Mosquito is a small and midge like insect that belongs to Culicidae family. According to AMCA (American mosquito control association) there are over 3000 species of mosquitoes in the world.
Most common and most dangerous species are in the Culex, Anophelese and Aedes genera. Research shown that, mosquito of Aedes, Anopheles, Culex and Armigeres genera are the most emergences in few last years and causes of many diseases in Pakistan.
Actually various type of disease caused by different genera of mosquitoes. Such as Dengue fever is caused by Aedes mousquito from the Aedes genera.
In 2017 KPK is badly affected by dengue disease. A report from WHO (World health organization) on 19-October-2017, has reported a cumulative total of 74,820 cases of suspected fever including 15,828 laboratory confirmed cases and 54 deaths.
In last few years, Malaria is also an emergence parasitic disease caused by Anopheles mosquito from the Anopheles genera. According to a recent survey of the WHO, Pakistan is included among the top countries that have accounted 81 percent of the estimated deaths globally due to Malaria. Malaria is second most reportedly disease with 4.5 million cases reported each year in Pakistan.
Culex, a large group of mosquitoes also known as common house mosquitoes, are the principal vectors that spread the viruses that cause Avian malaria, West Nile fever, as well as viral diseases of birds and horses and other viral diseases. There are many cases of WN-virus reported in southern region of Pakistan.
Life cycle
The mosquito life cycle has four stages: eggs, larval, pupae and adult.Hatching of egg takes place when exposed to water. Larva –lives in water; molts several times; most species surface to breathe air. Pupae does not feed. Adult mosquitoes live 6-8 weeks, and females may lay several batches of eggs.
Since mosquitoes have such short life cycles -approximately 7-8 days from egg to adult, depending on environmental conditions. it is possible for them to adapt to environmental pressures over time.
Groups of Mosquitoes:
Mosquito species are divided into group based on where the females lay their eggs and where the larvae develop.The center for disease control and prevention (CDC) has developed a convenient grouping of four mosquito types according to the habitats in which the larvae generally develop;
- Permanent pool group
- Transient water group
- Flood water group
- Artificial container and tree-hole group
However, when mosquito populations are exposed to intensive selection pressure from insecticides, they tend to become resistant. Humans have used everything from screens to chemical repellants to protect themselves from mosquitoes and the diseases they carry. Now, scientists say mosquitoes are finding ways to adapt to insecticides and other recent changes in their environments.
A single genetic mutation causes resistance to DDT and pyrethroids (an insecticide class used in mosquito nets), according to new research in the journal Genome Biology. As resistance to pyrethroids and DDT is already spreading in mosquito populations, scientists say that this knowledge could help improve malaria control strategies.
So, this is the little bit overview of emergence of mosquito disease in Pakistan. On the other hand there are also many viral, bacterial and parasitic disease also caused by mosquito.
Mosquito-borne diseases:
There are four living elements that are considered to be a major problem of Mosquito-borne diseases such as;
- Pathogen:Any organism that can cause disease
- Reservior: Animals in which pathogen lives and which serves as the source of the pathogen for the mosquitoes that transmit it.
- Susceptible Hosts:Animals that are being affected by the pathogen.
- Vectors:vectors are the mosquito species that can transmit the pathogen.
Dengue:
It is also called as breakbone fever.Aedes aegypti is responsible for transmitting dengue to people. Serious manifestations of this disease are known as dengue hemorrhagic fever and dengue shock syndrome.It’s transmission takes place from infected humans to susceptible humans.
Symptoms consist of following; the sudden onset of high fever, severe headache, backache, joint pains and a rash that appears on third or fourth day of Illness.
Yellow Fever:
“Urban type” of yellow fever , epidemics are the result of human to mosquito to human transmission of the virus by Aedes aegypti, the yellow fever mosquito. The virus is introduced into the blood stream through the saliva of the mosquito as it bites.
Symptoms consist of following; high fever, internal bleeding and jaundice.Illness from yellow fever may be acute and fatal or so mild that it is unapparent.
Malaria:
Malaria in humans is an acute or chronic disease caused by anyone of four species of microscopic protozoan parasites belonging to the genus Plasmodiumm. The parasites are transmitted from human to mosquito to human by the bite of Anopheles mosquitoes. It’s infection in people are vary from moderately severe to a highly fatal illness, depends upon the condition of the human at the time of infection and on the species of Plasmodium involved.
Anopheles freeborni and Anopheles quadrimaculatus are the two known species which are considered to be a significant vectors of Malaria.In the blood in humans, these parasite invade individual red blood cells eventually destroying these cells and asexual reproductioan takes place.A Malaria infection persist in human for many months or even years.
Malaria causes fecer and flu-like symptoms that may include chills, headache, muscleaches and fatigue. Nausea, vomiting and Diarrhea may also occur.
What is zika virus?
Zika virus is a mosquito-borne flavi virus which was invented first time in Uganda in 1947 in monkeys through a network that monitored yellow fever. AFter that it was identified in humans of Uganda in 1952 and the United Republic of Tanzania.It was a serious problem that were recorded in Africa, United States of America, Asia and the Pacific.
Firstly on large scale, this Zika infection was reported from the Island of Yap(Federated States of Micronesia) in 2007.
Sign and symptoms of zika virus
Sign and symptoms of zika virus is very similar to other arbovirus infections such as Dengue, including fever, skin rashes, muscle and joint pain, conjuctivitis, headache and malaise.These symptoms are mild that last for 2-7 days.
How zika virus transmitted?
Zika virus is transmitted into the human beings through the bite of an infected mosquito belongs to Aedes genus, mainly Aedes aegypti in tropical region.Aedes Mosquito is the same that transmits dengue, chikungunya and yellow fever.Zika virus can be sexually transmitted or blood transfusion of this zika virus transmission are also investigated.
How zika virus can be treated?
Diagnose of this virus infection can be confirmed through laboratoty test on bloods, body fluids like saliva or semen.Zika virus containing people should have to take rest as long as they can, treat pain and fever with common medicines.If patients are not cured, then they should seek medical care and advice because yet there are no discovery of vaccine that can be used against this zika virus.
Management:
Drain standing water:
- Drain water from garbage cans, buckets, pool covers, coolers, toys, flower pots or any other container where sprinkler or rain water has collected.
- Discard old tires, drums, bottles, broken appliances and other items that aren’t being used.
- Empty and clean the bird baths and pets’ water bowls atleast once or twice a week.
- Protect boats and vehicles from rain with tarps that don’t accumulate water.
- Maintain swimming pools in good condition and keep appropriately chlorinated.
- Empty plastic swimming pools when not in use.
Cover your skin with:
- Clothing: If you must be outside when mosquitoes are active, cover up, wear shoes, socks, long pants and long sleeves.
- Use Mosquito netting to protect children younger than two months old.
- Chemical control is done by using insect repellent like DEET, IR3535 or icaridin according to the product label instructions.
- Cover doors and windows with screens, that will keep mosquito out of your house.
- Repair broken screening on windows and doors.
Tips on Eliminating Mosquito Breeding Sites:
- Clean out troughs and gutters.
- Remove old tires or drill holes in those used in polygrounds to drain.
- Turn over or remove empty plastic pots.
- Pick up all beverage containers and cups.
- Check tarps on boats or other equipment that may collect water.
- Water should be replaced in birdbaths and pet or other animal feeding dishes atleast once a week.
- Change water in plant trays, including hanging plants, atleast once a week.
- Remove vegetation or obstructions in draining ditches that prevent the flow of water.Authors: Arzlan Abbas, Nawwal kaleem butt and Muhammad Usman, University of Agriculture Faisalabad, Pakistan.
Corresponding Authors: Arzlan Abbas