Question

Dr. Sam Wise, medical director at San Diego Valley Hospital, has just conducted a meeting in which he informed those in attendance of an acute outbreak of Zika virus. In the past 36 hours, two men and one woman, completely unrelated to one another, have presented to Valley’s ER with the symptoms of Zika virus. Their only commonality is that they all live within an area of 17 square miles.

Patient 1, Stevie, is a 24-year-old graduate student at San Diego State University. He is not in a relationship and has had no sexual contact in more than three months. He has not traveled out of the greater San Diego area in the past five months, and he has never left the west coast of the United States.

Patient 2, Tiffany, is a 31-year-old marketing executive. She is married with two children, ages 3 and 4. Tiffany was in Seattle for a weekend, two weeks ago, but she has, otherwise, not left San Diego in more than six months. Her husband and children have not left San Diego in more than a year. Tiffany’s husband and her children exhibit no symptoms of Zika.

Patient 3, Enrique, is a 39-year-old carpenter. He owns his own business, which has him traveling all over the region, within a 100-mile radius of San Diego. However, he has never traveled any farther than that. Enrique is married with four children, aged between 3 and 8 years of age. No one in Enrique’s family has exhibited any Zika symptoms.

Because all of the children are too young to date, and there are no extramarital behaviors in either Tiffany’s or Enrique’s relationships, the possibility of others being infected through sexual intercourse is eliminated. As well, none of the infected parties have traveled to a high risk area.

As the director of community relations at San Diego Valley Hospital, Dr. Wise has charged you with the task of writing an article to be released to the public through the local newspaper. Dr. Wise has charged you with informing the public of a potential Zika outbreak. Your article must include a discussion of the epidemiological triangle, modes of transmission, symptoms of Zika, high-risk populations, associated morbidities, known vaccines, prevention measures, etc. Your article must be written in a lay fashion. In order to assist you in writing the article, the hospital’s epidemiologist has provided you with these CDC-supported resources.

Answer 1

ALL ABOUT ZIKA....

THE epidemiological triangle :-

Agent- Zika virus is a member of the virus family Flaviviridae. It is spread by daytime-active Aedes mosquitoes, such as A. aegypti and A. albopictus....

host- The vertebrate hosts of the virus were primarily monkeys in a so-called enzootic mosquito-monkey-mosquito cycle, with only occasional transmission to humans....

Environmental-humans have created an environment for it to proliferate, by having all of these water containing containers around, and the mosquito has adapted so well…it’s really kind of a human parasite. It’s like the cockroach of the mosquito world.”...

Modes of transmission:-

• Mosquito:- Zika is primarily spread by the female Aedes aegypti mosquito, which is active mostly in the daytime.

• Sexual

  Zika can be transmitted from men and women to their sexual partners; most known cases involve transmission from symptomatic men to women..

• PregnancyEdit

  Zika virus can spread by vertical (or "mother-to-child") transmission, during pregnancy or at delivery.An infection during pregnancy has been linked to changes in neuronal development of the unborn child.Severe progressions of infection have been linked to the development of microcephaly in the unborn child, while mild infections potentially can lead to neurocognitive disorders in adulthood....

• Zika virus transmitted through blood transfusion

  All blood donations are now screened for the Zika virus. To further reduce the risk of transmitting Zika virus through blood transfusion in areas where there are no active Zika virus outbreaks, the Food and Drug Administration recommends not donating blood for four weeks if you:

• Have a history of Zika virus infection
• Traveled or lived in an area with active Zika virus transmission
• Have symptoms that are suggestive of Zika virus infection within two weeks of travel from an area with Zika virus
• Have had sexual contact with a partner who has been diagnosed with Zika virus infection
• Have had sexual contact with a partner who has traveled or lived in an area with active Zika virus transmission in the past three months....

Symptoms :-

As many as 4 out of 5 people infected with the Zika virus have no signs or symptoms. When symptoms do occur, they usually begin two to seven days after a person is bitten by an infected mosquito. Signs and symptoms of the Zika virus most commonly include:

• Mild fever
• Rash
• Joint or muscle pain

Other signs and symptoms may include:

• Headache
• Red eyes (conjunctivitis)

Most people recover fully, with symptoms resolving in about a week.

High risk population in Zika:-Have had sexual contact with a partner who has been diagnosed with Zika virus infection. Have had sexual contact with a partner who has traveled or lived in an area with active Zika virus transmission in the past three months.

Associated morbidities:-

Zika virus infections during pregnancy have been linked to miscarriage and microcephaly, a potentially fatal congenital brain condition.

The Zika virus may also cause congenital Zika syndrome, which includes these birth defects:

• Severe microcephaly with a partly collapsed skull
• Brain damage and reduced brain tissue
• Eye damage
• Joint problems, including limited motion
• Reduced body movement due to too much muscle tone after birth

The Zika virus also may cause other neurological disorders such as Guillain-Barre syndrome....

Vaccines:- no vaccines yet released but

In June 2016, the FDA granted the first approval for a human clinical trial for a Zika vaccine.] In March 2017, a DNA vaccine was approved for phase-2 clinical trials. This vaccine consists of a small, circular piece of DNA, known as a plasmid, that expresses the genes for the Zika virus envelope proteins. As the vaccine does not contain the full sequence of the virus, it cannot cause infection.As of April 2017, both subunit and inactivated vaccines have entered clinical trials....

Prevention measures:-

There is no vaccine to protect against the Zika virus.

The CDC recommends all pregnant women avoid traveling to areas where there is an outbreak of the Zika virus. If you have a partner who lives in or has traveled to an area where there is an outbreak of the Zika virus, the CDC recommends abstaining from sex during pregnancy or using a condom during sexual contact.

If you are trying to become pregnant, talk to your doctor about any upcoming travel plans and the risk of getting infected with the Zika virus. Your doctor may suggest you and your partner wait to try to conceive for several months.

During sexual contact, use a condom to reduce the risk of getting or spreading the Zika virus if you or your partner lives in or has traveled to an area where there is an outbreak of Zika virus. Or avoid sexual contact.

If you are living or traveling in tropical areas where the Zika virus is known to be, these tips may help reduce your risk of mosquito bites:

• Stay in air-conditioned or well-screened housing. The mosquitoes that carry the Zika virus are most active from dawn to dusk, but they can also bite at night. Consider sleeping under a mosquito bed net, especially if you are outside.
• Wear protective clothing. When you go into mosquito-infested areas, wear a long-sleeved shirt, long pants, socks and shoes.

• Use mosquito repellent. Permethrin can be applied to your clothing, shoes, camping gear and bed netting. You also can buy clothing made with permethrin already in it. For your skin, use a repellent containing at least a 10 percent concentration of DEET.

  When used as directed, insect repellents that are registered with the Environmental Protection Agency (EPA) are proven safe and effective for pregnant and breast-feeding women.

• Reduce mosquito habitat. The mosquitoes that carry the Zika virus typically live in and around houses, breeding in standing water that can collect in such things as animal dishes, flower pots and used automobile tires. Reduce the breeding habitat to lower mosquito populations.