Presentation
The clinical presentation starts after 5-14 days from tick bite. The following system-wise presentation is seen in erlichiosis:
General Appearance: Patients with erlichiosis may present with confusion in 20% of cases and malaise due to the rapid destruction of the white blood cells in the system. The general feeling of being unwell may lower patient’s appetite leading to anorexia and vomiting because solid foods may not be tolerated at this time.
Systemic: The inflammatory response of the body to the HME morulae may trigger high fever and nausea in patients.
Skin: Although infrequent, macular rashes and petechial spots may develop with HME with concentration at the trunk, legs and arms due to thrombocytopenia.
Head: Vascular headache may occur due to vasodilation of the temporal vessels from the systemic cytokine release. An immune mediated type of meningitis may ensue as one of HME’s complication may present as severe headache. Vascular fragility may manifest as petechial rash or maculo-papular rash of the face.
Chest: Tachycardia may ensue with high grade fever and impending cardiac complications of failure. Dyspnea may be an early sign of respiratory failure as a complication of HME.
Abdomen: Enlargement of the abdomen may be evident with splenomegaly. The rapid cycling of white blood cells and lymph will lead to the enlargement of the spleen [8].
Extremities: A generalized feeling of myalgia of the muscles is one of the inaugural signs of HME and this is related to the generalized immune response. Intermittent muscular rigors may occur in the late stages of the disease.
Immune System
- Splenomegaly
Splenomegaly, a characteristic feature of E. muris infection, was associated with an expanded and disorganized marginal zone and a nearly 66-fold increase in the level of Ter119(+) erythroid cells, indicative of splenic erythropoiesis. [ncbi.nlm.nih.gov]
During the acute or self-limiting phase of E canis infections, lesions generally are nonspecific, but splenomegaly is common. Histologically, there is lymphoreticular hyperplasia and lymphocytic and plasmacytic perivascular cuffing. [merckmanuals.com]
Abdomen: Enlargement of the abdomen may be evident with splenomegaly. The rapid cycling of white blood cells and lymph will lead to the enlargement of the spleen. [symptoma.com]
Hepatomegaly or splenomegaly occurs in as many as 50% of cases. Edema of the face and hands can occur in children. [clinicaladvisor.com]
- Generalized Lymphadenopathy
Clinical findings in acute cases include: Reticuloendothelial hyperplasia Fever Generalized lymphadenopathy Splenomegaly Thrombocytopenia Variable signs of anorexia, depression, loss of stamina, stiffness and reluctance to walk, edema of the limbs or [merckmanuals.com]
Entire Body System
- Fever
The second patient, a forest worker, was affected by Lyme disease, and in this case HGE was suspected because of fever, leukopenia, and seroconversion. [ncbi.nlm.nih.gov]
and Q fever). [columbia-lyme.org]
- Chills
Ehrlichiosis should be considered in each case where there is a history of tick bite together with the clinical picture (high fever, chills, muscle aches, headache, generalized weakness and malaise, and possible maculopapular rash). [ncbi.nlm.nih.gov]
People with ehrlichiosis will often have fever, chills, headache, muscle aches, and sometimes upset stomach. Doxycycline is the treatment of choice for adults and children of all ages with ehrlichiosis. [cdc.gov]
- Pain
The pain meds actually helped to dull the pain from this excruciatingly insanely painful headache, and the horrible body aches I was having. But, after a few days something was still not right. [lymedisease.org]
We report a unique case of HME diagnosed in a woman who presented with abdominal pain and acute appendicitis during early pregnancy and whose condition progressively deteriorated to adult respiratory distress syndrome. [ncbi.nlm.nih.gov]
Symptoms Fever, nausea, peticheal rash, headache, breathlessness, pain abdomen, and generalized weakness are the usual symptoms. [symptoma.com]
Symptoms may include fever, chills, muscle pain, severe headache, and fatigue. Less common signs and symptoms may include nausea, vomiting, diarrhea, joint pain, confusion, and rash. [dhs.wisconsin.gov]
- Malaise
Ehrlichiosis should be considered in each case where there is a history of tick bite together with the clinical picture (high fever, chills, muscle aches, headache, generalized weakness and malaise, and possible maculopapular rash). [ncbi.nlm.nih.gov]
Onset of illness, with fever, chills, headache, and malaise, is abrupt. Ehrlichiosis and anaplasmosis are related to rickettsial diseases. [merckmanuals.com]
- Fatigue
All four had fever, fatigue and headache and one patient also had nausea and vomiting. And all responded to treatment with the antibiotic doxycycline, a drug that is used with other forms of ehrlichiosis infections. [web.archive.org]
Symptoms may include fever, chills, muscle pain, severe headache, and fatigue. Less common signs and symptoms may include nausea, vomiting, diarrhea, joint pain, confusion, and rash. [dhs.wisconsin.gov]
Ehrlichia infect and kill white blood cells and may cause fever, body aches, headache and fatigue. More severe disease may involve multiple organs such as the lungs, kidneys and brain and require hospitalization. [sciencedaily.com]
Typical symptoms of ehrlichiosis include fever, headache, fatigue and muscle aches. Other signs and symptoms may include nausea, vomiting, diarrhea, cough, joint pains, confusion, and occasionally a rash, particularly in children. [epi.publichealth.nc.gov]
For those who do become ill, symptoms typically begin 5 to 10 days after a tick bite, and can initially include fever, headache, fatigue, and muscle aches. Other signs include nausea, vomiting, joint pain, diarrhea, and confusion. [floridahealth.gov]
Respiratoric
- Cough
Fifty-two year old patient was admitted to hospital due to high fever of over 40 degrees C that lasted two days, accompanied with chills, muscle aches, malaise, loss of appetite, headache, confusion, breathing difficulties, and mild dry cough. [ncbi.nlm.nih.gov]
Other signs and symptoms may include nausea, vomiting, diarrhea, cough, joint pains, confusion, and occasionally a rash, particularly in children. Usually, these symptoms occur within one or two weeks following a tick bite. [epi.publichealth.nc.gov]
Symptoms usually begin between 5 to 14 days after being bitten by an infected tick and can include mild fever, headache, chills, malaise, muscle aches, nausea, vomiting, diarrhea, fatigue, loss of appetite, joint pain, confusion, rash, and cough. [igenex.com]
- Dyspnea
She manifested known sequelae for this emerging disease, including dyspnea, pedal edema, increased transminases, and nephrotic syndrome. [ncbi.nlm.nih.gov]
Dyspnea may be an early sign of respiratory failure as a complication of HME. Abdomen: Enlargement of the abdomen may be evident with splenomegaly. The rapid cycling of white blood cells and lymph will lead to the enlargement of the spleen. [symptoma.com]
[…] cases include: Reticuloendothelial hyperplasia Fever Generalized lymphadenopathy Splenomegaly Thrombocytopenia Variable signs of anorexia, depression, loss of stamina, stiffness and reluctance to walk, edema of the limbs or scrotum, and coughing or dyspnea [merckmanuals.com]
- Dry Cough
Fifty-two year old patient was admitted to hospital due to high fever of over 40 degrees C that lasted two days, accompanied with chills, muscle aches, malaise, loss of appetite, headache, confusion, breathing difficulties, and mild dry cough. [ncbi.nlm.nih.gov]
- Pneumonia
She was treated with ceftriaxone and azithromycin for possible community-acquired pneumonia but declining mental status necessitated intensive care unit transfer. Vancomycin and doxycycline were added. [ncbi.nlm.nih.gov]
If untreated, the illness can cause internal bleeding and infections such as pneumonia. A research team lead by Jacob W. [webmd.com]
Gastrointestinal
- Nausea
A 42-year-old white man had headache, fever, chills, abdominal pain, nausea and vomiting, night sweats, and dark urine for 3 days before admission; he had history of a tick bite 6 weeks earlier. [ncbi.nlm.nih.gov]
Signs and symptoms of ehrlichiosis include: fever, headache, nausea, and body aches. Encephalitis/ meningitis may occur. Ehrlichiosis is transmitted to a person through the bite of an infected lone star tick (Amblyomma americanum). [maine.gov]
- Vomiting
A 42-year-old white man had headache, fever, chills, abdominal pain, nausea and vomiting, night sweats, and dark urine for 3 days before admission; he had history of a tick bite 6 weeks earlier. [ncbi.nlm.nih.gov]
Symptoms include fever, headache, chills, malaise, muscle pain, confusion, red eyes, nausea, vomiting and diarrhea. A skin rash is not a common symptom of ehrlichiosis, but some people infected with Ehrlichia may develop one. [healthvermont.gov]
Symptoms The following symptoms are commonly seen with this disease, however, it is important to note that the combination of symptoms varies greatly from person to person; fever, headache, chills, malaise, muscle pain, nausea/vomiting/diarrhea, confusion [health.ri.gov]
- Abdominal Pain
We report a unique case of HME diagnosed in a woman who presented with abdominal pain and acute appendicitis during early pregnancy and whose condition progressively deteriorated to adult respiratory distress syndrome. [ncbi.nlm.nih.gov]
Other common symptoms include nausea, vomiting, abdominal pain, and loss of appetite. The severity of disease ranges from asymptomatic infection to death. Half of the people with ehrlichiosis require hospitalization. [ok.gov]
- Loss of Appetite
Fifty-two year old patient was admitted to hospital due to high fever of over 40 degrees C that lasted two days, accompanied with chills, muscle aches, malaise, loss of appetite, headache, confusion, breathing difficulties, and mild dry cough. [ncbi.nlm.nih.gov]
Early Illness Early signs and symptoms (the first 5 days of illness) are usually mild or moderate and may include: Fever, chills Severe headache Muscle aches Nausea, vomiting, diarrhea, loss of appetite Confusion Rash (more common in children) Rash Up [cdc.gov]
Other common symptoms include nausea, vomiting, abdominal pain, and loss of appetite. The severity of disease ranges from asymptomatic infection to death. Half of the people with ehrlichiosis require hospitalization. [ok.gov]
Symptoms usually begin between 5 to 14 days after being bitten by an infected tick and can include mild fever, headache, chills, malaise, muscle aches, nausea, vomiting, diarrhea, fatigue, loss of appetite, joint pain, confusion, rash, and cough. [igenex.com]
The most common symptoms include fever, headache, loss of appetite, muscle aches, and fatigue. Other symptoms sometimes reported are nausea, vomiting, diarrhea, cough, joint pains, confusion and rash. [chfs.ky.gov]
Cardiovascular
- Heart Failure
The patient developed acute renal failure, thrombocytopenia, transaminitis, and, finally, severe myocarditis that led to congestive heart failure. [ncbi.nlm.nih.gov]
These complications can include: organ failure, including kidney and liver failure respiratory failure heart failure falling into a coma seizures While many of these complications can be treated if caught early enough, they may not be reversible. [healthline.com]
The following serious complications may arise from HME: Seizure Coma Heart failure Kidney failure Respiratory failure Toxic shock Ehrlichiosis is caused by a Rickettsia type of bacteria called Ehrlichia that is generally transmitted in the United States [symptoma.com]
Serious complications of untreated infection include: Kidney failure Respiratory failure Heart failure Seizures Coma Prevention The best way to steer clear of ehrlichiosis is to avoid tick bites. [mayoclinic.org]
In some cases, especially in those who have a weak immune system (such as from HIV or cancer), ehrlichiosis can cause serious complications, such as: Brain problems, like confusion, seizures, or coma Excess bleeding (hemorrhage) Heart failure Breathing [cedars-sinai.org]
Musculoskeletal
- Myalgia
Infections often cause fever, myalgia, and hematological abnormalities, and sometimes mild elevation in transaminases, creatinine, and urinary protein. [ncbi.nlm.nih.gov]
Rare diseases Search Search for a rare disease Ehrlichiosis Disease definition Human ehrlichiosis and anaplasmosis describe a group of acute febrile tick-borne diseases characterized by an overlapping clinical picture that includes fever, headache, myalgias [orpha.net]
- Arthralgia
This case review emphasizes the need for a thorough history and physical examination in all patients who present with relatively non-specific complaints such as headaches, chills, myalgias, and arthralgias. [ncbi.nlm.nih.gov]
[…] diseases Search Search for a rare disease Ehrlichiosis Disease definition Human ehrlichiosis and anaplasmosis describe a group of acute febrile tick-borne diseases characterized by an overlapping clinical picture that includes fever, headache, myalgias, arthralgias [orpha.net]
Symptoms among children with HGA include the following: Fever (93%), headache and myalgia (both 73%), and rigors (60%) are common Less frequently encountered symptoms and signs include the following: Nausea (33%), vomiting and abdominal pain (both 27%), arthralgias [clinicaladvisor.com]
Skin
- Skin Rash
A skin rash is not a common symptom of ehrlichiosis, but some people infected with Ehrlichia may develop one. The rash is more common in children with the disease than with adults. [healthvermont.gov]
— Elizabeth Cohen, CNN, "Survivor of near-fatal tick bite has a lesson for summer," 25 May 2018 Symptoms of ehrlichiosis include fever, nausea, headaches and chills, while Lyme disease symptoms usually involve fever, skin rashes, and body aches. — Lucas [merriam-webster.com]
Approximately one-third of patients develop a skin rash approximately 5 days after illness onset that varies from petechial to maculopapular or diffuse erythema. [clinlabnavigator.com]
- Petechiae
Thrombocytopenia is common, but petechiae may not be evident, and platelet decreases may be mild in some animals. Vasculitis and immune-mediated mechanisms induce a thrombocytopenia and hemorrhagic tendencies. [merckmanuals.com]
- Eruptions
[…] for a rare disease Ehrlichiosis Disease definition Human ehrlichiosis and anaplasmosis describe a group of acute febrile tick-borne diseases characterized by an overlapping clinical picture that includes fever, headache, myalgias, arthralgias, skin eruptions [orpha.net]
Urogenital
- Kidney Failure
Severe cases may have prolonged fever, kidney failure, blood clotting disorders, meningoencephalitis, adult respiratory distress syndrome, seizures, or coma. [chfs.ky.gov]
Symptoms of a more serious case of ehrlichiosis include: seizures difficulty breathing coma kidney failure. Ehrlichiosis feels like the flu at first. [familydoctor.org]
The following serious complications may arise from HME: Seizure Coma Heart failure Kidney failure Respiratory failure Toxic shock Ehrlichiosis is caused by a Rickettsia type of bacteria called Ehrlichia that is generally transmitted in the United States [symptoma.com]
Serious complications of untreated infection include: Kidney failure Respiratory failure Heart failure Seizures Coma Prevention The best way to steer clear of ehrlichiosis is to avoid tick bites. [mayoclinic.org]
(respiratory) failure Kidney failure Septic shock These complications may need additional treatments, such as fluids, breathing support, or kidney dialysis. [cedars-sinai.org]
Neurologic
- Headache
Ehrlichiosis should be considered in each case where there is a history of tick bite together with the clinical picture (high fever, chills, muscle aches, headache, generalized weakness and malaise, and possible maculopapular rash). [ncbi.nlm.nih.gov]
People with ehrlichiosis will often have fever, chills, headache, muscle aches, and sometimes upset stomach. Doxycycline is the treatment of choice for adults and children of all ages with ehrlichiosis. [cdc.gov]
Back in 2005 – a healthy 30 something – I began to have a horrible headache, body aches, flu-like joint pains and a low grade fever. The thing was, this headache, along with the fever, persisted for days and days. NOTHING I took would help. [lymedisease.org]
- Confusion
Fifty-two year old patient was admitted to hospital due to high fever of over 40 degrees C that lasted two days, accompanied with chills, muscle aches, malaise, loss of appetite, headache, confusion, breathing difficulties, and mild dry cough. [ncbi.nlm.nih.gov]
Less common symptoms include nausea and vomiting, as well as confusion. A maculopapular rash (easily distinguishable from Rocky Mountain spotted fever) can also occur. [columbia-lyme.org]
Symptoms include fever, headache, chills, malaise, muscle pain, confusion, red eyes, nausea, vomiting and diarrhea. A skin rash is not a common symptom of ehrlichiosis, but some people infected with Ehrlichia may develop one. [healthvermont.gov]
Symptoms The following symptoms are commonly seen with this disease, however, it is important to note that the combination of symptoms varies greatly from person to person; fever, headache, chills, malaise, muscle pain, nausea/vomiting/diarrhea, confusion [health.ri.gov]
Other signs and symptoms may include nausea, vomiting, diarrhea, cough, joint pains, confusion, and occasionally a rash, particularly in children. Usually, these symptoms occur within one or two weeks following a tick bite. [epi.publichealth.nc.gov]
Workup
The diagnosis of erlichiosis may be challenging because it may mimic several common viral disease in children and in adults. Presented with a patient having very high suspicion rate for erlichiosis with history of possible tick contact in endemic regions, it is medically prudent to check the entire body especially the hair part for the presence of the tick vector which is ardently removed.
The following laboratory tests are performed for patients with suspected erlichiosis afflictions:
- Complete blood count (CBC): The blood count will show an abnormally low white blood cell count. HME will also present with thrombocytopenia.
- Liver function tests: Erlichiosis may alter liver enzymes especially with impending liver failure complications.
- Polymerase Chain Reaction (PCR): This test is very specific in identifying Erlichia as the pathogen causing the disease process [9].
- Indirect Fluorescent Antibody test (IFA test): This test measures the quantitative load of antigen that the body develops.
Serum
- Leukopenia
I report a case of tick-borne ehrlichiosis in which the primary presentation suggested an infectious diarrhea, with impressive leukopenia and thrombocytopenia. [ncbi.nlm.nih.gov]
- Lymphopenia
In this study, we compared the immune responses in two patients with mild/non fatal and severe/fatal HME who had marked lymphopenia, thrombocytopenia and elevated liver enzymes. [ncbi.nlm.nih.gov]
Clinical laboratory findings may include thrombocytopenia, lymphopenia, leucopenia, and elevated liver enzymes. If not treated, anaplasmosis can lead to serious and occasionally fatal illness. [dhs.wisconsin.gov]
- Neutropenia
We present a previously healthy 5-year-old boy who was referred to the Hematology-Oncology Clinic to consider a bone marrow etiologic process after his pediatrician discovered progressive neutropenia, anemia, thrombocytopenia, and hepatosplenomegaly accompanied [ncbi.nlm.nih.gov]
As with HGA, thrombocytopenia, neutropenia, and elevated liver function tests may be found. Clinical features vary widely from asymptomatic, to a mild self-limiting febrile illness, to severe or even fatal cases in immunocompromised persons. [imugen.com]
- Decreased Platelet Count
These tests check for: increased liver enzymes decreased platelet count decreased white blood cell count During the first week of illness, a doctor may test a person's blood for tick-borne pathogens using a polymerase chain reaction or PCR assay. [medicalnewstoday.com]
Microbiology
- Borrelia Burgdorferi
@article{Skotarczak2002CoexistenceDO, title={Coexistence DNA of Borrelia burgdorferi sensu lato and Babesia microti in Ixodes ricinus ticks from north-western Poland.}, author={Bogumiła Skotarczak and Beata Wodecka and Agnieszka Cichocka}, journal={Annals [semanticscholar.org]
Ehrlichia species Wisconsin : recently identified [9], close relative of E. muris ; likely vector is the Ixodes scapularis tick (same as HGA and B. burgdorferi ). [hopkinsguides.com]
For acute and convalescent serology, sera from 26 September and 15 October were tested using indirect immunofluorescence assays (IFA), performed as previously described [ 10 ], to detect antibodies against Anaplasma phagocytophilum, Borrelia burgdorferi [doi.org]
Laboratory
- Leukocytosis
During the acute phase of E canis infection in dogs, the hemogram is usually normal but may reflect a mild normocytic, normochromic anemia; leukopenia; or mild leukocytosis. [merckmanuals.com]
The white blood cell count is usually low or within normal limits, although leukocytosis (23%) can also be observed. Platelet counts are often low or normal. [clinicaladvisor.com]
In contrast, leukocytosis (>10.2 × 10 9 cells/L) is associated with a low relative risk (0.10–0.71) for HGA [ 16 ]. [doi.org]
Treatment
In early erlichiosis, the prompt removal of tick vector from the host’s body may reverse the signs and symptoms of the disease arbitrarily. Physicians often prescribe doxycycline antibiotics for 7 to 10 days to address the infection in erlichiosis [10]. Pregnant women may be given rifampin instead because doxycycline is contraindicated with pregnancy. Flouroquinolones may also be used with antipyretics during the early stages of HME.
Prognosis
The disease erlichiosis heralds a good prognosis with a healthy host and with prompt antibacterial treatment [5]. The mortality rate in human monocytic erlichiosis is only 2% to 5%. Elderly patients beyond 60 years of age account for the majority of deaths encountered in HME [6]. Majority of erlichiosis cases are generally asymptomatic or with mild symptoms like fever and malaise. HME carries a high hospitalization rate of 60%.
Complications
Erlichiosis poses a serious threat for those who are not treated promptly. Immuno-compromised patients may even have a higher risk for life threatening outcomes. The following serious complications may arise from HME:
Etiology
Ehrlichiosis is caused by a Rickettsia type of bacteria called Ehrlichia that is generally transmitted in the United States by the bite of the Lone Star tick (Amblyomma americanum) in between mammalian hosts. Ehrlichia chaffeensis, Ehrlichia ewingii, and Ehrlichia muris-like may cause the disease.
A tick latches on the skin of a mammalian host where it gets its blood meal. They can either transmit the bacteria from their system or acquire it from its blood meal host. To effectively transmit the bacteria, the Lone Star tick requires at least 24 hours of latching on. Prompt removal of the transmitting tick may arrest the delivery of the bacterial load and prevent infection.
Epidemiology
The incidence of erlichiosis in the United States abounds in states where there is direct contact of the mammalian host to the tick vector. Majority of cases in the US are distributed in the Texas, California and the eastern regions of the country [2]. Studies suggest that erlichiosis is a seasonal disease that surfaces during the months of April to September [3]. This tick-borne disease occurs worldwide mirroring the relative distribution of its vector and it close proximity to human hosts [4].
Pathophysiology
The bacteria Erlichia chaffeensis is an obligate, intra-cytoplasmic and gram negative organism that closely resembles Rickettsia spp. Erlichia thrives and multiplies within the monocytes vacuoles (pahgosomes) forming a large mulberry shaped aggregate referred to as morula. The defective monocyte and macrophage in HME renders the mammalian host’s immune system incapacitated. A widespread systemic response may be observable when the body’s immune system attacks this abnormal white blood cells and inclusion bodies.
Prevention
Humans must reduce exposure in endemic areas to prevent contact with the vector. During camping trips, insect repellants must liberally be used to fend off the Lone star tick from latching on. Tucking one’s pants within the socks may reduce the tick’s point of entry to the skin. The regular self-examination for possible tick bites during outings is a prudent practice.
Summary
Erlichiosis is a tick-borne disease characterized by flu-like symptoms in humans. Patients may experience high fever and muscle pains within a week or two from the actual tick bite.
Erlichiosis generally resolves with the early introduction of appropriate antibiotics. Erlichiosis is an infection of the monocytes that may affect other mammals like dogs, sheep, cattle, horses and goats [1].
Patient Information
Definition
Erlichiosis is a tick borne disease characterized by high fever, flu-like symptoms, and muscle pains
Cause
It is caused by a Rickettsia type of bacteria called Erlichia chaffeensis that is generally transmitted by the bite of the Lone Star tick (Amblyomma americanum) in between mammalian hosts.
Symptoms
Fever, nausea, peticheal rash, headache, breathlessness, pain abdomen, and generalized weakness are the usual symptoms.
Diagnosis and Treatment
Patients who discover the tick in their skin must use fine tweezers to remove them being careful that the mouth parts left on the skin surface. The specimen must be placed on a covered jar on a moist cloth for future examination purposes when signs and symptoms occurs. Prompt medical attention must be given paramount priority when suspecting any tick-borne disease.
References
- Chapman AS, Bakken JS, Folk SM, et al. Diagnosis and management of tickborne rickettsial diseases: Rocky Mountain spotted fever, ehrlichioses, and anaplasmosis--United States: a practical guide for physicians and other health-care and public health professionals. MMWR Recomm Rep. Mar 31 2006; 55:1-27.
- Folkema AM, Holman RC, Dahlgren FS, Cheek JE, McQuiston JH. Epidemiology of ehrlichiosis and anaplasmosis among American Indians in the United States, 2000-2007.Am J Trop Med Hyg. 2012; 87(3):529-37 (ISSN: 1476-1645).
- Bakken JS, Dumler JS, Chen SM, et al. Human granulocytic ehrlichiosis in the upper Midwest United States. A new species emerging?. JAMA. Jul 20 1994;272(3):212-8.
- Strle F. Human granulocytic ehrlichiosis in Europe. Int J Med Microbiol. Apr 2004;293 Suppl 37:27-35
- Hamburg BJ, Storch GA, Micek ST, Kollef MH. The importance of early treatment with doxycycline in human ehrlichiosis. Medicine (Baltimore). Mar 2008;87(2):53-60.
- Pavelites JJ, Prahlow J. FAatal human monocytic ehrlichiosis: a case study.Forensic Sci Med Pathol. 2011; 7(3):287-93 (ISSN: 1556-2891)
- Ismail N, Walker DH, Ghose P, Tang YW. Immune mediators of protective and pathogenic immune responses in patients with mild and fatal human monocytotropic ehrlichiosis. BMC Immunol. 2012; 13:26 (ISSN: 1471-2172)
- Bluszcz-Roznowska A, Olszok I, Kucharz EJ. Ehrlichiosis. Przegl Lek. 2005; 62(12):1529-31 (ISSN: 0033-2240)
- Everett ED, Evans KA, Henry RB, McDonald G. Human ehrlichiosis in adults after tick exposure. Diagnosis using polymerase chain reaction. Ann Intern Med. May 1 1994;120(9):730-5.
- CDC. Ehrlichiosis.