Mouse-borne Louse-borne Tick-borne

Aboviruses are carried by...

Mosquitos

West Nile is carried by...

Mosquitos

Can a vector convey a disease by itself?

No

Does a person receive sterile immunity after being infected with Malaria?

No

Is there a durable immunity?

No

Is there a vaccine for Malaria?

No

Are reservoirs affected by the pathogens which they transmit?

No.

What parasite causes Malaria?

Plasmodium

Which is the most widespread of the two: Plasmodium vivax or Plasmodium falciparum?

Plasmodium vivax

Which of the two is found in endemic areas and some temperate areas: Plasmodium vivax or Plasmodium falciparum?

Plasmodium vivax

Main damage is in ___ Cells.

RBC

Schizogony

Red cell lysis

RBM stands for..

Roll Back Malaria

Is premunition for Malaria short lived or long lived?

Short Lived

Define Agent:

Single necessary cause of a disease

Mortality from Malaria is primarily in _____ _______ among children less than ____ years old.

Subsaharan Africa five years old

Lyme disease is carried by...

Tick, lice, mite and flea

Typhus is carried by...

Tick, lice, mite and flea

Pathogen= Bacteria Vectors=

Tick, mite, lice, flea

How does a vector spread infection?

Transmits pathogens from one host to another.

True or False: Immunity develops slowly

True

True or False: Only RBC trophozoites and schizonts cause disease.

True

True or false: falcuparum causes the more severe disease between itself and vivax:

True

How many hosts does the parasite life cycle involve?

Two

Pathogen for West Nile:

Viruses

Vector= Mosquito Pathogen=

Viruses

Can mosquitos carry malaria?

Yes

What is partial immunity?

You may obtain the disease, but it won't be serious or fatal.

Describe the sporozoite stage.

a motile sporelike stage in the life cycle of some parasitic sporozoans (e.g., the malaria organism) that is typically the infective agent introduced into a host.

What is a Vector?

a vector is an organism that does not cause disease itself but which spreads infection by conveying pathogens from one host to another.

When does Prodrome start?

at the end of incubation and before the first paroxysm

How can P. vivax and P. ovale causes relapses?

by invading the bloodstream weeks, or even months later.

In Eradication, there is the ____ of disease carrying agents for all but a contained few.

elimination

Radical cure

eradication of RBC trophozoites and schizonts and hepatic schizonts

_______ is the most sever species and causes cerebral malaria

falciparum

Sexual erythrocytic stages=

gameocytes

Relation between the two: Lower parasitemia, (more/less) severe symptoms

less

Sporozoites infect ___ cells.

liver

Pathogen= Protozoa Vectors= tse-tse fly, triatomine bug, ________, and _____

mosquito and sandfly

Define Premunition

naturally acquired protective immunity

Elimination: reduced number of ___ infection in a _____ _______.

new; defined area

Is transmission increased or reduced in elimination?

reduced

Sporozoites mature into___

schizonts

Why don't relapses occur when malaria is transmitted through blood transfusions?

through vivax/ovale; Because there is no dormant stage when one gets malaria by blood transfusion because it doesn't go to the liver.

Where is Plasmodium falciparum primarily found?

tropics and subtropics