World Mosquito Day is observed on August 20 every year. We remember this day because of British Dr. Sir Ronald Ross who discovered in 1897 that female mosquitos transmit malaria between humans. This year’s theme of World Mosquito Day is “Harness innovation to reduce the malaria disease burden and save lives“. Though mosquito borne diseases can occur throughout the year, they are most prevalent during the monsoon season. In India, Malaria, Dengue, Chikungunya, Zika, Filariasis, Viral Encephalitis are the most common mosquito borne infections.
Epidemics & endemicity are very common in our country. India has about 400 mosquito species, all of which carry infecting organisms & there are frequent outbreaks of such infections. Diseases which have been almost eradicated have resurged due to resistance developed by mosquitoes to pesticides & change in their characteristics. Dr. N.R. Shetty , Consultant, Internal Medicine at Kokilaben Dhirubhai Ambani Hospital shared her inputs on how to safeguard ourselves from these 5 mosquito-borne infections.
The following are the commonly seen mosquito-borne infections:
There are 4 types of malarial protozoa but vivax & falciparum are most common infection causing protozoa. Falciparum malaria can be quite critical as it causes systemic complications including cerebral fever.
The disease can be transmitted by infected anopheles mosquito and through person to person transmissions. High fever, chills, shivers, headache and vomiting are common symptoms. Low platelet counts, jaundice, kidney-respiratory failure, may occur in few patients especially in falciparum infections.
Malaria is more common in crowded unhygienic areas. Diagnosis is done by clinical features, fever patterns, blood smear and malarial antigen testing. Ideally blood collected during fever yields best results. Along with blood counts, electrolytes, liver and kidney function tests may also be done.
2. Dengue fever
Caused by dengue virus, this fever is common in monsoon and winter, usually caused by mosquito bite during the day time.
Dengue may be mild, haemorrhagic or progress to a dengue shock syndrome. The fever lasts 4-5 days causing severe headache, muscle-body pain, low backache, eye pain as common symptoms. Skin rashes and itching may occur as well in some cases. Severe bleeding from multiple sites, multi-organ failure, low blood pressure and collapse may occur.
Diagnosis include symptoms such as serial platelet and antigen testing. There is no specific anti dengue drugs or anti-viral treatment, therefore the treatment is mostly symptomatic including hydration and blood- platelet transfusions. Severe cases may require critical care and in such situations hospitalization where medical care is available full time should be considered where patient is continuously monitored for better recovery.
This virus is transmitted by direct mosquito bite. The symptoms include fever, chills, mild to severe joint pain, headache and skin rashes. The Joint pains in this condition are debilitating with multiple joints affected lasting days, weeks, months and sometimes even longer.
The diagnosis is made by IgG, IgM, RT PCR tests of blood samples. In the absence of specific therapy, treatment includes fluid administration, non-steroidal analgesics and antivirals for managing of symptoms.
4. Zika fever
In recent years sporadic cases of Zika fever have been observed in India. Muscle pain, headache, fever, skin rashes, eye pain and pink eyes are the common indicators of the infection. Additionally, pregnant women with zika infection may have miscarriages and new-born birth defects.
The diagnosis is done by IgM-ELISA antibodies testing. Like most mosquito borne infections, the treatment is symptomatic. During the treatment, unprotected sexual activity should be avoided in order to prevent further transmission of the infection
This infection is caused and transmitted by mosquito bites. High fever, chills shivers specifically in the night, swelling of leg or affected parts, redness, glandular enlargement such as scrotum are the commonly observed symptoms. Elephantiasis is a result of Filariasis.
The diagnosis includes blood smear testing for microfilariae particularly at midnight during fever. Clinical treatment is done with DCC antibiotics along with supportive medication.
Prevention of mosquito borne diseases:
Maintain proper hygiene and clean surroundings
Opting for clothing to adequately avoid mosquito bites and using skin creams to avoid the same
Use of mosquito screens, nets, bed protection and mosquito repellents to avoid mosquito bites and infection transmission
Spraying adequate insecticides in the house, society & other surroundings
Avoid storage of water in open spaces, water collection in spaces like flower pots, rubber tyres, glass pieces, fountains etc. and spraying them with insecticides
Seek medical advice for any of the above mentioned symptoms