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West Nile Virus

26 Thursday Mar 2020

Posted by Charis Renai Royal in Uncategorized

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West Nile Virus is an arbovirus of the flavivirus genus which is able to infect a range of vertebrate hosts such as humans, birds and horses1. Its history in the eastern hemisphere dates back to 1937 and is carried by Culex species of mosquitoes, which can infect mammals via bites1. This arbovirus was introduced to the Western hemisphere in 1999 in New York City (NYC) where it infected both birds and humans. While public health officials confirmed 61 human cases across NYC, door to door serostudies conducted throughout the next year estimated the infection rate to be up to 2.6% in the Queens area. This infection rate would estimate that there were closer to 8200 cases in Queens, most of which went undiagnosed due to asymptomatic infections1.

Many public health officials believed the introduction of WNV in the U.S. would spread slowly outside of NYC as Culex mosquitoes, the carrier of WNV, increased their range. However, in 2002, it was shown that WNV infected mosquitoes had rapidly disseminated when an outbreak of WNV was identified in 28 states with 4,156 confirmed cases of WNV2,3. Then, in 2003, the Culex mosquitoes carrying WNV were confirmed in all Eastern and Midwest states (sans Maine) and infected 9,862 individuals in the U.S. alone1,2 (Figure 1).

west nile f1 (2)

While mild infection of WNV and other arboviruses are similar to a seasonal cold in clinical symptoms, approximately 1 in 150 individuals will develop neuroinvasive disease which can lead to convulsions, organ failure and death3,4. Neuroinvasive disease became a reportable illness in the U.S. in 2001, while non-neuroinvasive disease became reportable in 2004, with all states having their own surveillance systems which then report to the national network called arboNET, which is maintained by the Centers for Disease Control and Prevention (CDC)4. Furthermore, recent research suggests that many arboviruses can lead to neurological deficits and diseases such as Guillain-Barre syndrome or congenital diseases such as microcephaly during pregnancy later on in life after initial infection4.

Mitigation of WNV is of concern to health officials due to the risk of developing the severe symptoms which can lead to death and the compounded concern of neurological deficits resulting from infection. Arboviruses also tend to have a cyclical infection cycle where a specific virus will have an increased number of infections during one year, level out over the next 8-10 years and then peak again2,4.

There is no treatment for West Nile and hospitals and providers generally provide care to cover the symptoms. Similarly, no vaccines in clinical trials been successful enough to be mass-produced and distributed4,5. With no other treatment options and the cyclical cycle of infection-causing different arboviruses to peak in different years, a non-disease specific way of controlling the vector (mosquito) populations is currently the supported means of controlling arbovirus infection rates (Figure 2). Both passive and active forms of vector control will be evaluated for efficiency over the last decade, with a recommendation towards using genetically modified mosquitoes within integrated vector management (IVM) approach as a long term means of vector control.

Epidemiology

Since its introduction to NYC in 1999, WNV has become the leading arbovirus infection and encephalitis in the U.S. Only about 1 in 5 individuals with an infection will have symptoms which include what is defined as an acute system febrile illness, the other 4 out of 5 individuals will be asymptomatic4. The most common symptoms seen with systemic febrile illness are a headache, arthralgia, rash, and gastrointestinal disturbances. In 1 out of 150 cases, individuals will develop neuroinvasive diseases such as meningoencephalitis, meningitis, encephalitis or acute flaccid paralysis (AFP), any one of which can be life threatening3,4.

Like many illnesses, WNV infection can affect vulnerable populations differently and a paper by CDC in 2010 calculated the rates of infection for different populations after analyzing the 28,961 cases that met clinical and laboratory criteria for WNV infection between 1999-2008. Of these cases, 17,139 (approximately 59%) were defined as non-neuroinvasive and 11,822 (41%) were defined as neuroinvasive (Table 1).

f2 (2)

Out of the 17,139 cases reported of non-neuroinvasive, males accounted for 8,972 approximately, 52% of the confirmed cases (Table 1). Similarly, for neuroinvasive cases, males accounted for 6,887 cases out of 11,822 reported cases (Table 1). Neuroinvasive disease and non-neuroinvasive affected older populations at a higher rate, with the median age being 57 years old and 47 years old, respectively. In Neuroinvasive, nearly 46% of cases were 60 years old or above, while 45% of non-neuroinvasive were between 40-59 years old. For both forms of the disease, between 88-95% of those affected were Caucasian with 82-90% of cases being non-Hispanic (Table 1).

Out of the 8925 cases with hospital data, the non-neuroinvasive cases had a hospitalization rate of 20.6/1000 and a fatality rate of 0.96/1000. Of the fatal cases, being above 70 years old increased your risk as 85 of 86 fatal cases were above 70. Neuroinvasive has a higher rate of hospitalization going from 20.6/1000 in non-neuroinvasive to 86/1000 in neuroinvasive1,4. Neuroinvasive cases also results in a higher fatality rate going from 47/1000 in non-neuroinvasive to 178/1000 in neuroinvasive. The mean annual incidence of neuroinvasive cases rose from 5/1000 for those younger than 10 to 135/1000 for those above 70. This trend continues for gender differences and age with a mean incidence of 48/1000 in men and 33/1000 for women below 70 years old but increasing to 200/1000 in men and 89/1000 for women above 70 years old1,4.

West Nile Virus is an arbovirus which is transmitted by mosquitoes through mosquito bites. For both forms of the disease, between 91-94% of cases occurred between July and September, the peak mosquito season4. As you can see in Figure 1, WNV disseminated across the U.S. within 6 years, and by 2006 is found in every state in the continental U.S. except for Maine. Similarly, all arboviruses follow a cyclical pattern of infection where one virus will surge during one year while the rest maintain a low infection rate and then the surging virus will level out for 8-10 years while other viruses surge periodically. Then after 8-10 the first virus will surge again; for West Nile virus you see this trend in 2002-2003 when it first enters the United States, levels out between 2003-2011 and then surges again in 2012 (Figure 2).

acd

References

  1. Assessing Capacity for Surveillance, Prevention, and Control of West Nile Virus Infection—United States, 1999 and 2004. Jama. 2006;295(15):1765.
  2. Provisional Surveillance Summary of the West Nile Virus Epidemic—United States, January–November 2002. Jama. 2003;289(3):293.
  3. Roehrig J. West Nile Virus in the United States — A Historical Perspective. Viruses. 2013 Oct;5(12):3088–108.
  4. Patel H, Sander B, Nelder MP. Long-term sequelae of West Nile virus-related illness: a systematic review. The Lancet Infectious Diseases. 2015;15(8):951–9.
  5. Bellini R, Zeller H, Bortel WV. A review of the vector management methods to prevent and control outbreaks of West Nile virus infection and the challenge for Europe. Parasites & Vectors. 2014;7(1):323.
  6. Benelli G. Research in mosquito control: current challenges for a brighter future. Parasitology Research. 2015;114(8):2801–5.
  7. Wilke ABB, Marrelli MT. Paratransgenesis: a promising new strategy for mosquito vector control. Parasites & Vectors. 2015;8(1).
  8. Dodson BL, Hughes GL, Paul O, Matacchiero AC, Kramer LD, Rasgon JL. Wolbachia Enhances West Nile Virus (WNV) Infection in the Mosquito Culex tarsalis. PLoS Neglected Tropical Diseases. 2014 Oct;8(7).
  9. Fradin MS, Day JF. Comparative Efficacy of Insect Repellents against Mosquito Bites. New England Journal of Medicine. 2002 Apr;347(1):13–8.
  10. Knox TB, Juma EO, Ochomo EO, Jamet HP, Ndungo L, Chege P, et al. An online tool for mapping insecticide resistance in major Anopheles vectors of human malaria parasites and review of resistance status for the Afrotropical region. Parasites & Vectors. 2014;7(1):76.
  11. Hamer GL, Anderson TK, Donovan DJ, Brawn JD, Krebs BL, Gardner AM, et al. Dispersal of Adult Culex Mosquitoes in an Urban West Nile Virus Hotspot: A Mark-Capture Study Incorporating Stable Isotope Enrichment of Natural Larval Habitats. PLoS Neglected Tropical Diseases. 2014;8(3).
  12. Jost CA, Pierson TC. Antibody-Mediated Neutralization of West Nile Virus: Factors that Govern Neutralization Potency. West Nile Encephalitis Virus Infection. 2009;219–47.

 

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Did you know? Public Health Fact of the week

14 Thursday Apr 2016

Posted by Charis Renai Royal in Uncategorized

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Did you know? The global life expectancy has increased 6 years since 1990. The average life expectancy is 70 years based on a range of 62-79 years worldwide.

New Video Series is coming!

06 Wednesday Apr 2016

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Hi All, I am starting a video series to interact with my viewers! Please Watch below and comment/share so we can name the series as well as have questions to answer on the next video!

Zika in Arizona!

30 Wednesday Mar 2016

Posted by Charis Renai Royal in Uncategorized

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The first case of Zika Virus has been confirmed in Maricopa County as of today by The Maricopa County Department of Public Health. The woman had traveled to Zika affected area and returned home to Arizona where she started having symptoms. However, Public health officials believe that there is little chance of the virus spreading or becoming an epidemic here in Arizona.

This confirmation comes just four days after the CDC released new guidelines for the virus that include prevention measures such as the use of condoms and abstinence for those sexually active.

As of March 25th, in the United States there have been 273 confirmed cases of travel associated Zika infections, 19 of which are pregnant women. In the US territories, there have been 282 locally acquired Zika Infections, 4 travel associated case, and out of those 282, 34 are pregnant women.

If you or someone you know has traveled to a Zika affected area (list here), and are displaying Zika symptoms (here), please see your doctor, or contact your local public health agency.

 

Zika on the rise!

13 Saturday Feb 2016

Posted by Charis Renai Royal in Uncategorized

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A little over a week ago, I posted a description of a now looking to become pandemic virus: Zika (you can read the previous description here). Zika virus has been around for decades, with a few cases here and there, but recently, a surge in the virus in South America has had Health Organizations scrambling to determine the threat against the global population.

Zika virus is now spreading to more countries and new advisories are going out:

  • The first case of Zika in the United States was confirmed in Texas, and transmitted through sexual intercourse.
  • First pregnant woman in Spain confirmed with Zika virus
  • CDC has stated that limiting sexual activities with a pregnant partner if living or travelling to Zika infected areas.
  • Florida’s Governor Issued a State of Emergency in the counties that 12 confirmed Zika cases are- None of which were infected in the United States.
  • Brazil has found Active Zika virus in urine and saliva.
  • El Salvador advises its citizen to avoid pregnancy for up to 2 years.
  • New York has 11 confirmed cases of Zika.
  • Pennsylvania has two confirmed cases
  • Delaware has 1 confirmed case
  • Ohio has 1 confirmed case
  • Indiana has 1 confirmed case
  • WHO states that as many as 3 to 4 million people are infected in Central and South America
  • CDC issued Travel alerts to 28 countries.
  • Three deaths of individuals with Zika virus in Venezuela (caused by complications not currently linked to infection).
  • 52 cases of travel acquired Zika virus confirmed in United States

The World Health Organization convened its first emergency meeting to discuss the Zika virus, its epidemiology, clinical signs and symptoms, spread, and link to neurological disorders and microcephaly. The committee then submitted guidelines to be approved:

  • The increased and enhanced surveillance of microcephaly and Guillain-Barre syndrome in areas with outbreaks of Zika or with potential to become an area
  • Research into the etiology of microcephaly and Guillain-Barre syndrome to determine causal links.

They also issued additional recommendations in precautionary measures:

Zika virus

  • Surveillance enhancement
  • Prioritization of  new diagnostics.
  • Risk communications should be enhanced to address
    • population concerns
    • enhance community engagement
    • improve reporting
    • ensure application of vector control and personal protective measures.
  • Control measures and PPE should be implemented.
  • Education of Pregnant women or those intending to become pregnant in how to reduce risk.
  • Resources should be provided to pregnant women exposed to virus

Longer-term measures

  • Appropriate research and development efforts into vaccines, therapeutics and diagnostics.
  • Increase in health services preparation for potential increase in neurological or congenital birth defects.

A recent article from Bogoch et al. has determined a potential transmission map for how the Zika virus might spread. Taking into account the number of people who travel in and out of Brazil, the researchers determine that the rest of Central and Northern South American countries will see a drastic increase, as well as the Caribbeans, Florida and will continue to spread up through the Eastern Seaboard of North America.

Zika.jpgBogoch et. Al.  2016. Anticipating the international spread of Zika virus from Brazil. The Lancet.

Conclusion:

The most important thing to remember about Zika virus is that it normally does not lead to death. The majority of individuals infected do not display symptoms and are not sick. the recent rash of Zika infection is unprecedented and researchers around the world are working faster diagnostics tests, treatment options and vaccines.

Holiday Gifts for my Fellow Science Nerds!

15 Tuesday Dec 2015

Posted by Charis Renai Royal in Uncategorized

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Choosing holiday gifts are difficult for the regular person- but if you are trying to figure out what to get for your buried in a lab- nose in a textbook friend- here are some gift ideas!

B5XRlELIEAAODC5

Kitchenware
GeNiUs coffee mugs – $50
GeNiUs

Test Tub Tea Infuser – $11

31FvwOHN9UL

Beaker Mug – $12
Beaker mug

Caffiene Molecule Mug –  $23
51MlRFVv6QL

Periodic Table Coaster Set – $20
Coaster Set

Jewelry

Anatomical Heart – $16-180 depending on metal used
Anatomical Heart

DNA Base Pair Molecules – $35+
Base Pair

DNA Helix Pendent – $29
DNA Helix

Chemical Formulas – Dopamine, Serotonin, and Acetylcholine – $2+
Molecular Formula Jewelry

Solar System Necklace – $31
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For the Chemical Nerds:

Periodic Table Shower Curtain – $30
8a2f_periodic_table_shower_curtain

And finally…For those who love the little wiggly microbes-

Microbe Plushies! – $10-25
bacteria

 

Have Happy Holidays my fellow Science Nerds!

Ebola! The facts and fiction.

08 Wednesday Jul 2015

Posted by Charis Renai Royal in Uncategorized

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When I was seven years old I watched a movie called Outbreak; an action packed movie that threw together Dustin Hoffman, Morgan Freeman and a cute monkey battling a mutating virus that began to overwhelm a small town. This movie led me on a an exploratory journey into the world of infectious diseases. Outbreak was loosely based on the book the Hot Zone, a nonfiction novel about the history of hemorrhagic fevers. I read this book over and over, and to this day still have the the same weather worn copy.

With the recent International outbreak of Ebola, I thought it would be a good idea to spread some wisdom about Ebola.

3890_lores

*Human Liver infected with Ebola.

Disease: Ebola virus disease
Also known as: Hemorrhagic Fever

Virus Family: Filoviridae

Transmission: Spread of bodily fluids or objects recently in contact with bodily fluids. Air transmission has not been seen in any form of transmission. Can spread through blood, vomit, mucus, and feces.

Pathogenic organism: Four Ebola virus strains are know to cause disease in humans: Zaire (EBOV) which now just known as Ebola Virus due it it being the most common virus, Bundibugyo (BDBV), Sudan (SUDV), and Taï Forest (TAFV). The fifth strain is not known to cause disease in humans and is named Reston (RESTV).

Ebola

*Evola Virus virion

History:

The first Ebola outbreak in history was in 1979 where two outbreaks occurred at the same time: one in Nzara, Sudan, and the other in Yambuku, Democratic Republic of Congo. The virus was named after the Ebola River in the Democratic Republic of Congo, then named Zaire which is the name of the most common form of the virus. The natural reservoir of the disease is thought to be a kind of bat from the family of Pteropodidae.

The disease has an incubation period of 2-21 days in which a person is infected and can infect others. Being symptomatic means a person is infectious. Symptoms include those similar to many other viruses such as: fever, sore throat, muscle pain and vomiting. Ebola typically has a case fatality rate of around 50% but can range from 25-90% depending on available healthcare, comorbidities and healthcare infrastructure.

The recent outbreak in Africa caused widespread panic across the world. Countries from all over the world sent healthcare aid, workers and supplies. Unfortunately, health care workers are at an increase risk of infection due to close contact with patients and their samples. As we’ve seen with the recent Ebola outbreak in Sierra Leone, Liberia and Guinea, the risk of health care workers being infected and travelling outside of the infection zone is a safety concern in any kind of outbreak. The key to controlling any outbreak is containment and healthcare mobilization.

If there are any questions you would like me to answer, comment below and I will happily answer!

* The information and pictures from this posted is references from the Center for Disease Control and Prevention Ebola Page on http://www.cdc.gov/vhf/ebola/ and on the World Health Organization on http://www.who.int/mediacentre/factsheets/fs103/en/ -Please visit these sites for more information!

Starting at the beginning…

11 Saturday Apr 2015

Posted by Charis Renai Royal in Uncategorized

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Okay… So not really at the beginning, but the beginning of Epidemiology and Public Health! That’s a good start… right? So I have added a few pages, one about me, one for resources, a glossary because I know people are not familiar with every term I will be using (I’m trying to make this non-sciency person friendly) I will be continuing to add major diseases in history, public health tips and so on… but continue on down to learn more about one of the most important diseases in epidemiology!

Disease: Cholera
Transmission: Sewage or waste water coming into contact with drinking water or fecal-oral transmission
Pathogenic organism: Vibrio cholera

Cholera-dish-38r

History:
While the earliest outbreaks of cholera are highly debated, the most notable outbreaks are those of 19th century. The first cholera pandemic hit the Eastern Hemisphere from 1817 to 1823, and then again sweeping through India and travelling all the way to England and then travelling to the Americas by the end of 1831.

Cholera is an important contributing factor to the history of infectious disease because this is the disease that prompted the research of Dr. John Snow that began the study of epidemiology and public health. In 1854, a large outbreak of cholera in the Soho district of London was caused by a large amount on people moving in and a lack of sewage systems. The government decided to run the wastes from this area into the Thames river to solve the problem of overcrowding and unsanitary living conditions. This waste dump contaminated the water supply, leading to one of the largest cholera outbreaks in England’s history. Within the first week, over a 125 people had died, by the end of the outbreak, over 600 had perished. Dr. Snow, a physician treating the outbreak, decided to try to research a way to prevent the spread of cholera deaths in London. At this point in time, cholera was believed to be caused by “breathing bad air”, however, Dr. Snow did not believe this theory and began investigating alternatives. To begin his research he began mapping the number of patients and where they lived in order to get a sense of what factors might affect the transmission of this disease. What he ended up finding was that a majority of the cases lived around a single water pump on Broad Street. After taking test samples and statistically mapping the outbreaks, Dr. Snow managed to convince public authorities to remove the water pump that worked the well. This action led to the decline of the outbreak and founded the beginning of Epidemiology!

Symptoms and Biological pathways:

Vibro cholera  enters the body through the mouth and travels down the gastrointestinal tract to lodge itself within the intestinal walls. It replicates rapidly within the next 2-3 days and begins to release a chemical toxin that affects the membranes of your intestinal cells. This change in permeability causes a rapid loss of water and nutrient uptake causing excessive diarrhea and vomiting. Other symptoms include a shrunken appearance, muscle cramps, and increased thirst. Massive dehydration occurs which leads to rapid drops in blood pressure, cardiac arrest and possibly death.

V.-cholerae-38r

Cholera today:

In general, industrialized or “Developed” nations in the world have very few causes of infectious diseases that rely on sanitation conditions for transmission. However, there are approximately 3-5 million cases a year in the world, mostly seen in Africa and Southeast Asia. The CDC cautions U.S. citizens from drinking non-bottled water when travelling to these areas and to immediately seek medical attention if showing any signs and symptoms.

* The information and pictures from this posted is references from the Center for Disease Control and Prevention Cholera Page on http://www.cdc.gov/cholera/index.html -Please visit this site for more information!

Please comment below if you have any suggestion or want to learn anything specific! I am still working out some kinks… so have some patience with me!

The beginning of an era…

06 Monday Apr 2015

Posted by Charis Renai Royal in Uncategorized

≈ 4 Comments

Hello!

I hope that you have come to this page to learn… as that is the whole reason it is here!

Since I was seven years old, I have been fascinated by the world of microorganisms and infectious diseases. Over the years this evolved from a simple fascination to a passion that has led me to where I am now- Four weeks away from graduating from Arizona State University with a Bachelors of Science in Biology and a Bachelors of Science in Anthropology; and to be honest, this is just the beginning!

I have chosen to study both Anthropology as well as Biology because it gives me a unique perspective on diseases, and how they have evolved over the course of human history. I believe that by studying how diseases present in the human population from their origin to current times, we can derive an understanding of how they are going to evolve in the future. I concentrate my focus on researching infectious diseases and understanding their impact on the human population.

This concern piqued my interest in infectious diseases and because of this I have expanded my research and am now working on identifying cultural factors that may affect the transmission of the coronavirus spreading in Saudi Arabia, called Middle Eastern Respiratory Syndrome (MERS-CoV). This disease is a sister virus to Severe Acute Respiratory Syndrome (SARS-CoV) and they are closely related in the phylogenetic tree of novel coronaviruses that have generated infections in humans.

My educational background and study of diseases have been focused on data analysis and the epidemiology of MERS-CoV. My professional background as an Emergency Medical Technician has given me a glimpse of the everyday need of a strong Public Health infrastructure. These are just a few reasons that I am determined to one day be on the frontlines to respond to and treat emergency situations such as biological and environmental emergencies, infectious disease outbreaks, and other situations that require emergency response.

My intent is to continue my education with this dual approach of combining hands-on medical knowledge with in depth research in order to understand the mechanisms of a disease on a population along with how to treat and help the infected individuals recover. Moving forward, I plan to tackle the problems of infectious diseases: how to treat, contain, and understand how they infect a population.  There are many different paths available to reach this goal, and being a part of this program with the limitless opportunities it presents to those interested in public health is a step in the right direction for anyone striving to better the world.

I want to devote my life to helping people and preventing these diseases from spreading. One of the best ways to do this is to educate the population on the fundamentals of biology, infectious diseases and public health. I hope you continue on this journey with me as I explore this Microbial World!

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