Snowy Owl
Retired in 2010, In Memoriam
Arial]Elephantiasis endemic in rural Indonesia
http://www.thejakartapost.com/detailfeatures.asp?fileid=20060927.T01&irec=0
[/FONT][FONT=Arial, Helvetica]J. Kevin Baird, Contributor, Jakarta[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica]You notice a slight swelling in your feet. It doesn't go away. Shoes don't fit. Pants become impossible to wear.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] [/FONT][FONT=Arial, Helvetica] It gets inexorably worse and worse as months and then years pass.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Your leg from the groin down has swollen to two to three times its normal size. Fungal and bacterial infections on the skin of the leg become a constant struggle. The skin becomes thickened and scarred.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] You have elephantiasis, or kaki gaja (elephant's foot), joining an estimated 40 million people in the tropics who live with this debilitating and disfiguring disease. You may also have very serious kidney problems caused by the infection.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Worms carried by mosquitoes cause elephantiasis. In Indonesia, there are three species of worms that cause this infection: Wuchereria bancrofti (occurring throughout the tropics), Brugia malayi (occurring in Southeast Asia), and Brugia timori (occurring only in the Lesser Sundas archipelago of eastern Indonesia).[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] This is the family of worms that cause lymphatic filariasis in humans. A billion people live at risk of this infection, and 120 million are infected already.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] There are other filarial worms that infect other tissues of humans, like Loa loa, Mansonella and Onchocerca (the cause of River Blindness in Africa), but none of those occur in Southeast Asia. [/FONT]
[FONT=Arial, Helvetica] A better-known member of this family of worms in the developed world is Dirofilaria, the cause of heartworm in dogs. [/FONT]
[FONT=Arial, Helvetica] ***** [/FONT]
[FONT=Arial, Helvetica] In lymphatic filariasis, pairs of male and female worms take up residence in lymphatic vessels, where they mate and give birth to many thousands of larval worms.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The young worms, each called a microfilaria, migrate to the bloodstream where they can be ingested by a feeding mosquito. Over a couple of weeks they mature in the mosquito and seek out a hiding place near or in its needle-like mouth.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] When the mosquito feeds, the infective larvae squirm out and into the wound left by the mosquito. The larval worms migrate to the lymphatic vessels, molt again and become sexually mature (and active) adult worms. [/FONT]
[FONT=Arial, Helvetica] The adult worms are hair-thin and several centimeters long, their young can only be seen under a microscope.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The lymphatic vessels represent the drainage system of the body, removing unwanted water and the waste of dead cells. Lymph nodes attached to this system contain immune cells that read and help process the waste.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The living worms are scarcely recognized by the immune system because they are cloaked in a sheath that conceals its presence almost completely. However, the worms eventually die (after four to six years if happy and healthy) and the body suddenly recognizes the big invaders. [/FONT]
[FONT=Arial, Helvetica] Dead worms spill out much that agitates the immune system, and a struggle with the corpses ensues. Overwhelmed by the mass of foreign matter, the immune system resorts to walling them off with scar tissue.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] This scarification damages the lymphatic vessel. The drainage channel becomes effectively blocked. The leg (or sometimes even both legs, and the arms, too) progressively swells as a result. [/FONT]
[FONT=Arial, Helvetica] The scrotum is often involved in men, swelling to the size of a mature jackfruit in severe cases, as may occur (less frequently) to the breasts or vulva in women.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Elephantiasis appears to be the terminal effect of a very long chain of events populated with repeated episodes of infection over several decades. In endemic areas, only adults have elephantiasis. Children do not get elephantiasis, and adolescents show only the bare beginnings of it. [/FONT]
[FONT=Arial, Helvetica] ***** [/FONT]
[FONT=Arial, Helvetica] When elephantiasis appears in a human population, as it was in some residents of Bogor a few weeks ago, it signals the presence of a very well established population of worms in people and mosquitoes. [/FONT]
[FONT=Arial, Helvetica] The infections responsible for that "outbreak" may have started 20 years ago, and most infected people would not have shown signs of elephantiasis.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Elephantiasis is the proverbial tip of the iceberg of long-standing endemic lymphatic filariasis. [/FONT]
[FONT=Arial, Helvetica] However, adult newcomers to endemic areas can develop elephantiasis within just a year. [/FONT]
[FONT=Arial, Helvetica] This casts some doubt on the belief that elephantiasis takes decades of many exposures, and it raises the possibility that children in endemic areas, though repeatedly infected, do not suffer from elephantiasis simply by virtue of perhaps a milder and more forgiving immune response to dead worms. [/FONT]
[FONT=Arial, Helvetica] If this is true, the problem in Bogor begins to look more like an outbreak -- with elephantiasis appearing in adults after only a year of experience with infection.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The health authorities attacked the worms in Bogor with two drugs for everyone in the affected area: one drug for adult worms (albendazole or ivermectin), and the other (diethylcarbamazine) for the microfilariae in blood.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] However, some infected people may be missed, and infected mosquitoes may still be about. This is why the authorities must repeat the measure each year for at least several years to attack endemic transmission.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] GlaxoSmithKline and Merck drug companies have made quantities of these effective drugs (albendazole and ivermectin) available free-of-charge through a WHO-sponsored program. The treatment does not cure elephantiasis, unless in the very early stages.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The damage to the lymphatics in advanced elephantiasis can be repaired surgically, but only in some cases. People with elephantiasis are instructed to carefully disinfect affected skin, and strict adherence prevents much of the disfiguration and debility linked to the disease.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] There is no vaccine and no drug is recommended for prophylaxis against lymphatic filariasis. Reducing risk of lymphatic filariasis among travelers and visitors involves minimizing exposure to biting mosquitoes at night.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Sleeping under an insecticide-impregnated mosquito net is essential when in remote areas without air conditioning. Using skin repellents (35% DEET works best, but do not use it on small children), wearing long pants and long-sleeved shirts all substantially reduce biting opportunities for mosquitoes. [/FONT]
[FONT=Arial, Helvetica] ***** [/FONT]
[FONT=Arial, Helvetica] Lymphatic filariasis is diagnosed by the examination of blood under a microscope. The presence of larval worms constitutes a firm and relatively easy diagnosis.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The blood sample is taken in the middle of the night because this is when the larval worms migrate to the peripheral circulation -- they will be absent during the day, and many infections are missed this way in routine clinical laboratory examinations.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] This behavior is an adaptation to the feeding behavior of the species of mosquitoes that can transmit the infection, typically the same mosquitoes that transmit malaria and bite only at night. [/FONT]
[FONT=Arial, Helvetica] The infected person typically will not develop any symptoms until after the adult worms die, and then a tender swelling will develop, often in the area of the groin, but other areas like the chest may also be involved.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Compared to malaria or dengue, the risk of this infection for travelers and visitors is relatively low. Whereas malaria and dengue routinely occur among expatriate visitors to Indonesia, a diagnosis of lymphatic filariasis is quite rare.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] A person would have to live in an endemic area for at least several months before the odds began to favor infection. Getting filariasis on a single short trip to an endemic area would be extremely unlucky. [/FONT]
[FONT=Arial, Helvetica] The map shows areas in Indonesian known to be endemic for lymphatic filariasis. Note that the other areas are marked as "uncertain" and these areas are by no means free of risk. Most of rural Indonesia may be considered endemic.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica](The author, an expert in tropical medicine and hygiene, served as microbiologist in the U.S. Navy, is a section editor for the American Journal of Tropical Medicine & Hygiene, and currently lives and works in Jakarta. He may be reached at jkb@vhasia.com.sg.)[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The life cycle of Brugia malayi, a common cause of elephantiasis in Southeast Asia. From the Centers for Disease Control, USA.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] [/FONT]
[FONT=Arial, Helvetica] A man with elephantiasis. From WHO.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Mosquitoes like this one become infected with filarial worms when they ingest larval worms circulating in the blood. After two weeks those larvae will have matured sufficiently to be injected into a new human host by the feeding mosquito. From WHO.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] [/FONT]
[FONT=Arial, Helvetica] A larval filarial worm, called a microfilaria, stained with chemicals and seen under a microscope. The red dots are human white blood cells (the red cells were lysed and rinsed away during staining). They tend to appear in the blood only at night, to increase their chances of being ingested by a feeding mosquito that bites only at night. From WHO.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] [/FONT]
[FONT=Arial, Helvetica] Areas of known risk of lymphatic filariasis in Indonesia. The map shows districts reporting confirmed cases. The absence of reported cases does not mean the absence of risk. From the Ministry of Health, Republic of Indonesia.[/FONT]
</td></tr></tbody></table></td></tr></tbody></table></td></tr></tbody></table>
http://www.thejakartapost.com/detailfeatures.asp?fileid=20060927.T01&irec=0
[/FONT][FONT=Arial, Helvetica]J. Kevin Baird, Contributor, Jakarta[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica]You notice a slight swelling in your feet. It doesn't go away. Shoes don't fit. Pants become impossible to wear.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] [/FONT][FONT=Arial, Helvetica] It gets inexorably worse and worse as months and then years pass.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Your leg from the groin down has swollen to two to three times its normal size. Fungal and bacterial infections on the skin of the leg become a constant struggle. The skin becomes thickened and scarred.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] You have elephantiasis, or kaki gaja (elephant's foot), joining an estimated 40 million people in the tropics who live with this debilitating and disfiguring disease. You may also have very serious kidney problems caused by the infection.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Worms carried by mosquitoes cause elephantiasis. In Indonesia, there are three species of worms that cause this infection: Wuchereria bancrofti (occurring throughout the tropics), Brugia malayi (occurring in Southeast Asia), and Brugia timori (occurring only in the Lesser Sundas archipelago of eastern Indonesia).[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] This is the family of worms that cause lymphatic filariasis in humans. A billion people live at risk of this infection, and 120 million are infected already.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] There are other filarial worms that infect other tissues of humans, like Loa loa, Mansonella and Onchocerca (the cause of River Blindness in Africa), but none of those occur in Southeast Asia. [/FONT]
[FONT=Arial, Helvetica] A better-known member of this family of worms in the developed world is Dirofilaria, the cause of heartworm in dogs. [/FONT]
[FONT=Arial, Helvetica] ***** [/FONT]
[FONT=Arial, Helvetica] In lymphatic filariasis, pairs of male and female worms take up residence in lymphatic vessels, where they mate and give birth to many thousands of larval worms.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The young worms, each called a microfilaria, migrate to the bloodstream where they can be ingested by a feeding mosquito. Over a couple of weeks they mature in the mosquito and seek out a hiding place near or in its needle-like mouth.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] When the mosquito feeds, the infective larvae squirm out and into the wound left by the mosquito. The larval worms migrate to the lymphatic vessels, molt again and become sexually mature (and active) adult worms. [/FONT]
[FONT=Arial, Helvetica] The adult worms are hair-thin and several centimeters long, their young can only be seen under a microscope.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The lymphatic vessels represent the drainage system of the body, removing unwanted water and the waste of dead cells. Lymph nodes attached to this system contain immune cells that read and help process the waste.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The living worms are scarcely recognized by the immune system because they are cloaked in a sheath that conceals its presence almost completely. However, the worms eventually die (after four to six years if happy and healthy) and the body suddenly recognizes the big invaders. [/FONT]
[FONT=Arial, Helvetica] Dead worms spill out much that agitates the immune system, and a struggle with the corpses ensues. Overwhelmed by the mass of foreign matter, the immune system resorts to walling them off with scar tissue.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] This scarification damages the lymphatic vessel. The drainage channel becomes effectively blocked. The leg (or sometimes even both legs, and the arms, too) progressively swells as a result. [/FONT]
[FONT=Arial, Helvetica] The scrotum is often involved in men, swelling to the size of a mature jackfruit in severe cases, as may occur (less frequently) to the breasts or vulva in women.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Elephantiasis appears to be the terminal effect of a very long chain of events populated with repeated episodes of infection over several decades. In endemic areas, only adults have elephantiasis. Children do not get elephantiasis, and adolescents show only the bare beginnings of it. [/FONT]
[FONT=Arial, Helvetica] ***** [/FONT]
[FONT=Arial, Helvetica] When elephantiasis appears in a human population, as it was in some residents of Bogor a few weeks ago, it signals the presence of a very well established population of worms in people and mosquitoes. [/FONT]
[FONT=Arial, Helvetica] The infections responsible for that "outbreak" may have started 20 years ago, and most infected people would not have shown signs of elephantiasis.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Elephantiasis is the proverbial tip of the iceberg of long-standing endemic lymphatic filariasis. [/FONT]
[FONT=Arial, Helvetica] However, adult newcomers to endemic areas can develop elephantiasis within just a year. [/FONT]
[FONT=Arial, Helvetica] This casts some doubt on the belief that elephantiasis takes decades of many exposures, and it raises the possibility that children in endemic areas, though repeatedly infected, do not suffer from elephantiasis simply by virtue of perhaps a milder and more forgiving immune response to dead worms. [/FONT]
[FONT=Arial, Helvetica] If this is true, the problem in Bogor begins to look more like an outbreak -- with elephantiasis appearing in adults after only a year of experience with infection.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The health authorities attacked the worms in Bogor with two drugs for everyone in the affected area: one drug for adult worms (albendazole or ivermectin), and the other (diethylcarbamazine) for the microfilariae in blood.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] However, some infected people may be missed, and infected mosquitoes may still be about. This is why the authorities must repeat the measure each year for at least several years to attack endemic transmission.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] GlaxoSmithKline and Merck drug companies have made quantities of these effective drugs (albendazole and ivermectin) available free-of-charge through a WHO-sponsored program. The treatment does not cure elephantiasis, unless in the very early stages.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The damage to the lymphatics in advanced elephantiasis can be repaired surgically, but only in some cases. People with elephantiasis are instructed to carefully disinfect affected skin, and strict adherence prevents much of the disfiguration and debility linked to the disease.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] There is no vaccine and no drug is recommended for prophylaxis against lymphatic filariasis. Reducing risk of lymphatic filariasis among travelers and visitors involves minimizing exposure to biting mosquitoes at night.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Sleeping under an insecticide-impregnated mosquito net is essential when in remote areas without air conditioning. Using skin repellents (35% DEET works best, but do not use it on small children), wearing long pants and long-sleeved shirts all substantially reduce biting opportunities for mosquitoes. [/FONT]
[FONT=Arial, Helvetica] ***** [/FONT]
[FONT=Arial, Helvetica] Lymphatic filariasis is diagnosed by the examination of blood under a microscope. The presence of larval worms constitutes a firm and relatively easy diagnosis.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The blood sample is taken in the middle of the night because this is when the larval worms migrate to the peripheral circulation -- they will be absent during the day, and many infections are missed this way in routine clinical laboratory examinations.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] This behavior is an adaptation to the feeding behavior of the species of mosquitoes that can transmit the infection, typically the same mosquitoes that transmit malaria and bite only at night. [/FONT]
[FONT=Arial, Helvetica] The infected person typically will not develop any symptoms until after the adult worms die, and then a tender swelling will develop, often in the area of the groin, but other areas like the chest may also be involved.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Compared to malaria or dengue, the risk of this infection for travelers and visitors is relatively low. Whereas malaria and dengue routinely occur among expatriate visitors to Indonesia, a diagnosis of lymphatic filariasis is quite rare.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] A person would have to live in an endemic area for at least several months before the odds began to favor infection. Getting filariasis on a single short trip to an endemic area would be extremely unlucky. [/FONT]
[FONT=Arial, Helvetica] The map shows areas in Indonesian known to be endemic for lymphatic filariasis. Note that the other areas are marked as "uncertain" and these areas are by no means free of risk. Most of rural Indonesia may be considered endemic.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica](The author, an expert in tropical medicine and hygiene, served as microbiologist in the U.S. Navy, is a section editor for the American Journal of Tropical Medicine & Hygiene, and currently lives and works in Jakarta. He may be reached at jkb@vhasia.com.sg.)[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] The life cycle of Brugia malayi, a common cause of elephantiasis in Southeast Asia. From the Centers for Disease Control, USA.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] [/FONT]
[FONT=Arial, Helvetica] A man with elephantiasis. From WHO.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] Mosquitoes like this one become infected with filarial worms when they ingest larval worms circulating in the blood. After two weeks those larvae will have matured sufficiently to be injected into a new human host by the feeding mosquito. From WHO.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] [/FONT]
[FONT=Arial, Helvetica] A larval filarial worm, called a microfilaria, stained with chemicals and seen under a microscope. The red dots are human white blood cells (the red cells were lysed and rinsed away during staining). They tend to appear in the blood only at night, to increase their chances of being ingested by a feeding mosquito that bites only at night. From WHO.[/FONT]
[FONT=Arial, Helvetica]
[/FONT]
[FONT=Arial, Helvetica] [/FONT]
[FONT=Arial, Helvetica] Areas of known risk of lymphatic filariasis in Indonesia. The map shows districts reporting confirmed cases. The absence of reported cases does not mean the absence of risk. From the Ministry of Health, Republic of Indonesia.[/FONT]
</td></tr></tbody></table></td></tr></tbody></table></td></tr></tbody></table>