Tuberculosis Diagnostic Delays and Treatment Outcomes among Patients with COVID-19, California, USA, 2020.

We assessed tuberculosis (TB) diagnostic delays among patients with TB and COVID-19 in California, USA. Among 58 persons, 43% experienced TB diagnostic delays, and a high proportion (83%) required hospitalization for TB. Even when viral respiratory pathogens circulate widely, timely TB diagnostic workup for at-risk persons remains critical for reducing TB-related illness.

Second Nationwide Tuberculosis Outbreak Caused by Bone Allografts Containing Live Cells - United States, 2023.

During July 7-11, 2023, CDC received reports of two patients in different states with a tuberculosis (TB) diagnosis following spinal surgical procedures that used bone allografts containing live cells from the same deceased donor. An outbreak associated with a similar product manufactured by the same tissue establishment (i.e., manufacturer) occurred in 2021. Because of concern that these cases represented a second outbreak, CDC and the Food and Drug Administration worked with the tissue establishment to determine that this product was obtained from a donor different from the one implicated in the 2021 outbreak and learned that the bone allograft product was distributed to 13 health care facilities in seven states. Notifications to all seven states occurred on July 12. As of December 20, 2023, five of 36 surgical bone allograft recipients received laboratory-confirmed TB disease diagnoses; two patients died of TB. Whole-genome sequencing demonstrated close genetic relatedness between positive Mycobacterium tuberculosis cultures from surgical recipients and unused product. Although the bone product had tested negative by nucleic acid amplification testing before distribution, M. tuberculosis culture of unused product was not performed until after the outbreak was recognized. The public health response prevented up to 53 additional surgical procedures using allografts from that donor; additional measures to protect patients from tissue-transmitted M. tuberculosis are urgently needed.

Characteristics of and Deaths among 333 Persons with Tuberculosis and COVID-19 in Cross-Sectional Sample from 25 Jurisdictions, United States.

Little is known about co-occurring tuberculosis (TB) and COVID-19 in low TB incidence settings. We obtained a cross-section of 333 persons in the United States co-diagnosed with TB and COVID-19 within 180 days and compared them to 4,433 persons with TB only in 2020 and 18,898 persons with TB during 2017‒2019. Across both comparison groups, a higher proportion of persons with TB-COVID-19 were Hispanic, were long-term care facility residents, and had diabetes. When adjusted for age, underlying conditions, and TB severity, COVID-19 co-infection was not statistically associated with death compared with TB infection only in 2020 (adjusted prevalence ratio 1.0 [95% CI 0.8‒1.4]). Among TB-COVID-19 patients, death was associated with a shorter interval between TB and COVID-19 diagnoses, older age, and being immunocompromised (non-HIV). TB-COVID-19 deaths in the United States appear to be concentrated in subgroups sharing characteristics known to increase risk for death from either disease alone.

Recommendations for Use of Video Directly Observed Therapy During Tuberculosis Treatment - United States, 2023.

U.S. clinical practice guidelines recommend directly observed therapy (DOT) as the standard of care for tuberculosis (TB) treatment (1). DOT, during which a health care worker observes a patient ingesting the TB medications, has typically been conducted in person. Video DOT (vDOT) uses video-enabled devices to facilitate remote interactions between patients and health care workers to promote medication adherence and clinical monitoring. Published systematic reviews, a published meta-analysis, and a literature search through 2022 demonstrate that vDOT is associated with a higher proportion of medication doses being observed and similar proportions of cases with treatment completion and microbiologic resolution when compared with in-person DOT (2-5). Based on this evidence, CDC has updated the recommendation for DOT during TB treatment to include vDOT as an equivalent alternative to in-person DOT. vDOT can assist health department TB programs meet the U.S. standard of care for patients undergoing TB treatment, while using resources efficiently.

Loss of Taste and Smell as Distinguishing Symptoms of Coronavirus Disease 2019.

In a household study, loss of taste and/or smell was the fourth most reported symptom (26/42 [62%]) among coronavirus disease 2019 (COVID-19) case patients and had the highest positive predictive value (83% [95% confidence interval [CI], 55%-95%) among household contacts. Olfactory and taste dysfunctions should be considered for COVID-19 case identification and testing prioritization.

Characteristics and Timing of Initial Virus Shedding in Severe Acute Respiratory Syndrome Coronavirus 2, Utah, USA.

Virus shedding in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can occur before onset of symptoms; less is known about symptom progression or infectiousness associated with initiation of viral shedding. We investigated household transmission in 5 households with daily specimen collection for 5 consecutive days starting a median of 4 days after symptom onset in index patients. Seven contacts across 2 households implementing no precautionary measures were infected. Of these 7, 2 tested positive for SARS-CoV-2 by reverse transcription PCR on day 3 of 5. Both had mild, nonspecific symptoms for 1-3 days preceding the first positive test. SARS-CoV-2 was cultured from the fourth-day specimen in 1 patient and from the fourth- and fifth-day specimens in the other. We also describe infection control measures taken in the households that had no transmission. Persons exposed to SARS-CoV-2 should self-isolate, including from household contacts, wear a mask, practice hand hygiene, and seek testing promptly.

Performance of existing and novel surveillance case definitions for COVID-19 in household contacts of PCR-confirmed COVID-19.

BACKGROUND: Optimized symptom-based COVID-19 case definitions that guide public health surveillance and individual patient management in the community may assist pandemic control. METHODS: We assessed diagnostic performance of existing cases definitions (e.g. influenza-like illness, COVID-like illness) using symptoms reported from 185 household contacts to a PCR-confirmed case of COVID-19 in Wisconsin and Utah, United States. We stratified analyses between adults and children. We also constructed novel case definitions for comparison. RESULTS: Existing COVID-19 case definitions generally showed high sensitivity (86-96%) but low positive predictive value (PPV) (36-49%; F-1 score 52-63) in this community cohort. Top performing novel symptom combinations included taste or smell dysfunction and improved the balance of sensitivity and PPV (F-1 score 78-80). Performance indicators were generally lower for children (< 18 years of age). CONCLUSIONS: Existing COVID-19 case definitions appropriately screened in household contacts with COVID-19. Novel symptom combinations incorporating taste or smell dysfunction as a primary component improved accuracy. Case definitions tailored for children versus adults should be further explored.

Anicteric Leptospirosis-Associated Meningitis in a Tropical Urban Environment, Brazil.

While studying aseptic meningitis in Salvador, Brazil, we diagnosed anicteric leptospirosis in 1.7% (5/295) of patients hospitalized for aseptic meningitis. Leptospirosis-associated meningitis patients had lower mean cerebrospinal fluid cell counts and protein than other-cause aseptic meningitis (p<0.05). Clinicians must consider leptospirosis-associated meningitis in appropriate clinical-epidemiologic contexts.

Isoniazid-associated pellagra during mass scale-up of tuberculosis preventive therapy: a case-control study.

BACKGROUND: Pellagra is caused by niacin (vitamin B3) deficiency and patients with pellagra present with a characteristic rash. Isoniazid disrupts intracellular niacin synthesis and might induce niacin deficiency. In 2017, Malawi scaled up continuous isoniazid preventive treatment (IPT) for tuberculosis prevention among people living with HIV. In addition, an under-diversified diet based on subsistence maize, as is commonly the case in Malawi, is a risk factor for pellagra. We aimed to investigate whether large-scale isoniazid exposure in Malawi contributed to the cumulative risk for pellagra in a nutritionally vulnerable population. METHODS: We did a matched case-control study to evaluate the association between daily, continuous isoniazid exposure and pellagra. We matched sequentially enrolled patients with pellagra each with four control participants by sex and age from referral dermatology centres in three IPT scale-up districts in Malawi (Lilongwe, Blantyre, and Zomba) to evaluate isoniazid as a risk for pellagra using multivariable conditional logistic regression. We established a community clinic referral system surrounding the dermatology clinic in each district to enhance case-finding and included all patients with pellagra, regardless of referral status. The primary outcome was dermatologist-diagnosed pellagra. We calculated the interval between isoniazid initiation and rash onset and assessed 30-day clinical outcomes after multi-B vitamin treatment containing 300 mg nicotinamide daily. FINDINGS: Between Feb 5 and Aug 9, 2019, we enrolled 197 patients with pellagra and 781 matched controls. Isoniazid exposure was associated with an increased risk of pellagra (adjusted odds ratio 42·6 [95% CI 13·3-136·6]). Significant covariates included HIV infection, referral status, food insecurity, underweight, excess alcohol consumption, and, among women, lactation. The median time from isoniazid initiation to rash onset was shorter during the season of food scarcity (5 months [IQR 3-7]) compared with the harvest season (9 months [8-11]; hazard ratio 7·2 [95% CI 3·2-16·2], log-rank p<0·0001). Those with isoniazid-associated pellagra who discontinued isoniazid and adhered to multi-B vitamin treatment showed 30-day clinical improvement. INTERPRETATION: Continuous IPT scale-up and the annual period of food scarcity both increased the risk of pellagra in Malawi. Use of shorter rifamycin-based regimens for tuberculosis prevention and food fortification in populations with undernutrition might reduce this risk. Niacin-containing multi-B vitamin co-administration with isoniazid as pellagra prevention is worth exploring further. FUNDING: This study was supported by the President's Emergency Plan for AIDS Relief through the US Centers for Disease Control and Prevention under project 7173.

Early-phase scale-up of isoniazid preventive therapy for people living with HIV in two districts in Malawi (2017).

BACKGROUND: Isoniazid preventive therapy (IPT) against tuberculosis (TB) is a life-saving intervention for people living with HIV (PLHIV). In September 2017, Malawi began programmatic scale-up of IPT to eligible PLHIV in five districts with high HIV and TB burden. We measured the frequency and timeliness of early-phase IPT implementation to inform quality-improvement processes. METHODS AND FINDINGS: We applied a two-stage cluster design with systematic, probability-proportional-to-size sampling of six U.S. Centers for Disease Control and Prevention (CDC)-affiliated antiretroviral therapy (ART) centers operating in the urban areas of Lilongwe and Blantyre, Malawi (November 2017). ART clinic patient volume determined cluster size. Within each cluster, we sequentially sampled approximately 50 PLHIV newly enrolled in ART care. We described a quality-of-care cascade for intensive TB case finding (ICF) and IPT in PLHIV. PLHIV newly enrolled in ART care were eligibility-screened for hepatitis and peripheral neuropathy, as well as for TB disease using a standardized four-symptom screening tool. Among eligible PLHIV, the overall weighted IPT initiation rate was 70% (95% CI: 46%-86%). Weighted IPT initiation among persons aged <15 years (30% [95% CI: 12%-55%]) was significantly lower than among persons aged ≥15 years (72% [95% CI: 47%-89%]; Rao-Scott chi-square P = 0.03). HIV-positive children aged <5 years had a weighted initiation rate of only 13% (95% CI: 1%-79%). For pregnant women, the weighted initiation rate was 67% (95% CI: 32%-90%), similar to non-pregnant women aged ≥15 years (72% [95% CI: 49%-87%]). Lastly, 95% (95% CI: 92%-97%) of eligible PLHIV started ART within one week of HIV diagnosis, and 92% (95% CI: 73%-98%) of patients receiving IPT began on the same day as ART. CONCLUSIONS: Early-phase IPT uptake among adults at ART centers in Malawi was high. Child uptake needed improvement. National programs could adapt this framework to evaluate their ICF-IPT care cascades.

Sociodemographic Characteristics, Comorbidities, and Mortality Among Persons Diagnosed With Tuberculosis and COVID-19 in Close Succession in California, 2020.

Importance: Tuberculosis (TB) and COVID-19 are respiratory diseases that disproportionately occur among medically underserved populations; little is known about their epidemiologic intersection. Objective: To characterize persons diagnosed with TB and COVID-19 in California. Design, Setting, and Participants: This cross-sectional analysis of population-based public health surveillance data assessed the sociodemographic, clinical, and epidemiologic characteristics of California residents who were diagnosed with TB (including cases diagnosed and reported between September 3, 2019, and December 31, 2020) and COVID-19 (including confirmed cases based on positive results on polymerase chain reaction tests and probable cases based on positive results on antigen assays reported through February 2, 2021) in close succession compared with those who were diagnosed with TB before the COVID-19 pandemic (between January 1, 2017, and December 31, 2019) or diagnosed with COVID-19 alone (through February 2, 2021). This analysis included 3 402 713 California residents with COVID-19 alone, 6280 with TB before the pandemic, and 91 with confirmed or probable COVID-19 diagnosed within 120 days of a TB diagnosis (ie, TB/COVID-19). Exposures: Sociodemographic characteristics, medical risk factors, factors associated with TB severity, and health equity index. Main Outcomes and Measures: Frequency of reported successive TB and COVID-19 (TB/COVID-19) diagnoses within 120 days, frequency of deaths, and age-adjusted mortality rates. Results: Among the 91 persons with TB/COVID-19, the median age was 58.0 years (range, 3.0-95.0 years; IQR, 41.0-73.0 years); 52 persons (57.1%) were male; 81 (89.0%) were born outside the US; and 28 (30.8%) were Asian or Pacific Islander, 4 (4.4%) were Black, 55 (60.4%) were Hispanic or Latino, 4 (4.4%) were White. The frequency of reported COVID-19 among those who received a TB diagnosis between September 3, 2019, and December 31, 2020, was 225 of 2210 persons (10.2%), which was similar to that of the general population (3 402 804 of 39 538 223 persons [8.6%]). Compared with persons with TB before the pandemic, those with TB/COVID-19 were more likely to be Hispanic or Latino (2285 of 6279 persons [36.4%; 95% CI, 35.2%-37.6%] vs 55 of 91 persons [60.4%; 95% CI, 49.6%-70.5%], respectively; P < .001), reside in low health equity census tracts (1984 of 6027 persons [32.9%; 95% CI, 31.7%-34.1%] vs 40 of 89 persons [44.9%; 95% CI, 34.4%-55.9%]; P = .003), live in the US longer before receiving a TB diagnosis (median, 19.7 years [IQR, 7.2-32.3 years] vs 23.1 years [IQR, 15.2-31.5 years]; P = .03), and have diabetes (1734 of 6280 persons [27.6%; 95% CI, 26.5%-28.7%] vs 42 of 91 persons [46.2%; 95% CI, 35.6%-56.9%]; P < .001). The frequency of deaths among those with TB/COVID-19 successively diagnosed within 30 days (8 of 34 persons [23.5%; 95% CI, 10.8%-41.2%]) was more than twice that of persons with TB before the pandemic (631 of 5545 persons [11.4%; 95% CI, 10.6%-12.2%]; P = .05) and 20 times that of persons with COVID-19 alone (42 171 of 3 402 713 persons [1.2%; 95% CI, 1.2%-1.3%]; P < .001). Persons with TB/COVID-19 who died were older (median, 81.0 years; IQR, 75.0-85.0 years) than those who survived (median, 54.0 years; IQR, 37.5-68.5 years; P < .001). The age-adjusted mortality rate remained higher among persons with TB/COVID-19 (74.2 deaths per 1000 persons; 95% CI, 26.2-122.1 deaths per 1000 persons) compared with either disease alone (TB before the pandemic: 56.3 deaths per 1000 persons [95% CI, 51.2-61.4 deaths per 1000 persons]; COVID-19 only: 17.1 deaths per 1000 persons [95% CI, 16.9-17.2 deaths per 1000 persons]). Conclusions and Relevance: In this cross-sectional analysis, TB/COVID-19 was disproportionately diagnosed among California residents who were Hispanic or Latino, had diabetes, or were living in low health equity census tracts. These results suggest that tuberculosis and COVID-19 occurring together may be associated with increases in mortality compared with either disease alone, especially among older adults. Addressing health inequities and integrating prevention efforts could avert the occurrence of concurrent COVID-19 and TB and potentially reduce deaths.

Symptoms and Transmission of SARS-CoV-2 Among Children - Utah and Wisconsin, March-May 2020.

BACKGROUND AND OBJECTIVES: Limited data exist on severe acute respiratory syndrome coronavirus 2 in children. We described infection rates and symptom profiles among pediatric household contacts of individuals with coronavirus disease 2019. METHODS: We enrolled individuals with coronavirus disease 2019 and their household contacts, assessed daily symptoms prospectively for 14 days, and obtained specimens for severe acute respiratory syndrome coronavirus 2 real-time reverse transcription polymerase chain reaction and serology testing. Among pediatric contacts (<18 years), we described transmission, assessed the risk factors for infection, and calculated symptom positive and negative predictive values. We compared secondary infection rates and symptoms between pediatric and adult contacts using generalized estimating equations. RESULTS: Among 58 households, 188 contacts were enrolled (120 adults; 68 children). Secondary infection rates for adults (30%) and children (28%) were similar. Among households with potential for transmission from children, child-to-adult transmission may have occurred in 2 of 10 (20%), and child-to-child transmission may have occurred in 1 of 6 (17%). Pediatric case patients most commonly reported headache (79%), sore throat (68%), and rhinorrhea (68%); symptoms had low positive predictive values, except measured fever (100%; 95% confidence interval [CI]: 44% to 100%). Compared with symptomatic adults, children were less likely to report cough (odds ratio [OR]: 0.15; 95% CI: 0.04 to 0.57), loss of taste (OR: 0.21; 95% CI: 0.06 to 0.74), and loss of smell (OR: 0.29; 95% CI: 0.09 to 0.96) and more likely to report sore throat (OR: 3.4; 95% CI: 1.04 to 11.18). CONCLUSIONS: Children and adults had similar secondary infection rates, but children generally had less frequent and severe symptoms. In two states early in the pandemic, we observed possible transmission from children in approximately one-fifth of households with potential to observe such transmission patterns.

Protocol for a Case-Control Study to Investigate the Association of Pellagra With Isoniazid Exposure During Tuberculosis Preventive Treatment Scale-Up in Malawi.

Background: Pellagra is caused by niacin (vitamin B3) deficiency and manifested by a distinctive dermatitis. Isoniazid is critical for treating tuberculosis globally and is a component of most regimens to prevent tuberculosis. Isoniazid may contribute to pellagra by disrupting intracellular niacin synthesis. In 2017, Malawian clinicians recognized a high incidence of pellagra-like rashes after scale-up of isoniazid preventive treatment (IPT) to people living with HIV (PLHIV). This increase in pellagra incidence among PLHIV coincided with a seasonal period of sustained food insecurity in the region, which obscured epidemiological interpretations. Although isoniazid has been implicated as a secondary cause of pellagra for decades, no hypothesis-driven epidemiological study has assessed this relationship in a population exposed to isoniazid. We developed this case-control protocol to assess the association between large-scale isoniazid distribution and pellagra in Malawi. Methods: We measure the relative odds of having pellagra among isoniazid-exposed people compared to those without exposure while controlling for other pellagra risk factors. Secondary aims include measuring time from isoniazid initiation to onset of dermatitis, comparing niacin metabolites 1-methylnicotinamide (1-MN), and l-methyl-2-pyridone-5-carboxamide (2-PYR) in urine as a proxy for total body niacin status among subpopulations, and describing clinical outcomes after 30-days multi-B vitamin (containing 300 mg nicotinamide daily) therapy and isoniazid cessation (if exposed). We aim to enroll 197 participants with pellagra and 788 age- and sex-matched controls (1:4 ratio) presenting at three dermatology clinics. Four randomly selected community clinics within 3-25 km of designated dermatology clinics will refer persons with pellagra-like symptoms to one of the study enrollment sites for diagnosis. Trained study dermatologists will conduct a detailed exposure questionnaire and perform anthropometric measurements. A subset of enrollees will provide a casual urine specimen for niacin metabolites quantification and/or point-of-care isoniazid detection to confirm whether participants recently ingested isoniazid. We will use conditional logistic regression, matching age and sex, to estimate odds ratios for the primary study aim. Discussion: The results of this study will inform the programmatic scale-up of isoniazid-containing regimens to prevent tuberculosis.

Prospective evaluation of accuracy and clinical utility of the Dual Path Platform (DPP) assay for the point-of-care diagnosis of leptospirosis in hospitalized patients.

Early detection of leptospirosis with field-ready diagnostics may improve clinical management and mitigate outbreaks. We previously validated the point-of-care Dual Path Platform (DPP) for leptospirosis with sera in the laboratory. This prospective study compares the diagnostic accuracy and clinical utility of the DPP using finger stick blood (FSB) against the serum DPP, venous whole blood (VWB) DPP, IgM-ELISA, and clinical impression. We sequentially enrolled 98 patients hospitalized for acute febrile illnesses, of which we confirmed 32 by leptospirosis reference tests. Among syndromes consistent with classic leptospirosis, the FSB DPP showed similar sensitivity and specificity (Se 93% and Sp 80%), and positive and negative predictive values (PPV 74% and NPV 95%), to VWB DPP (Se 96%, Sp 75%, PPV 68%, and NPV 97%), serum DPP (Se 85%, Sp 87%, PPV 79%, and NPV 91%) and IgM-ELISA (Se 81%, Sp 100%, PPV 100%, and NPV 90%). The FSB DPP provided a favorable likelihood ratio profile (positive LR 4.73, negative LR 0.09) in comparison to other assays and clinical impression alone. Additionally, we identified four of five leptospirosis-associated meningitis patients by whole blood DPP, none of which clinicians suspected. This demonstrates potential for the DPP in routine detection of this less common syndrome. The FSB DPP demonstrated similar discrimination for severe human leptospirosis compared with serum assays, and it is a simpler option for diagnosing leptospirosis. Its performance in other epidemiological settings and geographic regions, and for detecting atypical presentations, demands further evaluation.

Prevalence and characteristics associated with malnutrition at hospitalization among patients with acquired immunodeficiency syndrome in Brazil.

BACKGROUND: Brazil's National STD/AIDS Program is considered a model of success worldwide. However, AIDS-associated malnutrition continues in subgroups of Brazilian patients despite access to free highly active antiretroviral therapy (HAART). We aimed to identify the prevalence of malnutrition and associated factors among patients hospitalized with AIDS. METHODS: We conducted a cross-sectional nutritional assessment among 127 adults hospitalized with AIDS in Brazil's third largest city. Using anthropometric measurements, we determined the prevalence of malnutrition (body mass index <18.5 kg/m2) at hospitalization. Prevalence ratios of malnutrition by demographic, socioeconomic, and clinical conditions were estimated using log-binomial regression. RESULTS: One-third of participants were first informed of their HIV disease during the current hospitalization and recent treatment interruption was common (71%) among those on HAART. Forty-three percent were malnourished and 35% had severe weight loss at admission. Patient characteristics independently associated with malnutrition were older age (2% increased prevalence for each year; 95% confidence interval [CI] 0-4%) and very low daily per capita household income. Living on

Accuracy of a dual path platform (DPP) assay for the rapid point-of-care diagnosis of human leptospirosis.

BACKGROUND: Diagnosis of leptospirosis by the gold standard serologic assay, the microscopic agglutination test (MAT), requires paired sera and is not widely available. We developed a rapid assay using immunodominant Leptospira immunoglobulin-like (Lig) proteins in a Dual Path Platform (DPP). This study aimed to evaluate the assay's diagnostic performance in the setting of urban transmission. METHODOLOGY: We determined test sensitivity using 446 acute and convalescent sera from MAT-confirmed case-patients with severe or mild leptospirosis in Brazil. We assessed test specificity using 677 sera from the following groups: healthy residents of a Brazilian slum with endemic transmission, febrile outpatients from the same slum, healthy blood donors, and patients with dengue, hepatitis A, and syphilis. Three operators independently interpreted visual results without knowing specimen status. RESULTS: The overall sensitivity for paired sera was 100% and 73% for severe and mild disease, respectively. In the acute phase, the assay achieved a sensitivity of 85% and 64% for severe and mild leptospirosis, respectively. Within seven days of illness onset, the assay achieved a sensitivity of 77% for severe disease and 60% for mild leptospirosis. Sensitivity of the DPP assay was similar to that for IgM-ELISA and increased with both duration of symptoms (chi-square regression P = 0.002) and agglutinating titer (Spearman ρ = 0.24, P<0.001). Specificity was ≥93% for dengue, hepatitis A, syphilis, febrile outpatients, and blood donors, while it was 86% for healthy slum residents. Inter-operator agreement ranged from very good to excellent (kappa: 0.82-0.94) and test-to-test reproducibility was also high (kappa: 0.89). CONCLUSIONS: The DPP assay performed acceptably well for diagnosis of severe acute clinical leptospirosis and can be easily implemented in hospitals and health posts where leptospirosis is a major public health problem. However, test accuracy may need improvement for mild disease and early stage leptospirosis, particularly in regions with high transmission.

Automated detection of influenza-like illness using clinical surveillance markers at a Department of Veterans Affairs Medical Center.

BACKGROUND: Using demographic and clinical measures from emergency department evaluations, we developed an automated surveillance system for influenza-like illness (ILI). METHODS: We selected a random sample of patients who were seen at the Durham, NC Veterans Affairs Medical Center between May 2002 and October 2009 with fever or a respiratory ICD-9 diagnosis code and divided this into subsets for system development and validation. Comprehensive chart reviews identified patients who met a standard case definition for ILI. Logistic regression models predicting ILI were fit in the development sample. We applied the parameter estimates from these models to the validation sample and evaluated their utility using receiver-operator characteristic analysis. RESULTS: The models discriminated ILI very well in the validation sample; the C-statistics were >0.89. CONCLUSIONS: Risk estimates based on statistical models can be incorporated into electronic medical records systems to assist clinicians and could be used in real-time surveillance for disease outbreaks.