Mosquito borne diseases are most common during summer and fall months

Mosquito borne diseases are most common during summer and fall months.

by Nirmala Thapa

Mosquito borne diseases are flourishing day by day despite different control efforts in action. Mosquitoes are more active during summer and fall months and that increases the risk of mosquito borne diseases during these months. According to West Virginia Vector borne Disease Surveillance report (Vectorborne Disease Report), there were nine human cases of mosquito borne diseases reported in West Virginia from January 1 to July 18, 2016. Among the cases, eight were travel associated Zika virus disease and one travel associated Malaria. The Zika virus has not been found in any mosquitos in West Virginia yet.

Mosquitoes belong to the family Culicidae; some transmit extremely harmful diseases such as Malaria, Yellow fever, Chikungunya, West Nile virus, La Crosse Encephalitis, St. Louis Encephalitis, Western Equine Encephalitis, Dengue fever and Zika virus disease. The West Virginia Division of Infectious Disease Epidemiology states that La Crosse Encephalitis is the most commonly reported mosquito borne disease in West Virginia, 10-20 cases per year (Preventing La Crosse Encephalitis in West Virginia Pamphlet). Other travel associated mosquito borne disease (Dengue fever, malaria and now Zika virus disease) have also been reported.

People get malaria from the bite of mosquito infected with a malarial parasite. Symptoms of malaria are high fevers, shaking chills and flue like illness. It could be fatal in some cases. CDC states that about 1,500 malaria cases are diagnosed every year in the United States. Most of the cases are in travelers coming back from the places where Malaria occurs. According to West Virginia Division of Infectious Disease Epidemiology, 1-2 travel associated cases of Malaria are reported every year in West Virginia. Taking an antimalarial drug and preventing mosquito bites are the prevention measures for Malaria.

Yellow fever is an acute viral disease caused by Flavivirus, transmitted to humans by the bites of an infected aedes and homogenous mosquitos. Symptoms of Yellow fever include fever, headache, jaundice, muscle pain, nausea, vomiting and fatigue. Serious cases may cause fatal heart, liver and kidney conditions. Yellow fever is most common in tropical and subtropical areas in Africa and South America. Recent updates from CDC states that the cases of Yellow fever illness in US travelers is rare. Vaccination can prevent the disease.

West Nile Virus (WNV) is transmitted to human by infected mosquitos. People infected normally do not develop symptoms, only 1 in 5 infected has fever. There is no vaccination to prevent WNV. Cases of WNV are regularly reported in United States. According to West Virginia Division of Infectious Disease Epidemiology, WNV is not commonly reported in West Virginia however mosquitoes infected with WNV are regularly reported in a few counties.

Chikungunya, Zika virus and Dengue fever have many things in common. These are commonly transmitted to people from the bite of an infected mosquito commonly, Aedes aegypti and Aedes albopictus. Aedes albopictus are common mosquito species in United Sates and also found in many counties in West Virginia.  No vaccine is available for any of these three mosquito borne diseases. Chikungunya and Dengue fever have similar symptoms which include sudden onset of fever, joint pain, muscle pain, headache, nausea, fatigue and rash.

As of July 27, 2016, CDC reported 1,658 Zika cases in United Sates. All these cases are travel associated except one being laboratory acquired. According to CDC, there are 9 Zika cases in West Virginia till date and all are travel associated. Follow the link (http://www.cdc.gov/zika/geo/united-states.html) to get recent updates on Zika cases in the United States.

If you do have any symptoms of any mosquito borne diseases, visit your health care provider as soon as possible. If you notice any mosquito breeding site around your area notify your local health department. Sanitarians with the Monongalia County Health Department investigate the mosquito complaints and help with controlling mosquito breeding sites. The can be contacted at 304-598-5131 or file a complaint on the website at http://www.monchd.org/contact-environmental.html

You can prevent yourself from getting mosquito borne infections by using the Mosquito Bite Prevention Checklist.

Nirmala Thapa is an Environmental Health/Epidemiology Intern at Monongalia County Health Department.