1 views
Mosquitoes From Paradise
What Comes in your mind when you hear about Andaman and Nicobar Islands?
Golden Beaches like Radhanagar and Butler Bay surrounded by Turquoise Waters? Kalapani Jail? Barren Island? Water sports and Reefs? Century’s first Sunrise?
Well your answer can be anything but I am sure it won't be something like Mosquito, Right? Even we locals don’t think about our famous mosquitoes when we are far from home. But if you were an European from 18th or 19th Century, you would have possibly squeaked Mosquito and Malaria when heard about Nye Danmark (18th Century name for Andaman and Nicobar Islands).
My Islands witnessed first European Colonization by the Danish in the 18th Century. By 1755 to 1858, The Europeans had tried several times to build a European Settlement in Nye Danmark but each of their attempts went in vain just because of a small creature called Mosquito and a giant Killer called Malaria.
After Several Unsuccessful attempts from Danish, the Dutch, Austrian and Italians, The British in 1858 were successful in building a Penal Colony called Aberdeen (now Port Blair). Though British were also once unsuccessful but the might Europeans took more than a Century to establish their first Settlement in the Islands.
From that time onwards, the Unique and Rich Biodiversity of the Flora and Fauna had attracted many Scientists in the Islands.
The Earliest research on Mosquitoes in Andaman and Nicobar Islands was done by Herbert Christopher Robinson. He Discovered 8 species of Anopheles mosquito around Aberdeen in early years of 19th Century and had discovered a new species in Genus Uranotaemia. His research was particularly concentrated in Mangrove forests around Aberdeen.
Early research on Culex population were done by famous physician Gordon Covell in 1927; who was sent to islands during the Malarial Outbreak of 1927 in Andaman and Nicobar. Malaria and make some codes, which would be administered by Ross for protection and prevention from Malaria
By 1934 English Entomologist Philip James Barraud completed his research on the Mosquitoes of Andaman and Nicobar Islands. He did an Extensive research on the Culex populations and Eggs and larvae of Anopheles species. He also Studied and Classified Uranotaemia christopheri, the new species discovered by Herbert Christopher Robinson and placed it under Endemic Category and sent a pair of species to the British Museum. Barraud had also studied and classified Heizmannia covelli and Orthopodomyia andamanensis while being in Andaman and Nicobar.
After the Independence, the Islands saw several expeditions which were done on the mosquito populations of the Islands like by Basu in 1958, Krishnan in 1967, B.N. Nagpal and V.P. Sharma in 1982, Kumari in 1993, Kumari and Sharma in 1994,Sushil Kumar and Vijay Kumar in 1996, Nandi in 2000, Das in 2002, Nanda in 2004, Krishnamoorthy in 2005, Alam in 2006, A.R. Rajavel and R. Natarajan in 2006, Shanks in 2008, 2015 and 2016, Manimunda in 2011, Sunish in 2015, Patel in 2016, Shankar in 2016.
In 2016, According to the report published, Andaman and Nicobar Islands have 109 Mosquito species in 09 tribes, 25 Genus and 24 subgenera. According to estimates the total number of mosquito species can be higher as Survey on some Islands were not done.
Andaman and Nicobar Islands are also home to more than 25% of Mosquito species found in India and around 3% of mosquito species in the World; out of which only 2 are Endemic species.
Despite such high concentrations of Mosquitoes, Andaman and Nicobar Islands are relatively safe from diseases transmitted by Mosquitoes. According to local jokes and talks, the mosquitoes in Islands are very punctual regarding time; as they come out between time period of 4 PM to 7:30 PM.
Though out of 109 species only 2 are endemic; but these Islands are only places in India where one can find mosquito species from Genus Aedomyia, Armigers and Brucheharrisonius as these species aren’t found in Mainland India
Also, these Islands are ideal to see species from Genus Canocaedes, Finlaya, Rhinoskusea, Stegomiya, Lutzia and Malaya because of occurrence of several species in Healthy numbers. Andaman and Nicobar Islands is also famous for it’s healthy numbers of Giant-Sized Mosquito Species of Genus Toxorhynchites.
The Malaria causing Anopheles Family have 23 species in these Islands, The Culex group also have 23 species and Stegomiya or Aedes have 10 species among which Stegomiya seampi is Endemic.
Despite high number of Anopheles mosquitoes, Andaman and Nicobar are relatively at moderate to low risk for Malaria, that too in Rainy Season (April End to November).
Various Diseases like Anthrax, Rabies and Encephalitis hadn’t reached my Islands till now. Various European populations who came here to colonize these Islands were not able to transmit diseases in local Indigenous population to that extent as they did in America. British accounts wrote about Malaria, Filariasis and Weil’s disease and had also mentioned about Scabies and other Fungal infections as health problems prevalent in these Islands.
Malaria has always been a Curious case in Islands. Pre-dominance of Malaria can be explained by a detailed study of it Vectors the Anopheles Family which had further helped to bring down the deaths and incidences of Malaria. When Dr Gordon Covell encountered the Anopheles species of Islands, he found a strange contrast from the British India Mainland. The Anopheles culicifacies, responsible for more than 70% of cases in Mainland British India wasn’t responsible for Malaria in Andaman and Nicobar. That species had never reached the Islands. In Andaman and Nicobar Islands the Malaria was more severe and frequent due to various other reasons. Firstly, Unlike the Mainland British India and Neighbouring Dutch Indonesia and British Malaysia, in Andaman and Nicobar there is no predominant species. Anopheles stephensi and Anopheles sundaicus were equally present and cause Malaria. Also the ability of Anopheles sundaicus to breed in Brackish waters made this species hard to eradicate. Also stephensi and sandaicus populations increases rapidly. Further research revealed few species were more prone to transmit lethal plasmodium falciparum like Anopheles barbirostris and Anopheles karwari third and fifth biggest species of anopheles in Islands. Also other malarial vectors like Anopheles maculatus, Anopheles varuna, Anopheles phillipinesis and Anopheles annularis in huge numbers made Malaria a big threat. After Independence, the death rates decreased a bit as medical facilities became available to everyone. Malaria has been a Major threat more to Nicobar than Andaman. Especially the Islands of extreme south like Great Nicobar, Little Nicobar, Katchal, Nancowry and the Capital Pū (Car Nicobar Island). The Southernmost Island, the Great Nicobar was notoriously famous for it’s high concentrations of Mosquitoes. People even said that in those days, one can see more than 100 mosquitoes in their compounds in Great Nicobar Island.
By 1995, the government of Andaman and Nicobar under the leadership of Vakkom Purushothaman initiated various initiatives to decrease the incidence of Malaria. In Andaman the incidence was 11/1000 and in Nicobar it was 20/1000. South Nicobar was given special importance in the initiatives. Government had ensured the release of Gambusia affinis and made the availability of Anti-Malarial drugs to each and every individual various times free of cost. Every case of fever was considered to be Malaria. Availability of Chloroquine and Primaquine were more than Paracetamol in Southern towns like Campbell Bay. Andaman and Nicobar government and Union government of India had also invested a lot in awareness against Malaria. Every source of transmission like Newspaper, Radio and Television were filled with ads and jingles against Malaria. The results were positive. Just within 5 years by 2000, the incidence rate in Andaman fell up to 5/1000 and in Nicobar it was 8/1000. Though the incidence rates slightly increased again due to climatic, Tidal and Environmental changes caused by Tsunami of 2004.
Apart from Malaria, Incidence of Filariasis is constant since 1942.
The Dengue and Chikungunya virus never reached Andaman and Nicobar Islands until 21st Century.
The Chikungunya virus reached Andaman and Nicobar for the first time in 2006 during the Chikungunya Outbreak in Indian Ocean Islands.
The Chikungunya was very deadly for the Islands. The Aedes population overwhelmingly welcomed new pathogen. Climate and Indestructible number of vector produced a lethal combination for the local human population.
In Just 4 months (Upto September 2006), there were more than 1000 cases of Chikungunya cases in Islands.
The Government under the leadership of Bhopinder Singh, brought the cases in double digit by end of year and single digit by 2013.
Chikungunya had the potency to become a dangerous Endemic disease of the Islands but failed, but the Dengue is Emerging.
The first case of Dengue came from Andaman and Nicobar in 2009. According to an unauthorized source, A group of Labourers who were migrants to Andaman and Nicobar had brought the disease from Mainland India.
In 2010, 12 cases of Dengue haemorrhagic fever and Dengue Shock Syndrome were found. By 2011, there were 26 cases, By 2018, annual cases increased to 258. In 2021, 226 cases were reported. Dengue and Chikungunya viruses, both are abroviruses, both transmitted by same group of Vectors had a very different pattern for spread.
Chikungunya saw a sharp, Rapid increase and decline; but Dengue is setting it’s feet and spreading it’s root within the mosquitoes from Aedes group in the Islands.
The widespread increase in cases of Dengue can be due to presence of different species of Aedes in different Islands. Like the Aedes aegypti, the principal vector of DENV strain 2 is the most common mosquito in Urban Centers of South Andaman Island mainly in Port Blair, Ferrargunj and Bambooflat hence the DENV strain 2 was most common strain in Port Blair but DENV strain 3 was more common in Havelock Island because of Aedes albopicta, the principal vector of DENV-3. That’s why there was an contrast in the Dengue Outbreaks in South Andaman and Havelock Island.
Dengue is still prevalent; But only in South Andaman District. It hasn’t reached other parts of Islands still. Government had declared areas like Garacharama-I, Garacharama-II, Terlabad and Bathubasthi as Dengue Hotspots in Port Blair Tehsil and Manpur in Ferrargunj tehsil for the same.
At the end I want to say my Enchantingly beautiful Islands are fragile and Vulnerable. It’s distance from rest of the world had always Protected it but it’s shield is broke due to Globalization and it’s ambition to become a developed Economy. Dengue and Chikungunya can be case studies to how to deal with Encephalitis, Yellow Fever, Zika Virus and etc because one day, they can also reach my Islands. Close monitoring of Dengue cases from years helped a lot during Covid-19; probably this practice can also protect as from other Epidemics and Pandemics as Common diseases in other parts of world can be tragic here. My Islands have their biggest resource as it’s Rich and Healthy Biodiversity. Whether it’s being hosting closest relative of Extinct Dodo bird or having a wild strain of Candida auris, which is capable to cause next pandemic due to its multi-drug resistant nature. Mosquitoes are crucial part of this Biodiversity. Understanding them is very important as they are medically important vectors and accounts for a good proportion of patients which is greater than National Average of my Country India. Also, each Island has its own distinct geographical feature harbouring different species of mosquitoes transmitting different diseases in vivid pattern like we had saw in case of Dengue Outbreak in Havelock Island. A proper database of mosquitoes would help health officers and government to understand where there is a chance of an Outbreak of a disease transmitted by Mosquitoes or can help to locate vulnerable populations and degree of vulnerability to those diseases which hadn’t reached them till now. Understanding Mosquitoes can also help us to counter future possibilities of Diseases and even present scenario. Like researches are going on whether Anopheles sundaicus is capable to transmit Plasmodium knowlesi or not or Stegomiya malayensis whose population is increasing rapidly in South-East Asia and in Andaman and Nicobar is capable to transmit Dengue or not. Also we can use highly sensitive to malathion mosquito species like those in Toxorhynchites to feed on larvae of other Mosquitoe species like Aedes aegypti, Aedes albopictus and Anopheles stephensi. Though mosquito are smaller in size but should be respected as they are giant killers for human population.
By: Rithic Singh
© All Rights Reserved
Golden Beaches like Radhanagar and Butler Bay surrounded by Turquoise Waters? Kalapani Jail? Barren Island? Water sports and Reefs? Century’s first Sunrise?
Well your answer can be anything but I am sure it won't be something like Mosquito, Right? Even we locals don’t think about our famous mosquitoes when we are far from home. But if you were an European from 18th or 19th Century, you would have possibly squeaked Mosquito and Malaria when heard about Nye Danmark (18th Century name for Andaman and Nicobar Islands).
My Islands witnessed first European Colonization by the Danish in the 18th Century. By 1755 to 1858, The Europeans had tried several times to build a European Settlement in Nye Danmark but each of their attempts went in vain just because of a small creature called Mosquito and a giant Killer called Malaria.
After Several Unsuccessful attempts from Danish, the Dutch, Austrian and Italians, The British in 1858 were successful in building a Penal Colony called Aberdeen (now Port Blair). Though British were also once unsuccessful but the might Europeans took more than a Century to establish their first Settlement in the Islands.
From that time onwards, the Unique and Rich Biodiversity of the Flora and Fauna had attracted many Scientists in the Islands.
The Earliest research on Mosquitoes in Andaman and Nicobar Islands was done by Herbert Christopher Robinson. He Discovered 8 species of Anopheles mosquito around Aberdeen in early years of 19th Century and had discovered a new species in Genus Uranotaemia. His research was particularly concentrated in Mangrove forests around Aberdeen.
Early research on Culex population were done by famous physician Gordon Covell in 1927; who was sent to islands during the Malarial Outbreak of 1927 in Andaman and Nicobar. Malaria and make some codes, which would be administered by Ross for protection and prevention from Malaria
By 1934 English Entomologist Philip James Barraud completed his research on the Mosquitoes of Andaman and Nicobar Islands. He did an Extensive research on the Culex populations and Eggs and larvae of Anopheles species. He also Studied and Classified Uranotaemia christopheri, the new species discovered by Herbert Christopher Robinson and placed it under Endemic Category and sent a pair of species to the British Museum. Barraud had also studied and classified Heizmannia covelli and Orthopodomyia andamanensis while being in Andaman and Nicobar.
After the Independence, the Islands saw several expeditions which were done on the mosquito populations of the Islands like by Basu in 1958, Krishnan in 1967, B.N. Nagpal and V.P. Sharma in 1982, Kumari in 1993, Kumari and Sharma in 1994,Sushil Kumar and Vijay Kumar in 1996, Nandi in 2000, Das in 2002, Nanda in 2004, Krishnamoorthy in 2005, Alam in 2006, A.R. Rajavel and R. Natarajan in 2006, Shanks in 2008, 2015 and 2016, Manimunda in 2011, Sunish in 2015, Patel in 2016, Shankar in 2016.
In 2016, According to the report published, Andaman and Nicobar Islands have 109 Mosquito species in 09 tribes, 25 Genus and 24 subgenera. According to estimates the total number of mosquito species can be higher as Survey on some Islands were not done.
Andaman and Nicobar Islands are also home to more than 25% of Mosquito species found in India and around 3% of mosquito species in the World; out of which only 2 are Endemic species.
Despite such high concentrations of Mosquitoes, Andaman and Nicobar Islands are relatively safe from diseases transmitted by Mosquitoes. According to local jokes and talks, the mosquitoes in Islands are very punctual regarding time; as they come out between time period of 4 PM to 7:30 PM.
Though out of 109 species only 2 are endemic; but these Islands are only places in India where one can find mosquito species from Genus Aedomyia, Armigers and Brucheharrisonius as these species aren’t found in Mainland India
Also, these Islands are ideal to see species from Genus Canocaedes, Finlaya, Rhinoskusea, Stegomiya, Lutzia and Malaya because of occurrence of several species in Healthy numbers. Andaman and Nicobar Islands is also famous for it’s healthy numbers of Giant-Sized Mosquito Species of Genus Toxorhynchites.
The Malaria causing Anopheles Family have 23 species in these Islands, The Culex group also have 23 species and Stegomiya or Aedes have 10 species among which Stegomiya seampi is Endemic.
Despite high number of Anopheles mosquitoes, Andaman and Nicobar are relatively at moderate to low risk for Malaria, that too in Rainy Season (April End to November).
Various Diseases like Anthrax, Rabies and Encephalitis hadn’t reached my Islands till now. Various European populations who came here to colonize these Islands were not able to transmit diseases in local Indigenous population to that extent as they did in America. British accounts wrote about Malaria, Filariasis and Weil’s disease and had also mentioned about Scabies and other Fungal infections as health problems prevalent in these Islands.
Malaria has always been a Curious case in Islands. Pre-dominance of Malaria can be explained by a detailed study of it Vectors the Anopheles Family which had further helped to bring down the deaths and incidences of Malaria. When Dr Gordon Covell encountered the Anopheles species of Islands, he found a strange contrast from the British India Mainland. The Anopheles culicifacies, responsible for more than 70% of cases in Mainland British India wasn’t responsible for Malaria in Andaman and Nicobar. That species had never reached the Islands. In Andaman and Nicobar Islands the Malaria was more severe and frequent due to various other reasons. Firstly, Unlike the Mainland British India and Neighbouring Dutch Indonesia and British Malaysia, in Andaman and Nicobar there is no predominant species. Anopheles stephensi and Anopheles sundaicus were equally present and cause Malaria. Also the ability of Anopheles sundaicus to breed in Brackish waters made this species hard to eradicate. Also stephensi and sandaicus populations increases rapidly. Further research revealed few species were more prone to transmit lethal plasmodium falciparum like Anopheles barbirostris and Anopheles karwari third and fifth biggest species of anopheles in Islands. Also other malarial vectors like Anopheles maculatus, Anopheles varuna, Anopheles phillipinesis and Anopheles annularis in huge numbers made Malaria a big threat. After Independence, the death rates decreased a bit as medical facilities became available to everyone. Malaria has been a Major threat more to Nicobar than Andaman. Especially the Islands of extreme south like Great Nicobar, Little Nicobar, Katchal, Nancowry and the Capital Pū (Car Nicobar Island). The Southernmost Island, the Great Nicobar was notoriously famous for it’s high concentrations of Mosquitoes. People even said that in those days, one can see more than 100 mosquitoes in their compounds in Great Nicobar Island.
By 1995, the government of Andaman and Nicobar under the leadership of Vakkom Purushothaman initiated various initiatives to decrease the incidence of Malaria. In Andaman the incidence was 11/1000 and in Nicobar it was 20/1000. South Nicobar was given special importance in the initiatives. Government had ensured the release of Gambusia affinis and made the availability of Anti-Malarial drugs to each and every individual various times free of cost. Every case of fever was considered to be Malaria. Availability of Chloroquine and Primaquine were more than Paracetamol in Southern towns like Campbell Bay. Andaman and Nicobar government and Union government of India had also invested a lot in awareness against Malaria. Every source of transmission like Newspaper, Radio and Television were filled with ads and jingles against Malaria. The results were positive. Just within 5 years by 2000, the incidence rate in Andaman fell up to 5/1000 and in Nicobar it was 8/1000. Though the incidence rates slightly increased again due to climatic, Tidal and Environmental changes caused by Tsunami of 2004.
Apart from Malaria, Incidence of Filariasis is constant since 1942.
The Dengue and Chikungunya virus never reached Andaman and Nicobar Islands until 21st Century.
The Chikungunya virus reached Andaman and Nicobar for the first time in 2006 during the Chikungunya Outbreak in Indian Ocean Islands.
The Chikungunya was very deadly for the Islands. The Aedes population overwhelmingly welcomed new pathogen. Climate and Indestructible number of vector produced a lethal combination for the local human population.
In Just 4 months (Upto September 2006), there were more than 1000 cases of Chikungunya cases in Islands.
The Government under the leadership of Bhopinder Singh, brought the cases in double digit by end of year and single digit by 2013.
Chikungunya had the potency to become a dangerous Endemic disease of the Islands but failed, but the Dengue is Emerging.
The first case of Dengue came from Andaman and Nicobar in 2009. According to an unauthorized source, A group of Labourers who were migrants to Andaman and Nicobar had brought the disease from Mainland India.
In 2010, 12 cases of Dengue haemorrhagic fever and Dengue Shock Syndrome were found. By 2011, there were 26 cases, By 2018, annual cases increased to 258. In 2021, 226 cases were reported. Dengue and Chikungunya viruses, both are abroviruses, both transmitted by same group of Vectors had a very different pattern for spread.
Chikungunya saw a sharp, Rapid increase and decline; but Dengue is setting it’s feet and spreading it’s root within the mosquitoes from Aedes group in the Islands.
The widespread increase in cases of Dengue can be due to presence of different species of Aedes in different Islands. Like the Aedes aegypti, the principal vector of DENV strain 2 is the most common mosquito in Urban Centers of South Andaman Island mainly in Port Blair, Ferrargunj and Bambooflat hence the DENV strain 2 was most common strain in Port Blair but DENV strain 3 was more common in Havelock Island because of Aedes albopicta, the principal vector of DENV-3. That’s why there was an contrast in the Dengue Outbreaks in South Andaman and Havelock Island.
Dengue is still prevalent; But only in South Andaman District. It hasn’t reached other parts of Islands still. Government had declared areas like Garacharama-I, Garacharama-II, Terlabad and Bathubasthi as Dengue Hotspots in Port Blair Tehsil and Manpur in Ferrargunj tehsil for the same.
At the end I want to say my Enchantingly beautiful Islands are fragile and Vulnerable. It’s distance from rest of the world had always Protected it but it’s shield is broke due to Globalization and it’s ambition to become a developed Economy. Dengue and Chikungunya can be case studies to how to deal with Encephalitis, Yellow Fever, Zika Virus and etc because one day, they can also reach my Islands. Close monitoring of Dengue cases from years helped a lot during Covid-19; probably this practice can also protect as from other Epidemics and Pandemics as Common diseases in other parts of world can be tragic here. My Islands have their biggest resource as it’s Rich and Healthy Biodiversity. Whether it’s being hosting closest relative of Extinct Dodo bird or having a wild strain of Candida auris, which is capable to cause next pandemic due to its multi-drug resistant nature. Mosquitoes are crucial part of this Biodiversity. Understanding them is very important as they are medically important vectors and accounts for a good proportion of patients which is greater than National Average of my Country India. Also, each Island has its own distinct geographical feature harbouring different species of mosquitoes transmitting different diseases in vivid pattern like we had saw in case of Dengue Outbreak in Havelock Island. A proper database of mosquitoes would help health officers and government to understand where there is a chance of an Outbreak of a disease transmitted by Mosquitoes or can help to locate vulnerable populations and degree of vulnerability to those diseases which hadn’t reached them till now. Understanding Mosquitoes can also help us to counter future possibilities of Diseases and even present scenario. Like researches are going on whether Anopheles sundaicus is capable to transmit Plasmodium knowlesi or not or Stegomiya malayensis whose population is increasing rapidly in South-East Asia and in Andaman and Nicobar is capable to transmit Dengue or not. Also we can use highly sensitive to malathion mosquito species like those in Toxorhynchites to feed on larvae of other Mosquitoe species like Aedes aegypti, Aedes albopictus and Anopheles stephensi. Though mosquito are smaller in size but should be respected as they are giant killers for human population.
By: Rithic Singh
© All Rights Reserved
