Ehrlichiosis

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Ehrlichiosis
Amblyomma americanum tick.jpg
The lone star tick, which is one of three ticks that can spread Ehrlichiosis. It is characterized by the white dot on its back. [1]
Specialty Infectious diseases   OOjs UI icon edit-ltr-progressive.svg
Symptoms Fever, chills, severe headaches, muscle aches, nausea, vomiting, diarrhea, loss of appetite, confusion, and splotchy or pinpoint rash. More severe symptoms include brain or nervous system damage, respiratory failure, uncontrollable bleeding, organ failure, and death. [2]
CausesBite from an infected tick
Risk factors Age, being immunocompromised, having received an organ transplant, and certain medications

Ehrlichiosis is a tick-borne [3] bacterial infection, [4] caused by bacteria of the family Anaplasmataceae, genera Ehrlichia and Anaplasma . These obligate intracellular bacteria infect and kill white blood cells.

Contents

The average reported annual incidence is on the order of 2.3 cases per million people. [5]

Types

Six (see note below) species have been shown to cause human infection: [6]

Ixodes scapularis is another type of tick that can spread Ehrlichiosis muris eauclairensis. Ixodes scapularis.jpg
Ixodes scapularis is another type of tick that can spread Ehrlichiosis muris eauclairensis.

The latter three infections are not well studied. Ehrlichia muris eauclairensis was recently discovered and has low reporting numbers due to the fact that it is relatively new and because its symptoms are very similar to the symptoms caused by other Ehrlichia bacteria.

In 2008, human infection by a Panola Mountain (in Georgia, USA) Ehrlichia species was reported. [9] On August 3, 2011, infection by a yet-unnamed bacterium in the genus Ehrlichia was reported, carried by deer ticks and causing flu-like symptoms in at least 25 people in Minnesota and Wisconsin. Until then, human ehrlichiosis was thought to be very rare or absent in both states. [10] The new species, which is genetically very similar to an Ehrlichia species found in Eastern Europe and Japan called E. muris, was identified at a Mayo Clinic Health System hospital in Eau Claire. [10]

Ehrlichia species are transported between cells through the host-cell filopodia during the initial stages of infection; whereas, in the final stages of infection, the pathogen ruptures the host cell membrane. [11]

Signs and symptoms in humans

Specific symptoms include fever, chills, severe headaches, muscle aches, nausea, vomiting, diarrhea, loss of appetite, confusion, and a splotchy or pinpoint rash. [12] More severe symptoms include brain or nervous system damage, respiratory failure, uncontrollable bleeding, organ failure, and death. Ehrlichiosis can also blunt the immune system by suppressing production of TNF-alpha, which may lead to opportunistic infections such as candidiasis.[ citation needed ]

Most of the signs and symptoms of ehrlichiosis can likely be ascribed to the immune dysregulation that it causes.[ citation needed ] A "toxic shock-like" syndrome is seen in some severe cases of ehrlichiosis. Some cases can present with purpura and in one such case, the organisms were present in such overwhelming numbers that in 1991, Dr. Aileen Marty of the AFIP was able to demonstrate the bacteria in human tissues using standard stains, and later proved that the organisms were indeed Ehrlichia using immunoperoxidase stains. [13]

Experiments in mouse models further support this hypothesis, as mice lacking TNF-alpha I/II receptors are resistant to liver injury caused by Ehrlichia infection. [14]

About 3% of human monocytic ehrlichiosis cases result in death; however, these deaths occur "most commonly in immunosuppressed individuals who develop respiratory distress syndrome, hepatitis, or opportunistic nosocomial infections." [15]

Signs and symptoms in dogs

Ehrlichiosis in dogs will show obvious symptoms on the later part of infection. This is why some symptoms are already severe when diagnosed. There are three stages of ehrlichia infection - the acute (or the early stage), sub-clinical (symptoms are not yet evident), and clinical or chronic (symptoms are obvious and long-standing). [16]

Dogs infected with Ehrlichia often show lameness, lethargy, enlarged lymph nodes, and loss of appetite during the acute phase, which is one to three weeks after infection. Other symptoms include cough, diarrhea, vomiting, abnormal bruising and/or bleeding, fever, and loss of balance. [17]

Dogs with this disease can develop anemia which will show low platelet count which can eventually result to bleeding or blindness. Some doctors also check for arthritis-like symptoms, where the dogs cannot stand on one feet or more because of sore joints. Urinalysis may also be done to the dog to check if the kidneys were infected by the disease. [18]

Prevention

No human vaccine is available for ehrlichiosis. Tick control is the main preventive measure against the disease. However, in late 2012, a breakthrough in the prevention of canine monocytic ehrlichiosis was announced when a vaccine was accidentally discovered by Prof. Shimon Harrus, Dean of the Hebrew University of Jerusalem's Koret School of Veterinary Medicine. [19]

Measures of tick bite prevention include staying out of tall grassy areas that ticks tend to live in, treating clothes and gear that a tick could jump on, using EPA approved bug repellent, tick checks for all humans, animals, and gear that potentially came into contact with a tick, and showering soon after being in an area that ticks might also be in. [20]

Since prevention is the most advanced way of fighting the disease, the veterinarians advise dog owners to get rid of ticks and fleas by using products like Advantix®, Frontline Plus®, Vectra 3D® or Bravecto®. Oral chewable options include Nexgard®, Simparica®, Credelio®, or Bravecto®. [21]

Treatment

Doxycycline and minocycline are the medications of choice. For people allergic to antibiotics of the tetracycline class, rifampin is an alternative. [5] Early clinical experience suggested that chloramphenicol may also be effective, but in vitro susceptibility testing revealed resistance.[ citation needed ]

Since decline in platelets may also be evident in dogs with this disease, Eupherbia Hirta (Tawa-tawa in Philippines) can also be a supplemental treatment. This plant (or medicines which has this ingredient) helps with the increase of platelets. [22]

Epidemiology

Ehrlichiosis is a nationally notifiable disease in the United States. Cases have been reported in every month of the year, but most cases are reported during April–September. [23] [24] [25] These months are also the peak months for tick activity in the United States. [7] The majority of cases of Ehrlichiosis tend to be in the United States. The states affected most include "the southeastern and south-central United States, from the East Coast extending westward to Texas." [26]

Since the first case of Ehrlichiosis was reported in 2000, cases reported to the CDC have increased, for example, in 2000, 200 cases were reported and in 2019, 2,093 cases were reported. Fortunately, the "proportion of ehrlichiosis patients that died as a result of infection" has gone down since 2000. [27]

From 2008 to 2012, the average yearly incidence of ehrlichiosis was 3.2 cases per million persons. This is more than twice the estimated incidence for 2000–2007. [25] The incidence rate increases with age, with the ages of 60–69 years being the highest age-specific years. Children less than 10 years and adults aged 70 years and older have the highest case-fatality rates. [25] A documented higher risk of death exists among persons who are immunosuppressed. [23]

See also

Related Research Articles

Ehrlichiosis is a tick-borne disease of dogs usually caused by the rickettsial agent Ehrlichia canis. Ehrlichia canis is the pathogen of animals. Humans can become infected by E. canis and other species after tick exposure. German Shepherd Dogs are thought to be susceptible to a particularly severe form of the disease; other breeds generally have milder clinical signs. Cats can also be infected.

<span class="mw-page-title-main">Lyme disease</span> Infectious disease caused by Borrelia bacteria, spread by ticks

Lyme disease, also known as Lyme borreliosis, is a vector-borne disease caused by Borrelia bacteria, which are spread by ticks in the genus Ixodes. The most common sign of infection is an expanding red rash, known as erythema migrans (EM), which appears at the site of the tick bite about a week afterwards. The rash is typically neither itchy nor painful. Approximately 70–80% of infected people develop a rash. Early diagnosis can be difficult. Other early symptoms may include fever, headaches and tiredness. If untreated, symptoms may include loss of the ability to move one or both sides of the face, joint pains, severe headaches with neck stiffness or heart palpitations. Months to years later, repeated episodes of joint pain and swelling may occur. Occasionally, shooting pains or tingling in the arms and legs may develop. Despite appropriate treatment, about 10 to 20% of those affected develop joint pains, memory problems, and tiredness for at least six months.

<span class="mw-page-title-main">Babesiosis</span> Malaria-like parasitic disease caused by infection with the alveoate Babesia or Theileria

Babesiosis or piroplasmosis is a malaria-like parasitic disease caused by infection with a eukaryotic parasite in the order Piroplasmida, typically a Babesia or Theileria, in the phylum Apicomplexa. Human babesiosis transmission via tick bite is most common in the Northeastern and Midwestern United States and parts of Europe, and sporadic throughout the rest of the world. It occurs in warm weather. People can get infected with Babesia parasites by the bite of an infected tick, by getting a blood transfusion from an infected donor of blood products, or by congenital transmission . Ticks transmit the human strain of babesiosis, so it often presents with other tick-borne illnesses such as Lyme disease. After trypanosomes, Babesia is thought to be the second-most common blood parasite of mammals. They can have major adverse effects on the health of domestic animals in areas without severe winters. In cattle the disease is known as Texas cattle fever or redwater.

Tick-borne diseases, which afflict humans and other animals, are caused by infectious agents transmitted by tick bites. They are caused by infection with a variety of pathogens, including rickettsia and other types of bacteria, viruses, and protozoa. The economic impact of tick-borne diseases is considered to be substantial in humans, and tick-borne diseases are estimated to affect ~80 % of cattle worldwide. Most of these pathogens require passage through vertebrate hosts as part of their life cycle. Tick-borne infections in humans, farm animals, and companion animals are primarily associated with wildlife animal reservoirs. many tick-borne infections in humans involve a complex cycle between wildlife animal reservoirs and tick vectors. The survival and transmission of these tick-borne viruses are closely linked to their interactions with tick vectors and host cells. These viruses are classified into different families, including Asfarviridae, Reoviridae, Rhabdoviridae, Orthomyxoviridae, Bunyaviridae, and Flaviviridae.

<span class="mw-page-title-main">Tick-borne encephalitis</span> Medical condition

Tick-borne encephalitis (TBE) is a viral infectious disease involving the central nervous system. The disease most often manifests as meningitis, encephalitis or meningoencephalitis. Myelitis and spinal paralysis also occurs. In about one third of cases sequelae, predominantly cognitive dysfunction, persist for a year or more.

<i>Dermacentor variabilis</i> Species of tick

Dermacentor variabilis, also known as the American dog tick or wood tick, is a species of tick that is known to carry bacteria responsible for several diseases in humans, including Rocky Mountain spotted fever and tularemia. It is one of the best-known hard ticks. Diseases are spread when it sucks blood from the host. It may take several days for the host to experience symptoms.

Powassan virus (POWV) is a Flavivirus transmitted by ticks, found in North America and in the Russian Far East. It is named after the town of Powassan, Ontario, where it was identified in a young boy who eventually died from it. It can cause encephalitis, inflammation of the brain. No approved vaccine or antiviral drug exists. Prevention of tick bites is the best precaution.

<span class="mw-page-title-main">Anaplasmosis</span> Medical condition

Anaplasmosis is a tick-borne disease affecting ruminants, dogs, and horses, and is caused by Anaplasma bacteria. Anaplasmosis is an infectious but not contagious disease. Anaplasmosis can be transmitted through mechanical and biological vector processes. Anaplasmosis can also be referred to as "yellow bag" or "yellow fever" because the infected animal can develop a jaundiced look. Other signs of infection include weight loss, diarrhea, paleness of the skin, aggressive behavior, and high fever.

<i>Ehrlichia</i> Genus of bacteria

Ehrlichia is a genus of Rickettsiales bacteria that are transmitted to vertebrates by ticks. These bacteria cause the disease ehrlichiosis, which is considered zoonotic, because the main reservoirs for the disease are animals.

<i>Amblyomma americanum</i> Species of tick

Amblyomma americanum, also known as the lone star tick, the northeastern water tick, or the turkey tick, is a type of tick indigenous to much of the eastern United States and Mexico, that bites painlessly and commonly goes unnoticed, remaining attached to its host for as long as seven days until it is fully engorged with blood. It is a member of the phylum Arthropoda, class Arachnida. The adult lone star tick is sexually dimorphic, named for a silvery-white, star-shaped spot or "lone star" present near the center of the posterior portion of the adult female shield (scutum); adult males conversely have varied white streaks or spots around the margins of their shields.

Ehrlichia chaffeensis is an obligate intracellular, Gram-negative species of Rickettsiales bacteria. It is a zoonotic pathogen transmitted to humans by the lone star tick. It is the causative agent of human monocytic ehrlichiosis.

<i>Ehrlichia ewingii</i> Species of bacterium

Ehrlichia ewingii is a species of rickettsiales bacteria. It has recently been associated with human infection, and can be detected via PCR serological testing. The name Ehrlichia ewingii was proposed in 1992.

<span class="mw-page-title-main">Human granulocytic anaplasmosis</span> Medical condition

Human granulocytic anaplasmosis (HGA) is a tick-borne, infectious disease caused by Anaplasma phagocytophilum, an obligate intracellular bacterium that is typically transmitted to humans by ticks of the Ixodes ricinus species complex, including Ixodes scapularis and Ixodes pacificus in North America. These ticks also transmit Lyme disease and other tick-borne diseases.

<span class="mw-page-title-main">Human monocytotropic ehrlichiosis</span> Medical condition

Human monocytotropic ehrlichiosis is a form of ehrlichiosis associated with Ehrlichia chaffeensis. This bacterium is an obligate intracellular pathogen affecting monocytes and macrophages.

Ehrlichiosis ewingii infection is an infectious disease caused by an intracellular bacteria, Ehrlichia ewingii. The infection is transmitted to humans by the tick, Amblyomma americanum. This tick can also transmit Ehrlichia chaffeensis, the bacteria that causes human monocytic ehrlichiosis (HME).

Ehrlichia canis is an obligate intracellular bacterium that acts as the causative agent of ehrlichiosis, a disease most commonly affecting canine species. This pathogen is present throughout the United States, South America, Asia, Africa and recently in the Kimberley region of Australia. First defined in 1935, E. canis emerged in the United States in 1963 and its presence has since been found in all 48 contiguous United States. Reported primarily in dogs, E. canis has also been documented in felines and humans, where it is transferred most commonly via Rhipicephalus sanguineus, the brown dog tick.

Ehrlichia Wisconsin HM543746 is an unnamed tick bacterium that spread through Minnesota and Wisconsin in 2009 and is similar to Ehrlichia muris.

Heartland bandavirus, sometimes called Heartland virus (HRTV), is a tick-borne phlebovirus of the Bhanja virus serocomplex discovered in 2009. The lone star tick transmits the virus to people when feeding on blood. As of 2017, only five states in the Central United States have reported 20 human infections, namely Arkansas, Indiana, Missouri, Oklahoma, and Tennessee; symptoms resemble those of two other tick-borne infections ehrlichiosis and anaplasmosis. The reservoir host is unknown, but deer, raccoon, coyotes, and moose in 13 different states have antibody titers against the virus. By 2023 over 50 human infections were reported in at least eleven states.

<span class="mw-page-title-main">Bourbon virus</span> Species of virus

Bourbon virus is an RNA virus in the genus Thogotovirus of the family Orthomyxoviridae, which is similar to Dhori virus and Batken virus. It was first identified in 2014 in a man from Bourbon County, Kansas, United States, who died after being bitten by ticks. The case is the eighth report of human disease associated with a thogotovirus globally, and the first in the Western hemisphere. As of May 2015, a case was discovered in Stillwater, Oklahoma, and relatively little is known about the virus. No specific treatment or vaccine is available. The virus is suspected to be transmitted by ticks or insects, and avoidance of bites is recommended to reduce risk of infection. In June 2017 a 58-year-old female Missouri State Park employee died from an infection of the Bourbon virus after it had been misdiagnosed for a significant period of time.

In the United States, the National Notifiable Disease Surveillance System (NNDSS) is responsible for sharing information regarding notifiable diseases. As of 2020, the following are the notifiable diseases in the US as mandated by the Centers for Disease Control and Prevention:

References

  1. ↑ CDC (2019-01-17). "Ehrlichiosis home | CDC". Centers for Disease Control and Prevention. Retrieved 2021-11-03.
  2. ↑ CDC (2019-01-17). "Signs and symptoms of ehrlichiosis | CDC". Centers for Disease Control and Prevention. Retrieved 2021-11-03.
  3. ↑ "Ehrlichiosis". Division of Vector-Borne Diseases (DVBD), National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Centers for Disease Control and Prevention. 15 November 2013.
  4. ↑ Dawson, Jacqueline E.; Marty, Aileen M. (1997). "Ehrlichiosis". In Horsburgh, C.R.; Nelson, A.M. (eds.). Pathology of emerging Infections. Vol. 1. American Society for Microbiology Press. ISBN   1555811205.
  5. 1 2 3 Goddard J (September 1, 2008). "What Is New With Ehrlichiosis?". Infections in Medicine.
  6. ↑ Dumler JS, Madigan JE, Pusterla N, Bakken JS (July 2007). "Ehrlichioses in humans: epidemiology, clinical presentation, diagnosis, and treatment". Clin. Infect. Dis. 45 (Suppl 1): S45–51. doi:10.1086/518146. PMID   17582569.
  7. 1 2 CDC (2021-08-04). "Ehrlichiosis epidemiology and statistics | CDC". Centers for Disease Control and Prevention. Retrieved 2021-11-03.
  8. ↑ CDC (2021-08-04). "Ehrlichiosis epidemiology and statistics | CDC". Centers for Disease Control and Prevention. Retrieved 2021-12-02.
  9. ↑ Reeves WK, Loftis AD, Nicholson WL, Czarkowski AG (2008). "The first report of human illness associated with the Panola Mountain Ehrlichia species: a case report". Journal of Medical Case Reports. 2: 139. doi: 10.1186/1752-1947-2-139 . PMC   2396651 . PMID   18447934.
  10. 1 2 Steenhuysen, J. (3 August 2011). "New tick-borne bacterium found in upper Midwest". Reuters. Archived from the original on 2012-06-09.
  11. ↑ Thomas S, Popov VL, Walker DH (2010). Kaushal D (ed.). "Exit Mechanisms of the Intracellular Bacterium Ehrlichia". PLOS ONE. 5 (12): e15775. Bibcode:2010PLoSO...515775T. doi: 10.1371/journal.pone.0015775 . PMC   3004962 . PMID   21187937.
  12. ↑ Baker, Meghan; Yokoe, Deborah S.; Stelling, John; Kaganov, Rebecca E.; Letourneau, Alyssa R.; O'Brien, Thomas; Kulldorff, Martin; Babalola, Damilola; Barrett, Craig; Drees, Marci; Platt, Richard (2015). "Automated Outbreak Detection of Hospital-Associated Infections". Open Forum Infectious Diseases. 2 (suppl_1). doi: 10.1093/ofid/ofv131.60 . ISSN   2328-8957.
  13. ↑ Marty AM, Dumler JS, Imes G, Brusman HP, Smrkovski LL, Frisman DM (August 1995). "Ehrlichiosis mimicking thrombotic thrombocytopenic purpura. Case report and pathological correlation". Hum. Pathol. 26 (8): 920–5. doi:10.1016/0046-8177(95)90017-9. PMID   7635455.
  14. ↑ McBride JW, Walker DH (2011). "Molecular and cellular pathobiology of Ehrlichia infection: targets for new therapeutics and immunomodulation strategies". Expert Rev Mol Med. 13: e3. doi:10.1017/S1462399410001730. PMC   3767467 . PMID   21276277.
  15. ↑ Thomas, Rachael J; Dumler, J Stephen; Carlyon, Jason A (1 August 2009). "Current management of human granulocytic anaplasmosis, human monocytic ehrlichiosis and ehrlichiosis". Expert Review of Anti-infective Therapy. 7 (6): 709–722. doi:10.1586/eri.09.44. PMC   2739015 . PMID   19681699.
  16. ↑ "Ehrlichiosis in Dogs | VCA Animal Hospitals". Vca. Retrieved 2023-11-03.
  17. ↑ "Ehrlichiosis in Dogs". Pet MD. Retrieved 24 January 2023.
  18. ↑ "Ehrlichiosis in Dogs | VCA Animal Hospitals". Vca. Retrieved 2023-11-03.
  19. ↑ Rudoler N, Baneth G, Eyal O, van Straten M, Harrus S (December 2012). "Evaluation of an attenuated strain of Ehrlichia canis as a vaccine for canine monocytic ehrlichiosis". Vaccine. 31 (1): 226–33. doi:10.1016/j.vaccine.2012.10.003. PMID   23072894.
  20. ↑ CDC (2020-07-01). "Preventing tick bites on people | CDC". Centers for Disease Control and Prevention. Retrieved 2021-12-02.
  21. ↑ Jongejan, Frans; Crafford, Dionne; Erasmus, Heidi; Fourie, Josephus J.; Schunack, Bettina (2016-06-17). "Comparative efficacy of oral administrated afoxolaner (NexGard™) and fluralaner (Bravecto™) with topically applied permethrin/imidacloprid (Advantix®) against transmission of Ehrlichia canis by infected Rhipicephalus sanguineus ticks to dogs". Parasites & Vectors. 9 (1). doi: 10.1186/s13071-016-1636-9 . ISSN   1756-3305. PMC   4912781 .
  22. ↑ Sariego, Shyne. "TAWA TAWA LEAVES (Euphorbia hirta) SUPPLEMENTAL TABLET AS AN ALTERNATIVE TREATMENT FOR REDUCING HYPERCHOLESTEROLEMIA".{{cite journal}}: Cite journal requires |journal= (help)
  23. 1 2 Dahlgren FS, Heitman KN, Drexler NA, Massung RF, Behravesh CB. "Human granulocytic anaplasmosis in the United States from 2008 to 2012: a summary of national surveillance data". Am J Trop Med Hyg 2015;93:66–72. Archived 2021-11-12 at archive.today
  24. ↑ Drexler, Naomi A.; Dahlgren, F. Scott; Heitman, Kristen Nichols; Massung, Robert F.; Paddock, Christopher D.; Behravesh, Casey Barton (2016-01-06). "National Surveillance of Spotted Fever Group Rickettsioses in the United States, 2008-2012". The American Journal of Tropical Medicine and Hygiene. 94 (1): 26–34. doi: 10.4269/ajtmh.15-0472 . ISSN   1476-1645. PMC   4710440 . PMID   26324732.
  25. 1 2 3 Nichols Heitman, Kristen; Dahlgren, F. Scott; Drexler, Naomi A.; Massung, Robert F.; Behravesh, Casey Barton (2016-01-06). "Increasing Incidence of Ehrlichiosis in the United States: A Summary of National Surveillance of Ehrlichia chaffeensis and Ehrlichia ewingii Infections in the United States, 2008-2012". The American Journal of Tropical Medicine and Hygiene. 94 (1): 52–60. doi:10.4269/ajtmh.15-0540. ISSN   1476-1645. PMC   4710445 . PMID   26621561.
  26. ↑ CDC (2021-08-04). "Ehrlichiosis epidemiology and statistics | CDC". Centers for Disease Control and Prevention. Retrieved 2021-12-02.
  27. ↑ CDC (2021-08-04). "Ehrlichiosis epidemiology and statistics | CDC". Centers for Disease Control and Prevention. Retrieved 2021-12-02.
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