Salmonella typhi

Typhoid fever

1. PRESENTED BY Mrs.J.JEBA, M.Sc.,M.Phil., ASSOCIATE PROFESSOR ANNASAMY RAJAMMAL COLLEGE OF NURSING, ATHIYOOTHU

2. TYPHOID Typhoid  is a bacterial infection that can lead to a high fever, diarrhea, and vomiting. It can be fatal. It is caused by the bacteria Salmonella typhi . The infection is often passed on through contaminated food and drinking water I t is more prevalent in places where hand washing is less frequent .

3. HISTORY Antonius Musa , a Roman physician who achieved fame by treating the Emperor Augustus 2,000 year ago, with cold baths when he fell ill with typhoid. Thomas Willis who is credited with the first description of typhoid fever in 1659.    

4. French physician Pierre Charles Alexandre Louis first proposed the name “typhoid fever” William Wood Gerhard who was the first to differentiate clearly between typhus fever and typhoid in 1837.  

5. Carl Joseph Eberth who discovered the typhoid bacillus in 1880. Georges Widal who described the   ‘Widal agglutination reaction’ of the blood in 1896.

6. HISTORY Salmonella  is an important bacterial genus which causes one of the most common forms of food poisoning worldwide. Throughout history typhoid fever – caused by  Salmonella enterica  serovar Typhi – triggered many dire outbreaks, and people eventually recognized the link between this disease and contaminated food or beverages. Karl Joseph Eberth, a doctor and student of Rudolf Virchow, discovered the bacillus in the abdominal lymph nodes and the spleen in 1879. After he had published his observations in 1880 and 1881, his discovery was subsequently confirmed by German and English bacteriologists, including Robert Koch. The genus “Salmonella” was named after Daniel Elmer Salmon, a veterinary pathologist who ran a The United States Department of Agriculture (USDA) microorganism research program in the 1800s. Together with Theobald Smith, he found Salmonella in hogs that succumbed to the disease known as hog cholera .

7. The story of Mary Mallon Mary Mallon was born in Ireland and immigrated to the United States in 1884. She is considered the first famous carrier of typhoid fever in the United States. Initially engaged in 1906 as a cook by Charles Henry Warren, a wealthy New York banker, she was subsequently hired as a cook at several private homes throughout the New York area. Moving from household to household, Mary Mallon caused several typhoid outbreaks, always vanishing before an epidemic could be traced back to the particular household she was working in. Mary represents the first known case of a healthy carrier in the United States, and was proven responsible for the contamination of at least 122 people – including five dead. In 1907 almost 3000 inhabitants of New York had been infected by  Salmonella  Typhi, with Mary probably being the main reason for the outbreak. Due to a lack of antibiotic treatment and no immunization option at the time, a dangerous source like Mary had to be restrained.

8. After police intervened and  Salmonella  had been found in Mary’s stool, she was transferred to North Brother Island to Riverside Hospital, where she was quarantined in a cottage. As she was the first known healthy carrier of typhoid fever in the United States, she did not understand how someone healthy could spread disease; hence she tried to fight back.

9. Although the New York Supreme Court dismissed her petition for release, the city’s new health commissioner Ernst J. Lederle took pity on Mallon and released her on the promise that she will never again work as a cook . Nevertheless, she was found to be working as a cook, which was again causing typhoid outbreaks. She was sent back to North Brother Island, where she lived until her death in 1938.

10. There is still much speculation regarding the treatment that Mary received at the hands of the New York’s Department of Health. Instead of working with her to make her realize she was a risk factor, the state quarantined her twice and turned her a laboratory pet. This case is often cited as an example of how the health care system provokes prejudiced social attitudes towards disease carriers.

11. Salmonella -A Very complex group Contains more > 2,000 sp Typed on the basis of Serotyping, and species typing Divided into two groups 1. Enteric fever group, 2.Food poisoning group – Septicemias . Enteric Fever (Typhoid Fever )-Caused by Salmonella typhi, and other Groups called as Paratyphi A, B, C. Salmonella typhi - Causes Typhoid Salmonella Paratyphi A,B,C Causes Paratyphoid fevers . Food Poison group Spread from Animals – Humans Causes Gastroenteritis – Septicemias, Localized Infection

12. CAUSES Ingestion of contaminated food or water. Contact with an acute case of typhoid fever. Water is contaminated where inadequate sewage systems and poor sanitation. Contact with a chronic asymptomatic carrier. Typhoid carriers Even after antibiotic treatment, a small number of people who recover from typhoid fever continue to harbor the bacteria. These people, known as chronic carriers, no longer have signs or symptoms of the disease themselves. However, they still shed the bacteria in their feces and are capable of infecting others. Eating food or drinking beverages that handled by a person carrying the bacteria. Salmonella enteriditis and Salmonella typhimurium are other salmonella bacteria, cause food poisoning and diarrhoea.

13. Morphology of Salmonella Gram negative bacilli 1-3 / 0.5 microns Motile by peritrichous flagella   Arranged singly or in pairs N on–sporing Non–capsulated

14. Cultural Characters Aerobic / Facultative anaerobic Grows on simple media – Nutrient agar Temp 15 – 41ºc / 37º c   PH=6.5-7.5

15. MEDIUM Deoxycholate Citrate Agar (DCA) medium Salmonella – Shigella Agar medium Wilson & Blair bismuth sulfite medium Xylose Lysine Deoxycholate (XLD) medium Tetrathionate broth Selenite F Broth 

16. Peptone water and Nutrient Broth (NB) In liquid medium (Nutrient broth), most strains give abundant growth with uniform turbidity of their surface pellicle usually forms on prolong incubation.

17. NUTRIENT AGAR Colonies appear as large 2 -3 mm, circular, convex.  

18. BLOOD AGAR Blood Agar medium , the Salmonella typhi shows gamma hemolysis

19. MACCONKEY AGAR MacConkey Agar medium , the colonies of Salmonella typhi are colorless due to the lack of lactose fermentation 

20. WILSON BLAIR BISMUTH SULPHITE AGAR S. Typhi, S. Enteritidis,  and  S. Typhimurium  typically grow as black colonies with a surrounding metallic sheen resulting from hydrogen sulphide production and reduction of sulphite to black ferric sulphide. Salmonella Paratyphi A grows as light green colonies.

21. Selenite F broth & Tetrathionate broth Selenite F broth & Tetrathionate broth  are the enrichment medium for  Salmonella  species and commonly used for the isolation of the organism from the fecal sample where the density of  Salmonella   typhi  may be too low in early stages of infection. The fecal specimen inoculated in Selenite F broth are incubated for 6-12 hours generally (not more than 24 hours) and then sub cultured on Wilson & Blair bismuth sulfide medium or XLD medium or any other selective medium.

22. Xylose Lysine Dextrose Agar (XLD) Xylose Lysine Dextrose Agar (XLD) medium , the colonies of Salmonella appears red due to the fermentation of xylose which lowers the pH of medium and the presence of Phenol Red (indicator) imparts a pink or red color to the salmonella typhi colonies with a black center which is due to the production of H2S  

23. Salmonella Shigella Agar medium T he colonies of  Salmonella typhi  are Colorless with black center, due to the production of H 2 S (Hydrogen sulfide).

24. Antigenic structure of  Salmonella Salmonella  possess following antigens: Flagella antigen (H) Somatic antigen (O) Surface antigen (Vi )- found in some species Several strains carry fimbriae.

25. Ingestion of contaminated food or water Salmonella bacteria Invade small intestine and enter the bloodstream Carried by white blood cells in the liver, spleen, and bone marrow Multiply and re enter the bloodstream PATHOGENESIS

26. Bacteria invade the gallbladder, biliary system, and the lymphatic tissue of the bowel and multiply in high numbers Then pass into the intestinal tract and can be identified for diagnosis in cultures from the stool tested in the laboratory

27. SYMPTOMS No symptoms - if only a mild exposure; some people become " carriers " of typhoid. Poor appetite, Headaches, Generalized aches and pains, Fever, Lethargy, Diarrhea, Have a sustained fever as high as 103 to 104 degrees Fahrenheit (39 to 40 degrees Celsius), Chest congestion develops in many patients, and abdominal pain and discomfort are common, Constipation, mild vomiting, slow heartbeat.

28. Rose spots High fever Diarrhea Typhoid Meningitis Aches and pains Chest congestion Typhoid ulcer

29. Time frame Occurs gradually over a few weeks after exposure to the bacteria. Sometimes children suddenly become sick. The condition may last for weeks or even a month or longer without treatment. First-Stage Typhoid Fever The beginning stage is characterized by high fever, fatigue, weakness, headache, sore throat, diarrhea, constipation, stomach pain and a skin rash on the chest and abdominal area. Adults are most likely to experience constipation, while children usually experience diarrhoea.

30. Second stage Second-stage typhoid fever is characterized by weight loss, high fever, severe diarrhea and severe constipation. Also, the abdominal region may appear severely distended. Typhoid State When typhoid fever continues untreated for more than two or three weeks, the effected individual may be delirious or unable to stand and move, and the eyes may be partially open during this time. At this point fatal complications may emerge.

31. Complications Intestinal bleeding or holes Intestinal bleeding or holes in the intestine are the most serious complications of typhoid fever. They usually develop in the third week of illness. In this condition, the small intestine or large bowel develops a hole . Contents from the intestine leak into the stomach and can cause severe stomach pain, nausea, vomiting and bloodstream infection (sepsis). This life-threatening complication requires immediate medical care .

32. Other possible complications include: Inflammation of the heart muscle (myocarditis) Inflammation of the lining of the heart and valves (endocarditis) Infection of major blood vessels (mycotic aneurysm) Pneumonia Inflammation of the pancreas (pancreatitis) Kidney or bladder infections Infection and inflammation of the membranes and fluid surrounding your brain and spinal cord (meningitis) Psychiatric problems, such as delirium, hallucinations and paranoid psychosis

33. DIAGNOSIS Diagnosis of typhoid fever is made by Blood, bone marrow, or stool cultures test Widal test Slide agglutination Antimicrobial susceptibility testing

34. CULTURE TEST For the culture, a small sample of blood, stool, urine or bone marrow is placed on a special medium that encourages the growth of bacteria. The culture is checked under a microscope for the presence of typhoid bacteria.

35. WIDAL TEST " A test involving agglutination of typhoid bacilli when they are mixed with serum containing typhoid antibodies from an individual having typhoid fever; used to detect the presence of Salmonella typhi and S. paratyphi ."

36. STANDARD TEST TUBE METHOD Take four sets of 8 test tubes and label them 1 to 8 for O,H,AH and BH antibody detection.  Pipette it to the tube No.1 of all sets 1.9 ml of isotonic saline. To each of the remaining tubes (2 to 8) add 1.0 ml of isotonic saline. To the tube No. 1 tube in each row add 0.1 ml of the serum sample to be tested and mix well. Transfer 1ml of the diluted serum from tube no.1 to tube no.2 and mix well. Discard the 1ml of the diluted serum from tube no.8 of each set.

37. Tube no.8 in all sets,serves as a saline control. Now the dilution of the serum sample achieved in each set is as follows: Tube no. 1 2 3 4 5 6 7 8 (control) Dilutions 1:20 1:40 1:80 1:160 1:320 1:640 1:1280 – To all tubes (1 to 8) of each set add one drop of the respective WIDAL TEST antigen suspension (O,H,AH,BH) from reagent vials and mix well. Cover the tubes and incubate at 37 C overnight (approx. 18 hrs). Dislodge the sedimented button gently and observe.

38.   How do you read Widal test results for typhoid fever? The highest dilution of the patients serum in which agglutinations occurs is noted, ex. if the dilution is 1 in 160 then the titer is 160. Agglutination in dilution up to <1:60 is seen in normal individuals . Agglutination in dilution 1:160 is suggestive of Salmonella infection. Agglutination in dilution of and more than 1:320 is confirmatory of Enteric fever .  

39. Ciprofloxacin (Cipro). Azithromycin (Zithromax) Ceftriaxone Ampicillin Chloramphenicol Amoxicillin MEDICATION

40. OTHER TREATMENTS Drinking fluids.  This helps prevent the dehydration that results from a prolonged fever and diarrhea. If severely dehydrated, may need to receive fluids through a vein (intravenously). Surgery.  If intestines become torn,need surgery to repair the hole.

41. Prevention

42. Types of Typhoid Vaccination There are two types of typhoid vaccination. They are:    Inactivated Typhoid Vaccine: It is an injectable vaccine that provides protection and a booster dose is required after every 2 years.   Live oral Ty21a typhoid vaccine (Oral): It provides protection for about 5 years. It is taken orally as a course of four doses in one week

43. Wash your hands.  Frequent hand-washing in hot, soapy water is the best way to control infection. Wash before eating or preparing food and after using the toilet. Carry an alcohol-based hand sanitizer for times when water isn't available. Avoid drinking untreated water.  Contaminated drinking water is a particular problem in areas where typhoid fever is endemic. For that reason, drink only bottled water or canned water. Avoid raw fruits and vegetables.  Because raw produce may have been washed in contaminated water.

44. Choose hot foods.  Avoid food that's stored or served at room temperature. Steaming hot foods are best. And although there's no guarantee that meals served at the finest restaurants are safe, it's best to avoid food from street vendors — it's more likely to be infected. Do not have ice in drinks Avoid eating at street food stands