Specimen Collection in Swine Origin and Seasonal Influenza and RSV – Can You Afford to Miss the Diagnosis?

By Kurtis Waters MD, Medical Director, M-Pro, LLC

Introduction

When it comes to the most common viral diseases that burden our health care system, it would seem imperative to maximize our capability of diagnosing these pathogens. All diagnostic laboratory tests start with proper specimen collection. For respiratory viral pathogen detection such as influenza and RSV, nasopharyngeal aspiration is considered the gold standard collection method, which maximizes sensitivities and results. However, numerous institutions have not implemented this as their preferred method of collection due to historical barriers that can now be overcome. The recent spread of the H1N1 swine-origin influenza A virus (S-OIV) has led many institutions, clinics, and emergency rooms to reevaluate their protocols and methods of viral detection. It is necessary for institutions to consistently give reliable and sensitive testing, regardless of who is collecting the specimen and where they may be in the institution. Early recognition of new influenza strains is vitally important for implementing effective control measures to limit spread. NPak (nasopharyngeal aspiration kit) is a cost-effective and rapid-collection method that is a highly significant contribution to diagnostics, which will greatly enhance the capacity to deal with future influenza and RSV outbreaks. This kit eliminates the previous barriers that made institutions turn away from nasopharyngeal aspiration as their preferred specimen collection method. It now allows nasopharyngeal aspiration to be standard protocol, assuring proper patient care management and disease containment, resulting in cost savings for institutions that implement NPak as part of their protocol.

Previous Barriers resulted in less-than-ideal alternatives in specimen collection that continue to be used

Although nasopharyngeal aspiration has proven consistently in studies to give the best sensitivities compared to a nasopharyngeal swab, wash or throat swab, many institutions and labs continue to use these alternative methods of collection. In the past, nasopharyngeal aspiration has been difficult to perform due to the need for a suction machine, significant preparation, cost for equipment, and discomfort to the patient. Only certain individuals knew how to perform the aspiration and only certain parts of the hospitals or institutions had suction available. Additionally, makeshift catheters and tubing were utilized, making this procedure extremely uncomfortable for the patient.

A few years ago the makers of NPak asked the question, “Is it possible to make an easy-to-use nasopharyngeal aspiration kit that requires no additional suction machine, utilizes a catheter that is more comfortable than a NP swab, can be used for all ages, and gives the most reliable and sensitive results in respiratory pathogen specimen collection?” The NPak is an all-inclusive kit that has a soft flexible catheter that can be used for all ages, requires no outside suction, and is quick and easy to use by all health care providers.

Financial Impact to Hospitals

The financial impact upon hospitals to accurately diagnose viral pathogens is related to proper patient care management and disease containment/spread.

Proper Patient Care
Certainly differentiating between a bacterial pneumonia versus viral pneumonia directs more appropriate treatment options in addition to potential length of stay in the hospital. Proper diagnosis must be physician directed. Many physicians routinely and appropriately order viral detection tests as part of their workup. Unfortunately, a certain degree of ignorance regarding the relationship of specimen collection and sensitivities is not uncommon. The physician ordering an influenza or RSV test is often not aware of the type of collection method that is utilized as this is typically collected by ancillary staff such as nurses or respiratory therapists. Little do they know, their order may result in a patient having a nasal swab or nasopharyngeal swab performed by a less-than-experienced nurse, which may result in false negative results. It has been shown that recovery of the virus is highly dependent on the training and interest of the personnel collecting the samples (Ruuskanen & Ogra, 1993). One study undertaken to assess the quality of nasopharyngeal aspirate taken by staff from an emergency department demonstrated almost 1/3 of the samples contained insufficient sample, capable of achieving a result with good negative predictive value. Properly identifying the type of pneumonia is imperative. Viral panels can now be utilized that screen for multiple viral pathogens with a single nasopharyngeal aspiration sample and can be billed accordingly. Proper diagnosis affects patient management decisions by selecting the proper antiviral medication and/or minimizing the use of unnecessary antibiotics. Proper management affects the patient's length of stay, which ultimately affects hospital reimbursement.

Containment of viral spread and nosocomial infection
Containment of highly infectious respiratory pathogens should be a primary role for the hospital not only for the community’s sake, but also within the hospital. During epidemics, season-high community attack rates of 10% for influenza and 40% for RSV exist in groups with high risks for infection within hospitals and nursing homes. These respiratory viruses are also well established as agents capable of nosocomial transmission. Explosive outbreaks are thus possible. They represent a significant financial burden on hospitals by prolonging hospital stays, increasing mortality in vulnerable patient groups, and increasing staff absences.
To prevent outbreaks, close cooperation between the microbiology department and infection control team is essential. A key element of this is rapid communication of positive results on all patients in the hospital, especially at the start of the winter season. To facilitate this, proper testing protocols include standardizing specimen collection and employing proper viral assays. A variety of methods are available, but regardless of sensitivity and specificity, how the specimen is collected is the key to success in controlling infection.

Conclusion

The NPak is an easy-to-perform collection method for detecting both seasonal influenza A virus, RSV and the emerging H1N1 swine-derived influenza A. Labs and institutions will recognize the importance of quality control, isolation of the disease, and the financial cost savings once standardization mandates are in place for specimen collection. NPak has eliminated the barriers for viral specimen collection by maximizing sensitivities, improving patient comfort, and allowing standardization and ease of use for all staff.