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At the beginning of the swine influenza (H1N1) pandemic in the spring of 2009, there were still stories of human seasonal influenza A circulating in the New York area. Adult patients admitted with influenza-like illnesses (ILIs) (fever > 102°F, dry cough, and myalgias) presented diagnostic problems. First, clinicians had to differentiate ILIs from influenza, and then differentiate human seasonal influenza A from H1N1 in hospitalized adults with ILIs and negative chest films (no focal segmental/lobar infiltrates). Human seasonal influenza A was diagnosed by rapid influenza diagnostic tests (RIDTs), but H1N1 was often RIDT negative. Reverse transcriptase-polymerase chain reaction for H1N1 was restricted or not available. The Winthrop-University Hospital Infectious Disease Division developed clinical diagnostic criteria (a diagnostic weighted point score system) to rapidly and clinically diagnose H1N1 in patients with negative RIDTs. The point score system was modified and shortened for ease of use, that is, the diagnostic H1N1 triad (any 3 of 4) (ILI, see above) plus thrombocytopenia, relative lymphopenia, elevated serum transaminases, or an elevated creatine phosphokinase. Our clinical experience during the pandemic allowed us to develop the swine diagnostic H1N1 triad. In the process, similarities and differences between human seasonal influenza A and H1N1 were noted. We present 2 illustrative cases of severe influenza, one due to human seasonal influenza A and one due to H1N1, for clinical consideration reflective of our experiences early in the H1N1 pandemic in 2009., (Copyright © 2011 Elsevier Inc. All rights reserved.)

In patients with swine influenza (H1N1) pneumonia, the admission chest film is critical to rapidly detect simultaneous bacterial pneumonia due to Staphylococcus aureus or subsequent bacterial pneumonia due to Streptococcus pneumoniae or Haemophilus influenzae by the presence of focal infiltrates. Our objective was to characterize the chest film findings in 25 adults hospitalized with H1N1 pneumonia during the pandemic and detect focal infiltrates indicative of bacterial coinfection, that is, bacterial pneumonia. Chest films were obtained on admission, after 48 hours, and thereafter as indicated throughout hospitalization. Chest film findings were classified as no infiltrates, clear with accentuated bibasilar lung markings, or focal segmental/lobar infiltrates. The presence or absence of pleural effusion and cavitation was also noted. Admitted adults with H1N1 pneumonia had negative chest films or accentuated basilar lung markings. After 48 hours, 13% of patients developed patchy bilateral interstitial infiltrates. No patients had or subsequently developed focal segmental/lobar infiltrates indicative of bacterial community-acquired pneumonia during hospitalization. The most common chest film finding was no infiltrates or an accentuation of bibasilar lung markings in hospitalized adults with H1N1 pneumonia. No patients had focal segmental/lobar infiltrates indicative of superimposed bacterial community-acquired pneumonia., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: In general, viral infections of the central nervous system (CNS) manifest as encephalitis and, less commonly, as meningoencephalitis or aseptic meningitis. Varicella zoster virus (VZV) is an uncommon cause of encephalitis., Methods: Herpes zoster (shingles) is a cutaneous reactivation of previous chickenpox infection due to VZV. Herpes zoster may be dermatomal (ie, <3 dermatomes) or disseminated (ie, >3 dermatomes). Decreased cell-mediated immunity from stress, steroids, or immunosuppressive drugs often precede dermatomal/disseminated herpes zoster. With herpes zoster, the closer the dermatomal involvement is to the CNS (ie, head/neck shingles), the more likely a patient will have symptomatic CNS involvement (eg, encephalitis). Except for the association of the herpes zoster rash and the simultaneous/subsequent encephalitis, there are few clinical features that distinguish VZV encephalitis from that due to other viruses. The cerebrospinal fluid (CSF) profile of VZV encephalitis is usually clinically indistinguishable from that due to of other causes of viral encephalitis. In VZV meningoencephalitis or encephalitis, the CSF typically shows a modest lymphocytic pleocytosis with normal CSF glucose levels, variably elevated CSF protein levels, and normal CSF lactic acid levels. Atypical lymphocytes are rare in the CSF with VZV encephalitis., Results: We present the case of a 75-year-old woman who developed VZV encephalitis after having herpes zoster on her forehead. Except for facial herpes zoster, there were no clinically distinguishing features to determine the cause of her encephalitis. Her CSF had 800 white blood cells/high power field with 26% lymphocytes (17% atypical lymphocytes). The patient's CSF glucose and CSF lactate dehydrogenase levels were normal, and her CSF protein was elevated. The CSF lactic acid was minimally elevated secondary to red blood cells in the CSF. Electroencephalogram showed general background slowing bilaterally, typical of viral encephalitis. The absence of unilateral focal frontotemporal/parietal lobe focus on electroencephalogram argued against the diagnosis of herpes simplex encephalitis. CSF atypical lymphocytes provided the key clue to the etiology of her encephalitis. CSF atypical lymphocytes are not uncommon in Epstein-Barr virus or cytomegalovirus encephalitis. Less commonly, atypical lymphocytes may be present in the CSF with enteroviruses, West Nile encephalitis, and Japanese encephalitis. VZV is a rare cause of atypical lymphocytes in the CSF but was the clue to the diagnosis before CSF polymerase chain reaction results for VZV were available. Her CSF polymerase chain reaction was negative for Mycobacterium tuberculosis, herpes simplex virus, human herpesvirus-6, cytomegalovirus, enteroviruses, and West Nile virus, but was positive for VZV. She made an uneventful recovery with acyclovir., Conclusion: CSF atypical lymphocytes, if present, are an important diagnostic clue in some causes of viral encephalitis. The most common cause of nonseasonal viral encephalitis is herpes simplex virus, which is not associated with CSF atypical lymphocytes. Patients with Epstein-Barr virus, cytomegalovirus, West Nile encephalitis, and enteroviruses usually have extra-CNS signs and symptoms which should suggest the cause of the patient's encephalitis. CSF atypical lymphocytes limit the differential diagnostic possibilities in patients with viral encephalitis and may be the key clue to the diagnosis, as in the case presented., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: In adults hospitalized with atypical community-acquired pneumonia (CAP), Legionnaires' disease is not uncommon. Legionnaire's disease can be differentiated from typical CAPs and from other atypical CAPs based on its characteristic pattern of extrapulmonary organ involvement. The first clinically useful diagnostic weighted point score system for the clinical diagnosis of Legionnaires' disease was developed by the Infectious Disease Division at Winthrop-University Hospital in the 1980s. It has proven to be diagnostically accurate and useful for more than two decades, but was time-consuming. Because Legionella spp. diagnostic tests are time-dependent and problematic, a need was perceived for a rapid, simple way to render a clinical, syndromic diagnosis of Legionnaires' disease pending Legionella test results. During the "herald wave" of the swine influenza (H1N1) pandemic in the New York area, our hospital, like others, was inundated with patients who presented to the Emergency Department with influenza-like illnesses (ILIs) for H1N1 testing/evaluation. Most patients with ILIs did not have swine influenza. Hospitalized patients with ILIs who tested positive with rapid influenza diagnostic tests (RIDTs) were placed on influenza precautions and treated with oseltamivir. Unfortunately, approximately 30% of adult patients admitted with an ILI had negative RIDTs. Because the definitive laboratory diagnosis of H1N1 pneumonia by reverse transcription-polymerase chain reaction(RT-PCR), testing was restricted by health departments, resulted in clinical and infection control dilemmas in determining which RIDT-negative patients did, in fact, have H1N1 pneumonia., Objective: Accordingly, a diagnostic weighted point score system was developed for H1N1 pneumonia patients, based on RT-PCR positivity by the Infectious Disease Division at Winthrop-University Hospital. This diagnostic point score system for hospitalized adults with negative RIDTs was time-consuming. As the pandemic progressed, a simplified diagnostic swine influenza (H1N1) triad was developed for the rapid clinical diagnosis of probable H1N1 pneumonia, which also differentiated it from its mimics as well as from bacterial pneumonia, eg, Legionnaires' disease. During the "herald wave" of the H1N1 pandemic, we noticed an unexplained increase in Legionnaires' disease CAPs. Because clinical resources were stressed to the maximum during the pandemic, it was critically important to rapidly identify patients rapidly with Legionnaire's disease who did not require influenza precautions or oseltamivir, but who did require anti-Legionella antimicrobial therapy., Methods: Based on the Winthrop-University Hospital Infectious Disease Division's diagnostic weighted point score system for Legionnaires' disease (modified), key indicators were identified and became the basis for the diagnostic Legionnaires' disease triad. The diagnostic Legionnaires' disease triad was used to make a clinical diagnosis of Legionnaires' disease until the results of Legionella diagnostic tests were reported. The diagnostic Legionnaires' disease triad diagnosed Legionnaires' disease in hospitalized adults with CAPs with extrapulmonary findings (atypical CAP) and relative bradycardia, accompanied by any three (ie, a triad) of the following: otherwise unexplained relative lymphopenia, early/mildly elevated serum transaminases (SGOT/SGPT), highly increased ferritin levels (> or =2 x n), or hypophosphatemia. The diagnostic Legionnaires' disease triad provides clinicians with a rapid way to clinically diagnose Legionnaires' disease, pending Legionella test results., Results: The accuracy of the diagnostic Legionnaires' disease triad was confirmed in our 9 cases of Legionnaires' disease by subsequent Legionella diagnostic testing., Conclusions: The diagnostic Legionnaires' disease triad is particularly useful in situations where a rapid clinical syndromic diagnosis is needed, ie, during an H1N1 pandemic., (Copyright 2010 Elsevier Inc. All rights reserved.)

Background: New York area hospitals were hit hard by the swine influenza (H1N1) pandemic in spring and summer 2009. During a pandemic, the initial cases may be difficult to recognize, but subsequent clinical diagnoses were relatively straightforward, given the high volume of cases and their typical clinical presentation. Swine influenza pneumonia presents as an influenza-like illness (ILI) with dry cough, fever >102 degrees F and myalgias. A variety of other viral pneumonias, eg, cytomegalovirus, human parainfluenza virus 3 (HPIV 3), and adenovirus, as well as bacterial community-acquired pneumonias (CAPs) that may present with some of the clinical and laboratory features of H1N1 pneumonia. Most adults admitted to hospitals with ILIs during the pandemic had, in fact, definite or probable H1N1 pneumonia. The Infectious Disease Division at Winthrop-University Hospital developed a diagnostic weighted point score to identify probable H1N1 cases in hospitalized adults with rapid negative influenza diagnostic tests (RIDTs)., Methods: We present a case of an elderly male who presented with an ILI and negative RIDTs during the H1N1 pandemic. He was admitted with a diagnosis of possible H1N1, and placed on influenza precautions and oseltamivir. Although the patient had features consistent with H1N1 pneumonia, Legionnaires' disease was included in the differential diagnosis because of his elevated serum ferritin levels. A Legionella urinary antigen test was positive for Legionella pneumophila (serogroups 01-06)., Results: The peak seasonal incidence of sporadic Legionnaires' disease occurs in the summer and fall. Even in the midst of a pandemic, clinicians should be on the alert for other infectious diseases that may mimic H1N1 pneumonia. In our experience, the best way to differentiate H1N1 from ILIs or other bacterial CAPs is through the Winthrop-University Hospital Infectious Disease Division's diagnostic weighted point score system for H1N1 pneumonia or its rapid simplified version, ie, the diagnostic swine influenza triad. Legionnaires' disease is the atypical CAP pathogen most likely to mimic H1N1 pneumonia., Conclusions: Based on this and other nine cases at our institution during the "herald wave" of pandemic, we conclude that Legionnaires' disease may mimic swine influenza (H1N1) pneumonia., (Copyright 2010 Elsevier Inc. All rights reserved.)

Kawasaki's disease is a disease of unknown cause. The characteristic clinical features of Kawasaki's disease are fever> or =102 degrees F for> or =5 days accompanied by a bilateral bulbar conjunctivitis/conjunctival suffusion, erythematous rash, cervical adenopathy, pharyngeal erythema, and swelling of the dorsum of the hands/feet. Kawasaki's disease primarily affects children and is rare in adults. In children, Kawasaki's disease is more likely to be associated with aseptic meningitis, coronary artery aneurysms, and thrombocytosis. In adult Kawasaki's disease, unilateral cervical adenopathy, arthritis, conjunctival suffusion/conjunctivitis, and elevated serum transaminases (serum glutamic oxaloacetic transaminase [SGOT]/serum glutamate pyruvate transaminase [SGPT]) are more likely. Kawasaki's disease in adults may be mimicked by other acute infections with fever and rash, that is, group A streptococcal scarlet fever, toxic shock syndrome (TSS), and Rocky Mountain Spotted Fever (RMSF). Because there are no specific tests for Kawasaki's disease, diagnosis is based on clinical criteria and the syndromic approach. In addition to rash and fever, scarlet fever is characterized by circumoral pallor, oropharyngeal edema, Pastia's lines, and peripheral eosinophilia, but not conjunctival suffusion, splenomegaly, swelling of the dorsum of the hands/feet, thrombocytosis, or an elevated SGOT/SGPT. In TSS, in addition to rash and fever, there is conjunctival suffusion, oropharyngeal erythema, and edema of the dorsum of the hands/feet, an elevated SGOT/SGPT, and thrombocytopenia. Patients with TSS do not have cervical adenopathy or splenomegaly. RMSF presents with fever and a maculopapular rash that becomes petechial, first appearing on the wrists/ankles after 3 to 5 days. RMSF is accompanied by a prominent headache, periorbital edema, conjunctival suffusion, splenomegaly, thrombocytopenia, an elevated SGOT/SGPT, swelling of the dorsum of the hands/feet, but not oropharyngeal erythema. We present a case of adult Kawasaki's disease with myocarditis and splenomegaly. The patient's myocarditis rapidly resolved, and he did not develop coronary artery aneurysms. In addition to splenomegaly, this case of adult Kawasaki's disease is remarkable because the patient had highly elevated serum ferritin levels of 944-1303 ng/mL; (normal<189 ng/mL). To the best of our knowledge, this is the first report of adult Kawasaki's disease with highly elevated serum ferritin levels. This is also the first report of splenomegaly in adult Kawasaki's disease. We conclude that Kawasaki's disease should be considered in the differential diagnosis in adult patients with rash/fever for> or =5 days with conjunctival suffusion, cervical adenopathy, swelling of the dorsum of the hands/feet, thrombocytosis and otherwise unexplained highly elevated ferritin levels., (Copyright 2010 Elsevier Inc. All rights reserved.)

Background: The "herald wave" of the H1N1 pandemic spread from Mexico to the United States in spring 2009. Initially, the epicenter of H1N1 in the United States was in the New York area. Our hospital, like others, was inundated with large numbers of patients who presented at the Emergency Department (ED) with influenza-like illnesses (ILIs) for swine influenza testing and evaluation., Methods: The Winthrop-University Hospital ED used rapid influenza (QuickVue A/B) tests to screen for H1N1 infection. Patients who were rapid influenza A test-positive were also reverse transcription-polymerase chain reaction (RT-PCR) positive for H1N1. In our ED, 30% of patients with ILIs and possible H1N1 pneumonia had negative rapid influenza A screening tests. Because H1N1 RT-PCR testing was restricted, there was no laboratory test to confirm or rule out H1N1. Other rapid influenza diagnostic tests (RIDTs), e.g., the respiratory fluorescent antibody (FA) viral panel test, were used to identify H1N1 patients with negative RIDTs., Results: Unfortunately, there was not a good correlation between RIDT results and RT-PCR results. There was a critical need to develop a clinical syndromic approach for diagnosing hospitalized adults with probable H1N1 pneumonia with negative RIDTs. Early in the pandemic, the Winthrop-University Hospital Infectious Disease Division developed a diagnostic weighted point score system to diagnose H1N1 pneumonia clinically in RIDT-negative adults. The point score system worked well, but was time-consuming. As the "herald wave" of the pandemic progressed, our ED staff needed a rapid, simplified method to diagnose probable H1N1 pneumonia in hospitalized adults with negative RIDTs. A rapid and simplified diagnosis was based on the diagnostic weighted point score system, which we simplified into a triad of key, nonspecific laboratory indicators. In adults hospitalized with an ILI, a fever >102 degrees F with severe myalgias, and a chest x-ray without focal segmental/lobar infiltrates, the presence of three indicators, i.e., otherwise unexplained relative lymphopenia, elevated serum transaminases, and an elevated creatinine phosphokinase, constituted the diagnostic swine influenza triad. The Infectious Disease Division's diagnostic swine flu triad was used effectively as the pandemic progressed, and was not only useful in correctly diagnosing probable H1N1 pneumonia in hospitalized adults with negative RIDTs, but was also in ruling out mimics of swine influenza, e.g., exacerbations of chronic bronchitis, asthma, or congestive heart failure, as well as bacterial community-acquired pneumonias (CAPs), e.g., legionnaire's disease., Conclusion: Clinicians can use the Winthrop-University Hospital Infectious Disease Division's Diagnostic swine influenza triad to make a rapid clinical diagnosis of probable H1N1 pneumonia in hospitalized adult patients with negative RIDTs., (2010 Mosby, Inc. All rights reserved.)

Fever of unknown origin (FUO) refers to prolonged fevers of > or = 101 degrees F and that persists for > 3 weeks that remain undiagnosed after an intensive in-hospital/outpatient workup. The most common FUO categories of are infectious, neoplastic, rheumatic/inflammatory, and miscellaneous causes. Malignancies have supplanted infectious diseases as the most common cause of FUOs in the adult population. Rheumatic/inflammatory causes of FUO are relatively less common than previously because of the introduction over the years of sophisticated diagnostic tests for most rheumatic diseases. The rheumatic/inflammatory disorders that remain important causes of FUO today are those that cannot be readily diagnosed by readily available/noninvasive tests, for example, adult Still's disease and temporal arteritis (TA). In older patients with FUO, TA can be a difficult diagnosis when the characteristic findings (ie, scalp tenderness, jaw claudication) are not present. Patients with TA presenting as FUO often have only headaches that may be accompanied by bilateral jaw discomfort. Endocrine causes of FUOs are rare. The most common endocrine disorder rarely presenting as an FUO is de Quervain's subacute thyroiditis. As in TA, subacute thyroiditis may present with headache and pain at the angle of the jaw. Both TA and subacute thyroiditis may be accompanied by fatigue, weight loss, and night sweats. We present a case of 55-year-old woman who presented with an FUO with clinical and laboratory findings suggesting TA. However, the absence of thrombocytosis and a normal alkaline phosphatase argued against the diagnosis of TA. Also against the diagnosis of TA was weight loss without loss of appetite and a slightly increased pulse. After nonspecific laboratory test results suggested that TA was not the cause of her FUO, additional tests were ordered. Thyroid function test results suggested the possibility of de Quervain's subacute thyroiditis as the cause of her FUO. To the best of our knowledge, this is the first case of de Quervain's subacute thyroiditis presenting as an FUO with elevated ferritin levels., (2010 Elsevier Inc. All rights reserved.)

Fever of unknown origin (FUO) refers to infectious, neoplastic, or rheumatic/inflammatory disorders that present with fevers of 101 degrees F or greater for 3 weeks and that remain undiagnosed after an intensive in-hospital or outpatient workup. The noninfectious causes of FUO in adults are most often lymphomas or rheumatic/inflammatory disorders. Among the rare causes of rheumatic/inflammatory FUOs is Kikuchi's disease. Kikuchi's disease (Kikuchi-Fujimoto disease) is also known as histiocytic necrotizing lymphadenitis, a benign, self-limited disorder usually in middle-aged women of Asian descent. Cervical adenopathy is typical and often accompanied by leukopenia. In middle-aged adults patients presenting with an FUO, the presence of otherwise unexplained cervical adenopathy should suggest the possibility of lymphoma or, rarely, Kikuchi's disease.