Tag: #mosquitoes

KALA AZAR (visceral leishmaniasis)

BY DAKSHITA NAITHANI

INTRODUCTION

After moving to internal organs such as the liver, spleen, and bone marrow, a parasite causes illness. If not treated, it nearly invariably leads to death.

People get this condition by sandfly bites, which contracted the parasite after consuming the blood of a parasite-infected person. There are more than 20 distinct Leishmania parasites that cause the illness around the globe, and 90 different sandfly species that carry the infection.

However, in India, there is just one parasitic species, Leishmania donovani, and only one sandfly species, Phlebotomus argentipes, that spreads the illness.

Visceral leishmaniasis, commonly known as kala-azar, is marked by recurrent bouts of fever, significant weight loss, spleen and liver enlargement, and anaemia (which may be serious).

In underdeveloped nations, if the illness is not treated, the mortality rate can reach 100% in as little as two years.

SYMPTOMS

When people develop visceral leishmaniasis, the most typical symptoms are

 FEVER

 ENLARGEMENT OF SPLEEN AND LIVER

Misdiagnosis is critical, because kala-azar has a near-100 percent death rate if not treated properly. It does not always leave its hosts unmarked, even after restoration. A secondary form of the illness called post kala-azar dermal leishmaniasis, or PKDL, may develop after effective treatment—usually a few months after kala-azar, but as long as many years with the Indian strain. This illness begins with tiny, measles-like skin lesions on the face that grow in size and spread throughout the body.

In individuals who have recovered from the illness , it is characterised by a hypopigmented macular, maculopapular, and nodular rash and  generally emerges 6 months to a year or more after the disease appears to be cured, although it can happen sooner or even simultaneously.

It is thought to have a crucial role in the disease’s maintenance and transmission, notably by functioning as a parasite reservoir. The lesions may eventually consolidate into disfiguring, bloated formations that resemble leprosy, causing blindness in certain cases if they extend to the eyes.

The visceral type of Leishmania is caused by two different species of Leishmania. L. donovani is the species found in East Africa and the Indian subcontinent, whereas L. infantum, also known as L. chagasi, is found in Europe, North Africa, and Latin America.

LIFE CYCLE

 Life cycle is completed in two hosts: humans and sandflies. The adult female sandfly feeds at night and is a bloodsucker. When a Leishmania-infected person is bitten by a fly, the parasite is consumed along with the blood.

The protozoan is an amastigote, which is spherical, non-motile, and just 3–7 micrometres in diameter. The amastigotes inside the sandfly’s stomach soon change into the promastigotes, which are elongated and motile forms. It is spindle-shaped and thrice the size of the amastigote, and has a single flagellum that allows it to move. They live extra cellularly in the alimentary canal reproducing asexually and migrating to the proximal end of the gut where they become ready for a transmission.

The promastigotes are introduced after being released locally at the biting site as the fly bites. Promastigotes infect macrophages once inside the human host. They revert to their tiny amastigote form inside the cells.

In macrophage cells, amastigotes reproduce. They tear down their host cell by sheer mass pressure after repeated replication, although there is also new hypothesis that they are able to exit the cell via activating the macrophage’s exocytosis response.

The protozoans in the daughter cells then move to new hosts in fresh cells or through the circulation. The infection progresses and affects the spleen and liver in particular. Sandflies eat the liberated amastigotes in peripheral tissues, which starts a new phase.

TREATMENT

The traditional treatment is with

  • Sodium stibogluconate 
  • Meglumine antimoniate

Resilience is increasingly prevalent in India, with resistance rates as high as 60% in some regions of Bihar. Amphotericin B in its many liposomal formulations is now the treatment of choice for visceral leishmaniasis acquired in India. The first oral therapy for this illness was miltefosine. Miltefosine had a cure rate of 95% in Phase III clinical studies.

The medicine is typically well tolerated compared to other medications. Gastrointestinal disruption on the first or second day of therapy (a 28-day course of treatment) is the most common adverse effect, but it has no influence on effectiveness. Miltefosine is a medication of choice since it is accessible as an oral formulation, which eliminates the cost and inconvenience of hospitalisation and allows for outpatient delivery of the drug.

The drawbacks include that after a decade of usage, there is evidence of decreased effectiveness. It is teratogenic and should not be used by women who are planning to have children. Sodium stibogluconate (Pentostam) and meglumine antimoniate have been used to treat kala-azar (Glucantime). Only injections can be used to deliver these medications. They are poisonous, have several adverse effects, and are administered over a 30-day period.

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“What is the difference between Blogging and Journalism?”

Before we continue we must first of all find out what the two really are and then we will be able to identify the difference between them.

So then, what is blogging?  Blogging was actually created by Justin Hall. It all started in 1994 when many witness the   birth of the first blog. According to creative blog,  It was  called  Links.net  – a place where  creator  Justin Hall could share his musings and  his favorite  links  with the world .  It was a page where he could express himself, share his ideas and content on the web (Creative blog).

As years went by and technology progressed   in 1997 ,  many people started using their own personal websites as a place  to spotlight their ideas, the term “ weblog” was coined and  shortened to “ blog”   in 1999( Creative blog) .

People needed a place to share ideas, thoughts, express their feelings, and experiences. They found that having a place where you could share ideas and express yourself was an ideal way to share intimate information with people who are very close to you, friends and family.

According to creative blog,   when people first started blogging   they did not have to share it on Facebook or join a content network   or outwardly promote it. It was actually private   and people shared it with people they knew and they knew where to find them.

Before, blogging grew to what we know it today,   early blogger’s hosted contents on sites like Xanga. It was founded in 1998, and live journal in 1999.  Both were simple to use,  but  were  mostly  only able  to swap  out colors schemes  and minor  layout pieces, but very  effective  at allowing users to publish  quickly  and easily( Creative blog).

Many people became very interested in this new thing that they started looking beyond their intimate circle for more information to read. They started exploring, looking for the best blog and content on the web.    Blogging actually gained it roots when Charlotte Observer set up its blog and used it to share information in mainstream news something that had not been done before.  They used it and kept people informed. The Bonnie Blog set   records for page views on the observer’s site. They also set the stage along with Drudge reports breaking of the Clinton –Lewinsky scandal, for a major shift in the way blogging platform were used (Creative Blog).

Soon people started showing interest in blogging and online news.  They needed to find new ways on how to manage the content and share these ideas with the public.  According to creative blog, I n 2003 Google launch AdSense, this allowed bloggers to earn income for their work.  Soon many people were blogging. This gave them the opportunity to earn an income for the work that they do. Now it has become a profession for some people whereby they learn how to blog and make money. As we have seen what was once consider to be expression of people’s feelings , passion, ideas , thoughts and what was  going on around the world, like current events has evolve to a whole new phenomenon. Blog is abbreviated of “Weblog,”   it is used to describe websites that maintain an ongoing chronicle of information.  A blog is like a personal diary type commentary and links to articles on other websites.   It ranges from personal to political and can focus on concerns of the people. It is a place where most people feel very free to write and share their concerns.

Add context to a story by linking and commenting on other material found online.  Basically  when journalist blogs , they express their view about the issues surrounding whatever they are reporting on and even does it better because there are no restrictions  like when they are actually doing journalistic work.  To be a journalist one needs an academic training or formal training from a reputable school of journalism.  To be a blogger one needs a website and need to know how to express him or herself by writing.

Simply, blogging is viewed by many as unreliable because it’s someone’s opinion and the other one is viewed as reliable because one has to verify the source of the information before it can be broadcast the world. However, I think it is a perception issue of what the public view as reliable or unreliable and I say this because when we look at the evolvement of blogging over the years we can infer that blogging has become a huge deal that even major companies are using blogs to promote their businesses on their websites  and different forums. It has become one of the reliable sources that most people rely on to read and make decisions about whether they want to do business with the firm, purchase from them or inquire about what they do and what it entails.  As mentioned before, even journalist  and others have taken to blogs in order  to share information with others.

Why Do Mosquitoes Buzz?

They’re actually singing mating songs for each other.

mosquito buzz

The drawing to the right showing part of the mosquito’s wing is what makes the buzzing or whining sound. The comb-like half, shown in blue, scrapes against the part shown in yellow, whenever the mosquito flaps its wings. (Source: “On a Possible Stridulating Organ in the Mosquito”)

Why do mosquitoes buzz in your ears? The short answer: They can’t help it. Mosquitoes’ wings make that annoying buzz or whining sound whenever they fly. When they circle your head, looking for a place to land and bite, their buzz sounds louder whenever they’re close to your ear.

Both male and female mosquitoes buzz, since they both have wings, but you probably won’t notice the whine of the males, because they don’t want to drink your blood. So they stay away from your ears, eating nectar, while the females come near to annoy you.

Scientists have discovered that the buzz of mosquitoes is more than just a way to annoy you. It’s actually important to help them find suitable mates.

Since female mosquitoes are larger, they flap their wings slower, and males know it. They use the distinctive pitch of the females’ buzz to recognize them. Louis M. Roth, who studied yellow fever mosquitoes for the U.S. Army during World War II, noticed that males ignored females whenever the females were quietly resting, but whenever the females were flying, and therefore buzzing, the males wanted to mate with them. The males even wanted to mate with recordings of female mosquitoes or tuning forks that vibrated at the same pitch.

“A delightful African folk tale for anyone who hates the sound of mosquitoes buzzing in their ears. Kids will learn the lesson not to gossip, and they’ll enjoy looking for the little pink bird in the colorful pictures too.”

Dr. Christopher Johnston of Baltimore, Maryland had already discovered how mosquitoes can hear, almost a hundred years before. He found that they have an organ in their antenna, which was named the Johnston organ after him. It allows them to recognize the buzz of other mosquitoes.

It took other scientists to discover exactly what made the sound. Though you hear the buzz whenever mosquitoes fly, it’s not actually caused by the wings beating against the air. There’s an organ at the base of the wings which scrapes and makes the sound when the wings move. British entomologists A. E. Shipley and Edwin Wilson published a paper describing it in 1902, which they called “On a Possible Stridulating Organ in the Mosquito.” Stridulating means to make noise, and the toothed organ they found made noise as it rubbed against itself, while the wings moved.

By the middle of the 20th Century, scientists had figured out that mosquitoes have special organs to whine or buzz as they fly, that other mosquitoes can hear the noise, and that the buzz of female mosquitoes makes males want to mate with them.

It wasn’t until more recently that researchers Gabriella Gibson and Ian Russell discovered that mosquitoes actually change their buzz to “sing” to each other before they mate. They discovered that when males and females flew nearby, they altered the pitch of their buzz to match each other, and if they matched well enough, they mated. Cornell researchers tried the same experiment with mosquitoes which carry the dangerous disease dengue, and found the same thing.https://www.youtube.com/embed/F9uVyCInhhI?rel=0

As scientists learn more about why mosquitoes buzz, they may be able to use that knowledge to help keep them from mating. Fewer mosquitoes mean fewer mosquito bites, and fewer diseases being spread. For example, in this article, researcher Lauren Cator suggests that if scientists can make sterile male mosquitoes who “sing” to females just as well as fertile males, the females will choose the sterile males, and won’t produce fertile eggs.

There are a few myths about the mosquitoes you hear buzzing near your ears. Some people say that mosquitoes which buzz, don’t bite. Well, that’s true. As long as they’re buzzing, they’re flying, so they won’t bite you. But as soon as they land, look out!

Does anybody actually enjoy the sound of mosquitoes buzzing? Apparently, teenagers do! With what scientists are learning about mosquitoes, I suppose it’s fitting that teenagers are using an electronic sound called a mosquito buzz as their mating “call.”

Cornell researchers have found out that mosquitoes not only buzz in your ears, they buzz in each others’ “ears” too.

The commitment a mother bears her children, biological imperative though it may be, can produce some astounding behavior. Fathers, take note. Not one of the 3,000 known species of mosquitoes features a male willing to dine on blood for his kids.

In most species the female requires a meal of blood to aid in egg production, in addition to her usual diet of nectar.

To find victims, the mother-to-be follows cues like our body heat, moisture and carbon dioxide emissions. In particular, the carbon dioxide we exhale attracts the insect to our heads, where they fly around looking for a tasty spot.

I would write a brilliant blog tonight, but I am tired. Not because of bad dreams or pressure at work. No, I am sleepy because of a small winged, creature who snuck into my room and proceeded to offer a high pitched tone directly into my ear. When I turned on the lights to find it, it was not there. When I gave up and attempted sleep, buzzzz… or maybe zzzzinnng? I would find the perfect word, but as mentioned, I am too tired.

Dang mosquito.

Mosquitoes are actually the most dangerous animals in the world, killing more than two million people per year. In the United States alone, there are 150 different species, each carrying a different type of disease. The most common species found in the U.S. include the Aedes albopictus, Culex pipiens and Anopheles quadrimaculatus, but what I am interested in tonight is, why do they buzz? Why right in my ear? Why?

According to the West African tale, it happened this way: a mosquito said something foolish to the iguana who put sticks in his ears to hear no more of such foolishness. This frightened the next animal and thus created a chain of panic until a monkey killed an owlet which caused the mother owl to mourn and neglect her duties of waking the sun. The animals were furious with the mosquito. So, mosquitoes buzz in people’s ears cause they are asking if everyone is still angry with them. I’m not buying it.

A ranger at a local park told me that since mosquitoes are attracted by the smell of carbon dioxide, given off by us when we exhale, perhaps the mosquitoes benefit from our jumping about when they try to buzz us, causing more breathing and more carbon goodness. Another expert said it was a little warning sign, a gift from nature, like a snake’s rattle. Another said the tone attracts the male. Then why in MY ear? Does anybody really know?

Here’s a few things I do know:

  • Mosquitoes are crepuscular, most active at dawn and dusk.
  • Only female mosquitoes suck blood so that their eggs can mature prior to laying. The blood serves no nourishment. Both males and females feed on nectar.
  • She will often drink more than her weight in blood in one “sitting.”
  • A mosquito does not “bite”, but siphon the blood out by a tube.
  • The only place mosquitoes do not live is Antarctica.
  • You can scare off mosquitoes by eating garlic! For more tips on keeping them away, check out: http://www.doityourself.com/stry/mosquitopesticides
  • You can get a mosquito buzz ringtone on your mobile phone that is rumored to be at a frequency too high for those over 40 to hear. (17KHz Mosquito .wav). I could hear it fine, by the way, but why would anyone want to?

I am now off to sleep with no answers, fearing another night of mystery buzz tones. If anyone can tell my why mosquitoes buzz in our ears, please do. With sleep and knowledge, I promise my next blog will be brilliant.