1. Review of intestinal helminths
Ascaris lumbricoides (roundworm)
似蚓蛔线虫（蛔虫）
Trichuris trichiura (whipworm)
毛首鞭形线虫 （鞭虫）
Enterobius vermicularis (pinworm)
蠕形住肠线虫（蛲虫）
Ancylostoma duodenale
Necator americanus
可以没有症状和体征
(hookworms) 钩虫

4. --Filaria 丝虫 Trichinella spiralis 旋毛形线虫 Wuchereria bancrofti 班氏吴策线虫
Tissue-blood dwelling nematodes
Trichinella spiralis 旋毛形线虫
Wuchereria bancrofti 班氏吴策线虫
Onchocerca volvulus 旋盘尾丝虫
--Filaria 丝虫

5. The history of Trichinella spiralis
In year 1835，Young Jim Paget, a first year medical student at London Hospital Medical School, rushed into the autopsy room. The 51 yr-old Italian bricklayer who had died of tuberculosis, and that they were now dissecting, also had "sandy diaphragm," a condition that dulled even the sharpest of scalpels. Well, anyway, when they had all cleared the room, Jim quietly stole back in and removed a small bit of muscle tissue from the diaphragm. He was more than curious as to the nature of "sandy diaphragm". He first examined it with his trusty hand lens he carried for just such a situation. He thought he saw small worms coiled up inside each nodule. Upon even higher magnification, the presence of coiled worms was revealed (From
Trichina worms were described in 1835 from a human autopsy. 
Young Jim Paget, a first year medical student at London Hospital Medical School, rushed into the autopsy room. The 51 yr-old Italian bricklayer who had died of tuberculosis, and that they were now dissecting, also had "sandy diaphragm," a condition that dulled even the sharpest of scalpels. Well, anyway, when they had all cleared the room, Jim quietly stole back in and removed a small bit of muscle tissue from the diaphragm. He was more than curious as to the nature of "sandy diaphragm". He first examined it with his trusty hand lens he carried for just such a situation. He thought he saw small worms coiled up inside each nodule. Upon even higher magnification, the presence of coiled worms was revealed (From

6. Trichinella spiralis
Jim Paget Worms in the “sandy diaphragm”

7. Trichinella spiralis
Trichina worms were observed in pork in 1846 by Joseph Leidy. He saved hundreds of lives by recommending cooking pork at a high enough temperature to kill the organism.
Life cycle work out in1850’s
By Rudolph Virchow.

8. Trichinella control Rudolf Virchow (Germany) suggested mandatory
diagnosis of all meat at the
slaughterhouses in 1877
 This has greatly reduced
trichinellosis as human health
Problem.

9. Trichinella spiralis - cause 旋毛虫病
trichinosis, trichiniasis, or trichinelliasis
Worldwide Distribution
Parasitic zoonosis
Food borne parasitosis
1835年尸检发现旋毛虫，1846年在猪肉中发现，1860年发现与人类疾病有关，1964年在中国西藏首次发现该病
我国病人估计超2000万
Trichina worms were described in 1835 from a human autopsy. 
Young Jim Paget, a first year medical student at London Hospital Medical School, rushed into the autopsy room. The 51 yr-old Italian bricklayer who had died of tuberculosis, and that they were now dissecting, also had "sandy diaphragm," a condition that dulled even the sharpest of scalpels. Well, anyway, when they had all cleared the room, Jim quietly stole back in and removed a small bit of muscle tissue from the diaphragm. He was more than curious as to the nature of "sandy diaphragm". He first examined it with his trusty hand lens he carried for just such a situation. He thought he saw small worms coiled up inside each nodule. Upon even higher magnification, the presence of coiled worms was revealed (From

10. Distribution of Trichinella spiralis
Trichinosis is most common in temperate and arctic climates - high prevalence in pork-eating areas of the world.
arctic
temperate
Incidence of infection is always higher than suspected because of the vagueness of  symptoms, which usually suggests other conditions; more than 50 different disease have been diagnosed incorrectly as trichinosis.

11. Adults of Trichinella spiralis
Adults : small, 1.5~4 mm
Larva: females give birth to larva
( Eggs: hatch in uterus 子宫)
特点：直接产幼虫
stichosome
杆状体
成虫形态在诊断上无意义！
Hatched Larva

12. Encysted larva 幼虫囊包-- infective stage
0.25~0.5mm × 0.21~0.42mm
Lemon shape
1~2 larva in the cyst

13. Life cycle

14. Adult female in mucosa of small intestine
Trichina cysts in skeletal muscle骨骼肌

15. Nausea, vomiting, diarrhea, abdominal pain, headache with slight fever
Pathogenisis
3 stages ：
1. Invasion – 1 week
first symptoms appear 12 hours to 2 days following ingestion of trichina cysts
Nausea, vomiting, diarrhea, abdominal pain,
headache with slight fever

16. 2. migration of larvae – 2 week to 2 months
penetration and encystment in skeletal muscles 骨骼肌

17. migration of larvae – 2 week to 2 months
Weakness， Headache and dizziness 头昏，
Fever,chills and sweating, Myalgia 肌痛
splinter hemorrhages
（under finger nails）
perorbital edema
Eosinophilia 嗜酸性细胞增多
Deaths are rare and due to myocarditis 心肌炎, encephalitis 脑炎 and pneumonia肺炎

18. 3.calcification (if one survives stage2!)
- occurs several months after infection
- calcium is deposited around the cysts
- Larva eventually die in a year or longer
In human infections,
5 larvae/gram body weight are fatal.

19. Diagnosis Muscle biopsy : trichina cysts can be seen with microscope
Muscle samples were squeezed between two glass plates
肌肉压片 
2. ELISA to identify Trichinella antibodies
Others？:

20. Epidemiology 1. Cosmopolitan distribution
2. Source of infection is pork or pork products
infection is most frequents among ethnic groups disposed to eat raw or poorly cooked pork products

21. Treatment of Trichinella spiralis
Drugs: Mebendazole（甲苯哒唑）
Albendazole（阿苯哒唑,丙硫咪唑）
Others:

22. Prevention of Trichinella spiralis
Thorough cooking
(temperature above 58o C)
microwave cooking of pork roasts and chops (with bone) is NOT effective in killing trichina
2. freezing for 20 days will kill temperate climate strain
- freezing is NOT effective against the arctic strain
- smoking, salting, and drying pork, bear or other meat will NOT kill trichina larvae

23. Prevention of Trichinella spiralis
3.  - Do not feed pork scraps in garbage to pigs
- eliminate rats in areas where pigs are kept

24. Wuchereria bancrofti 班氏吴策线虫 Onchocerca volvulus 旋盘尾丝虫
Tissue-blood dwelling nemotodes
Filaria
-cause filariasis
Four important filarial worms parasitic in humans are:
Wuchereria bancrofti 班氏吴策线虫
Onchocerca volvulus 旋盘尾丝虫
Brugia malayi 马来布鲁线虫
Loa loa 罗阿罗阿线虫

25. More than 80 million were affected
淋巴丝虫九亿人受威胁，九千万人感染，其中班氏丝虫八千万余
W. bancrofti is strictly a human pathogen and is distributed in tropical areas worldwide
More than 80 million were affected

26. Orient, South Pacific, and Southern Asia to India – overlaps with Wuchereria bancrofti - but does not occur in Africa or South America
B. malayi infects a number of wild and domestic animals

27. Morphology--Adults of Wuchereria bancrofti
Adults occur in the lymphatic vessels
（Adult B. malayi are only half the size of W. bancrofti ）

28. filariform larva 丝状蚴

29. Microfilariae of Wuchereria bancrofti
Microfilariae are seen in blood smears and are DIAGNOSTIC
worms are µm long

31. Morphological differences of microfilariae of Wuchereria bancrofti and Brugia malayi
Wuchereria bancrofti Brugia malayi
Length × × 5 -6
(µm)
Appearance graceful sweeping Irregular kinky
体态 curves curves
Cephalic space length equals width length twice width 头隙
Body nuclei well defined, discrete, blurred, intermingled
体核 round, uniform sized nuclei crowded together
Tail no terminal nuclei two terminal nuclei 尾核

32. Filariform larve--infective stage

34. Microfilariae of Wuchereria bancrofti
Nocturnal periodicity of microfilariae 夜现周期性

35. Pathology of Wuchereria bancrofti
Incubation period
no symptoms
3 clinical phases:
microfilaremia - no symptoms or mild symptoms
微丝蚴血症

36. Acute allergic inflammatory phase
a. lymphadenitis, lymphangitis
淋巴结炎 淋巴管炎

37. Acute allergic inflammatory phase
b. filarial fever 丝虫热
c. funiculitis, orchitis, epididymitis
精索炎， 睾丸炎，附睾炎

38. 3. chronic Obstructive phase
Elephantiasis 象皮肿
The disfigured legs of lymphatic filariasis patients waiting for medical attention

39. b. chyluria 乳糜尿

40. hydrocele testis 鞘膜积液

41. Brugia malayi 马来丝虫
Adults live in lymphatic vessels and cause elephantiasis in arm and leg.
Difference between W.r and B.m? —— discuss later

42. Diagnosis
Identifying microfilaria in blood or other fluid
direct blood films
concentrations of blood specimens and urine specimens
Identifying adults
Serologic testing

43. Epidemilogy World Wide distribution
Source of infection: patients and infected patients
Transmission: by mosquitto
Brugia malayi
Wuchereria bancrofti

44. Treatment of Wuchereria bancrofti
Drugs : hetrazan 海群生
are somewhat effective
kill microfilariae and adults with careful administration

45. Global Programme to Eliminate Lymphatic Filariasis
6 mg/kg diethylcarbamazine citrate (DEC) mg albendazole;
150 µg/kg ivermectin mg albendazole (in the case of co-endemicity with onchocerciasis)
A third option is to follow a treatment regimen using DEC-fortified cooking salt daily for a period of 12 months.

46. Drug 
Year of registration
Indication
Partners
Praziquantel
1980
Schistosomiasis
Bayer
Mefloquine
1984
Malaria
Hoffman La Roche, WRAIR
                                                             
Ivermectin
1987
Onchocerciasis
Merck
                                                              
Halofantrine
1988
Smith Kline Beecham,  WRAIR
                               
Eflornithine
1991
African Tryp.
Marion Merrel Dow
Liposomal  amphotericin B
1994
Leishmaniasis  (Kala azar)
NeXstar

47. Artemether
1997
Malaria
Rhone Poulenc Rorer, Kunming
                               
Artemether- umefantrine
1999
Novartis
Artemotil  (beta-arteether)
2000
Artecef, WRAIR, Dutch Min. Dev.
Miltefosine
2002
Leishmaniasis  (Kala azar)
Zentaris,  Indian CMR
Chlorproguanil- dapsone
2003
Glaxo Smith Kline, DFID

48. others:
Pressure bandages on enlarged limbs forces lymph out.
弹力绷带捆绑
Surgery can be used to remove elephantoid tissue if muscle involvement is minimal.
外科手术

49. Onchocerca volvulus 旋盘尾丝虫
Causative agent of onchocerciasis （river blindness）
90 million, million, 326 thousand

50. Adults of Onchocerca volvulus
Microscopic section showing adults and scar tissue reaction
Skin nodule

51. Microfilariae of Onchocerca volvulus
Unsheathed microfilariae occur in the skin, never the bloodsteam

52. Simulium 蚋

53. Pathogenisis of adults
Nodules (about ½ -1 inch in diameter) are most common in Africa
Nodules in Central & South America.
Nodules are relatively benign

55. Pathogenisis of Microfilariae
Microfilariae in the skin  
- itching is so severe some people have committed suicide

56. Microfilariae in skin
- in parts of Africa, the skin of the scrotum 阴囊 and inguinal area 腹股沟 loses its elasticity

57. 2. Microfilariae invade the eye
(occur as microfilariae die in the eye)

58. Microfilariae invade the eye
In many parts of Africa, the sighted young are responsible for leading the older blind adults.

59. Diagnosis of Onchocerca volvulus
Examination of microfilariae or adult in skin nodule, eye etc.

60. TREATMENT of Onchocerca volvulus
Drugs
Ivermectin （150mg/kg )
Every 6-12month
2. excise of skin nodule etc

61. Onchocerca volvulus
PREVENTION –
blackflies control

62. Loa loa
Vector : chrysops 斑虻
“眼虫”
about 2 million

63. occasionally migrate through the eye
adults
Calabar swelling 卡拉巴丝虫性肿 块
Microfilariaes present during the daytime

64. Pathogenesis of Loa loa
Adults cause Calabar swellings.
Eye swells when worms migrate through.

65. Diagnosis and control of Loa Loa
Control： drugs are not so effective for adults
surgical removal of worms

66. 讨论课要求 以2~3人组成小组，以小组为单位计分，要求小组成员分工合作完成 每组同学自由讲解时间控制在12分钟，留3分钟提问和讨论
每位同学必须至少参加一次讨论
每位同学还必须完成一次课后作业（另行布置）
班长负责协调统计

67. 人体寄生虫学讨论课
讨论主题：总论、线虫
人群土源性线虫的感染率是衡量一个国家或地区整体发展水平和文明程度的重要指标，如果你是某农村疾控中心的人员，你在控制土源性线虫感染方面有哪些具体的措施？
淋巴丝虫病是WHO要求全球范围内限期消除的寄生
虫病，请从生物学及社会学等因素分析人类提出该目标的依据及具体的措施？
3. 当前哪些因素导致新现和再现寄生虫病的上升，请举例说明。

68. 补充：
1. 人体寄生虫学研究发展史。
2. 人类能最终消灭人体寄生虫病吗，谈谈你的观点。
3. 寄生虫对人类社会的贡献。
4. 各国（地区）人体寄生虫流行及防治介绍