《传染病学》课程教学资源（PPT课件）Bacillary dysentery（菌痢）

Infectious diarrhea Bacillary dysentery Shigellosis Yu Zebo

Bacillary dysentery Shigellosis Infectious diarrhea Yu Zebo

Case report Patient xxx,female,25-year-old,nursemaid,Suddenly onset 2 days ago with general malaise, chill fever,fatigue,headache and cramping abdominal pain,especially in left inferior abdomen ,then followed diarrhea with water stool initially,and then bloody purulent stools,10~20 times per day,accompanied with burning sensation at Anus-tenesmus. Five days ago this woman had nursed a diarrhea patient. Term explanation:Tenesmus is the constant feeling of the need to pass stool,accompanied by pain,cramping because of inflammatory of the bowel,but little stool is passed. 2025/3/26 Shigellosis 2

2025/3/26 Shigellosis 2 ◼ Patient xxx,female,25-year-old,nursemaid, Suddenly onset 2 days ago with general malaise, chill ,fever ,fatigue ,headache and cramping abdominal pain ,especially in left inferior abdomen ,then followed diarrhea with water stool initially, and then bloody purulent stools, 10~20 times per day ,accompanied with burning sensation at Anus- tenesmus. Five days ago this woman had nursed a diarrhea patient. Case report Term explanation： Tenesmus is the constant feeling of the need to pass stool, accompanied by pain, cramping because of inflammatory of the bowel, but little stool is passed

PE:T39.5℃，R30/m,P110/m,BP110/80mmHg。Press- pain on the left inferior abdomen Blood test:WBC 12.5X 10%/L;neutrophilic leukocyte 85%. Stool test:WBC 50~60/HP,RBC20~30/HP. Questions 1.What disease is the patient suffered from? 2.What is the principle of treatment for this patient? 3.How to prevent this disease? 2025/3/26 Shigellosis

2025/3/26 Shigellosis 3 ◼ PE：T 39.5℃，R 30/m，P 110/m，BP 110/80mmHg。Press￾pain on the left inferior abdomen ◼ Blood test: WBC 12.5×109 /L;neutrophilic leukocyte 85%。 Stool test: WBC 50~60/HP，RBC20~30/HP。 Questions ◼ 1.What disease is the patient suffered from? ◼ 2.What is the principle of treatment for this patient? ◼ 3.How to prevent this disease?

Contents ■General condition ■ Etiology←= It's specific features that there are ■Epidemiology microorganisms for infectious diseases ■Pathogenesis chemical factors Clinical manifestation physic factors Laboratory examination ■Diagnosis ■ Differential diagnosis No microorganisms ■Treatment ■Prevention 2025/3/26 Shigellosis 4

2025/3/26 Shigellosis 4 Contents ◼ General condition ◼ Etiology ◼ Epidemiology ◼ Pathogenesis ◼ Clinical manifestation ◼ Laboratory examination ◼ Diagnosis ◼ Differential diagnosis ◼ Treatment ◼ Prevention It’s specific features that there are microorganisms for infectious diseases chemical factors physic factors No microorganisms

1.General condition Definition: Shigellosis is also called bacillary dysentery,this is an acute bacterial disease characterized by fever, nausea,vomiting,cramps,diarrhea and feeling of tenesmus caused by Shigella species.In most cases,the stools contain blood and mucus. Tenesmus is the constant feeling of the need to pass stool, accompanied by pain,cramping because of inflammatory of the bowel,but little stool is passed 2025/3/26 Shigellosis

2025/3/26 Shigellosis 5 1. General condition ◼ Definition: Shigellosis is also called bacillary dysentery, this is an acute bacterial disease characterized by fever, nausea, vomiting, cramps, diarrhea and feeling of tenesmus caused by Shigella species. In most cases, the stools contain blood and mucus. Tenesmus is the constant feeling of the need to pass stool, accompanied by pain, cramping because of inflammatory of the bowel, but little stool is passed

Typical clinical features Shigella is transmitted directly or indirectly via the fecal-oral route and may occur due to the ingestion of contaminated food or water. Whole body symptoms fever and toxemia (chill ,fatigue ,headache) Local symptoms diarrhea,bloody purulent stools, abdominal pain,tenesmus. Signs Press-pain on the left inferior abdomen. Laboratory examination Blood test::WBC↑，neutrophil↑ Stool test:WBC↑，RBC↑ 2025/3/26 Shigellosis 6

2025/3/26 Shigellosis 6 ◼ Typical clinical features ◼Shigella is transmitted directly or indirectly via the fecal-oral route and may occur due to the ingestion of contaminated food or water. ◼Whole body symptoms :fever and toxemia (chill ,fatigue ,headache ) ◼Local symptoms :diarrhea, bloody purulent stools, abdominal pain, tenesmus. ◼Signs :Press-pain on the left inferior abdomen. Laboratory examination : Blood test: WBC , neutrophil Stool test: WBC , RBC

2.Etiology ■ Shigella: ■ Gram-,facultative anaerobic(with or without oxygen), rod bacteria Very similar to E.coli pH:survives in neutral pH, resistant to stomach acids Temperature:(depends on serotype.) Can survive at 4 C for 21 days in cheese,potato,salad and mayonnaise Can survive and grow at under 25 C for 50 days in flour,milk,eggs,shrimps,oysters 2025/3/26 Shigellosis

2025/3/26 Shigellosis 7 2. Etiology ◼ Shigella : ◼ Gram - ,facultative anaerobic(with or without oxygen), rod bacteria ◼ Very similar to E.coli ◼ pH: survives in neutral pH, resistant to stomach acids ◼ Temperature: (depends on serotype.) ◼ Can survive at 4°C for 21 days in cheese, potato,salad and mayonnaise ◼ Can survive and grow at under 25 °C for 50 days in flour, milk, eggs, shrimps, oysters

Etiology 4 serogroups: ■A:S.dysenteriae Most severe-"Bacillary dysentery";developing countries in Africa,Latin America,Asia ■B:S.flexneri Most common Shigella in developing countries; becoming more common in developed countries ■ C:S.boydii ■ D:S.sonnei ◆ Least severe;developed countries (In china:B and D) 2025/3/26 Shigellosis 8

2025/3/26 Shigellosis 8 Etiology 4 serogroups: ◼ A: S. dysenteriae ◼ Most severe “Bacillary dysentery”; developing countries in Africa, Latin America, Asia ◼ B: S. flexneri ◼ Most common Shigella in developing countries; ◼ becoming more common in developed countries ◼ C: S. boydii ◼ D: S. sonnei ◼ Least severe; developed countries ◼ (In china :B and D)

Shigella sonnei 25 2025/3/26 Shigellosis 9

2025/3/26 Shigellosis 9 25 Shigella sonnei

Shigella bacteria in a stool sample (Under high power microscope) 2025/3/26 Shigellosis 10

2025/3/26 Shigellosis 10 Shigella bacteria in a stool sample (Under high power microscope)