Examples of Sources of Infection, Mode of Transmission, and Why Is This a Concern?
Depending on its type, there are often several vectors by which a virus like West Nile virus (WNV) and the consequent West Nile fever (WNF) can be transmitted. Many of the emerging novel diseases in the Western hemisphere appear to be transmitted zoonotically (that is, through animals and insects) and as a result of travel (that is, infected people traveling from one country to another and bringing with them diseases like SARS). In the case of WNV/WNF, zoonotic vectors are the most common, and WNV is commonly attributed to mosquitos and birds (Chancey, Grinev, Volkova, & Rios, 2015; McVey, Wilson, & Gay, 2015). This is a concern because it is difficult to treat bird and insect populations and to know when they’ve contracted and will therefore propagate the virus. Furthermore, both of these zoonotic populations are highly mobile and can travel very far afield, thereby spreading the disease further.
The Use of Antibody Titers for Confirming Diagnosis
As noted in the study, Jason’s doctor ordered serologic tests. These tests will reveal antibody titers in Jason’s blood. The significance of these titers is that they reveal the body’s response to the virus; that is, once a virus has infected the host, the host’s immune response will generate antibodies to fight the virus. Seropositivity regarding WNV is a common diagnostic tool and can reveal the severity of the infection (Chancey et al., 2015).
Stage of Illness and Physiologic Mechanisms for Signs/Symptoms
Based on Jason’s symptoms, he was likely fully infected; the virus had fully invaded his body. The physiologic mechanisms associated with such signs and symptoms related to the body’s inflammatory response. The invasion of the virus prompts the body’s immunity response which triggers inflammation (McVey, Wilson, & Gray, 2015), causing fever and malaise as well as nausea and diarrhea.
Virus Replication and Explanation to Patient
As noted, WNV has a single-stranded RNA genome. In order to replicate, it invades the host’s normal cells and uses its RNA to ‘convert’ the host’s cells (Chancey et al., 2015). I would explain to the patient that once these host cells have been invaded and converted, they go through their usual processes, but now they ‘serve’ the virus. As they replicate, they do not produce normal, healthy cells. They produce cells which are coded for the virus.
Pharmacologic Modalities and Standards of Care
According to the Centers for Disease Control and Prevention (CDC) (2015), there is currently “no vaccine or specific antiviral treatment” for WNV. Standards of care include treating the symptoms such as fever and aches through over-the-counter medications (CDC, 2015). Anti-diarrheal and anti-emetics can reduce or treat diarrhea and nausea. In severe cases, patients may require hospitalization to receive “intravenous fluids, pain medication, and nursing care” (CDC, 2015).
Influences on Responses to Treatment Modalities
There are several things which could influence a patient’s response to treatment modalities. Age seems to be a significant factor; the elderly are generally more vulnerable to infection and therefore more susceptible to adverse outcomes, including more advanced forms of the virus such as meningo-encephalitis (McVey, Wilson, & Gray, 2015). If an individual already experiences immune suppression or chronic disorders like hypertension, diabetes, and chronic kidney failure, they are more likely to see progression to a more severe form of the disease which would require hospitalization for management (Chancey et al., 2015).
- Centers for Disease Control and Prevention. (2015). West Nile virus: Symptoms and treatment.
West Nile virus. Retrieved from http://www.cdc.gov
- Chancey, C., Grinev, A., Volkova, E., & Rios, M. (2015). The global ecology and epidemiology
of West Nile virus. BioMed Research International, 1-20.
- McVey, D. S., Wilson, W. C., & Gay, C. G. (2015). West Nile virus. Revue Scientifique Et
Technique (International Office of Epizootics), 34(2), 431-439.