Tuesday, January 26, 2016

Concern for Zika Virus - Mosquito transmitted disease of South and Central America

The Zika virus is a growing concern as it spreads throughout South and Central America as well as the Pacific Islands.  The mosquito is the primary vector.  While for most people, the symptoms of the viral infection are mild , there is a concern for pregnant women who become infected in that it may lead to microcephaly, a rare neurological condition in which an infant's head is significantly smaller which is associated with incomplete brain development.  Yikes.  (But this has not yet been totally proven.)

Cases of infection in the US have been seen in those who have traveled to areas where the virus is present.

Damn mosquitos...West Nile Virus was bad enough, now we got something else to worry about.  Mosquitos also carry other diseases including Chikungunya, dengue, yellow fever and malaria.

 
CDC Website
Zika Virus
 
Zika virus is spread to people through mosquito bites. The most common symptoms of Zika virus disease are fever, rash, joint pain, and conjunctivitis (red eyes). The illness is usually mild with symptoms lasting from several days to a week. Severe disease requiring hospitalization is uncommon.
 
Outbreaks of Zika have occurred in areas of Africa, Southeast Asia, the Pacific Islands, and the Americas. Because the Aedes species mosquitoes that spread Zika virus are found throughout the world, it is likely that outbreaks will spread to new countries. In December 2015, Puerto Rico reported its first confirmed Zika virus case. Locally transmitted Zika has not been reported elsewhere in the United States, but cases of Zika have been reported in returning travelers.


There is no vaccine to prevent or medicine to treat Zika. Travelers can protect themselves from this disease by taking steps to prevent mosquito bites. When traveling to countries where Zika virus (see map(http://www.cdc.gov/zika/geo/index.html)) or other viruses spread by mosquitoes have been reported, use insect repellent, wear long sleeves and pants, and stay in places with air conditioning or that use window and door screens.
 
TRANSMISSION
Through mosquito bites
 
  • Zika virus is transmitted to people primarily through the bite of an infected Aedes species mosquito. These are the same mosquitoes that spread dengue and chikungunya(http://www.cdc.gov/chikungunya/index.html) viruses.
  • These mosquitoes typically lay eggs in and near standing water in things like buckets, bowls, animal dishes, flower pots and vases. They are aggressive daytime biters, prefer to bite people, and live indoors and outdoors near people.
  • Mosquitoes become infected when they feed on a person already infected with the virus. Infected mosquitoes can then spread the virus to other people through bites.
Rarely, from mother to child
  • A mother already infected with Zika virus near the time of delivery can pass on the virus to her newborn around the time of birth, but this is rare.
  • It is possible that Zika virus could be passed from mother to fetus during pregnancy. This mode of transmission is being investigated.
  • To date, there are no reports of infants getting Zika virus through breastfeeding. Because of the benefits of breastfeeding, mothers are encouraged to breastfeed even in areas where Zika virus is found.
Possibly through infected blood or sexual contact
  • There has been one report of possible spread of the virus through blood transfusion and one report of possible spread of the virus through sexual contact.
Symptoms
  • About 1 in 5 people infected with Zika virus become ill (i.e., develop Zika).
  • The most common symptoms of Zika are fever, rash, joint pain, or conjunctivitis (red eyes). Other common symptoms include muscle pain and headache.
  • The illness is usually mild with symptoms lasting for several days to a week.
  • Severe disease requiring hospitalization is uncommon.
  • Deaths are rare.
Diagnosis
  • The symptoms of Zika are similar to those of dengue and chikungunya(http://www.cdc.gov/chikungunya/index.html), which are diseases caused by other viruses spread by the same type of mosquitoes.
  • See your healthcare provider if you develop the symptoms described above and have visited an area where Zika is present.
  • If you have recently traveled, tell your healthcare provider when and where you traveled.
  • Your healthcare provider may order blood tests to look for Zika or other similar viruses like dengue or chikungunya.
Treatment
  • No vaccine or medications are available to prevent or treat Zika infections.
  • Treat the symptoms:
  • Get plenty of rest
  • Drink fluids to prevent dehydration
  • Take medicines, such as acetaminophen or paracetamol, to relieve fever and pain
  • Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs), like ibuprofen and naproxen, should be avoided until dengue can be ruled out to reduce the risk of hemorrhage. If you are taking medicine for another medical condition, talk to your healthcare provider before taking additional medication.
  • If you have Zika, avoid mosquito bites for the first week of your illness.
  • During the first week of infection, Zika virus can be found in the blood and passed from an infected person to another mosquito through mosquito bites.
  • An infected mosquito can then spread the virus to other people.
    
CDC adds countries to interim travel guidance related to Zika virus
Media Statement
Friday, January 22, 2016
 
Contact: CDC Media Relations 404-639-3286
 
CDC is working with other public health officials to monitor for ongoing Zika virus‎ transmission. Today, CDC added the following destinations to the Zika virus travel alerts: Barbados, Bolivia, Ecuador, Guadeloupe, Saint Martin, Guyana, Cape Verde, and Samoa. On January 15, CDC issued a travel alert (Level 2-Practice Enhanced Precautions) for people traveling to regions and certain countries where Zika virus transmission is ongoing: the Commonwealth of Puerto Rico, a U.S. territory; Brazil; Colombia; El Salvador; French Guiana; Guatemala; Haiti; Honduras; Martinique; Mexico; Panama; Paraguay; Suriname; and Venezuela. Specific areas where Zika virus transmission is ongoing are often difficult to determine and are likely to continue to change over time.
 
As more information becomes available, CDC travel alerts will be updated. Travelers to areas where cases of Zika virus infection have been recently confirmed are at risk of being infected with the Zika virus. Travelers to these areas may also be at risk of being infected with dengue or chikungunya viruses. Mosquitoes that spread Zika, chikungunya, and dengue are aggressive daytime biters, prefer to bite people, and live indoors and outdoors near people. There is no vaccine or medicine available for Zika virus. The best way to avoid Zika virus infection is to prevent mosquito bites.
 
Some travelers to areas with ongoing Zika virus transmission will become infected while traveling but will not become sick until they return home. Symptoms include fever, rash, joint pain, and red eyes. Other commonly reported symptoms include muscle pain, headache, and pain behind the eyes. The illness is usually mild with symptoms lasting from several days to a week. Severe disease requiring hospitalization is uncommon and case fatality is low. Travelers to these areas should monitor for symptoms or illness upon return. If they become ill, they should tell their healthcare professional where they have traveled and when.
 
Until more is known, and out of an abundance of caution, CDC continues to recommend that pregnant women and women trying to become pregnant take the following precautions:
 
Pregnant women in any trimester should consider postponing travel to the areas where Zika virus transmission is ongoing. Pregnant women who must travel to one of these areas should talk to their doctor or other healthcare professional first and strictly follow steps to avoid mosquito bites during the trip.
Women trying to become pregnant should consult with their healthcare professional before traveling to these areas and strictly follow steps to prevent mosquito bites during the trip.
 
Guillain-Barré syndrome (GBS) has been reported in patients with probable Zika virus infection in French Polynesia and Brazil. Research efforts will also examine the link between Zika and GBS.

 
Dengue

With more than one-third of the world’s population living in areas at risk for infection, dengue virus is a leading cause of illness and death in the tropics and subtropics. As many as 400 million people are infected yearly. Dengue is caused by any one of four related viruses transmitted by mosquitoes. There are not yet any vaccines to prevent infection with dengue virus and the most effective protective measures are those that avoid mosquito bites. When infected, early recognition and prompt supportive treatment can substantially lower the risk of medical complications and death.

Dengue has emerged as a worldwide problem only since the 1950s. Although dengue rarely occurs in the continental United States, it is endemic in Puerto Rico and in many popular tourist destinations in Latin America, Southeast Asia and the Pacific islands


Q. What is dengue?
A. Dengue (pronounced den' gee) is a disease caused by any one of four closely related dengue viruses (DENV 1, DENV 2, DENV 3, or DENV 4). The viruses are transmitted to humans by the bite of an infected mosquito. In the Western Hemisphere, the Aedes aegypti mosquito is the most important transmitter or vector of dengue viruses, although a 2001 outbreak in Hawaii was transmitted by Aedes albopictus. It is estimated that there are over 100 million cases of dengue worldwide each year.

Q.What is dengue hemorrhagic fever (DHF)?
A.DHF is a more severe form of dengue infection. It can be fatal if unrecognized and not properly treated in a timely manner. DHF is caused by infection with the same viruses that cause dengue fever. With good medical management, mortality due to DHF can be less than 1%.

Q.How are dengue and dengue hemorrhagic fever (DHF) spread?
A. Dengue is transmitted to people by the bite of an Aedes mosquito that is infected with a dengue virus. The mosquito becomes infected with dengue virus when it bites a person who has dengue virus in their blood. The person can either have symptoms of dengue fever or DHF, or they may have no symptoms. After about one week, the mosquito can then transmit the virus while biting a healthy person. Dengue cannot be spread directly from person to person.

Q.What are the symptoms of the disease?
A. The principal symptoms of dengue fever are high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding (e.g., nose or gums bleed, easy bruising). Generally, younger children and those with their first dengue infection have a milder illness than older children and adults.

Dengue hemorrhagic fever is characterized by a fever that lasts from 2 to 7 days, with general signs and symptoms consistent with dengue fever. When the fever declines, symptoms including persistent vomiting, severe abdominal pain, and difficulty breathing, may develop. This marks the beginning of a 24- to 48-hour period when the smallest blood vessels (capillaries) become excessively permeable (“leaky”), allowing the fluid component to escape from the blood vessels into the peritoneum (causing ascites) and pleural cavity (leading to pleural effusions). This may lead to failure of the circulatory system and shock, followed by death, if circulatory failure is not corrected. In addition, the patient with DHF has a low platelet count and hemorrhagic manifestations, tendency to bruise easily or other types of skin hemorrhages, bleeding nose or gums, and possibly internal bleeding.

Q.What is the treatment for dengue?
A. There is no specific medication for treatment of a dengue infection. Persons who think they have dengue should use analgesics (pain relievers) with acetaminophen and avoid those containing aspirin. They should also rest, drink plenty of fluids, and consult a physician. If they feel worse (e.g., develop vomiting and severe abdominal pain) in the first 24 hours after the fever declines, they should go immediately to the hospital for evaluation.

Q.Is there an effective treatment for dengue hemorrhagic fever (DHF)?
A. As with dengue fever, there is no specific medication for DHF. It can however be effectively treated by fluid replacement therapy if an early clinical diagnosis is made. DHF management frequently requires hospitalization. Physicians who suspect that a patient has DHF may want to consult the Dengue Branch at CDC, for more information.

Q. Where can outbreaks of dengue occur?
A.Outbreaks of dengue occur primarily in areas where Ae. aegypti (sometimes also Ae. albopictus) mosquitoes live. This includes most tropical urban areas of the world. Dengue viruses may be introduced into areas by travelers who become infected while visiting other areas of the tropics where dengue commonly exists.

Q.What can be done to reduce the risk of acquiring dengue?
A.There is no vaccine for preventing dengue. The best preventive measure for residents living in areas infested with Ae. aegypti is to eliminate the places where the mosquito lays her eggs, primarily artificial containers that hold water.

Items that collect rainwater or to store water (for example, plastic containers, 55-gallon drums, buckets, or used automobile tires) should be covered or properly discarded. Pet and animal watering containers and vases with fresh flowers should be emptied and cleaned (to remove eggs) at least once a week. This will eliminate the mosquito eggs and larvae and reduce the number of mosquitoes present in these areas.

Using air conditioning or window and door screens reduces the risk of mosquitoes coming indoors. Proper application of mosquito repellents containing 20% to 30% DEET as the active ingredient on exposed skin and clothing decreases the risk of being bitten by mosquitoes. The risk of dengue infection for international travelers appears to be small. There is increased risk if an epidemic is in progress or visitors are in housing without air conditioning or screened windows and doors.

Q.How can we prevent epidemics of dengue hemorrhagic fever (DHF)?
A.The emphasis for dengue prevention is on sustainable, community-based, integrated mosquito control, with limited reliance on insecticides (chemical larvicides, and adulticides). Preventing epidemic disease requires a coordinated community effort to increase awareness about dengue fever/DHF, how to recognize it, and how to control the mosquito that transmits it. Residents are responsible for keeping their yards and patios free of standing water where mosquitoes can be produced.




Chikungunya (pronunciation: \chik-en-gun-ye) virus is transmitted(http://www.cdc.gov/chikungunya/transmission/index.html) to people by mosquitoes. The most common symptoms of chikungunya virus infection are fever and joint pain. Other symptoms may include headache, muscle pain, joint swelling, or rash. Outbreaks have occurred in countries(http://www.cdc.gov/chikungunya/geo/index.html) in Africa, Asia, Europe, and the Indian and Pacific Oceans. In late 2013, chikungunya virus was found for the first time in the Americas(http://www.cdc.gov/chikungunya/geo/index.html) on islands in the Caribbean. There is a risk that the virus will be imported to new areas by infected travelers. There is no vaccine to prevent or medicine to treat chikungunya virus infection. Travelers can protect themselves by preventing(http://www.cdc.gov/chikungunya/prevention/index.html) mosquito bites. When traveling to countries with chikungunya virus, use insect repellent, wear long sleeves and pants, and stay in places with air conditioning or that use window and door screens.

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