Cross-species pathogen transmission and disease emergence in primates

Amy B Pedersen 1 , T Jonathan Davies

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PMID: 20232229 PMCID: PMC7087625 DOI: 10.1007/s10393-010-0284-3

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Abstract

Many of the most virulent emerging infectious diseases in humans, e.g., AIDS and Ebola, are zoonotic, having shifted from wildlife populations. Critical questions for predicting disease emergence are: (1) what determines when and where a disease will first cross from one species to another, and (2) which factors facilitate emergence after a successful host shift. In wild primates, infectious diseases most often are shared between species that are closely related and inhabit the same geographic region. Therefore, humans may be most vulnerable to diseases from the great apes, which include chimpanzees and gorillas, because these species represent our closest relatives. Geographic overlap may provide the opportunity for cross-species transmission, but successful infection and establishment will be determined by the biology of both the host and pathogen. We extrapolate the evolutionary relationship between pathogen sharing and divergence time between primate species to generate "hotspot" maps, highlighting regions where the risk of disease transfer between wild primates and from wild primates to humans is greatest. We find that central Africa and Amazonia are hotspots for cross-species transmission events between wild primates, due to a high diversity of closely related primate species. Hotspots of host shifts to humans will be most likely in the forests of central and west Africa, where humans come into frequent contact with their wild primate relatives. These areas also are likely to sustain a novel epidemic due to their rapidly growing human populations, close proximity to apes, and population centers with high density and contact rates among individuals.

"Missing link" is a non-scientific term for a transitional fossil. It is often used in popular science and in the media for any new transitional form. The term originated to describe the hypothetical intermediate form in the evolutionary series of anthropoid ancestors to anatomically modern humans (hominization). The term was influenced by the pre-Darwinian evolutionary theory of the Great Chain of Being and the now-outdated notion (orthogenesis) that simple organisms are more primitive than complex organisms.

A symbolic portrayal of human evolution, wrongly implying that evolution is linear and progressive.

Phylogenetic tree of hominid evolution

The term "missing link" has fallen out of favor with biologists because it implies the evolutionary process is a linear phenomenon and that forms originate consecutively in a chain. Instead, last common ancestor is preferred since this does not have the connotation of linear evolution, as evolution is a branching process.

In addition to implying a linear evolution, the term also implies that a particular fossil has not yet been found. Many of the famous discoveries in human evolution are often termed "missing links". For example, there were the Peking Man and the Java Man, despite the fact that these fossils are missing. Transitional forms that have not been discovered are also termed missing links; however, there is no singular missing link. The scarcity of transitional fossils can be attributed to the incompleteness of the fossil record.

Evidence of zoonotic leprosy in Pará, Brazilian Amazon, and risks associated with human contact or consumption of armadillos

Moises B. da Silva , Juliana M. Portela ,Wei Li, Mary Jackson, Mercedes Gonzalez-Juarrero, Andrea Sánchez Hidalgo, John T. Belisle, Raquel C. Bouth, Angélica R. Gobbo, Josafá G. Barreto, Antonio H. H. Minervino, Stewart T. Cole, Charlotte Avanzi, [ … ], John S. Spencer [ view all ]

Published: June 28, 2018

https://doi.org/10.1371/journal.pntd.0006532

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Abstract

Mycobacterium leprae (M. leprae) is a human pathogen and the causative agent for leprosy, a chronic disease characterized by lesions of the skin and peripheral nerve damage. Zoonotic transmission of M. leprae to humans by nine-banded armadillos (Dasypus novemcinctus) has been shown to occur in the southern United States, mainly in Texas, Louisiana, and Florida. Nine-banded armadillos are also common in South America, and residents living in some areas in Brazil hunt and kill armadillos as a dietary source of protein. This study examines the extent of M. leprae infection in wild armadillos and whether these New World mammals may be a natural reservoir for leprosy transmission in Brazil, similar to the situation in the southern states of the U.S. The presence of the M. leprae-specific repetitive sequence RLEP was detected by PCR amplification in purified DNA extracted from armadillo spleen and liver tissue samples. A positive RLEP signal was confirmed in 62% of the armadillos (10/16), indicating high rates of infection with M. leprae. Immunohistochemistry of sections of infected armadillo spleens revealed mycobacterial DNA and cell wall constituents in situ detected by SYBR Gold and auramine/rhodamine staining techniques, respectively. The M. leprae-specific antigen, phenolic glycolipid I (PGL-I) was detected in spleen sections using a rabbit polyclonal antibody specific for PGL-I. Anti-PGL-I titers were assessed by ELISA in sera from 146 inhabitants of Belterra, a hyperendemic city located in western Pará state in Brazil. A positive anti-PGL-I titer is a known biomarker for M. leprae infection in both humans and armadillos. Individuals who consumed armadillo meat most frequently (more than once per month) showed a significantly higher anti-PGL-I titer than those who did not eat or ate less frequently than once per month. Armadillos infected with M. leprae represent a potential environmental reservoir. Consequently, people who hunt, kill, or process or eat armadillo meat are at a higher risk for infection with M. leprae from these animals.

Author summary

Armadillos have been shown to be a natural reservoir of Mycobacterium leprae infection in the southern states of the U.S. and have been implicated in the zoonotic transmission of leprosy to humans. To investigate this in Brazil, we conducted surveys of armadillos in western Pará state in the Brazilian Amazon region where leprosy is hyperendemic in humans. Individuals living in the small town of Belterra were surveyed for the extent and frequency of interaction with armadillos (hunting, preparing the meat for cooking, or eating the meat for food). We also took samples of liver and spleen from armadillos to look for M. leprae infection in the tissues. We found that a majority of residents had some contact with armadillos (~65%) and that infection by M. leprae in armadillos in this area was also very high (62%). Those individuals who ate armadillo meat more than once a month had a significantly higher antibody titer to the M. leprae-specific antigen, PGL-I. Understanding the dynamics of leprosy transmission in different geographic regions and knowing the behavioral risks of humans interacting with potentially infected animals will help clarify the relative risk of zoonotic transmission of leprosy in this region.

Probable Zoonotic Leprosy in the Southern United States

List of authors.

Richard W. Truman, Ph.D., Pushpendra Singh, Ph.D., Rahul Sharma, Ph.D., Philippe Busso, Jacques Rougemont, Ph.D., Alberto Paniz-Mondolfi, M.D., Adamandia Kapopoulou, M.S., Sylvain Brisse, Ph.D., David M. Scollard, M.D., Ph.D., Thomas P. Gillis, Ph.D., and Stewart T. Cole, Ph.D.

April 28, 2011

N Engl J Med 2011; 364:1626-1633

DOI: 10.1056/NEJMoa1010536

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BACKGROUND

In the southern region of the United States, such as in Louisiana and Texas, there are autochthonous cases of leprosy among native-born Americans with no history of foreign exposure. In the same region, as well as in Mexico, wild armadillos are infected with Mycobacterium leprae.

METHODS

Whole-genome resequencing of M. leprae from one wild armadillo and three U.S. patients with leprosy revealed that the infective strains were essentially identical. Comparative genomic analysis of these strains and M. leprae strains from Asia and Brazil identified 51 single-nucleotide polymorphisms and an 11-bp insertion–deletion. We genotyped these polymorphic sites, in combination with 10 variable-number tandem repeats, in M. leprae strains obtained from 33 wild armadillos from five southern states, 50 U.S. outpatients seen at a clinic in Louisiana, and 64 Venezuelan patients, as well as in four foreign reference strains.

RESULTS

The M. leprae genotype of patients with foreign exposure generally reflected their country of origin or travel history. However, a unique M. leprae genotype (3I-2-v1) was found in 28 of the 33 wild armadillos and 25 of the 39 U.S. patients who resided in areas where exposure to armadillo-borne M. leprae was possible. This genotype has not been reported elsewhere in the world.

CONCLUSIONS

Wild armadillos and many patients with leprosy in the southern United States are infected with the same strain of M. leprae. Armadillos are a large natural reservoir for M. leprae, and leprosy may be a zoonosis in the region. (Funded by the National Institute of Allergy and Infectious Diseases and others.)

Leprosy in the Bible☆

Author links open overlay panelAndrzejGrzybowskiMD, PhDabMałgorzataNitaMD, PhDc

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https://doi.org/10.1016/j.clindermatol.2015.10.003Get rights and content

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Andrzej Grzybowski, Małgorzata Nita

Erratum to “Leprosy in the bible” [Clin Dermatol 2016:34 3–7]

Clinics in Dermatology, Volume 34, Issue 3, May–June 2016, Pages 429

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Abstract

For many years, the biblical term tzaraat has referred to leprosy. In fact, the disease or diseases described under this name have no relationship to leprosy, as it was known in the Middle Ages or today; moreover, the term referred not only to skin disease, but also to the state of the ritual impurity and punishment for the sins.

Although the real nature of tzaraat remains unknown, the differential diagnosis might include the following: Psoriasis, seborrheic dermatitis, favus, dermatophyte infections, nummular dermatitis, atopic dermatitis, pityriasis rosea, crusted scabies, syphilis, impetigo, sycosis barbae, alopecia areata, furuncles, scabies, neurodermatitis, scarlet fever, lupus erythematosus, lichen sclerosus et atrophicus, folliculitis decalvans, morphea, sarcoidosis, and lichen planopilaris.

Leprosy became interchangeable with the biblical leprosy due to two inaccurate translations: The Hebrew tzaraat was first translated into Greek as leprosy in the sixth century, and later, the word leprosy was translated into Arabic as lepra in the ninth century.

Social Distancing: Not Just for Humans – How Diseases Spread in Mountain Gorillas

TOPICS:ConservationGorillasInfectious DiseasesPopular

By DIAN FOSSEY GORILLA FUND OCTOBER 7, 2021

https://scitechdaily.com/social-distancing-not-just-for-humans-how-diseases-spread-in-mountain-gorillas/

The leper apes: Leprosy is discovered in wild CHIMPANZEES for the first time with tell-tale lumps on their faces

Chimp populations in two West African sites confirmed to suffer from leprosy

The chronic disease can cause skin lesions and loss of body parts

Researchers say giving antibiotics to wild chimpanzees would be a challenge

By JONATHAN CHADWICK and RYAN MORRISON FOR MAILONLINE

PUBLISHED: 11:00 EDT, 13 October 2021 | UPDATED: 09:34 EDT, 21 October 2021

https://www.dailymail.co.uk/sciencetech/article-10088389/Leprosy-discovered-wild-CHIMPANZEES-time.html

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>>14845595

I put a hit on a dog.

>>14845676

Oh no, this dog is supposed to die. Nothing can stop it from happening!

>>14845760

Soon there won’t be anymore moms!