Week 8 Flashcards
1
Q
What are the NTDs?
A
Neglected tropical diseases
2
Q
What are the key trait of NTDs?
A
Usually low fatality but with high burden of disease
3
Q
What is the most common form of transmission for NTDs?
A
Vectors from animal reservoirs
4
Q
What impact does NTDs have on people?
A
NTDs trap people in a cycle of poverty and disease
5
Q
Can reinfections happen?
A
Yes, many communities are vulnerable so reinfection is common
6
Q
How many people were treated of NTDs in 2020 , even with covid?
A
757 million people
7
Q
How many people are affected each year?
A
1 billion
8
Q
How many preventive treatments are needed every year?
A
1.7 million a year
9
Q
How fast has progress been?
A
43 countries have eliminated at least 1 NTD
10
Q
What is the correlation between GDP per capita and NTD cases?
A
Poorer countries (often near equator) have more cases
11
Q
What pathogen causes Dracunuliasis?
A
Dracunculus medinensis
12
Q
What is the scale of Dracunuliasis infections?
A
20 countries in mid 80s now 4 with 27 cases
13
Q
What is the lifecycle of Dracunculus medinensis?
A
Baby worms –> water –> copepods –> ingested –> mature –> baby worms
14
Q
What is the common name for the disease caused by Dracunculus medinensis?
A
Guinea worm disease (nematode)
15
Q
Is there a treatment for Dracunculus medinensis?
A
No
16
Q
What pathogen causes Bruruli ulcer?
A
Mycobacterium ulcerans
17
Q
What is the scale of Bruruli ulcer infections?
A
33 countries, roughly 2500-5000 cases a year
18
Q
What is the method of Bruruli ulcer transmission?
A
Currently unknown
19
Q
What pathogen causes rabies?
A
Rabies Lyssavirus
20
Q
What is the scale of Rabies infections?
A
~$8.6 billion a year and 10,000 deaths per year
21
Q
What is the mode of transmission for Rabies?
A
Scratch/bite of infected animal
22
Q
What pathogen causes Lymphatic filariasis?
A
3 species of Nematodes
23
Q
What does Lymphatic filariasis do?
A
Block lymphatic system (causes swelling mostly in legs)
24
Q
What is the scale of Lymphatic filariasis infections?
A
51 million (2018), 74% decline since 2000
25
What is the mode of transmission for Lymphatic filariasis?
Mosquitoes (multiple species)
26
What pathogen causes Echinococcosis?
Echinococcus tapeworms
27
What is the scale of Echinococcosis cases?
More than 1 million people at a time
28
What is the transmission of Echinococcosis?
Humans are intermediate host
Carnivores are definitive host
29
What are the socio-economic impact of NTDs?
NTDs directly affect almost every major development and global health issue
NTDs prevent children from attending school and negatively impact an adult economic productivity and their ability to look after loved ones
30
How do NTDs have a more severe impact on?
Women and girls
31
What is the relationship between latitude and NTDs burden?
Overwhelmingly impacts tropical and subtropical regions
32
How does NTDs impact health?
NTDs can cause blindness, swelling of limbs and death. Schistosomiasis is the biggest cause of death from parasites after malaria
33
How does NTDs impact education?
Children with NTDs are often too sick to attend or perform well and healthy children have to care for sickly family members
34
How did deworming medicine impact school attendance?
School absenteeism decreased by 25% when students where given deworming medicines
35
How did treating hookworm impact future wage earnings?
An increase to future wage earnings by 43%
36
How to NTDs impact hunger and nutrition?
Anemia and malnutrition are common symptoms of several NTDs and areas with high NTDs have less access to food. Children can sufer delays in physical and cognitive development
37
How does NTDs impact pregnancy?
More severe impacts on women and girls and can increase infection, miscarriage and death in pregnant women
38
How many women and girls have genital schistosomiasis?
More than 16 million, this makes them 3x more likely to become infected with HIV than those without
39
How does improving water, sanitation and hygiene impact NTD cases?
Reduce trachoma (bacteria) by 27%
ascariasis (type of roundworm) by 29%
Schistosomiasis (trematode) by 77%
40
What are the 3 pillars for tackling NTDs?
Accelerating programmatic action
Intensifying cross-cutting approaches
Changing operating models and culture to facilitate country ownership
41
When does the WHO want to end NTDs?
2030
42
What are symbionts?
Individuals of one species lives on or in individuals of the other species
43
What are the 3 types of symbionts?
Parasitism, commensalism and mutualism
44
How many insect species does Wolbachia are symbionts with?
60%
45
What is special about Wolbachia?
It varies from group to group whether it is parasitic or mutalist?
46
What insect supergroups are Wolbachia parasitic?
Arthropods
47
What insect supergroups do Wolbachia have a mutalistic relationship?
Nematodes (Filarial and Dipetalonema)
48
How does Wolbachia impact Blue Moon butterflies?
It kills male embryos (Females to males 100:1)
49
How does Wolbachia help bed bugs?
Makes vitamin B which it cant get from its diet
50
What is Wolbachia?
A bacteria
51
Can parasites be both good and bad?
Yes
52
How is the bacteria Helicobacter pylori both parasitic and mutalistic?
Causes Stomach cancer and stomach ulcers
Protects against esophageal cancer
53
How is the bacteria Bacillus thuringiensis (Bt) benefit farmers?
Lyse holes with toxins in insect exoskeleton, leaking of beneficial bacteria that then causes sepsis. Allowing for natural pesiticide helping organic farmers.
54
How does Mitochondria leaking into cells impact immune system?
Immune cells still see the mitochondria as a pathogen so triggers a Systemic Inflammaory response (SIRs)
55
What is Amphibiosis?
A natural partnerships that are helpful in some contexts and harmful in others
56
What trait in pathogens is a primitive trait in parasites?
Virulence
57
Why is virulence a primitive trait in parasites?
Virulene is an indication of a recent association between a parasite and its host. As evolution will lead to commensalism, mutaulism the extinction of the host and/or parasite
58
What determines parasite fitness?
Transmission: High transmission= High fitness
59
Why does low virulence help parasites?
Low virulence increases transmission and parasites depend on the host for transmission
60
What parasites in humans go against convential wisdom of low virulence is best?
Virulent, obligate pathogens like Neisseria gonorrhoeae
Long associations with humans, agents of malaria and TB
61
What is the relationship between hospitals and virulence of parasites?
Hospitals have parasites greater virulence
62
What is the virulence-transmission trade off theory?
Virulence provides a fitness cost of host death + benefit of high replication
63
What strength of virulence is typically selected for?
Intermidiate virulence
64
What determines virulence?
Level of intermidiae virulence depends on ecology and the system
65
Why is intermidiate virulence selected for?
Highest transmission
Low recovery rate
66
How does transmission strategy impact virulence?
Direct transmission > Require active hosts prefers low virulence
Vector borne --> Might prefer inactive hosts > High virulence
67
How virulent are waterborn infections?
High virulent
68
How does ecological community impact transmission and virulence?
There is intraspecific competition between coinfections of multiple strains of the same species
Interspecific competiton between multiple species
Or both
69
How does competition impact virulence?
Competition can increase or decrease virulence on a case by case basis
70
Do the same behaviour impact on actor and recipient apply to bacteria?
Yes, the same 4 of mutual benefit, selfishness, altruism and spite
71
Can microorganisms display kin discrimination?
Yes, even viruses can display kin discrimination
72
What are the 3 behaviours for kin selection?
Prudence, public goods cooperation and spiteful interactions
73
What is Prudence?
Individuals limit resource use for the benefit of others (In a high relatedness environment lowers virulence but the opposite is true)
74
What is Public good cooperation?
Individuals donate resources that are of benefit to others (Seen in bacteria Pseudomonas aerginosa which produces siderophores, iron-scavenging molecules, which are beneficial for growth this is favoured in areas of high relatedness)
75
What are spiteful interactions?
Costly to all (Seen when Pseudomonas aeruginosa are injected into wax moth larvae this is costly to all involved)
76
Why did the treating of hookworm cause malaria to become more virulent?
Mass hookworm deworming caused a 2-3x gretaer intensity of malaria
Due to competition for RBC: The strain P.vivax less competitive with worms than P.falciparum
Treatments were modified
77
What was the experiment were they found microbes helped the immune response?
Caenorhabditus eleganus (worm) ate Staphylococcus aureus (pathogen) and Enterococcus faecalis (helpful). Over sucessive generations the Staphylococcus aureus became less virulent when exposed to Enterococcus faecalis
78
Why did the Staphylococcus aureus become less virulent?
The Enterococcis faecalis stole resources and killed the Staphylococcus aureus. So in response the Staphylococcus aureus produced less siderophores which starved both bacteria but made the Staphylococcus aureus less virulent
79
What is the advantage of coevolution and coinfections?
Can shape interactions towards defensive symiosis and allowing protective bacteria to colonise is a form of immune defense
80
What controls our symbiont?
Phages and mucus
81
What are the steps for phage, mucus defense?
1) Epithelial cells secrete mucus
2) Phage adhere to mucus through Ig-like domains
3) Adherent phage form anti-microbial layer
4) Mucus-adherent phage have increased chance of replicative sucess
5) Phage and bacteria are shed with mucus
82
Why is the beneficial trait for mucus?
Mucus is quite impenetrable
Mucus is universal to animals and phages universal to all mucus
83
How does phage mucus defense benefit phages?
Phages 15x more likely to find bacterial host if it sticks to mucus
84
When did the phage mucus defense evolve?
Started at dawn of animal kingdom
Phages the original immune system (one of the many theories of the origin of the immune system)
85
What is the main function of the immune system?
To manage animal relaionship with its microbes
