ENTO EXAM 3

Why are neglected tropical diseases common?

 1. High prevalence



◦Among the most common infections in poor/low SES populations



 2. Often associated with rural communities



 3. Non-emergent, ancient diseases



 4. Chronic conditions that cause disability, disfigurement, etc.



 5. High disease burden but often low mortality

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What is the chagas and sleeping sickness disease pathogen?

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◦*Trypanosoma* (genus)

What is African Trypanosomiasis ?

Sleeping sickness

What is American Trypanosomiasis ?

Chagas disease

Where are trypomastigotes found?( sleeping sickness)

Found in feces and blood

When epimastigotes multiply, how does it affect our body?

Will destroy muscle and neuron cells

what is the vector for chagas disease?T.cruzi vector

kissing bug

At what stages do Trypanosoma cruzi vectors blood feed?

All stages blood feed, high vectorial capacity

What are the infectious rates of Trypanosoma cruzi  ( chagas)?

50-60% in endemic areas

What to vectors transmit Trypanosoma cruzi ( chagas)?

 *Triatoma infestans*



 *Rhodnius prolixus*

Are Trypanosoma cruzi exclusively human feeders?

No, feed on donkeys, cattle, goats, horses, pigs, cats, dogs, chicken

What is another name for triatoma infestans ?

Vinchuca

What is the most imporant vector of T.cruzi and where is it prominent?

vinchuca in the south

What chagas vector is prominent in the north?( second most important vector)

Rhodnius prolixus ( second most important vector)

How often do kissing bugs lay eggs?

Female lay 1-2 eggs a day

How long is the life cycle of a kissing bug?

3-10 month or up to a year in large species

Can adult kissing bugs survive without blood meal?

adults can go without blood meal for months

Are kissing bugs endophilic and nocturnal?

yes

Is vectorial capacity affected by poop ?

If they don’t poop on host, it will have low vectorial capacity

What is chagoma? ( in accute phase of chagas)

swelling at site of bite

When does acute phase of chaga begin?

begins shortly after infection, lasts several weeks

What occurs in the acute phase of chagas?

swollen lymph nodes, body aches, loss of appetite and anemia

is acute phase of chagas fatal?

no

When does chronic phase of chaga occur?

only 30% chance of adults that survive acute phase enter chronic phase after 10-30 years of asymptomatic infection.decrease in parasite in blood.

What occurs in the chronic phase of chagas?

Hearth rhythm abnormalities, dilated esophagus/colon, blood production abnormalties, muscle cells get destroyed thru lesions, can develop an autoimmune disorder

What is the treatment for chagas?

Once chronic phase hits, you attempt to manage symptoms. can need heart transplant, medication to regulate heartbeat.

For chaga vectors, do female and males blood feed?

yes

What if lymphatic filariasis?

 a parasitic infection caused by worms (nematodes) 

What is a onchocerca volvulus vector?

black fly aka buffalo gnat

Do both male and female black flys blood feed?

Only females blood feed and blood feed during the day

What are onchocerciasis symptoms? ( river blindness)

blindness, extreme pruritus( itchiness) due to dead microfilaria -wolbacchia

Is onchocerciasis ( riverblindness) lethal?

rarely lethal

What other physical symptom occurs due to onchocerciasis ( riverblindess) ?

nodules of adult worms on head arms or below the waist.

What other affects does the extreme itcing (pruritis) cause the skin?

skin disease, the immune system is attacked so the skin changes colors and is inflamed, eye disease

What disease do black flies transmit?

Riverblindness

What is another name for river blindness?

Onchocerciasis

What is the treatment for onchocerciasis( riverblindness)?

invermectin

How does invermectin combat onchocerciasis ( riverblindness)?

Prevents the production of microfilaria

Is DEC recommended for treatment of onchocerciasis ( riverblindness)?

No because it kills the adults which makes them sick and then causes death

What efforts are used to control black fly reproduction?

* bednets
* Larvicide rivers

Is IRS effective in controlling black flies?

No, black flies are not very endophilic so IRS is ineffective

What is endophilic?

a mosquito that tends to inhabit/rest indoors

Where in africa is blindness due to onchocerca volvulus ( riverblindness) more common?

West Africa

In endemic areas what percentage of the population is infected?

30%

What is required for mass drug administration?

 1. Highly effective drug



 2. Long-acting



 3. Safe



 4. Inexpensive



 5. Community participation

What are the impacts of onchocerciasis (riverblindness)?

\-inability to work

\-social impacts

\-suicide

Where are you most likely to be bitten by *Lutzomyia spp.* and infected with *Leishmania*?

south america

What is a significant risk factor for developing visceral leishmaniasis after cutaneous leishmaniasis?

manultrition

Which drug(s) would be effective during Stage 3 (meningoencephalitic) of infection with *Trypanosoma brucei rhodesiense*?

Melarsoprol

____________is the drug that effectively treats certain stages of Sleeping Sickness and was produced by Aventis, who halted manufacturing for many years due to lack of profits.

Eflornithine

A patient presents with a distended abdomen, an ulcerated lesion, and bloodwork that shows evidence of liver damage. With what disease is your patient most likely afflicated?

Visceral leishmaniasis

This status is awarded to certain medications and their associated companies to encourage development of drugs for rare or underrepresented disease cycles, and allows for perks such as tax incentives, patent protection, exclusive marketing rights, and additional funding. 

orphan drug status

Why does treatment need to begin early for sleeping sickness (african trypanosomiasis)?

They can change their protein code to not be recognized

Is trypanosoma brucei brucei pathogenic to humans?

No, it is not pathogenic to humans

What does ***Trypanosoma brucei gambiense cause?***

Chronic sleeping sickness in West Africa

What does ***Trypanosoma brucei rhodesiense cause?***

Acute sleeping sickness in East Africa

Who is the main reservoir for *Trypanosoma brucei gambiense ?*

humans

what is the mortality rate for *Trypanosoma brucei gambiense (chronic sleeping sickness)?*

◦100% fatality with no treatment

Who is main reservoir for *Trypanosoma brucei rhodesiense?*

◦wild antelopes, cattle. Humans are accidental hosts

What is the fatality rate for acute sleeping sickness? (*Trypanosoma brucei rhodesiense)*

100% fatality with no treatment

Who is the sleeping sickness vector?

Tsetse fly

What is the genus of the tsetse fly that transmits sleeping sickness?

Glossina

Where are Trypomastigotes found in sleeping sickness life cycle?

In feces

What group is the glossina from in the west african vectors?

Glossina palpalis

where is glossina palapalis ( sleeping sickness vector) found in africa?

West Africa

Where is Glossina morsitans ( sleeping sickness) vector found?

East Africa

In what areas is the west african vector of sleeping sickness found? ( glossina palpalis group)

Around rivers and forests

In what areas is the east African vector of sleeping sickness found? (glossina morsitants group)

In the woodland savannah

What does the Glossina palpalis group feed on? W

Feeds on humans

What does the Glossina morsitans group feed on?

Feed mostly on cattle

What sex of tsetse flies blood feed?

Both male and female flies blood feed

Why are tsetse flies k strategist?

◦High investment in few offspring

◦Long generation times

◦Populations slow to rebound

What symptoms occur in stage 1 of sleeping sickness?

◦Within 1-2 weeks of infection- lesion

What symptoms occur in stage 2 of sleeping sickness? within 1-3 weeks of infection

fatigue, joint pain, swelling of lymph nodes

What is Hemolymphatic disease?

disorders that affect the red and white blood cells, platelets, endothelial cells, or lymphoid cells and tissues.

What is sleeping sickness mistaken for?

often mistaken for malaria

if treatment is started at stage 2 of sleeping sickness, can someone recover?

yes

What is stage 3 of sleeping sickness?

disorientation, headaches, abnormal behavior, coma, death

How quickly does death come for T.brucei gambiense ( sleeping sickness)?

within 5-10 years

How quickly does death come for those infected with T.brucei rhodiense (sleeping sickness)?

within 12 months

Can you recover from stage 3 of sleeping sickness?

It’s hard to recover , can see success of treatment but organ damage may be present already. Damage to red blood cells that carry nutrients.

How to treat stages 1 and 2 of sleeping sickness?

◦Pentamidine for *T. b. gambiense*

◦Suramine for *T. b. rhodesiense*

How to treat stage 3 of sleeping sickness?

◦Melarsoprol

◦Eflornithine

◦Only for *T. b. gambiense* infections

◦Less toxic

◦Intensive – 56 I.V.s required

What treatment of stage 3 has difficult side effects?

Melarsoprol, treametn can be fatal ( low chance).

How was sleeping sickness controlled?

\-screening and treating

\-control of wildlife

\-traps

\-insecticide treatment of cattle

\-sterile insect technique

What is sterile insect technique?

Release sterile males to decrease reproduction

What is considered in sterile insect technique?

◦Single mating of a female



◦Female-only blood feeding



◦Rate of reproduction

How is stage 1 and 2 of chronic sleeping sickness treated?

petamidine

How is stage 1 and 2 of acute sleeping sickness treated?

suramine

What is the leishmaniasis disease pathogen?

trypanosomatidae ( familly)

What is the genus for leishmaniasis?

leishmania

what happens when immune system is repressed due to leishmania?

Typically kills the human due to a second hand bacteria infection

What is the leishmania vector?

sand fly

What is the genus for the leishmania vector of the old world strain?

*Phlebotomus*

What is the genus for the leishmania vector of the new world strain?

Lutzomyia

Is Lutzomyia vector present all year round or seasonal?

Year round

Is Phlebotomus vector present all year round or seasonal?

seasonal

What are the leishmania vectors characteristics?

quiet, painless bite, night time feeders, come indoors, cannot fly far

True or False. Only female leishmania vectors will blood feed?

True

In what ways can leishmaniasis transmit?

congenital and blood transfusion