#leishmaniasis

[destielmemenews]

"The infection is most common in parts of Africa, Brazil and the eastern Mediterranean region, like Iraq, Somalia, Sudan and Yemen, according to the World Health Organization. "

"All leishmaniasis infections are caused by Leishmania parasites but can have varying clinical presentations. The most common form – called cutaneous leishmaniasis – can cause ulcers and permanent scars. Some more severe variations of the disease can be fatal, according to the CDC."

source

[mindblowingscience]

Back in 2014, dermatologist Bridget McIlwee saw a 3-year-old patient in central Texas with unusual bumps on his ear. "They looked a little bit like almost kind of a benign mole that you would see in a child, except that you wouldn't expect something like that to come up quickly and then multiply," she says. McIlwee sent off a sample for laboratory testing, and the results came back pointing to a surprising culprit: The boy had tested positive for cutaneous leishmaniasis, a neglected tropical disease. The World Health Organization says between 600,000 and 1 million new infections happen worldwide every year, mostly in tropical regions of the Americas, the Mediterranean basin, the Middle East and Central Asia — not in Texas. These illnesses can be disfiguring, even if they are rarely fatal. "I was shocked, because in medical school, we're taught that this is a tropical disease, something that you see in immigrants, military returning from deployment, people who went on vacation to South America or Asia or Africa," McIlwee says.

Continue Reading.

[flyonthewallmedstudent]

Leishmaniasis

Case Reports, like we're on a episode of house

23M in Kenya, presenting with months of LOW, persistent fevers, and abdo fullness, found to have massive splenomegaly.

examination: massive splenomegaly (10 cm below costophrenic margin, and will definitely cross midline) and hepatomegaly

pancytopaenic on bloods, plt's down to 40s

diagnosis confirmed on BMAT (parasite seen)

normal HIV, liver and kidney function

Bodies seen on the BMAT below are part of the lifecycle of the parasite that is intracellular, hence you can see the macrophages/neutrophils loaded with them, even bursting

What is it:

think of it when you get a patient with pancytopaenia and hepatosplenomegaly, who either traveled to or is in/from a tropical/subtropic region (where sand flies are)

cause - protozoa parasite Leishmania, transmitted by infected sandflies

Epidemio (when to consider it)

tropics, subtropics (South America, Asia, AFrica), Southern Europe

Microbiology/Transmission

parasite, replicates intracellularly (Leishmania donovani)

transmitted in sand flies (can be unnoticeable and usually bite in dawn or dusk - evenings or night), can also be transmitted via needles/blood

more common in rural areas

I've simplified this, but is more extensively covered in StatPearls and Wiki (there's different species of Leish and sandflies that transmit it)

once bitten, the protozoa are phagocystosed by skin macrophages, which then becomes full of the "bodies" (part of the lifecycle). Eventually these burst to release more of the bodies that infect more macrophages

they eventually are spread via blood to liver/spleen/BM and LNs

Random history:

ancient, records of disease date back to Egyptian mummies from 3000 BC --> positive DNA amplication for Leishmania and on papyrus from 1500 BC

multiple physicians from different times have described the disease, but it's named for 2 who described the parasite's intracellular ovoid body stage in smears from infected patients in India: Lt General William Boog Leishman and Captain Charles Donovan (Ronald Ross named the bodies after the 2 --> "Leishman Donovan bodies"

significant disease in Allied troops in Sicily in WWII, called "jericho buttons" (image on wiki from a WWI trooper serving in the middle east)

Leishman: Scottish pathologist and British Army medical officer, later it's director general in the 20s, did extensive research into the parasite named for him by Sir Ronald Ross. He mistook the parasite he observed for trypanosomes (cause of Chagas in South America and African sleeping sickness in Africa)

Donovan: Irish parasitologist, medical officer in India, observed an epidemic across India just after the rebellion of 1857, discovered the "bodies" in spleen tissue as the causative agent for what the locals called "kala azar" (severe visceral leishmaniasis - see below)

Donovan also discovered the "bodies" of Klebsiella granulomatis, hence these too are named after him (cause of ulcerative granulomas)

It became scandalous as both wanted credit for the "discovery" of this newly identified organism. So Sir Ronald Ross named it for both of them.

Sir Ron, by the way, won a Nobel in Medicine for discovering that malaria is transmitted via mossies (this was also a source of scandal, he was meant to share it with another physician who he accused of fraud - and they never received the award)

finally, it was actually a Russian physician who identified it first, but well, he published in a little known Russian journal which was promptly forgotten.

Clinical features

cutaneous type vs visceral organ type (spleen, liver, bones)

From wiki

can be asymptomatic

cutnaeous: can be there for years and resemble leprosy, causes an open chronic wound (most common), incubation 2-4 weeks on average (nodules at site of inoculation that eventually form ulcers), can heal spontaneously in 2-5 yrs

in diffuse cutaneous cases, can affect face, ears, extensor surfaces

can be muscosal = eg nasal symptoms/epistaxis, severe: perforated septum, this occurs in 1/3 after resolution of cutaenous symptoms (can be severe/lifte threatning, as it can affect vocal cords and cartilage, but oddly not bone)

visceral (incubation periods of up to years until immuncompromise): fever, weight loss, hepatosplenomegaly (spleen more than liver), pancytoaepnia, high total protein and low albumin with hypergammaglobulinaemia

this has seasonal peaks related to sandfly habits and humidity

interestingly it is an infective cause of massive splenomegaly, such that it crosses the midline

Extreme - but noticeable hepatosplenomgealy/abdo fullness, from medscape

can be atypical in HIV co infected patients, LAD in seom regions like Africa

Kala azar = black fever in some severe cases (fatal due to secondary mycobacterial infection or bleeding), refers to damage fto spleen, liver and anaemia

invstigations:

serology not great (minimal humoral response to the parasite), so often requires histopath (tissue sample) for which BMAT is safest in visceral organ involvement

visualisation of amastigotes (or Leishman-Donovan bodies), as intracellular --> can be seen in macrophages (small round bodies) post Giemsa staining

PCR of DNA also possible (as done in the Egyptian mummies)

Image source:

Treatment

liposomal amphotericin B (holy shit strong stuff) in visceral, PO: miltefosine (caution in pregnancy), all have significant ADRs, or paromycin. however, mortality of 10% if visceral left untreated

mixed results with azoles

in HIV co infection - start the HAARTs! can improve survival, mortality is 30% in HIV patients

cutaneous: stibolgluconate (have never heard of these drugs) and megluaine antimoniate, but limited disease often spotnaeously gets cleared by the innate system

prevention:

use DEET insect repellant at dawn and dusk

loose fitting clothing that covers all skin

no vaccine (were attempts at vaccinating dogs, which decreased rates)

sandflies are smaller than mossies, so requires small netting

Differentials for hepatosplenomegaly

Sources:

WHO guidelines

CDC guidlelines

Wiki - Haven't covered pathophysio, but wiki does extensively

StatPearls

DermNet - great resource for all things derm, that my derm colleagues pointed out to me

[a-dog-like-that]

Xivu has very thin fur in a lot of places, mostly because of the Leishmaniasis (and maybe because of another parasite she got diagnosed with recently (Acanthocheilonema reconditum) but that one is treatable).

She gets cold pretty easily, as in a few weeks ago we had some slightly colder weather (like 20°C during the day and at most 10°C at night) and she was cold enough to need a sweater at night.

I've bought some warm costs for the winter, but I do hope she'll grow some of the fur back.

I'm most worried about her ears, the tips are completely bald and at risk for frostbite once it gets cold.

Her back is basically the only place she has decent fur, everywhere else is super thin.

Could you tell that a spot was shaved 2 weeks ago?

And her belly is still completely bald from getting spayed 6+ months ago

(Bonus her very strangely placed teats)

[onlyhurtforaminute]

LEISHMANIASIS-KILL THE PIG

[starvedmacrophage]

[gmartinezmolina]

#RG @imt_ucv Sección de #Inmunoparasitología del Instituto de Medicina Tropical #leishmaniasis https://www.instagram.com/p/CpS8dKJuKYz/?igshid=NGJjMDIxMWI=

[cheriemariii]

ʕ•ᴥ•ʔ

[travellingwiththedead]

Leishmaniasis of the skin

[jyunism]

ml is so

cringe

[a-dog-like-that]

Introducing Xivu!

She's a Malinois, about 3.5 years old and was originally found roaming the streets in southern Spain.

She's been in a foster home in Germany since February and with us since yesterday.

She does unfortunately have leishmaniasis, but has been responding really well to medication, but for now it's left her with very sparse fur in some places.

Character wise, she's just a really lovely dog. Settles down easily, very cuddly, friendly with almost all humans (some tall men still scare her a bit) and dogs, likes to work and is easily motivated by food (and toys, but I need to improve my skills with those first).

She's watchful without being overly bark-y or being bothered by the construction noises currently happening in our house.

She settled in extremely fast, slept though the first night and for the most part has just been chilling and napping while I do online school.

She did however pee on my bed yesterday xD

[noticlick]

Villa Montes inicia campaña de prevención de Leishmaniasis Visceral.

Luego que se declarara a Villa Montes municipio endémico, las autoridades de salud de la región chaqueña comenzaron con una campaña de prevención y control de Leishmaniasis Visceral desde el 13 hasta el 25 de noviembre. El plan de acción contará con la participación de 70 miembros entre la universidad, el servicio departamental de salud, Red de Salud, Gobierno Regional de Villa Montes, UAJMS, y…

[nuadox]

Test detects co-infection by novel species of parasite in severe cases of visceral leishmaniasis

- By Julia Moióli , Agência FAPESP -

In recent years, physicians and scientists in parts of Brazil where visceral leishmaniasis (VL) is endemic have seen rising numbers of cases of co-infection by Leishmania infantum and Crithidia, also a protozoan but hitherto believed to be a mosquito parasite that cannot infect humans or other mammals.

Accurate diagnosis is hindered by a lack of simple specific tests (more at: https://agencia.fapesp.br/42072 and https://agencia.fapesp.br/31581). 

To accelerate and facilitate detection of the pathogens involved, supporting appropriate decisions regarding treatment, researchers at the Federal University of São Carlos (UFSCar) have developed a PCR test which analyzes the genetic material in the sample and produces a result in less than two hours. An article on the study was published in the journal Tropical Medicine and Infectious Disease.

Leishmaniasis is a neglected disease and is considered a global public health problem. Brazil reports more than 3,500 cases per year, according to the Health Ministry, or 93% of all cases in Latin America. The disease caused 165 deaths in Brazil in 2020.

VL is the most severe form of the disease, affecting the spleen, liver, bone marrow and lymph nodes, and can be lethal if it is not correctly treated or is misdiagnosed. The main agent of VL is L. infantum. 

The study was funded by FAPESP via nine projects (16/18527-3, 16/20258-0, 17/16328-6, 18/26799-9, 19/19789-0, 20/14011-8, 20/15771-6, 21/10358-6 and 21/12464-8).

The novel method is an advance on the usual diagnostic technique. In the study, it was highly accurate in identifying and quantifying L. infantum and Crithidia in samples obtained in vitro or collected from human hosts as well as dogs, cats and insects by means of skin biopsies or bone marrow aspiration.

“Although there are other molecular methods for identifying species, they require DNA sequencing of the sample, which is laborious, slow and expensive. Our test analyzes the parasite’s genetic material directly from vectors and human or animal tissue,” said Sandra Regina Costa Maruyama, last author of the article and a professor of evolutionary genetics and molecular biology at UFSCar. 

Unlike the quick tests used by health clinics and pharmacies, which do not detect pathogens directly but identify the relevant antibodies, the researchers designed their dye-based quantitative PCR assay on the basis of targeted sequences from L. infantum and Crithidia in experimental and clinical samples. A test had to be performed first to detect the former parasite, followed by another to identify the latter.

“The targets resulted from our analysis of the two species’ genomes. Our most recent study showed specificity in different sample types. The test can now be optimized to show in a single reaction whether the infection was caused by L. infantum, Crithidia or both,” Maruyama said.

The test can be performed by any diagnostic laboratory capable of performing qPCR tests (now more widespread following the COVID-19 pandemic). It can also be used in epidemiological research, parasite load monitoring, and treatment follow-up.

Co-infection cases

The study involved analysis of 62 parasites isolated from VL patients’ tissues, with 51 testing positive for Crithidia. In addition, bone marrow co-infection by Crithidia and L. infantum was identified in two new cases of VL in Brazil. In May the group published an article on a case of severe VL in which both species were detected.

According to Maruyama, beyond the efficacy of the test, the results show that infection by Crithidia is more frequent than has hitherto been supposed, and that co-infection by both protozoans appears to occur above all in the most severe cases.

“We don’t yet understand the clinical implications of the presence of Crithidia in cases of VL, but we suspect that co-infection exacerbates the disease or prevents patients from responding to the recommended treatment for L. infantum,” she said. “Identifying the species of parasite correctly ensures that appropriate measures can be taken quickly to prevent progression of the patient’s clinical condition, potentially reducing mortality. It also points to the possible development of more specific drugs and treatments in future.”

The article “Parasite detection in visceral leishmaniasis samples by dye-based qPCR using new gene targets of Leishmania infantum and Crithidia” is at: https://www.mdpi.com/2414-6366/8/8/405.

This text was originally published by FAPESP Agency according to Creative Commons license CC-BY-NC-ND. Read the original here.

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Header image: The protozoan Leishmania infantum, which causes visceral leishmaniasis, can affect the spleen, liver, lymph nodes and bone marrow. Credit: Francis W. Chandler/CDC/Wikimedia Commons.

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[gmartinezmolina]

#RG @imt_ucv Sección de #Inmunoparasitología del Instituto de Medicina Tropical #leishmaniasis https://www.instagram.com/p/Cou8fMtOX4F/?igshid=NGJjMDIxMWI=

[bogotter]

shirt that says IDIOPATHIC JUVENILE ARTHRITIS

honestly i need a tshirt that just says "BOTULISM" on it. there's no bit no inside joke that's it.

[qyresearchmedica]

The Leishmaniasis Treatment market is projected to grow at a rate of 8.40% in terms of value, from USD 124.4 Million in 2020 to reach USD 237.7 Million by 2030.