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Background: Schools are primary venues of influenza amplification with secondary spread to communities. We assessed K-12 student absenteeism monitoring as a means for early detection of influenza activity in the community. Materials and methods: Between September 2014 and March 2020, we conducted a prospective observational study of all-cause (a-TOT), illness-associated (a-I), and influenza-like illness–associated (a-ILI) absenteeism within the Oregon School District (OSD), Dane County, Wisconsin. Absenteeism was reported through the electronic student information system. Students were visited at home where pharyngeal specimens were collected for influenza RT-PCR testing. Surveillance of medically-attended laboratory-confirmed influenza (MAI) occurred in five primary care clinics in and adjoining the OSD. Poisson general additive log linear regression models of daily counts of absenteeism and MAI were compared using correlation analysis. Findings: Influenza was detected in 723 of 2,378 visited students, and in 1,327 of 4,903 MAI patients. Over six influenza seasons, a-ILI was significantly correlated with MAI in the community (r = 0.57; 95% CI: 0.53–0.63) with a one-day lead time and a-I was significantly correlated with MAI in the community (r = 0.49; 0.44–0.54) with a 10-day lead time, while a-TOT performed poorly (r = 0.27; 0.21–0.33), following MAI by six days. Discussion: Surveillance using cause-specific absenteeism was feasible and performed well over a study period marked by diverse presentations of seasonal influenza. Monitoring a-I and a-ILI can provide early warning of seasonal influenza in time for community mitigation efforts. [ABSTRACT FROM AUTHOR]

Residents of long-term care facilities (LCTFs) have high morbidity and mortality associated with acute respiratory infections (ARIs). Limited information exists on the virology of ARI in LTCFs, where virological testing is reactive. We report on findings of a surveillance feasibility substudy from a larger prospective trial of introducing rapid influenza diagnostic testing (RIDT) at 10 Wisconsin LTCFs. Any resident with symptoms consistent with ARI had a nasal swab specimen collected for RIDT by staff. Following RIDT, the residual swab was placed into viral transport medium and tested for influenza using Reverse transcription polymerase chain reaction, and for 20 pathogens using a multiplex polymerase chain reaction respiratory pathogen panel. Numbers of viruses in each of 7 categories (influenza A, influenza B, coronaviruses, human metapneumovirus, parainfluenza, respiratory syncytial virus, and rhinovirus/enterovirus) across the 3 years were compared using χ2. Totals of 160, 215, and 122 specimens were collected during 2016‒2017, 2017‒2018, and 2018‒2019, respectively. Respiratory pathogen panel identified viruses in 54.8% of tested specimens. Influenza A (19.2%), influenza B (12.6%), respiratory syncytial virus (15.9%), and human metapneumovirus (20.9%) accounted for 69% of all detections, whereas coronaviruses (17.2%), rhinovirus/enterovirus (10.5%) and parainfluenza (3.8%) were less common. The distribution of viruses varied significantly across the 3 years (χ2 = 71.663; df = 12; P <.001). Surveillance in LTCFs using nasal swabs collected for RIDT is highly feasible and yields high virus identification rates. Significant differences in virus composition occurred across the 3 study years. Simple approaches to surveillance may provide a more comprehensive assessment of respiratory viruses in LTCF settings. [ABSTRACT FROM AUTHOR]

BACKGROUND. Large outbreaks of influenza A and B may occur in nursing homes despite high resident vaccination rates, even when the vaccine strain is matched to the circulating strain. This study reports the occurrence of separate influenza A and B outbreaks in a nursing home where more than 85% of residents were vaccinated. METHODS. Prospective surveillance was used to identify symptomatic residents in a rural Wisconsin nursing home with 680 residents. Viral cultures were obtained from all consenting residents identified with new respiratory symptoms even in the absence of temperature elevation. A "case" refers to a resident with a respiratory illness and an influenza isolate. RESULTS. During the 1992-93 season, 86% of 670 total residents were vaccinated, 104 (15.5%) were cases with influenza B. During the 1993-94 season, 89% of 690 total residents were vaccinated, 68 (9.8%) were cases with influenza A. The antigenic matches between vaccine and epidemic strains were characterized as "identical or minimal difference" by the Centers for Disease Control and Prevention. CONCLUSIONS. There is still a need to protect residents from infectious secretions and for contingency plans to permit the rapid use of antiviral agents. Future efforts are needed to develop vaccines that provide greater protection and to improve staff vaccination rates. [ABSTRACT FROM AUTHOR]

The Wisconsin Clinical Laboratory Network (WCLN) at the University of Wisconsin-Madison is a partnership of 138 clinical and public health laboratories (as of February 2019) coordinated by the Wisconsin State Laboratory of Hygiene. This article describes the WCLN, its current activities, and lessons learned through this partnership. A laboratory technical advisory group, which consists of representatives from clinical laboratories, provides clinical laboratory perspective to the WCLN and fosters communication among laboratories. Activities and resources available through the WCLN include annual regional meetings, annual technical workshops, webinars, an email listserv, laboratory informational messages, in-person visits by a WCLN coordinator to clinical laboratories, and laboratory-based surveillance data and summaries distributed by the Wisconsin State Laboratory of Hygiene. One challenge to maintaining the WCLN is securing continual funding for network activities. Key lessons learned from this partnership of more than 20 years include the importance of in-person meetings, the clinical perspective of the laboratory technical advisory group, and providing activities and resources to clinical laboratories to foster sharing of data and clinical specimens for public health surveillance and outbreak response.

The role of the public health laboratory (PHL) in support of public health response has expanded beyond testing to include a number of other core functions, such as emergency response, training and outreach, communications, laboratory-based surveillance, and laboratory data management. These functions can only be accomplished by a network that includes public health and other agency laboratories and clinical laboratories. It is a primary responsibility of the PHL to develop and maintain such a network. In this article, we present practical recommendations-based on 17 years of network development experience-for the development of statewide laboratory networks. These recommendations, and examples of current laboratory networks, are provided to facilitate laboratory network development in other states. The development of laboratory networks will enhance each state's public health system and is critical to the development of a robust national Laboratory Response Network.

The need for effective influenza antiviral susceptibility surveillance methods has increased due to the emergence of near-universal adamantane resistance in influenza A/H3N2 viruses during the 2005-2006 season and the appearance of oseltamivir resistance in the influenza A/H1N1 virus subtype during the 2007-2008 season. The two classes of influenza antivirals, the neuraminidase inhibitors (NAIs) and the adamantanes, are well characterized, as are many mutations that can confer resistance to these drugs. Adamantane resistance is imparted mainly by a S31N mutation in the matrix gene, while NAI resistance can result from a number of mutations in the neuraminidase gene. During the 2007-2008 season, a neuraminidase mutation (H274Y) conferring resistance to the NAI oseltamivir emerged worldwide in the A/H1N1 virus subtype. Surveillance methodology and data from New York (NY) and Wisconsin (WI) for the 2006-2007 and 2007-2008 influenza seasons are presented. We used an existing pyrosequencing method (R. A. Bright et al., Lancet 366:1175-1181, 2005) and a modified version of this method for detection of adamantane resistance mutations. For NAI resistance mutation detection, we used a mutation-specific pyrosequencing technique and developed a neuraminidase gene dideoxy sequencing method. Adamantane resistance in the A/H3N2 virus samples was 100% for 2007-2008, similar to the 99.8% resistance nationwide as reported by the CDC. Adamantane resistance was found in only 1.2% of NY and WI A/H1N1 virus samples, compared to that found in 10.8% of samples tested nationwide as reported by the CDC. Influenza A/H1N1 virus H274Y mutants were found in 11.1% of NY samples for 2007-2008, a level comparable to the 10.9% nationwide level reported by the CDC; in contrast, mutants were found in 17.4% of WI samples. These results indicate the need for regional influenza antiviral surveillance.

Daycare attendance and siblings are associated with viral-induced wheezing in children. Preexisting immunologic factors may influence the expression of viral infections in infancy, and in turn, recurrent infections may influence the development of immune responses. A total of 285 children were enrolled in the Childhood Origins of Asthma Project at birth and followed for at least 1 year. Cord blood and 1-year mononuclear cells were stimulated with phytohemagglutinin, and cytokine-response profiles were measured by enzyme-linked immunosorbent assay. Nasal lavage was performed for moderate to severe respiratory illnesses. Daycare attendance and/or siblings significantly increased the likelihood of contracting respiratory syncytial virus (1.5-1.6-fold increase) and rhinovirus (1.8-2.1-fold increase), and increased the risk of rhinovirus-induced wheezing (14-18% vs. 2%, p = 0.011). Cord blood IFN-gamma responses were inversely related to the frequency of viral respiratory infections (r(s) = -0.11, p = 0.05), and more significant for subjects with high exposure to other children (r(s) = -0.27, p = 0.028). The interval change in infantile IFN-gamma responses correlated positively with the frequency of viral infections in infancy (r(s) = 0.12, p = 0.047). These data suggest that neonatal IFN-gamma responses may influence antiviral activity, or may represent a marker of antiviral immunity maturation. Conversely, the frequency of viral infections in infancy can influence IFN-gamma responses.

Influenza poses a significant threat to public health worldwide. In the United States alone, mortality attributed to annual epidemics of influenza is estimated at 36,000 deaths per year. Influenza viruses also cause pandemics, during which the rates of illness and death can be expected to be much higher. In order to optimize prevention and control strategies for influenza, a variety of surveillance activities are carried out year-round internationally, nationally, and at the state level. This article summarizes relevant features of influenza and the surveillance activities carried out at each of these levels to monitor influenza activity. Particular emphasis is given to the state's laboratory-based surveillance network, developed and coordinated by the Wisconsin State Laboratory of Hygiene, that features strong and productive partnerships with private sector clinicians and laboratories and that provides a solid foundation for surveillance directed at other public health threats such as Severe Acute Respiratory Syndrome and bioterrorism.