Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
28 Cards in this Set
- Front
- Back
|
What is the distribution of Pv?
|
most widespread, found in most endemic areas including some temperate zones
|
|
|
What is the distribution of Pf?
|
primarily tropics and subtropics
|
|
|
What is the distribution of Pm?
|
similar range as P. falciparum, but less common and patchy distribution
|
|
|
What is the distribution of Po?
|
occurs primarily in tropical west Africa
|
|
|
What additional plasmodium species may be infecting humans?
|
parasites with same morphologically as P. vivax
- CSP sequence = P. simiovale (primate) - vivax-like variant is found globally P. ovale clades as distinct species? P. malariae and P. brasilianum - nearly identical sequences - possible human → primate transfer? morphological variants of P. malariae in SE Asia → P. knowlesi |
|
|
What is the 5th human species and where is it found?
|
unusually high incidence of P. malariae in Malaysia (especially island of Borneo)
- 86% identified as P. knowlesi by PCR - 4 fatalities (high parasitemias, 24 hr cycle) P. knowlesi, a natural parasite of macaque monkeys, infects humans more frequently than previously believed. Foci of human infections have been observed in parts of Malaysia and other countries in Southeast Asia. Furthermore, these foci tend to be in areas bordering the jungle suggesting a zoonosis. |
|
|
What is the vector for Pk?
|
Anopheles latens is probably vector
- attracted to monkeys and humans - feeds in forest and forest - fringe after dusk - i.e., zoonosis |
|
|
What is unstable or EPIdemic malaria?
|
dramatic increase in malaria incidence
little immunity in population high morbidity and mortality Unstable, or epidemic, malaria refers to an increase in malaria in areas of low endemicity or to outbreaks in areas previously without malaria or among nonimmune persons. Morbidity and mortality can be quite high in these nonimmune populations. These outbreaks are often attributed to changes in human behavior or effects on the environment. Changes in the ecology caused by natural disasters or public works projects, such as building roads or dams, can also impact malaria transmission and lead to epidemics. |
|
|
What is the definition of stable or ENDemic malaria?
|
~constant incidence over several years - includes seasonal transmission
immunity and disease tolerance correlates with level of endemicity (especially adults) Stable malaria refers to a situation in which there is a measurable incidence of natural transmission over several years and this incidence remains somewhat constant. This would also include areas which experience seasonal transmission. |
|
|
Definition and prevalence of HYPOendemic.
|
Areas with low levels transmission of malaria
Prevalence: <=10% |
|
|
Definition and prevalence of MESOendemic.
|
Usually small rural communities with varying intensity of malaria
Prevalence: 11–50% |
|
|
Definition and prevalence of HYPERendemic.
|
Areas with intense, but seasonal, transmission of malaria
Prevalence: 51–75% |
|
|
Definition and prevalence of HOLOendemic.
|
Areas with a high degree of year-long malaria transmission
Prevalence: ≥75% |
|
|
What are the mosquito transmission factors?
|
susceptibility of anopheline species
human contact mosquito density climatic factors ecological factors |
|
|
The potential of the mosquito to serve as a vector depends on what factors?
|
the ability to support sporogony, mosquito abundance, and contact with humans, which are all influenced by climatic and ecological factors
|
|
|
What are the sporogony factors that influence vectorial capasity?
|
Temperature
Mosquito longevity Mosquito species The ability to support sporogony is largely dependent upon species in that not all species of Anopheles are susceptible to Plasmodium infection. Ambient temperature and mosquito longevity are other key factors affecting the parasite’s interaction with the vector. Development of P. falciparum requires a minimum temperature of 16–19°C, whereas the minimum temperature for P. vivax is 14–16°C. Temperature also affects the time of development in that the duration of sporogony is substantially shorter at higher temperatures. A shorter duration of sporogony increases the chances that the mosquito will transmit the infection within its lifespan. |
|
|
What are the mosquito density factors that influence vectorial capasity?
|
Temperature
Altitude Rainfall Breeding places Mosquito density and feeding habits also influence the transmission of malaria. Temperature, altitude, rainfall, and the availability of breeding places are factors that affect mosquito density. |
|
|
What are the human contact factors that influence vectorial capasity?
|
Anthropophilic (human-seeking or human-preferring)
Indoor vs. outdoor Feeding time |
|
|
What are the three major prevention and malaria control strategies?
|
Reduce human-mosquito contact
Reduce vector density Reduce parasite reservoir |
|
|
What are the main strategies to Reduce human-mosquito contact?
|
Impregnated bed nets
Repellents, protective clothing Screens, house spraying |
|
|
What are the main strategies to Reduce vector density?
|
Environmental modification
Larvicides/insecticides Biological control |
|
|
What are the main strategies to Reduce parasite reservoir?
|
Case detection and treatment
Chemoprophylaxis |
|
|
What are the malaria control program considerations?
|
infrastructure of existing health care services and other resources
intensity and seasonality of transmission mosquito species - ecological requirements - behavioral characteristics - insecticide sensitivity parasite species and drug sensitivities cultural and social characteristics of the population presence of social and ecological change |
|
|
When targeting sporozoite for a potential vaccine strategy, name how it will protect and mechanism of action.
|
Protection: Anti-infection
Mechanism: Prevent or eliminate liver stage |
|
|
When targeting merozoite for a potential vaccine strategy, name how it will protect and mechanism of action.
|
Protection: Antiparasite
Mechanism: Decrease efficiency of merozoite invasion |
|
|
When targeting infected erythrocyte for a potential vaccine strategy, name how it will protect and mechanism of action.
|
Protection:Antiparasite
Mechanism: Increase clearance of infected erythrocytes |
|
|
When targeting exo-antigens for a potential vaccine strategy, name how it will protect and mechanism of action.
|
Protection: Antidisease
Mechanism: Lower production of inflammatory cytokines |
|
|
When targeting sexual stages for a potential vaccine strategy, name how it will protect and mechanism of action.
|
Protection: Antitransmission
Mechanism: Eliminate gametes or prevent infection of mosquitoes |
