Something on Scrub Typhus
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Dr L Bina Chanu
Contd from previous issue
Inside the egg shell, an inactive transitional embryo known as Deuto-vum (Prelarva) with mor- phological change is formed. The stage changes to the Parasitic Chigger larva which is the only feeding stage of the vector during whose feeding on animals or humans can transmit the scrup typhus bacteria Orientia tsutsugamushi. This stage of the cetor do not suck blood but they attach to the skin pores or hair follicles where they inject specialised salivary enzymes to liquify the surrounding skin cells. The suck this liquified tissues through their feeding tubes known as stylostome. They feed continuously on the host for 3- 5 days, engorge themselves and drop off back onto the soil. They enter into an inactive, dormant resting stage known as Nymphochrysalis (Proto-nymph) in the damp soil during which its fourth pairs of legs develop. Then again, they change into an active, free-living ground dweller with 8 legs stage known as Nymph (Deutonymph) which is completely nonparasitic to any animal. It act as a soil predator feeding on soft bodied soil insects and insects’ eggs.
The final stage of the vector is known as Imagochrysalis (Trito-nymph) which is pupa- like resting stage in the soil where the nymph reorganizes its body tissue to transform into an adult. The fully grown adult is velvet like living entirely in the soil. It is also a harmless soil predator eating eggs of other insects. Then adults will mate, lay eggs and repeat their cycle.
Only when the chigger larva bites, the bacteria responsible for the disease is transmitted. There are two methods of transmission of the Orientia tsutsugamushi bactrium in the vector itself through two important routes – through their eggs or the bacteria remains alive inside the mite, grows there and evolves through each life stages.
The early symptoms of scrub typhus usually appear 6 to 21 days after an infected chigger bites the skin. These symptoms develop quickly and can closely resemble a severe case of the flu, malaria, or dengue fever. The earliest symptom is the appearance of a painless, dark, black scab surrounded by a pink or red ring that looks like a small cigarette burnt on the skin armpits, groin, waistline, behind the knees, or neck. It does not itch or hurt, so many patients do not notice it until a doctor performs a full-body examination. The fever is associated with shaking chills and heavy sweating, severe headache, muscle pain and swollen lymph nodes. Early dry cough, nausea, vomiting or mild abdominal discomfort is also associated.
Doxycycline antibiotic is the most frequently drug of choice for the disease symptoms. If not treated in time severe complications usually develop during the second week of the illness. Lungs, brain, heart and its circulatory systems may be damaged. A dangerous drop in blood pressure that deprives vital organs of oxygen- rich blood, leading to sudden cardiovascular collapse. Kidney and liver failure and multi-organ dysfunction syndrome are associated.
Diagnosing scrub typhus relies on a combination of checking a patient’s physical symptoms and conducting specialized laboratory blood tests. Because early symptoms like fever and headache look exactly like dengue, malaria, or typhoid, specific medical tests are essential to confirm the disease and start correct treatment. The primary diagnostic tools used by doctors include clinical indicators, blood marker examinations, and molecular tests.
For people living in Manipur, practicing daily prevention is the most effective way to stay safe from Khullai-laipha. Covering our skin by wear long-sleeved shirts and thick trousers is the best way to avoid the bite. We should avoid sitting, resting, or sleeping directly on the bare grass or soil while working in the fields. If we want to do so, a thick plastic sheet, tarpaulin, or woven mat should always throw first. We should not place lunch bags, clothes, or tools directly on unkept vegetation. Mites can hitch a ride onto them. The grasses and weeds around houses should be cut very short. Wild bushes should be cleared regularly especially within 10 to 15 meters from living quarters. As rats and field mice carry these mites into the yards, kitchen wastes should be covered, clear out piles of firewood or junk near the house, and use traps to keep rodents away. Regularly hanging mats, jute sacks, blankets, and clothes out in direct, bright sunlight should be performed as the mites cannot tolerate heat and dry environment.
After agricultural works are don from fields and forests, when we return home, outdoor clothes should be removed, wash them in hot water with soap or dry the clothes in full sunlight. The entire body especially armpits, groin, waistline and behind the knees should be washed off thoroughly with soaps. While utilizing outdoor spaces, strictly avoid squatting in dense, low-hanging grass or wild shrubs.
This position brings warm, sensitive areas of skin into direct contact with ground mites. Always apply an insect repellent containing DEET or Picaridin to your exposed skin and the rims of your clothing (socks, cuffs, and collar).
Contd from previous issue
Inside the egg shell, an inactive transitional embryo known as Deuto-vum (Prelarva) with mor- phological change is formed. The stage changes to the Parasitic Chigger larva which is the only feeding stage of the vector during whose feeding on animals or humans can transmit the scrup typhus bacteria Orientia tsutsugamushi. This stage of the cetor do not suck blood but they attach to the skin pores or hair follicles where they inject specialised salivary enzymes to liquify the surrounding skin cells. The suck this liquified tissues through their feeding tubes known as stylostome. They feed continuously on the host for 3- 5 days, engorge themselves and drop off back onto the soil. They enter into an inactive, dormant resting stage known as Nymphochrysalis (Proto-nymph) in the damp soil during which its fourth pairs of legs develop. Then again, they change into an active, free-living ground dweller with 8 legs stage known as Nymph (Deutonymph) which is completely nonparasitic to any animal. It act as a soil predator feeding on soft bodied soil insects and insects’ eggs.
The final stage of the vector is known as Imagochrysalis (Trito-nymph) which is pupa- like resting stage in the soil where the nymph reorganizes its body tissue to transform into an adult. The fully grown adult is velvet like living entirely in the soil. It is also a harmless soil predator eating eggs of other insects. Then adults will mate, lay eggs and repeat their cycle.
Only when the chigger larva bites, the bacteria responsible for the disease is transmitted. There are two methods of transmission of the Orientia tsutsugamushi bactrium in the vector itself through two important routes – through their eggs or the bacteria remains alive inside the mite, grows there and evolves through each life stages.
The early symptoms of scrub typhus usually appear 6 to 21 days after an infected chigger bites the skin. These symptoms develop quickly and can closely resemble a severe case of the flu, malaria, or dengue fever. The earliest symptom is the appearance of a painless, dark, black scab surrounded by a pink or red ring that looks like a small cigarette burnt on the skin armpits, groin, waistline, behind the knees, or neck. It does not itch or hurt, so many patients do not notice it until a doctor performs a full-body examination. The fever is associated with shaking chills and heavy sweating, severe headache, muscle pain and swollen lymph nodes. Early dry cough, nausea, vomiting or mild abdominal discomfort is also associated.
Doxycycline antibiotic is the most frequently drug of choice for the disease symptoms. If not treated in time severe complications usually develop during the second week of the illness. Lungs, brain, heart and its circulatory systems may be damaged. A dangerous drop in blood pressure that deprives vital organs of oxygen- rich blood, leading to sudden cardiovascular collapse. Kidney and liver failure and multi-organ dysfunction syndrome are associated.
Diagnosing scrub typhus relies on a combination of checking a patient’s physical symptoms and conducting specialized laboratory blood tests. Because early symptoms like fever and headache look exactly like dengue, malaria, or typhoid, specific medical tests are essential to confirm the disease and start correct treatment. The primary diagnostic tools used by doctors include clinical indicators, blood marker examinations, and molecular tests.
For people living in Manipur, practicing daily prevention is the most effective way to stay safe from Khullai-laipha. Covering our skin by wear long-sleeved shirts and thick trousers is the best way to avoid the bite. We should avoid sitting, resting, or sleeping directly on the bare grass or soil while working in the fields. If we want to do so, a thick plastic sheet, tarpaulin, or woven mat should always throw first. We should not place lunch bags, clothes, or tools directly on unkept vegetation. Mites can hitch a ride onto them. The grasses and weeds around houses should be cut very short. Wild bushes should be cleared regularly especially within 10 to 15 meters from living quarters. As rats and field mice carry these mites into the yards, kitchen wastes should be covered, clear out piles of firewood or junk near the house, and use traps to keep rodents away. Regularly hanging mats, jute sacks, blankets, and clothes out in direct, bright sunlight should be performed as the mites cannot tolerate heat and dry environment.
After agricultural works are don from fields and forests, when we return home, outdoor clothes should be removed, wash them in hot water with soap or dry the clothes in full sunlight. The entire body especially armpits, groin, waistline and behind the knees should be washed off thoroughly with soaps. While utilizing outdoor spaces, strictly avoid squatting in dense, low-hanging grass or wild shrubs.
This position brings warm, sensitive areas of skin into direct contact with ground mites. Always apply an insect repellent containing DEET or Picaridin to your exposed skin and the rims of your clothing (socks, cuffs, and collar).