ESCMID Online Lecture Library © by Author

Disclosures Funding Ehrlichiosis, Anaplasmosis, and US National Institutes of Allergy and Infectious Diseases grants – R01 AI044102 (Dumler) Neoehrlichiosis in humans: – R01 AI082695 (Grab) – R21 AI080911 (Dumler) Clinical aspects – R21 AI096062 (Dumler) – U01AI068613 (Eshleman) – K23AI083931 (Reller) J. Stephen Dumler, MD Bill and Melinda Gates Foundation – NIMR Supplemental Project to #48027 Departments of Pathology and Microbiology & Immunology J. Stephen Dumler, M.D. receives periodic patent license royalty payments for University of Maryland School of Medicine, and antigen preparation methods used in: Departments of Pathology, Molecular Microbiology and Immunology “Anaplasma phagocytophilum IFA IgG Substrate Slide”, a commercial The Johns Hopkins Medical Institutions product marketed by Focus Diagnostics, Inc. Baltimore, MD USA

David H. Walker, MD

© by author Johan S Bakken, MD

Rickettsia typhi Rickettsia rickettsii Anaplasmataceae Ehrlichia muris ESCMID OnlineEhrlichia (Cowdria) Ehrlichia chaffeensis Lecture Library Orientia tsutsugamushi ruminantium Ehrlichia ewingii • bacteria with specificity for mammalian leukocytes, Ehrlichia canis endothelial cells, erythrocytes, or platelets Anaplasma • Small, pleomorphic, coccoid to ellipsoidal obligate marginale intracellular bacteria that reside within the Anaplasma (Ehrlichia) platys cytoplasmic vacuoles (morulae) in hematopoietic Anaplasma phagocytophilum cells, e.g. leukocytes, endothelial cells, (Ehrlichia phagocytophila, Ehrlichia equi, HGE agent) erythrocytes, or platelets, of mammalian hosts • Gram-negative cell wall • Biological vectors are ticks and mechanical vectors Wolbachia pipientis E. coli include biting flies or other fomites. • Organisms grow in ixodid tick vectors. Neorickettsia Neorickettsia helminthoeca (Ehrlichia) risticii Neorickettsia (Ehrlichia) sennetsu 0.1 Pathogenesis of Rickettsial infections

phagosome escape

Rickettsia endothelial cells

Ehrlichia chaffeensis Anaplasma phagocytophilum Anaplasma marginale phagolysosome fusion inhibition

Ehrlichia and Anaplasma macrophages and neutrophils

Neorickettsia risticii Wolbachia pipientis Rickettsia rickettsii

Histopathology in HME and HGA Human Anaplasmataceae infections (human ehrlichiosis)

• human monocytic ehrlichiosis (HME) - E. chaffeensis Ehrlichia chaffeensis • Human granulocytic anaplasmosis (HGA) - Spleen - HGA Spleen - HME Liver - HME Anaplasma phagocytophilum • Other human ehrlichioses – ehrlichiosis “Ewingii” - caused by E. ewingii, A. phagocytophilum genetically like E. chaffeensis, phenotypically like HGA – Ehrlichia muris (Upper Midwest USA) bone marrow - HGA bone marrow - HME Brain - HME – Panola Mountain Ehrlichia - genetically similar to Ehrlichia ruminantium (Southeast USA) E. ewingii – Ehrlichia canis (Venezuela) – Neoehrlichia mikurensis (Europe) • Ehrlichioses are undifferentiated febrile illnesses with typical laboratory findings. Lung - HGA lung - HME © byCSF - HME author

Tick-Borne Rickettsial Diseases (TBRD) Cases of ehrlichiosis and anaplasmosis in the U.S. US Incidence, 1920-2012 reported to the CDC, 1986 - 2012 ESCMID(data derived fromOnline PHS, CDC, MMWR) Lecture Library 3000 7000 HME 2500 6000 HGA E. ewingii 5000 2000 not specified all ehrlichiosis 4000 1500 3000

2000 1000 number of cases number of cases

1000 500

0 0 1920 1924 1928 1932 1936 1940 1944 1948 1952 1956 1960 1964 1968 1972 1976 1980 1984 1988 1992 1996 2000 2004 2008 2012 1987 1989 1991 1993 1995 1997 2000 2002 2004 2006 2008 2010 2012 RMSF HME HGA E ewingii ehrlichiosis nos total TBRD ** no data available for 1998 Tick-Borne Rickettsial Diseases (TBRD) US Incidence, 1920-2012 (data derived from PHS, CDC, MMWR)

7000 Increasing incidence and prevalance… 6000 but are tick-borne rickettsial infections important? 5000

4000

3000

2000 number of cases

1000

0 1920 1924 1928 1932 1936 1940 1944 1948 1952 1956 1960 1964 1968 1972 1976 1980 1984 1988 1992 1996 2000 2004 2008 2012

RMSF HME HGA E ewingii ehrlichiosis nos total TBRD 2009 No. cases

Geographic distribution of proven and serologically suspected ehrlichiosis and anaplasmosis in humans

No. cases (ehrlichiosis cases x 5.6 estimated© true incidence) by author

HGA – Anaplasma phagocytophilum HME - Ehrlichia chaffeensis and ESCMID Online Lectureepidemiology and ecology Library epidemiology and ecology – risk for disease increased with age, male sex –risk for disease increased with age, male sex – upper Midwest and northeast US, northern –south central and southeastern US; World-wide? California, Europe, Eastern Asia –transmitted by A. americanum active in summer months – transmitted by Ixodes spp. nymphs and adults –reservoir white-tailed deer – reservoir small mammals, cervids, ruminants Ixodes scapularis - North America

Ixodes pacificus - Ixodes ricinus - Ixodes persulcatus Haemaphysalis Amblyomma americanum California Europe - Asia concinna - China Frequent clinical features of ehrlichiosis vs. RMSF Seroprevalence and clinical disease (meta analysis median percentages of patients with clinical feature) History, signs, or B. burgdorferi R. rickettsii A. phagocytophilum E. chaffeensis HME HGA in North America symptoms Lyme disease* RMSF HGA HME • Seroprevalence • Seroprevalence Fever 47 100 100 96 – Tennessee 3.3 to 12.5% – 3.7% overall cross-sectional – Arkansas 1.3% – Northwest Wisconsin 14.9% Rash 74** 90 6** 26*** – Connecticut 0.6 to 0.9% Rash on palms and soles 082 00 • Prevalence of disease • Prevalence of disease – Tennessee 330 cases / 100,000 – Northwest Wisconsin 26 - 58 cases Headache 48 91 82 72 population (0.3%) / 100,000 population (0.06%) Myalgia/arthralgia – Missouri 414 cases / 100,000 – Connecticut 24 - 51 cases / 53 72 77 68 population (0.4%) 100,000 population (0.05%) Nausea not reported 39 57 • Ratio disease : seroprevalence • Ratio disease : seroprevalence 60 – 3 to 30 : 100 – 0. 4 to 6 : 100 Vomiting not reported 22 47 N Engl J Med. 1995 ; 333:420; Emerg Infect Dis 2003; 9: 1579 Clin Infect Dis. 1998 ; 27:1491; J Infect Dis 2000; 181: 1388 J Infect Dis 2000; 181: 1082 Transfusion 2002; 42: 1585 Pneumonitis or cough not reported 12 27 28 HGA in Europe Confusion/ altered MS 526 17 20 • Seroprevalence • Prevalence of disease * From 58 culture or seropositive patients in Maryland, 2001-2002 (J Clin Microbiol 2005; 43:5080) – 8.2% overall cross-sectional – Approximately 65 cases ** erythema migrans only • Ratio disease : seroprevalence *** varies with age (young>>old) – Presumed to be very low

Laboratory abnormalities in ehrlichiosis (%) Laboratory abnormalities in ehrlichiosis (%) Laboratory finding Lyme Disease RMSF HGA HME Laboratory finding Lyme Disease RMSF HME HGA White blood cell count White blood cell count > 10,000/L 7 28 11 > 10,000/L 72811 < 5,000/L 33 55 60 < 5,000/L 33 55 60 > 10% bands 69 76 > 10% bands 69 76 Platelet count/L Platelet count/L < 150,000 7 52 75 79 < 150,000 75275 79 Serum sodium < 132 mEq/L 56 Serum sodium < 132 mEq/L 56 ALT or AST  2x normal value 12 62 83 88 ALT or AST  2x normal value 12 62 83 88 Cerebrospinal fluid Cerebrospinal fluid Pleocytosis 48 60 rare Pleocytosis 48 60 rare mononuclear cell predominance 46 67 mononuclear cell predominance 46 67 neutrophil predominance 50 33 neutrophil predominance 50 33 Glucose  50 mg/dL 8 14 Glucose  50 mg/dL 8 14 Protein  50 mg/dL 35 44 Protein  50 mg/dL 35 44 Opening pressure 250 mm H Opening pressure  250 mm H O 14  2O1©4 by author2

HME and HGA - diagnosis ESCMIDOutcomes and complications of reportedOnline cases of HME and HGA, 2000-2007 Lecture Library • blood smear (acute phase only) E. chaffeensis E. chaffeensis A. phagocytophilum – HME – 2% sensitive Hospitalized 570/1173 (48.6%) 687/1907 (36%) – HGA – 25 to 75% sensitive Died 19/1027 (1.9%) 11/1921 (0.6%) • PCR on blood (acute phase only) – Sensitivity ~90-95% during acute phase Life threatening complications N=113 N=60 A. phagocytophilum – no chronic phase in humans, brief ARDS 20 (18.2%) 8 (13.3%) persistence of DNA after therapy DIC 14 (12.7%) 2 (3.3%) • Serology (paired acute and Meningitis/encephalitis 32 (29.1%) 5 (8.3%) convalescent) Renal Failure 34 (30.9%) 12 (20.0%) – IFA – preferred Other 48 (43.6%) 37 (61.7%) • No specific serologic tests for E. ewingii Dahlgren FS, Mandel EJ, Krebs JW, Massung RF, McQuiston JH. Increasing incidence of Ehrlichia chaffeensis and Anaplasma phagocytophilum in the United States, 2000-2007. Am J Trop Med Hyg. 2011; 85:124-31. Sensitivity and specificity of serological tests for HME and HGA - therapy confirmation of HME and HGA. • Clinical suspicion most important – Exposure to or known vector bites – Appropriate clinical manifestations Disease Serological Assay Sensitivity Specificity • Doxycycline – 200 mg po twice daily for 3-5 days after afebrile IFA IgG 88% Not determined – empirical clinical efficacy – good in vitro activity HME IFA IgM 86% Not determined • Rifampin for pregnancy and children? – scant empirical efficacy data – good in vitro activity IFA IgG 82-100% 82*-100% – Potentially useful in children, pregnancy HGA • Fluoroquinolones? IFA IgM 27-37% 83*-100% – Potentially active against A. phagocytophilum (HGA), but apparently non bactericidal – Not active against E. chaffeensis (HME) * Cross-reactions with Ehrlichia chaffeensis • gyrA QRDR serine 83 (susceptible)  alanine (resistant)

Geographic distribution of proven and serologically suspected ehrlichiosis and anaplasmosis in humans

Ehrlichia ewingii infection of humans •South central and southeastern USA • Serological cross‐reactivity with E. chaffeensis in human sera •Not yet cultured, so no specific serologic test •Present in Amblyomma americanum ticks in south central and southeastern USA • Clinical manifestations indistinguishable from HME and HGA • 82% of patients are immune compromised (HIV, organ transplants, rheumatoid arthritis, Amblyomma americanum North America COPD) Rhipicephalus sanguineus Cameroon, Africa •No fatalities have been identified Haemaphysalis longicornis © by author Japan

ESCMID OnlineISE6 tick cells Lecture Library

Ehrlichia muris‐like agent (EMLA) infection • Identified so far only in Minnesota and Wisconsin, USA • Serological reactivity in human sera from Japan and Russia (Perm) •Present in Ixodes scapularis ticks in upper midwest USA

• Clinical manifestations Haemaphysalis flava Ixodes ovatus Ixodes persulcatus indistinguishable from HME and HGA Japan Japan Asia • 39% of patients are immune compromised • 23% of patients are hospitalized, but no fatalities have been identified Ixodes scapularis Ixodes ricinus North America Europe Frequent clinical features of ehrlichiosis vs. RMSF (meta analysis median % of patients with clinical feature) A. phagocytophilum E. chaffeensis E. ewingii EMLA N. mikurensis History, signs, or HGA HME ehrlichiosis infection infection symptoms n=750 n-451 n=8 n=48 n=13

Fever 100 96 100 87 92

Rash 6* 26** 00 31

Rash on palms and soles 0000 0

Headache 82 72 63 66 62

Myalgia/arthralgia 77 68 38 69 38

Nausea 39 57 25 - 38

Vomiting 22 47 25 - 38

Pneumonitis or cough 27 28 0- 31

Confusion/ altered MS 17 20 0- 8

* erythema migrans only ** varies with age (young>>old)

Frequent clinical features of ehrlichiosis vs. RMSF (meta analysis median % of patients with clinical feature) A. phagocytophilum E. chaffeensis E. ewingii EMLA N. mikurensis History, signs, or HGA HME ehrlichiosis infection infection symptoms n=750 n-451 n=8 n=48 n=13

Fever 100 96 100 87 92

Rash 6* 26** 0 0 31

Rash on palms and soles 00000

Headache 82 72 63 66 62

Myalgia/arthralgia 77 68 38 69 38

Nausea 39 57 25 - 38

Vomiting 22 47 25 - 38

Pneumonitis or cough 27 28 0 - 31

Confusion/ altered MS 17 20 0 - 8

Case fatality rate 0.6 2.7 0 deaths 0 deaths 1 death * erythema migrans only ** varies with age (young>>old) © by author ESCMID Online Lecture Library