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Rapid diagnosis of trichinosis by percutaneous muscle biopsy
Journal of Infection (1985) Ix, 2Ol-2O3
R a p i d diagnosis o f t r i c h i n o s i s by p e r c u t a n e o u s m u s c l e biopsy K. K. Pun
Department of Medicine, University of Hong Kong Accepted for publication 23 January 1985 Summary A new rapid diagnostic procedure for trichinosis is described. Percutaneous needle biopsy of the medial gastrocnemius muscle was used to obtain tissue for examination by a compression method. This procedure may facilitate early diagnosis and treatment of symptomatic trichinosis.
Introduction T h e diagnosis of trichinosis is often difficult because of its uncommon occurrence and the non-specific nature of its symptoms. 1 Trichinosis is rarely reported in south-east Asia. 2-~ T h e first documented outbreak of trichinosis in Hong Kong Chinese was reported only in i982. 7 Although various serological tests are now available, 8-1t muscle biopsy with demonstration of larvae or cysts remains the most definitive test. 6 Material is usually obtained by excision from the deltoid or gastrocnemius muscles. 6 A portion is then compressed between two glass slides and examined with a low-power microscope for the presence of larvae and cysts. This procedure usually leaves behind a scar several centimetres in length. We here report a simple procedure for rapid diagnosis which requires percutaneous biopsy only.
Methods Muscle biopsies were obtained from the medial gastrocnemius muscle, with a ' T r u c u t ' biopsy needle (Travenol Laboratories Ltd). Material was taken from a point half way between the medial tibial plateau and the medial maUeolus with the aim of obtaining I "5 cm of fresh muscle. T h e site of biopsy was carefully chosen beforehand so that the biopsy track would be away from nerves and blood vessels. After applying local anaesthetic, t h e ' T r u c u t ' needle was pushed carefully into muscle which gave a characteristic 'give '. T h e n the needle was directed parallel to the skin so as to avoid damaging underlying structures and material obtained in the usual manner. A total of five muscle biopsies were performed through the same puncture site. Material obtained was kept moist by wrapping in wet gauze before further examination. T h e procedures were performed by the same person, someone who had experience of performing ' T r u c u t ' biopsies of liver, kidney, muscle and subcutaneous metastatic masses. Informed consent was obtained from both patients in this study. T h e tissues were examined by the compression method. 6 o163-4453/85/o6o2ol +03 $02.o0/o
© 1985 The British Society for the Study of Infection
202
K.K.
PUN
Case reports Patient
x
In January I983 a 44-year-old executive officer was admitted to hospital for evaluation of fever and muscle pain of I week's duration. A m o n t h earlier, he had consumed incompletely cooked pork which was served after brief immersion in boiling water. Approximately 3 weeks later, he felt feverish with anorexia, malaise and diffuse myalgia. He was given ampicillin and antipyretics by his family practitioner without relief. On admission the patient was seen to be a well-developed m a n with a blood pressure of I2O/8O m m H g and a temperature of 39 °C. Examination of the cardiovascular system did not reveal any abnormalities, neither was enlargement of l y m p h glands or viscera detected. T h e muscles of the arms and legs were tender and weak, but the deep tendon reflexes were normal. T h e initial absolute eosinophil count was 2-14 x io9/1 (normal: < 0"4 x io9/1). Subsequent counts ranged between 2"9 and I .o x lO9/1. T h e erythrocyte sedimentation rate (Westergren) was 35 m m / h . Urinalysis did not reveal any cellular elements b u t I + proteinuria ('Albustix equivalent to o'3 g/1 urine) was found. Stool examination did not reveal any parasites or ova. Routine biochemical blood tests for sodium, potassium, chloride, bicarbonate, urea, creatinine, total protein, albumen, calcium, phosphate, bilirubin (total) and bilirubin (direct) were all within normal limits. Muscle enzyme concentrations were raised: creatine phosphokinase was 3259 # m o l / m i n / 1 (normal: 2I-2O5 #mol/min/1) and lactate dehydrogenase 953 # m o l / m i n / 1 (normal: 13o-275)#mol/min/1. In order to obtain a definitive diagnosis, percutaneous muscle biopsy was performed by the m e t h o d outlined above. Immediate microscopical examination of material by the compression technique revealed living and active larvae of Trichinella spiralis. A course of thiabendazole (2"5 g/day) was given in divided doses. T h e symptoms were relieved on the third day of treatment. Patient 2
In January 1984 a 22-year-old laundry worker was admitted because of fever, chills, myalgia, and puffiness of the eyelids for 5 days. About 4 weeks previously he had eaten semi-cooked pork which was served after brief immersion in boiling water. On the basis of a clinical diagnosis of trichinosis, a peripheral blood smear was examined and showed marked eosinophilia. In order to confirm the diagnosis rapidly, a percutaneous muscle biopsy was done on the day of admission and confirmed the presence of Trichinella spiralis. F u r t h e r investigations showed a raised absolute eosinophil Count of 5"3 x lO9/1, raised muscle enzymes (lactate dehydrogenase: 736 # m o l / m i n / 1 , creatine phosphokinase: 3oo2#mol/min/1), an IgE antibody concentration of 7784 I U / m l (normal: < IOO I U / m l ) and strongly positive Trichinella spiralis serological tests as performed by enzyme-linked i m m u n o s o r b e n t assay and counterimmunoelectrophoresis. After confirming the diagnosis, the patient was treated immediately with thiabendazole 2. 5 g/day. T h e r e was dramatic symptomatic relief 24 h later and the concentrations of muscle enzymes gradually reverted to normal over a period of 4 weeks.
R a p i d Diagnosis of Trichinosis
203
Discussion T h e s e two cases show that percutaneous ' T r u c u t ' biopsy m a y be used as a simple bedside procedure to obtain a rapid definitive diagnosis of trichinosis. T h e disfiguring scars and possible complications o f an excisional biopsy m a y thus be avoided. Needle biopsy has not been widely used for diagnosing muscle diseases because the sample is usually squashed during the procedure, thereby m a k i n g fine histological examination difficult. T h i s is not so significant, however, for trichinosis w h e n d e m o n s t r a t i o n of living larvae is more i m p o r t a n t t h a n structural examination of the tissue. T h e biopsy site in this study was carefully p l a n n e d so that the track of the needle would be several centimetres away from i m p o r t a n t structures, especially the tibial nerve and the posterior tibial artery. T h e gastrocnemius muscle was chosen because it has been shown to contain m a n y parasites. 6 A ' T r u c u t ' needle is used because it is sharp and less traumatic than a special muscle biopsy needle. Both patients responded to thiabendazole dramatically with m i n i m u m side effects. 6 T h i s again emphasizes the importance of early diagnosis and treatment to minimise suffering. A rapid and simple procedure such as the ' T r u c u t ' needle biopsy helps to achieve this. Successful demonstration of larvae, however, will depend on the parasitic load of the patient. References I. Singal M, Schantz PM, Wermer SB. Trichinosis acquired at sea--report of an outbreak. Am J Trop Med Hyg 1978; 298: 1178-118o. 2. World Health Organisation, Parasitic Disease Programme. Epidemiology of trichinosis. Medline search, I966-I98O (179 references). Geneva: WHO. 3. Yamashita J. Trichinosis in Asia. In Gould SE, Ed. Trichinosis in man and animals. Springfield, Illinois: CC Thomas, I97O: 457-464. 4. Holck SN. The distribution of Trichinella spiralis in countries in Southeast Asia and the Far East. Proc ISt Int Congr Parasitol 1964; 2: 666-668. 5. Chung Shah Medical College. Human Parasitology. ISt Edition. Chinese Health Publishers, 198o: pp. 205-208. 6. Campbell WC (ed). Trichinella and trichinosis. New York: Plenum Press, I983. 7. Pun KK, Wong WT, Wong PHC. The first documented outbreak of trichinellosis in Hong Kong Chinese. A m J Trop Med Hyg 1983; 32: 772-775. 8. Ljungstrom I, Engvall E, Ruitenberg EJ. ELISA--a new technique for serodiagnosis of trichinosis. Parasitology 1974; 69: 24-30. 9. Kagan IG. Advances in the immunodiagnosis of parasitic infections. Z Parasitenk 1974; 45: I63-I95. IO. Despommier D, Miller M, Jenks B, Fruitstone M. Immunodiagnosis of human trichinosis using counterelectrophoresis and agar gel diffusion techniques. Am J Trop Ailed Hyg I974: 23(I): 41-44. I I. Ruitenberg EJ, Steerenberg PA, Brosi BJM. Microsystem for the application of ELI SA in the serodiagnosis of Trichinella spiralis infection. Medikon Netherland 1975; 4: 30-33.
R a p i d diagnosis o f t r i c h i n o s i s by p e r c u t a n e o u s m u s c l e biopsy K. K. Pun
Department of Medicine, University of Hong Kong Accepted for publication 23 January 1985 Summary A new rapid diagnostic procedure for trichinosis is described. Percutaneous needle biopsy of the medial gastrocnemius muscle was used to obtain tissue for examination by a compression method. This procedure may facilitate early diagnosis and treatment of symptomatic trichinosis.
Introduction T h e diagnosis of trichinosis is often difficult because of its uncommon occurrence and the non-specific nature of its symptoms. 1 Trichinosis is rarely reported in south-east Asia. 2-~ T h e first documented outbreak of trichinosis in Hong Kong Chinese was reported only in i982. 7 Although various serological tests are now available, 8-1t muscle biopsy with demonstration of larvae or cysts remains the most definitive test. 6 Material is usually obtained by excision from the deltoid or gastrocnemius muscles. 6 A portion is then compressed between two glass slides and examined with a low-power microscope for the presence of larvae and cysts. This procedure usually leaves behind a scar several centimetres in length. We here report a simple procedure for rapid diagnosis which requires percutaneous biopsy only.
Methods Muscle biopsies were obtained from the medial gastrocnemius muscle, with a ' T r u c u t ' biopsy needle (Travenol Laboratories Ltd). Material was taken from a point half way between the medial tibial plateau and the medial maUeolus with the aim of obtaining I "5 cm of fresh muscle. T h e site of biopsy was carefully chosen beforehand so that the biopsy track would be away from nerves and blood vessels. After applying local anaesthetic, t h e ' T r u c u t ' needle was pushed carefully into muscle which gave a characteristic 'give '. T h e n the needle was directed parallel to the skin so as to avoid damaging underlying structures and material obtained in the usual manner. A total of five muscle biopsies were performed through the same puncture site. Material obtained was kept moist by wrapping in wet gauze before further examination. T h e procedures were performed by the same person, someone who had experience of performing ' T r u c u t ' biopsies of liver, kidney, muscle and subcutaneous metastatic masses. Informed consent was obtained from both patients in this study. T h e tissues were examined by the compression method. 6 o163-4453/85/o6o2ol +03 $02.o0/o
© 1985 The British Society for the Study of Infection
202
K.K.
PUN
Case reports Patient
x
In January I983 a 44-year-old executive officer was admitted to hospital for evaluation of fever and muscle pain of I week's duration. A m o n t h earlier, he had consumed incompletely cooked pork which was served after brief immersion in boiling water. Approximately 3 weeks later, he felt feverish with anorexia, malaise and diffuse myalgia. He was given ampicillin and antipyretics by his family practitioner without relief. On admission the patient was seen to be a well-developed m a n with a blood pressure of I2O/8O m m H g and a temperature of 39 °C. Examination of the cardiovascular system did not reveal any abnormalities, neither was enlargement of l y m p h glands or viscera detected. T h e muscles of the arms and legs were tender and weak, but the deep tendon reflexes were normal. T h e initial absolute eosinophil count was 2-14 x io9/1 (normal: < 0"4 x io9/1). Subsequent counts ranged between 2"9 and I .o x lO9/1. T h e erythrocyte sedimentation rate (Westergren) was 35 m m / h . Urinalysis did not reveal any cellular elements b u t I + proteinuria ('Albustix equivalent to o'3 g/1 urine) was found. Stool examination did not reveal any parasites or ova. Routine biochemical blood tests for sodium, potassium, chloride, bicarbonate, urea, creatinine, total protein, albumen, calcium, phosphate, bilirubin (total) and bilirubin (direct) were all within normal limits. Muscle enzyme concentrations were raised: creatine phosphokinase was 3259 # m o l / m i n / 1 (normal: 2I-2O5 #mol/min/1) and lactate dehydrogenase 953 # m o l / m i n / 1 (normal: 13o-275)#mol/min/1. In order to obtain a definitive diagnosis, percutaneous muscle biopsy was performed by the m e t h o d outlined above. Immediate microscopical examination of material by the compression technique revealed living and active larvae of Trichinella spiralis. A course of thiabendazole (2"5 g/day) was given in divided doses. T h e symptoms were relieved on the third day of treatment. Patient 2
In January 1984 a 22-year-old laundry worker was admitted because of fever, chills, myalgia, and puffiness of the eyelids for 5 days. About 4 weeks previously he had eaten semi-cooked pork which was served after brief immersion in boiling water. On the basis of a clinical diagnosis of trichinosis, a peripheral blood smear was examined and showed marked eosinophilia. In order to confirm the diagnosis rapidly, a percutaneous muscle biopsy was done on the day of admission and confirmed the presence of Trichinella spiralis. F u r t h e r investigations showed a raised absolute eosinophil Count of 5"3 x lO9/1, raised muscle enzymes (lactate dehydrogenase: 736 # m o l / m i n / 1 , creatine phosphokinase: 3oo2#mol/min/1), an IgE antibody concentration of 7784 I U / m l (normal: < IOO I U / m l ) and strongly positive Trichinella spiralis serological tests as performed by enzyme-linked i m m u n o s o r b e n t assay and counterimmunoelectrophoresis. After confirming the diagnosis, the patient was treated immediately with thiabendazole 2. 5 g/day. T h e r e was dramatic symptomatic relief 24 h later and the concentrations of muscle enzymes gradually reverted to normal over a period of 4 weeks.
R a p i d Diagnosis of Trichinosis
203
Discussion T h e s e two cases show that percutaneous ' T r u c u t ' biopsy m a y be used as a simple bedside procedure to obtain a rapid definitive diagnosis of trichinosis. T h e disfiguring scars and possible complications o f an excisional biopsy m a y thus be avoided. Needle biopsy has not been widely used for diagnosing muscle diseases because the sample is usually squashed during the procedure, thereby m a k i n g fine histological examination difficult. T h i s is not so significant, however, for trichinosis w h e n d e m o n s t r a t i o n of living larvae is more i m p o r t a n t t h a n structural examination of the tissue. T h e biopsy site in this study was carefully p l a n n e d so that the track of the needle would be several centimetres away from i m p o r t a n t structures, especially the tibial nerve and the posterior tibial artery. T h e gastrocnemius muscle was chosen because it has been shown to contain m a n y parasites. 6 A ' T r u c u t ' needle is used because it is sharp and less traumatic than a special muscle biopsy needle. Both patients responded to thiabendazole dramatically with m i n i m u m side effects. 6 T h i s again emphasizes the importance of early diagnosis and treatment to minimise suffering. A rapid and simple procedure such as the ' T r u c u t ' needle biopsy helps to achieve this. Successful demonstration of larvae, however, will depend on the parasitic load of the patient. References I. Singal M, Schantz PM, Wermer SB. Trichinosis acquired at sea--report of an outbreak. Am J Trop Med Hyg 1978; 298: 1178-118o. 2. World Health Organisation, Parasitic Disease Programme. Epidemiology of trichinosis. Medline search, I966-I98O (179 references). Geneva: WHO. 3. Yamashita J. Trichinosis in Asia. In Gould SE, Ed. Trichinosis in man and animals. Springfield, Illinois: CC Thomas, I97O: 457-464. 4. Holck SN. The distribution of Trichinella spiralis in countries in Southeast Asia and the Far East. Proc ISt Int Congr Parasitol 1964; 2: 666-668. 5. Chung Shah Medical College. Human Parasitology. ISt Edition. Chinese Health Publishers, 198o: pp. 205-208. 6. Campbell WC (ed). Trichinella and trichinosis. New York: Plenum Press, I983. 7. Pun KK, Wong WT, Wong PHC. The first documented outbreak of trichinellosis in Hong Kong Chinese. A m J Trop Med Hyg 1983; 32: 772-775. 8. Ljungstrom I, Engvall E, Ruitenberg EJ. ELISA--a new technique for serodiagnosis of trichinosis. Parasitology 1974; 69: 24-30. 9. Kagan IG. Advances in the immunodiagnosis of parasitic infections. Z Parasitenk 1974; 45: I63-I95. IO. Despommier D, Miller M, Jenks B, Fruitstone M. Immunodiagnosis of human trichinosis using counterelectrophoresis and agar gel diffusion techniques. Am J Trop Ailed Hyg I974: 23(I): 41-44. I I. Ruitenberg EJ, Steerenberg PA, Brosi BJM. Microsystem for the application of ELI SA in the serodiagnosis of Trichinella spiralis infection. Medikon Netherland 1975; 4: 30-33.