Management of Norovirus and the Disease Prevention - Term Paper Example

Executive summary Norovirus is known to cause epidemic gastroenteritis, which is responsible for approximately 50% of all gastroenteritis outbreaks globally. The virus is also a serious cause of food borne diseases. Considerable advances have been commenced in epidemiology, infection control, immunology, and diagnostic methods of Norovirus. There have been a significant improvement in molecular diagnostic techniques and have become widely available. Hence, there has been an increase in detection and reporting outbreaks of norovirus. While the inability to culture noroviruses in nitro has vastly hampered these advancements, assessment of disinfectants performance has been boosted by the invention of new, cultivatable surrogates. Additionally, the sporadic emergences of outbreaks in specific places and epidemic strains have been exemplified. This report reviews current developments and also establishes guidelines for management of norovirus and the disease prevention. These recommendations can be used by professionals in public health to investigate acute gastroenteritis outbreaks, and by research institutions. Table of Contents Table of Contents 2 1.0 Introduction 3 2.0 Scope and Rationale 3 3.0 Literature review 4 3.1 Signs and symptoms of norovirus infection 4 3.2 Notovirus incubation period 5 There is a short lag that extends to up to 2 days from the moment the patient is infected and the time they show symptoms. During this 2 days period, individuals may be highly contagious. All people with symptoms are contagious and even those who appear to have recovered from the virus continue to the tool shed virus and may be a source of infection to uninfected persons. People with weak immune systems i.e. those undergoing organ transplant and those receiving chemotherapy can shed the norovirus for months (Koopmans, 2002). 5 3.3 Diagnosis 5 3.4 Summary of Key Findings 8 3.5 Verification of the Diagnosis Results 9 3.6 Implications on Investigation, Control or Preventive Measures in the long run 10 4.0 Conclusions 11 5.0 References 12 1.0 Introduction Norovirus is a minute virus that has Ribonucleic acid and it has a protein coating. In reference to Belkin and Colwell (2006), through RNA sequencing, scientists have discovered different types of norovirus. At first, strains were named in accordance to the place where they were first identified and one common strain was referred to as Norwalk virus (Belkin & Colwell, 2006). Noroviruses are the most common cause of gastroenteritis outbreaks. As indicated by Belkin and Colwell (2006), the consumption of raw shellfish has an association with gastroenteritis outbreaks. In Australia, norovirus outbreak has been associated with consumption of raw shellfish. There are several reports of norovirus outbreaks linked with oysters even with adherence to the recommended food regulatory measures. Norovirus outbreaks occur all through the year; however, they are more common in winters. People contracted the disease from dining in the restaurant. 2.0 Scope and Rationale Noroviruses was first linked with shellfish-borne gastroenteritis in 1976 and since then enteric viruses that cause gastroenteritis have been linked to outbreaks of shellfish-vectored illness on many occasions in different countries. The rationale behind focusing on norovirus in shellfish is the fact that shellfish can act as a means of transmitting noroviruses. In accordance to Lees (2000), there is a substantial regional trade in bivalve molluscan shellfish that may lead to new viruses. Norovirus serve as a model of enteric viruses. Out of 54 people who attended the golf event in early September 19 of them were ill. The team did a hypothesis testing and found the source of the outbreak. It was from the dinning restaurant. The consumers did show signs of illness. Other people did not show signs. The most astonishing case was of the food handler. The food handler did participate in cooking and serving food. He was also an ill patient. The disease investigators normally inspect the facility. There was no sign of breaches in the food handling standards by the restaurant staff. The days in which the oysters were supplied to the restaurant show high incidences of the disease. Fresh oysters from the environmental studies did test negative for pathogens. Even norovirus was absent in the specimen. This indicates that the pathogenic studies need thorough investigation before drawing conclusions from the results. 3.0 Literature review Studies indicate that human consumption of oysters is a viral cause of the illness. The shellfish is capable of viral accumulation in the digestive food tracts. This is highly relative to the surrounding water environments. One of the studies did indicate an F+ coliphage, the density of the concentration was 19 times higher than that of the surrounding estuarine waters. Infections are a common cause of deaths nowadays. The approximate number of deaths is fifteen million people. It is now a global concern. There is a wide range of communicable diseases. This can range from person to person and in some cases, it can be person to parasites. The disease agents can cause respiratory infections. 3.1 Signs and symptoms of norovirus infection Hunter (2009) indicates that most of the infected persons get sick within 12 to 48 hrs after ingesting norovirus. Hunter (2009) further indicates the symptoms to include watery diarrhea or vomiting or even both. Norovirus patients get cramping abdominal pain, headache, a feeling of weariness, fever and muscle aches (Hunter, 2009). Infected people are generally thirsty but, in some cases have difficulty maintaining the fluids down. Generally, infected people who can orally ingest almost the same level of fluid they lose from their body through vomiting and diarrhea or both recover speedily. In reference to Hunter (2009), debilitated elderly patients have more severe symptoms; he further states that individuals with difficulties in replacing fluids and developing signs of dehydration should get medical attention. Majority of people have mild ailments that can go for 2 to 4 days. The length of infection may be long in hospitalized patients or in minors. Norovirus cause severe inflammation of infants’ colon and the disease has flares in children with inflammatory bowel disease it is not clear what the role of norovirus is in this conditions. 3.2 Notovirus incubation period There is a short lag that extends to up to 2 days from the moment the patient is infected and the time they show symptoms. During this 2 days period, individuals may be highly contagious. All people with symptoms are contagious and even those who appear to have recovered from the virus continue to the tool shed virus and may be a source of infection to uninfected persons. People with weak immune systems i.e. those undergoing organ transplant and those receiving chemotherapy can shed the norovirus for months (Koopmans, 2002). 3.3 Diagnosis The symptoms of norovirus resemble those of rotavirus and other common viral diarrheas; hence it is necessary to do specific tests that will enable to identify norovirus. This virus can not be cultured in a laboratory, but the RNA inside the virus can be detected directly through the use of polymerase chain reaction tests. Detecting the virus in the stool sample can also be done by Enzyme-based immunoassays (EIA). The EIA assay, Ridascreen Norovirus 3rd Generation is set for approval by the FDA to detect the virus when several people have concurrently contracted gastroenteritis and the avenue of contracting the virus is clear (Neighbors, 2006). Immunoassay testing of blood samples has revealed that human body makes antibodies against norovirus. However, it takes the body 10 to 14 days to makes these antibodies, this mean that this test is not useful for real time diagnosis. The moment norovirus is detected in an outbreak setting, it becomes unnecessary to test all persons and people with typical symptoms can be assumed to have contacted the virus. Norovirus has no specific medication, it is critical that those infected drink plenty fluids and remain well hydrated. Data from gastroenteritis was assessed to test stool samples to see if norovirus is present in the specimen. The number of reasonable specimens to determine norovirus is crucial (Martinez, 2008). The study reasonably identified and used four specimens. This is done within less than seven days since the diarrhea began. The study aims at establishing the pathogens causing the disease. The infection is a food borne disease and the patients contracted norovirus after consuming shellfish (Martinez, 2008). There was a limitation on the identification of disease agents. This can be attributed to limited number of specimens in the laboratory for conducting the test (Koopmans, 2002). The stool tests were done only in confirmed cases. The acute cases from some patients were taken for lab test. The norovirus is an aggregation of nonrelated RNA viruses (Marianne & Ruth, 2010). They are non-enveloped and have a single strand. It is advisable to review the available data to assess the sensitivity of stool to the disease at different stages from right after the inception of the infection. There are high chances of a number of people contracting and spreading the norovirus disease outbreak (Koopmans, 2002). The team used a confidence level of 95%. The relative risk and the disease attack rate also were useful to assess the relationship between the disease and the shellfish consumption. Upon depuration of the virus particles, there is a possibility of even after 64 hours that the disease may still survive, especially with viral contaminates. Food poisoning is a common form of disease causing mechanism (Marianne & Ruth, 2010). Toxin food substances produce poison. Tiny organisms attach themselves to algae. The shellfish eat the algae food which is in turn consumed by the human population. The fish that feed on oceanic water food usually carry the toxin. The seafood are then carried to the market for selling, this is how the organisms are transferred. According to Vijay and John (2010), there are different cases of food poisoning associated with shellfish. The first one is the paralytic shellfish poisoning. This is a common and serious disease that affects the nervous system. The effect is usually spontaneous. This can occur within less than half an hour to two hours. The second form is Amnesic poisoning. This can cause death or put a person in a coma. The affected body parts are the nervous system and gut. A day after consuming the shellfish the symptoms can be seen. The third form is the neurotoxin shellfish poisoning. It is usually not severe. The signs are cleared within a few days. 3.4 Summary of Key Findings There was a review of acute reports of gastroenteritis in the outbreak scenario. The norovirus was seen as a possible cause of the disease. This was as early as the period of incubation. There was sufficient consideration of symptoms, period of occurrence and length of the disease among the victims. The other part of the outbreak investigation included clinical and demographics in the review process of the specific cases of the disease. There was the gathering of exposure information in all cases. The environmental health officers did all the tests in the earliest time possible and kept records. There was a link between the clinical and epidemiological information in the studies. This was after the process of cluster identification was executed. There was real time testing of the specimens in the event the outbreak did occur. The disease outbreak scenario did record a 55% mark. This was also the global record. The case patients had a record 90% abdominal pain. The other results were as follows; vomiting-71%, nausea-85%, and diarrhea-42.75% (Koopmans, 2002). The disease remission was within one and two day’s duration. The detection of norovirus was done from the six fecal samples. The food handler who showed symptoms did not eat the shellfish. The food handler only served the shellfish to the clients. The results from the analysis of the two cases showed no viruses presence. The viral strain in all cases did not change. This is as per the molecular analysis. The Analysis and Commentary on the Steps of Investigation of the Disease Outbreak There was contact of the relevant agencies in the centre for disease control. The facility also passed the test of credibility. This is a result of the public health officers conducting real time testing of the specimens. The officers were able to establish the existence of the outbreak in time. This was as a result of people reporting the information to the health agencies as soon as the outbreak was suspected. The testing was not limited to confirmed cases only. There was an extension to even the unconfirmed case patients. This was intended to spread wide scope of the study. 3.5 Verification of the Diagnosis Results The testing of the shellfish food intake was critical. The diagnosis results did conform to the epidemiological and other related clinical results. This was possible since the medical team did conduct a test on 4 specimens and within a period of less than 7 days. There was also real time diagnosis and recording of the test results in all cases. The Construction of the Working Case Definition The case was constructed on the basis of available clinical and epidemiological studies. The health officers availed the data and the results they laid reliance to do their tests. The team was able to identify cases of diarrhea and collect the required information on the same. The information formed the basis of the report. The subsequent description of epidemiological results forms the basis of case definition in all incidences. It is not always possible to detect toxic fish. The appearance, taste and texture of fish are not sufficient to indicate the toxic levels of the fish. Some of the food preservation methods can not eliminate the toxins from the foods. These are freezing, cooking and even other advanced food treatment techniques. It is only 5 in every 19 people from the study. The significance of quality assurance in the oyster industry is crucial. In the study area, the industry usually funds a shell fish program for research. The main objective of the research is to conduct quality assurance studies. So, what are the implications from the research on the outbreak? The report is a collection of cohort studies to investigate epidemiological evidence. There is a close association between oysters as a disease agent and gastroenteritis as a disease. The advance studies can reveal that viral contamination which causes the virus to accumulate in the oysters is a sufficient result of the disease. The sewage spills prior to the harvesting (usually two weeks) can show the signs. Public safety is at risk. This is because the system to ascertain quality assurance has questionable capacity to address the problem. 3.6 Implications on Investigation, Control or Preventive Measures in the long run Food borne diseases are on the rise. The outbreak not only affects food consumers but also food handlers. According to Luten (2006), the public health experts need to extend the scope of their work to other possible culprits of the outbreaks. It is of the essence to search for affected patients in all incidences. The public should be educated with the right health education. The hand washing of food handlers must be promoted in all areas. It is necessary to conduct investigations into norovirus gastroenteritis. The process of food manipulation should enhance both personal and environmental hygiene. The cleaning facilities and the disinfectants should be of high hygienic standards. The study was concrete in the analysis of epidemiological and clinical results. This is because the inferences from the research ought to translate into the formulation of policies to address health concerns. The responsible government bodies and organizations have the duty to avail facilities to local health centers. This will accelerate the incidence of disease control and avoid possible spread to other areas. The public should be alert at all time. The process of public health surveillance is crucial in any economy. The cost of disease prevention is lower compared to the expenses incurred in curing a disease. The overall risk element in this scenario aims to address health issues. Implementation of various policy recommendations should be professionally and effectively implemented. A campaign should be carried out on enlightening the general public on how to uphold hygiene in food handling 4.0 Conclusions Norovirus have been linked with the consumption of raw and lightly cooked shellfish. This sickness has been considered mild and self-limiting; however, there are evidences of severe clinical features in patients with other underlying ailments. Apart from the secondary and tertiary waves of transmission that can be established after consuming contaminated shellfish, consuming shellfish that contains a cocktail of noroviruses may lead to recombinant norovirus strains that can have critical epidemiological implications. Contact with fecally contaminated water can have shellfish harboring other type’s pathogenic viruses that act as an indicator for noroviruses. The consent of releasing shellfish derived from prohibited areas when they comply with microbiological standards raises that alarm as mentioned in the threat profile on the norovirus-shellfish product. The strategies of risk management must be put in place to properly address the occurrence of viral contamination of oysters and shellfish. 5.0 References Belkin, S & Colwell, R. (2006). Oceans and health : pathogens in the marine environment. New York, NY: Springer Science+Business Media. Burnell, G. & Allan, G (2009). New technologies in aquaculture : improving production efficiency, quality and environmental management. Boca Raton Oxford: CRC Press Woodhead Pub. Hunter, B. (2009). Infectious connections : how short-term foodborne infections can lead to long-term health problems. Laguna Beach, Calif: Basic Health Publications. Koopmans, M. (2002). Foodborne viruses : an emerging problem. Washington, D.C. Brussels: ILSI Press ILSI Europe. Koopmans, M. and Duizer, E., (2004). Foodborne viruses: an emerging problem, Int. Journal. Food. Microbiol. 90:23-41 Lees D. (2000). Viruses and bivalve shellfish. International. Journal. Food Microbiol. 59(1-2); 81-116. Luten, B. (2006). Seafood research from fish to dish : quality, safety and processing of wild and farmed fish. Wageningen, the Netherlands: Wageningen Academic Publishers. Marianne N. & Ruth T. (2010): A gastroenteritis outbreak due to norovirus associated with a Colorado hotel.Journal of Environmental Health 66(5), 13-17. Martinez, A. (2008). The Catalan Viral Gastroenteritis Study Group: Epidemiology of food borne Norovirus outbreaks in Catalonia. Department of Health, Barcelona, Spain Neighbors, M. (2006). Human diseases. Australia: Delmar Learning. Vijay K. &, John N (2010). Pathogens and toxins in foods : challenges and interventions. Washington, DC: ASM Press. Read More