Karen C. Bloch

The Management of Encephalitis: Clinical Practice Guidelines by the Infectious Diseases Society of America

Guidelines for the diagnosis and treatment of patients with encephalitis were prepared by an Expert Panel of the Infectious Diseases Society of America. The guidelines are intended for use by health care providers who care for patients with encephalitis. The guideline includes data on the epidemiology, clinical features, diagnosis, and treatment of many viral, bacterial, fungal, protozoal, and helminthic etiologies of encephalitis and provides information on when specific etiologic agents should be considered in individual patients with encephalitis.

Case Definitions, Diagnostic Algorithms, and Priorities in Encephalitis: Consensus Statement of the International Encephalitis Consortium

BACKGROUND Encephalitis continues to result in substantial morbidity and mortality worldwide. Advances in diagnosis and management have been limited, in part, by a lack of consensus on case definitions, standardized diagnostic approaches, and priorities for research. METHODS In March 2012, the International Encephalitis Consortium, a committee begun in 2010 with members worldwide, held a meeting in Atlanta to discuss recent advances in encephalitis and to set priorities for future study. RESULTS We present a consensus document that proposes a standardized case definition and diagnostic guidelines for evaluation of adults and children with suspected encephalitis. In addition, areas of research priority, including host genetics and selected emerging infections, are discussed. CONCLUSIONS We anticipate that this document, representing a synthesis of our discussions and supported by literature, will serve as a practical aid to clinicians evaluating patients with suspected encephalitis and will identify key areas and approaches to advance our knowledge of encephalitis.

Infections with Ehrlichia chaffeensis and Ehrlichia ewingii in Persons Coinfected with Human Immunodeficiency Virus

The clinical course and laboratory evaluation of 21 patients coinfected with human immunodeficiency virus (HIV) and Ehrlichia chaffeensis or Ehrlichia ewingii are reviewed and summarized, including 13 cases of ehrlichiosis caused by E. chaffeensis, 4 caused by E. ewingii, and 4 caused by either E. chaffeensis or E. ewingii. Twenty patients were male, and the median CD4(+) T lymphocyte count was 137 cells/microL. Exposures to infecting ticks were linked to recreational pursuits, occupations, and peridomestic activities. For 8 patients, a diagnosis of ehrlichiosis was not considered until > or =4 days after presentation. Severe manifestations occurred more frequently among patients infected with E. chaffeensis than they did among patients infected with E. ewingii, and all 6 deaths were caused by E. chaffeensis. Ehrlichiosis may be a life-threatening illness in HIV-infected persons, and the influence of multiple factors, including recent changes in the epidemiology and medical management of HIV infection, may increase the frequency with which ehrlichioses occur in this patient cohort.

Human Ehrlichiosis and Anaplasmosis

Human ehrlichiosis and anaplasmosis are acute febrile tick-borne diseases caused by various members of the genera Ehrlichia and Anaplasma (Anaplasmataceae). Human monocytotropic ehrlichiosis has become one of the most prevalent life-threatening tick-borne disease in the United States. Ehrlichiosis and anaplasmosis are becoming more frequently diagnosed as the cause of human infections, as animal reservoirs and tick vectors have increased in number and humans have inhabited areas where reservoir and tick populations are high. Ehrlichia chaffeensis, the etiologic agent of human monocytotropic ehrlichiosis (HME), is an emerging zoonosis that causes clinical manifestations ranging from a mild febrile illness to a fulminant disease characterized by multiorgan system failure. Anaplasma phagocytophilum causes human granulocytotropic anaplasmosis (HGA), previously known as human granulocytotropic ehrlichiosis. This article reviews recent advances in the understanding of ehrlichial diseases related to microbiology, epidemiology, diagnosis, pathogenesis, immunity, and treatment of the 2 prevalent tick-borne diseases found in the United States, HME and HGA.

Detection of medically important Ehrlichia by quantitative multicolor TaqMan real-time polymerase chain reaction of the dsb gene.

Ehrlichia species are the etiological agents of emerging and life-threatening tick-borne human zoonoses, in addition to causing serious and fatal infections in companion animals and livestock. We developed the first tricolor TaqMan real-time polymerase chain reaction assay capable of simultaneously detecting and discriminating medically important ehrlichiae in a single reaction. Analytical sensitivity of 50 copies per reaction was attained with templates from Ehrlichia chaffeensis, Ehrlichia ewingii, and Ehrlichia canis by amplifying the genus-specific disulfide bond formation protein gene (dsb). Ehrlichia genus-specific dsb primers amplified DNA from all known Ehrlichia species but not from other rickettsial organisms including Anaplasma platys, Anaplasma phagocytophilum, Rickettsia conorii, or Rickettsia typhi. High species specificity was attained as each species-specific TaqMan probe (E. chaffeensis, E. ewingii, and E. canis) identified homologous templates but did not cross-hybridize with heterologous Ehrlichia templates at concentrations as high as 10(8) copies. Identification of E. chaffeensis, E. ewingii, and E. canis from natural and experimental infections, previously confirmed by polymerase chain reaction and serological or microscopic evidence, demonstrated the comparable specificity and sensitivity of the dsb real-time assay. This assay provides a powerful tool for prospective medical diagnosis for human and canine ehrlichioses and for ecologic and epidemiological studies involving arthropod and mammalian hosts.

Dual Infections of the Central Nervous System with Epstein-Barr Virus

We describe clinical and laboratory characteristics of 16 patients with central nervous system (CNS) infection caused by Epstein-Barr virus (EBV) and another pathogen. Seven of 10 immunocompromised patients had coinfection with viruses (3 with cytomegalovirus, 2 with JC virus, and 2 with varicella zoster virus) and 3 with nonviral pathogens (2 with pneumococcus and 1 with Cryptococcus species). Three of 6 immunocompetent patients had coinfections with viruses (1 each with herpes simplex virus, varicella zoster virus, and West Nile virus), and 3 had coinfections with nonviral pathogens (2 with Ehrlichia chaffeensis and 1 with Mycoplasma pneumoniae). The EBV load was similar in immunocompromised and immunocompetent patients and in patients with viral and nonviral coinfections. EBV lytic-cycle mRNA was detected in the cerebrospinal fluid of 5 of 6 tested samples, indicating EBV replication in the CNS during coinfection.

Reduction in HPV 16/18-associated high grade cervical lesions following HPV vaccine introduction in the United States – 2008–2012☆

BACKGROUND Prevention of pre-invasive cervical lesions is an important benefit of HPV vaccines, but demonstrating impact on these lesions is impeded by changes in cervical cancer screening. Monitoring vaccine-types associated with lesions can help distinguish vaccine impact from screening effects. We examined trends in prevalence of HPV 16/18 types detected in cervical intraepithelial neoplasia 2, 3, and adenocarcinoma in situ (CIN2+) among women diagnosed with CIN2+ from 2008 to 2012 by vaccination status. We estimated vaccine effectiveness against HPV 16/18-attributable CIN2+ among women who received ≥1 dose by increasing time intervals between date of first vaccination and the screening test that led to detection of CIN2+ lesion. METHODS Data are from a population-based sentinel surveillance system to monitor HPV vaccine impact on type-specific CIN2+ among adult female residents of five catchment areas in California, Connecticut, New York, Oregon, and Tennessee. Vaccination and cervical cancer screening information was retrieved. Archived diagnostic specimens were obtained from reporting laboratories for HPV DNA typing. RESULTS From 2008 to 2012, prevalence of HPV 16/18 in CIN2+ lesions statistically significantly decreased from 53.6% to 28.4% among women who received at least one dose (Ptrend<.001) but not among unvaccinated women (57.1% vs 52.5%; Ptrend=.08) or women with unknown vaccination status (55.0% vs 50.5%; Ptrend=.71). Estimated vaccine effectiveness for prevention of HPV 16/18-attributable CIN2+ was 21% (95% CI: 1-37), 49% (95% CI: 28-64), and 72% (95% CI: 45-86) in women who initiated vaccination 25-36 months, 37-48 months, and >48 months prior to the screening test that led to CIN2+ diagnosis. CONCLUSIONS Population-based data from the United States indicate significant reductions in CIN2+ lesions attributable to types targeted by the vaccines and increasing HPV vaccine effectiveness with increasing interval between first vaccination and earliest detection of cervical disease.

Herpes Simplex Encephalitis during Treatment with Tumor Necrosis Factor-α Inhibitors

We report 3 cases of herpes simplex virus encephalitis in patients receiving tumor necrosis factor-alpha (TNF-alpha) inhibitors for rheumatologic disorders. Although TNF-alpha inhibitors have been reported to increase the risk of other infectious diseases, to our knowledge, an association between anti-TNF-alpha drugs and herpes simplex virus encephalitis has not been previously described.

Inability To Make a Premortem Diagnosis of Acanthamoeba Species Infection in a Patient with Fatal Granulomatous Amebic Encephalitis

ABSTRACT Granulomatous amebic encephalitis (GAE), an infection of immunocompromised hosts, is almost uniformly fatal. A case of GAE in a patient who failed to mount a serologic response to Acanthamoeba polyphaga is presented. Although Acanthamoeba polyphaga that is sensitive to multiple antimicrobials grew from brain tissue, an inability to make a premortem diagnosis precluded therapy.

Human papillomavirus genotypes in high grade cervical lesions in the United States

BACKGROUND Two vaccines protect against human papillomaviruses (HPV) 16 and 18, which cause 70% of cervical cancer and 50% of cervical intraepithelial neoplasia 2/3 and adenocarcinoma in situ (CIN2+). Monitoring HPV types in CIN2+ may be used to assess HPV vaccine impact. METHODS As part of a multisite vaccine impact monitoring project (HPV-IMPACT), biopsy specimens used to diagnose CIN2+ were obtained for HPV DNA typing for women aged 18-39 years. RESULTS Among 4,121 CIN2+ cases reported during 2008-2009 in 18- to 39-year-old women 3058 (74.2%) were tested; 96% were HPV DNA positive. HPV 16 was most common (49.1%), followed by HPV 31 (10.4%) and HPV 52 (9.7%). HPV 18 prevalence was 5.5% overall. Proportion of CIN2+ cases associated with HPV 16/18 was highest (56.3%) in 25- to 29-year-old women. HPV 16/18-associated lesions were less common in non-Hispanic blacks (41.9%) and Hispanics (46.3%) compared with non-Hispanic whites (59.1%) (P < .0001); the difference remained significant when adjusted for covariates. Compared to non-Hispanic whites, HPV 35 and 58 were significantly more common in non-Hispanic blacks (14.5% vs 4.2%; 12.3% vs 3.4%) and HPV 45 was higher in Hispanics (3.7% vs 1.5%). CONCLUSIONS Age and racial/ethnic differences in HPV type distribution may have implications for vaccine impact and should be considered in monitoring trends.