Vector Disease


Daniel Markowski, Ph. D.

Recent Posts

VDCI Proud Supporter of AMCA's Young Professionals Shadowing Program

Posted by Daniel Markowski, Ph. D. on Mar 10, 2016 2:45:00 PM
Written By Daniel Markowski, Ph. D.
The American Mosquito Control Association (AMCA) started the Young Professionals (YP) Program to increase the participation of students as well as professionals new to the mosquito industry (~5 years or less). The YP group provides these AMCA members with opportunities to build relationships with each other as well as network with experienced professionals. The main outlet for this engagement is the annual AMCA meeting. 2016 marked the 3rd year of YP activities, which included an informal dinner, a fieldtrip, and the highlight of the week - the YP symposium! The roundtable format encourages YPs to speak with experts in different mosquito-related fields to gain unique perspectives and new skills.

While the annual meeting is a great opportunity, it can be difficult for YPs to attend for various reasons – with budget related obstacles topping the list. To help bring a greater number of YPs to the annual meeting, a Shadowing Program was implemented in 2016. The program asked industry partners to support AMCA YPs with travel stipends, allowing for greater attendance, and VDCI was eager to partner with the program.

Read More

Topics: Industry News

What You Should Know About Zika Virus

Posted by Daniel Markowski, Ph. D. on Feb 16, 2016 10:30:27 AM
Written By The Staff at VDCI
What is Zika virus?
Zika virus (ZIKV) was first discovered in 1947 in the Zika Forest of Uganda. Shortly thereafter, it was isolated from mosquitoes in the area and then humans in 1968. ZIKV is a flavivirus similar to yellow fever, dengue, Japanese encephalitis, and West Nile virus (WNV). The disease had only been detected in central Africa and throughout Southeast Asia until associated with a diesease outbreak on Yap Island, in the South Pacific in 2007. From there, it spread to South America with human cases first reported in 2014.
How does the virus spread?
ZIKV does not appear to require an animal reservoir, like WNV, which is perhaps a factor in the rapid spread throughout the Americas. Non-infected mosquitoes are able to acquire the virus after feeding directly on infected humans. Without a "middle man" in the endemic cycle of ZIKV, the virus can spread quite rapidly where abundant, competent vector mosquitoes and humans are present together. Today, there is active transmission of the virus throughout South and Central America and the Caribbean Islands. Please refer to Figure 1 in VDCI's Zika Virus Fact Sheet.
Read More

Topics: Mosquito-Borne Diseases

Mosquito of the Month: Sabethes cyaneus – the Paddle-legged Beauty

Posted by Daniel Markowski, Ph. D. on Feb 4, 2016 11:03:00 AM
Written By Michael “Doc” Weissmann, Ph.D., Chief Entomologist
Valentine’s season is upon us -- whether we like it or not, our obsession with courtship seems to take center stage. Indoor creatures, like humans, are not deterred by the winter; but, for most insects in the Northern Hemisphere, it is still too cold outside for mating. Meanwhile, in the tropics, many species are active throughout the year. Outside of a geeky entomology laboratory, it is quite rare for a discussion about courtship to include any mention of mosquitoes; the vast majority of species don’t display any behavioral patterns complex enough to even qualify for the term. For most mosquitoes, mating is a fast and haphazard occurrence with swarms of males circling around and waiting for the sound of female wing-beats. Once detected, the male rushes after the female and immediately attempts copulation mid-air without so much as a “how do you do?” – this is not courtship. 

paddle_mos.jpgThere is one notable exception, the paddle-legged beauty, Sabethes cyaneus. This tropical forest species lay their eggs in shaded natural and artificial containers such as tree-holes, bamboo hollows, and even fallen banana leaves filled with rainwater. Sabethes larvae develop in these small source pools and feed on bacteria, algae, and other organic material. The beautiful adult Sabethes mosquitoes are usually encountered in close proximity to the small habitats of their youth.
Read More

Topics: Mosquito of the Month Series

Zika Virus: An Emerging Mosquito-Borne Infection in the Americas

Posted by Daniel Markowski, Ph. D. on Jan 27, 2016 2:51:47 PM
Written By Broox Boze, Ph.D., Contract Supervisor in Colorado
Zika_2.0.jpgOver the past couple weeks Zika virus has taken the media by storm and US Health officials from the Centers for Disease Control and Prevention (CDC) have issued an advisory for pregnant women traveling to areas where the virus is known to be active. While this is not a new disease, it is the first time we’ve seen it in the Western Hemisphere and it is a major cause for concern as we understand more about the potential link between Zika virus and birth defects such as microcephaly.

The Zika virus was first isolated from a rhesus macaque in Uganda in 1947 and documented in humans as early as 1968. The reason we haven’t heard much about Zika until now is that the vast majority of human cases present with little to no symptoms. In fact, the CDC reports that only 1 in 5 individuals who contract the virus will become ill, and those that do will experience mild flu-like symptoms including fever, rash, joint pain, headache and conjunctivitis (red eyes).
Read More

Topics: Mosquito-Borne Diseases

2015 Mosquito-Borne Disease Year in Review

Posted by Daniel Markowski, Ph. D. on Jan 21, 2016 9:53:06 AM
Written By The Staff at VDCI
WNV_2015_Map.jpgIn 2015, we saw a continuation of serious mosquito-borne disease cases in the United States. This blog covers three of many diseases that were transmitted by mosquitoes in 2015: West Nile Virus (WNV), Eastern equine encephalitis (EEE), and chikungunya. These three represent the most common mosquito-borne diseases we find in the United States, with WNV being far and away the most common threat in U.S. territories. All of the information in this year in review post was taken from the Center for Disease Control (CDC)’s data points and website as of 12/31/2015.
West Nile Virus (WNV): WNV is the most common virus transmitted by mosquitoes to humans in the United States. While most infected people will have no symptoms, roughly one in five will develop symptoms that may include a combination of fever, headache, body aches, skin rash, or swollen lymph nodes. Other symptoms may include a stiff neck, sleepiness, disorientation, or even paralysis.
Read More

Topics: Mosquito-Borne Diseases

Mosquito of the Month: Aedes albopictus – the Asian Tiger Mosquito

Posted by Daniel Markowski, Ph. D. on Jan 7, 2016 9:04:46 AM
Written By Michael “Doc” Weissmann, Ph.D., Chief Entomologist
Asian TigerAs if we didn’t have enough mosquitoes in the USA to deal with already, someone had to go and import one from across the ocean.  Great – thanks a lot!.  
Nobody is really sure exactly when the first of these invaders arrived into the USA , but the original recognized North American specimen of the Asian Tiger Mosquito, Aedes albopictus, was collected in June 1983 from a cemetery in Memphis, Tennessee. The species has since become one of the most challenging mosquitoes to control, and brings with it a host of other disease-related challenges.   
So what makes this invader such a challenge for mosquito control programs? While most mosquitoes are vampire-like in their avoidance of the sun, waiting until after sunset to seek a blood meal, the Asian Tiger Mosquito can more likely be found actively biting during the daytime in full sunlight. That’s not good. Most modern adult mosquito control occurs after sunset in order to avoid negatively impacting day-flying insects like bees, butterflies, and other popular pollinators. Any pesticides sprayed at night are dissipated by the time the Asian Tiger Mosquitoes take to the wing the next day.   
Read More

Topics: Mosquito of the Month Series

Fight the Bite for a Bite: A Source Reduction Strategy

Posted by Daniel Markowski, Ph. D. on Dec 17, 2015 9:52:47 AM
Written By Kellie Lowery, Contract Supervisor
mosquitoesIn my local community of Ruston, Louisiana, my biggest concern as a mosquito biologist is not the Culex species that is associated with West Nile Virus (WNV), but the Aedes albopictus species of mosquitoes (and Aedes aegypti, which we no longer have in Ruston). I don’t want to downplay Culex species and the potentially deadly role they play in the transmission of many diseases, but I do want to make you aware of Aedes mosquitoes and how they are potentially life threatening as well. Dengue (den' gee) and Chikungunya (chik-en-gun-ye) are two of the newest mosquito-borne viruses to hit the United States, and they are vectored by mosquitoes we have right here in Ruston, LA.
I have been with VDCI since the start of our services in my hometown of Ruston, LA.  Part of my job is to track mosquito populations and species throughout the city.  While we have experienced some WNV, we have been able to locate most of the large source breeding spots of Culex and work with the City of Ruston to clean up and clean out these areas for permanent source reduction.  This has greatly increased our ability to manage the Culex populations in Ruston.  Credit goes to the City for their willingness to work with us on these types of projects, because unfortunately, most cities do not have the ability or desire to undertake such tasks.  While I have watched the Culex population dwindle in this area, I have also seen Aedes albopictus populations grow to large numbers.  Knowing that we have the vectors (mosquitoes that are competent in the transmission of a virus), we decided that we should do some proactive work in getting these mosquitoes to manageable numbers. 
Read More

Topics: Public Education

Mosquito of the Month: Culex pipiens - Northern House Mosquito

Posted by Daniel Markowski, Ph. D. on Dec 2, 2015 10:06:38 AM
Written By Michael “Doc” Weissmann, Ph.D., Chief Entomologist
Culex_Pipiens.jpgIt is winter and all the mosquitoes have died, right? Well, not exactly.  
While many species of mosquitoes laid eggs last summer or fall and then died, others including the Northern House Mosquito, Culex pipiens, overwinter as an adult, waiting until next spring to lay their eggs. Throughout temperate zones of North America, Europe, and Asia, there may be snow on the ground outside, but these mosquitoes can still be found if one knows where to look for them.  
In late summer and early autumn, these mosquitoes forego the blood meals and instead fuel up on nectar or other sugary fluids, storing it as fat in their body. Before human construction, they likely spent the winter in caves or hollow trees – protected from the worst of the winter elements.  In such shelters they remain warm enough to keep from freezing to death, but cool enough that they don’t burn up all of their fat reserves before spring.  Humans have provided them with additional safe winter hiding places, including culverts, barns, stables, garages, basements, and sheds.  Some populations have even developed the ability to be active year-round in warmer structures such as the London Underground railway system, where they were notorious for attacking the city’s citizens who were seeking shelter in the subway tunnels during bombing air-raids of World War II.  If you find a mosquito flying around your garage on a warmer-than-normal December day, or resting on the wall of your shed in the middle of winter, it is likely this species.  
Read More

Topics: Mosquito of the Month Series

Tick Talk: An Integrated Approach to Tick Management

Posted by Daniel Markowski, Ph. D. on Nov 18, 2015 11:42:00 AM
Written By Emily Hibbard, Program Supervisor
tickAs the leaves change and winter approaches, the fear of ticks and tick-borne disease seems to fade from people’s thoughts. Fall is a beautiful time to enjoy outdoor activities, such as camping, hiking, and fishing, but be aware that with the cooler weather comes the next wave of ticks.  
Fall is the time when the adult stage of blacklegged ticks begins to emerge in full force. Blacklegged ticks, also known as deer ticks, are the primary culprits involved in the transmission of Lyme disease, as well as a barrage of other pathogens. Deer ticks require two years to complete their life cycle from egg to larvae to nymph to adult. Adults are typically active from October to May and can be found throughout the winter if the temperature exceeds 40 degrees Fahrenheit. Females lay an egg mass in late spring then larvae emerge in late summer. After a blood meal, the larvae will molt over winter and re-emerge the following spring as a nymph. Nymphs are most active from May through August. The poppy seed-sized nymphs are known to be the most responsible in human disease transmission due to their extremely small size, often going unnoticed when attached. Additionally, the nymphal ticks have experienced increased disease exposure from infected hosts during the prior summer.
Read More

Topics: Integrated Tick Management (ITM)

Mosquito of The Month Series, General Overview

Posted by Daniel Markowski, Ph. D. on Nov 4, 2015 9:27:00 AM
Written By Michael “Doc” Weissmann, Ph.D., Chief Entomologist
mosquito2“Seriously?  You get paid to identify mosquitoes?  How many kinds of mosquitoes are there?” 
Years ago when I started working in a mosquito control surveillance laboratory, some of my non-scientific relatives and friends were surprised to hear that there were so many different species of mosquitoes, and that there was a need to tell one kind of mosquito from another.  In fact, according to the Walter Reed Biosystematics Unit/Smithsonian Institution, there are nearly 3,300 named mosquito species currently recognized worldwide.   In the United States alone, more than 175 species have been recorded. 
With so many species of mosquitoes discovered so far, it would take almost 275 years to run out of species to write about for a Mosquito of the Month blog posting.  However, for many mosquitoes, we only have a name, physical description, and location where they have been discovered – little or nothing is known about their biology, natural history, and behavior.  A relatively few species have been studied in more detail, yet for those species that we do know more about, mosquitoes turn out to be a highly diverse and fascinating group.  
Read More

Topics: Mosquito of the Month Series