49

African trypanosomiasis, or sleeping sickness, is caused by the protozoan Trypanosoma brucei, a single-celled eukaryote. Being eukaryotic, it has a cell nucleus and a larger genome than most bacteria; it also has a flagellum with which it can propel itself. Infection with T. brucei occurs via the bite of a blood-sucking fly, one of several species of ...


19

There is a genetic component to mosquito's attraction to humans. Female mosquitoes display preferences for certain individuals over others, which is determined by differences in volatile chemicals produced by the human body and detected by mosquitoes. ... Overall, there was a strong narrow-sense heritability of 0.62 (SE 0.124) for relative attraction and ...


14

First part of the answer - Yes fleas (Siphonaptera) can be drowned. But not as easily as the internet would lead you to believe. There are many claims on the internet (and printed works) expounding on how simple it is to drown fleas. The best science I found so far on the topic is in Forensic Entomology: An Introduction By Dorothy Gennard; John Wiley & ...


12

Short answer T. solium infection can be identified in pork meat by visual inspection. Background The stage of the life cycle of the tape worm T. solium in pigs is characterized by cysticerci, which is the larval stage consisting of a protoscolex (head) of the tapeworm. Humans are the definitive host, which means they are the species in which the parasite ...


12

Short answer There is no evidence whatsoever that the parasitic arthropod Cymothoa exigua develops itself into a functional tongue. Instead, it consumes the fish's tongue and occupies the freed buccal space to continue feeding onto the fish's blood or mucus. Background The linked wikipedia page that states that Cymothoa exigua arthropods form fully ...


10

Plasmodium falciparum (the main causative agent of malaria) and other Plasmodium species have a very complex life cycle, with stages in the female host Anopheles mosquito, in the human liver, and in the human circulatory system, where it primarily resides in the erythrocytes (red blood cells, or RBCs): During a blood meal, a malaria-infected mosquito ...


9

The diversity of parasites shows a gradient with increasing diversity from the poles to the equator. Several reasons have been brought forth to explain the latitude-dependency of parasite diversity: An increased diversity overall around the equator; species diversity in general is greater in the rain forests and hence more hosts are available and thus more ...


9

It is Giant Stomach Worm (Hirudinella Ventricosa). It is a platyhelmith parasitic to Wahoo fish, feeding on its blood and found inside the stomach. It makes 98% of Wahoo's parasitic infections. It is a fleshy worm that varies in size and shape; with extended worms the size of a mans finger and contracted ones about the size of a walnut. It requires ...


8

This is a really old thread but just in case someone happens upon it, this isn't a bed bug. I am not an expert but it looks like it's likely a book louse or psocid. See comparison photos of unfed first instar bed bug nymphs vs. psocids/booklice here: http://bedbugger.com/2008/03/04/booklice/ It's all about the shape of the head and body.


8

Yes it is possible to culture plasmodia but they don't grow in a simple constituted medium. Usually RPMI supplemented with serum and erythrocytes is used for growing plasmodia ex-vivo. This article discusses the issues related to plasmodial culture in detail. The authors say that sometimes a certain growth stage (in particular gametocyte) is lost on ...


8

Female mosquitoes need blood for laying their eggs. This actually means that they need a source of rich protein and iron for their kids and hence, prey on us. It is worthwhile for us to pause here and ponder over the difference between clumping and clotting before proceeding to the actual answer. Agglutination tests as you may have come across are ...


6

Is consumption of blood more "dangerous" compared to meat? Actually yes, a simple high dose of blood is enough to kill. The cause is, though it is most important thing to live when flowing the vessel, it's highly toxic when consumed. There are high chances of getting haemochromatosis or Iron overload. Source and More on this: http://www....


6

With humans infected with malaria, the parasite load in the blood can be quite high. It ranges from 10 to 108 Plasmodium falciparum parasites per ml . When a female Anopheles mosquito bites an infected human, they take in infected blood, not just the parasite. They take in a few micro liters of blood, which in usually enough to get themselves infected, and ...


6

There are many examples of parasite manipulation in nature, if you want more examples you can look up the paper of Lefevre and Thomas (2008). I think the key is, in order for a parasite to develop such behaviour, that it should be giving them a fitness advantage. So I don't think it would ever happen for no reason. The paper discusses a few examples where ...


5

A reservoir host most obviously is a long-term carrier organism of a given pathogen that doesn't exhibit the disease caused by the pathogen. A vector is literally any agent that transfers the pathogen to another organism. If you think about it, a reservoir doesn't have to be a vector i.e. there's no route of transmission they participate in, but a vector ...


5

Okay, I found the last part of your question the most interesting and can't give a full answer to that, but I just noticed I can answer the rest so here goes. How it works (the simple version) It works on the principles of buoyancy. The eggs and oocysts are less dense (lighter) than the fecal flotation solution and, consequently, they float on the very ...


5

The De Vlaminck Lab has extensively studied the origins of circulating cell-free DNA (cfDNA) in human plasma and its utility in detecting infections and organ injury.1,2 Concerning your question of parasite DNA detection and parsing signal from noise, I don't think you'll find a better resource than their 2020 publication in Microbiome.3 If the (uncited) ...


5

Hyperparasitism is one possible term. According to the linked article it is commonplace in certain types of insects, but also in fungi. Apparently the cases of at least three levels are known: a fungus on a fungus on a fungus on a tree.


4

If you have or can get access to it, you might try looking in the Incidence and Prevalence database: http://thomsonreuters.com/incidence-and-prevalence-database/ Another possibility is the GIDEON database: http://www.gideononline.com/. It is possible to sign up for a 15-day trial. For Europe, statistics are available from the WHO CISID at http://data.euro....


4

Do not forget domesticated animals that we now keep as pets. It's not unreasonable to argue that the relationship between dogs/cats and humans has a symbiotic character. The pet gets foodand shelter whereas the owner benefits in other ways, e.g. companionship, deterrence of enemies, herding,...


4

Here are some examples: symbiosis between genetic modified yeast cell populations (Shou W et al. 2007) symbiosis between green algae and embryonic chick connective tissue (Buchsbaum R et al. 1934) symbiosis between EcoBot II and microbial fuel cells (Ieropoulos, Ioannis, et al. 2005)


4

All research on saliva tests I've found involve antibody detection which, as you suspected, can produce false negatives depending on the disease process or the presence of immune disfunction (such as due to AIDS). Thus, if you can isolate T. gondii gDNA from the saliva, a genetic assay may be more sensitive. However, Amato Neto et al. report: In 26 ...


4

A very basic model of virus inactivation is exponential decay. You can describe exponential decay with the $N(t) = N_0e^{-\lambda t}$ equation, of if you want to use half-time, then with the $N(t) = N_02^{-t/t_{1/2}}$, where $N$ is the value which reduces by time, $t$ is the time, $\lambda$ is the exponential decay constant and $t_{1/2}$ is the half-life (...


4

It is a well documented observation that Plasmodium (vivax and knowlesi) infection is dependent on the Duffy blood groups [1]. Individuals lacking the Duffy antigens (Fya and Fyb) have lower susceptibility to malaria. Plasmodium expressed Duffy Binding Proteins facilitate in establishing the initial contact between the merozoite and the RBCs. However, ...


4

Just to add to Christiaan's excellent answer: The authors of his cited study state: [the tongues] replacement by a parasite would not appear to be a complex phenomenon. Implying that this is a very basic process, according to what they observed. To answer your question as it was posed: Wikipedia states the tongue becomes fully functional. The authors ...


4

If there are drugs that can cause this kind of disorder you described, then it is possible to engineer a microbe, that can produce these drugs and maintain a chronic infection, which does not necessarily kills the host. Walking dead is not possible, human bodies cannot move with rotting muscles or without muscles, so you won't see real zombies, just insane ...


4

For a mosquito, there is really no benefit to targeting those visible blood vessels. Mosquitoes take only a small amount of blood, and their proboscis is going to be a limiting factor anyways. However, mosquitoes also aren't just blinding sticking their proboscis into the extracellular space. They actually do target individual vessels, and scientists have ...


4

Not much is known about the mechanisms involved, but they do appear to differ significantly from parasite to parasite. I'll discuss a few different examples here, and try to provide as much information as is currently known about how the parasites are doing it. There are likely to be many more different examples and mechanisms than these, and researchers ...


4

Schistosoma recognize human skin by mechanical, thermal and chemical stimuli from host. Attachment of parasite to skin is stimulated by L-arginine. Schistosomes specifically bind to L -argine by chemotaxis. L-arginine guides this parasite towards site of penetration. The lipids on the human skin surface also serve as signal for host invasion. It is also ...


4

Trichenellosis from pork occurs in about about 5 people per year since the 1980's in the US. it has a 0.2% mortality rate there. We can say that 1 American/ 1 European dies from pig meat every 20 years. That's a fair concession. Worldwide the death rate is in the 100ds per year from pork, compared to 3 million who die from the fat in beef and chicken and ...


Only top voted, non community-wiki answers of a minimum length are eligible