PUBHEPI 2410 Epidemiology

1. Choose any reportable disease or condition other than Zika Virus, HIV, or Lyme Disease and look up a current and historic case definition for that disease from the CDC  National Notifiable Disease Surveillance System (Links to an external site.)Links to an external site. or from any state or nation. Describe how the case definition has changed over time and any contributing factors to the change in this definition. Keep in mind that this does not have to be an infectious disease. You can also choose a reportable environmental exposure, toxin exposure, or chronic disease. You just need to be able to find a current and historic (at least 5 years ago) definition.

2.Find the cumulative incidence for the condition you chose for the two years that you're comparing. If you use a CDC definition then cite the national incidence for each year. If you use a state definition or a definition from another country, then cite the state or country's cumulative incidence for each year.

Your description should be between one and two pages and should include the old and new case descriptions, citations of where they were posted including web addresses, your description of how and why the definition has changed over time, and the cumulative incidence for each year of the case definition. You will likely need to look up secondary resources to understand why the case definition changed and you should cite those resources as well.

Epidemology

Dengue virus infections

2015 Case definition

CSTE Position Statement(s)

14-ID-10

Subtype(s)

Dengue

Dengue fever

Severe dengue

Background

Dengue is a lethal disease caused due to any four of the viruses (DENV-1, -2, -3, and -4). It is  a problem of concern world wide. About 400 millions of cases about the DENV cases have been reported (Ferreira, 2012). DENV are transmitted through the vector Aedes aegypti. These mosquitoes are endemic in the tropical countries; the people from the tropical countries are more susceptible to the disease ("Nationally Notifiable Diseases | Healthy Water | CDC", 2017)

Laboratory criteria for the diagnosis of dengue virus

Confirmatory tests:

• Diagnosis of the dengue virus in the plasma serum, blood, CSF of brain and other body fluids by using polymerase chain reaction.
• Isolation of the DENV by the cell culture of the plasma of the serum or the specimen of CSF.
• Identification of the IgM anti DENV by immunoassay of the serum specimen.
• Identification of the DENV antigen in the immune fluorescence assay.
• Identification of IgM anti-DENV by the immunoassay in the serum or CSF in a person who stays in an area that is dengue endemic or non-endemic or recent vaccination against a flavivirus.

2010 Case definition of dengue virus infections

Clinical Description

It is an acute feverish illness that is characterized by retro-ocular pain, frontal headache, pain in muscles and joints, followed by rashes.  The communicable disease is spread by the mosquito Aedes aegypti and is confined to the tropical countries. Manifestations like dengue hemorrhagic fever is rare, but can be lethal. ("Nationally Notifiable Diseases | Healthy Water | CDC", 2017).

Laboratory Criteria for the Diagnosis

• Detection of dengue virus from serum and autopsy samples.
• Detection of a fourfold increase or fall in reciprocal IgG or IgM antibody titers in serum samples to one or more dengue virus antigens. 
• Detection of dengue virus antigen in autopsy tissue samples by immunofluorescence technique or by using hybridization probe.

How the case definitions have changed with time?

Lineage antigenic shift in the antigenic property of the dengue virus has lead to the changes in the case definition of the dengue virus. Envelope of the virus is the major antigenic proteins that cater to the antigenic shift in the virus. The pathogens are becoming immune to the different generations of the antibiotics. Due to this shift the different diagnostic procedures and the medications are altering itself (Guha-Sapir & Schimmer, 2005). Further more different strains of the virus are being discovered, which have different mechanisms of pathogenecity which have expanded the paws of the disease.

Cumulative incidence

Cumulative incidence for year 2015

MANILA, Philippines – The Department of Health (DOH) has noted about 55,079 suspected  cases of dengue virus infection from January 1 to August 8, 2015.

This record is 9.15% higher than the 50,462 cases that have been recorded during the same period in 2014.

It was found that most of the cases involve Calabarzon (15.2 %), Northern Mindanao (8.7%), and central Luzon (13%).

Cumulative incidence for the year 2010

There had been 893 reported cases about the deaths for dengue virus in Korea and 1,054 in Japan in between the years 2011 and 2015. Cumulative incidence shows that, in spite of Japan’s big population the number of overseas travelers did not differ from that of Korea. These results indicate that the Koreans travel overseas, more than the Japanese. In south east Asia Korea and Japan has shown the maximum cases of infection about 89.4% vs. 75.4%, respectively. It should be noted that the Philippines and Indonesia were the leading origin countries for most of the Korean and Japanese cases. Seasonal distribution analyses that August and September were the months during which most of the cases have been found to occur in Korea and Japan, respectively (Guha-Sapir & Schimmer, 2005). The following differences are due to the difference in the timings and the travel destinations.

References

Ferreira, G. L. (2012). Global dengue epidemiology trends. Revista do Instituto de Medicina Tropical de São Paulo, 54, 5-6.

Guha-Sapir, D., & Schimmer, B. (2005). Dengue fever: new paradigms for a changing epidemiology. Emerging themes in epidemiology, 2(1), 1.

 Miki, S., Lee, W.-C., & Lee, M.-J. (2017). A Comparative Study of the Trends of Imported Dengue Cases in Korea and Japan 2011 - 2015. Journal of Clinical Medicine Research, 9(7), 650–653. http://doi.org/10.14740/jocmr3022w

Nationally Notifiable Diseases | Healthy Water | CDC. (2017). Cdc.gov. Retrieved 31 August 2017, from https://www.cdc.gov/healthywater/statistics/surveillance/notifiable.html