APPLICATIONS ON CONTACT DISEASES

1. Application of cases on
contact infections
By
Noha Hesham
Under supervision of
Prof dr Mona Aboserea
Zagzazig University

2. Case (1): A surgeon was exposed to a needle stick injury,
while placing a central line.
1- what are the pathogens might be transmitted from
this contaminated needle?
2- what are the factors that affect pathogens
transmission?
3- how to manage this case?

3. 1- The major pathogens are: 1- HBV (30%):
if the source is HBsAg +ve and HBeAg –ve ( 22%-36%)
if the source is HBsAg +ve and HBeAg –ve (36%-72%)
2- HCV (2-3%) average 1.8%
3- HIV (0.3% )
2- factors affecting disease transmission:
1- The design of the device:
More dangerous if: a) hollow bore needle rather than solid.
b) needle need manipulation
c) syringes that retain an exposing needle after use.
2- The device contaminated with visible blood or not.
3- Viral load and presence of specific antigen or antibody.
4- Direct penetration to blood vessels or skin injury.
5- Skin intact or lacerated.
6- Depth of injury.

4. 3- Management:
1- local care of injured site 2- exposure report
3- evaluation of exposure source 4- evaluation of
exposed person
5- PEP 6- counseling
7- follow up
A- local site care:
1- wash the wound and skin with soap and water, mucous membrane flushed with water.
2- no evidence for the rule of squeezing.
3- the use of antiseptic is not contraindicated.
4- use of caustic agent or injection of disinfectants to the wound is not recommended.

5. B- report:
Done immediately, includes:
1- Date and time.
2- Details of the procedures( where, when, how. Type of sharp object and its
description).
3- Details of the exposure: a- type and amount of material or fluid.
b- severity of exposure and depth of injury.
c- skin intact or lacerated.
4- Details on the exposure source:
-whether have HBV,HCV, HIV.
-if HIV +ve ( stage, treatment, resistance, load)
5- Details of exposed person:
HBV vaccination, vaccine response state.
6- Details about counseling, PEP, follow up.

6. C- Evaluation of exposure source:
From medical records, if not available do lab for HBV,HCV,HIV.
D- Evaluation of the exposed person:
Asses the immune state for HBV vaccination and the respose.
E- Management of HBV:
Source: HBsAg +ve Source: HBsAg -ve Source unkown, not
avaialbe
Unvaccinated HBIg + HBV vaccine HB vaccine HB vaccine
Previously vaccinated:
Responder
no treatment No treatment No treatment
non responder HBIg + vaccine
HBIg twice
No treatment If high risk source treat as
positive
unkown response Test exposed person for
anti-HBs:
1- if adequate : no
treatment.
2- if inadequate:
HBIg + booster
no treatment Test exposed person for
anti-HBs:
1- if adequate : no
teratment.
2- if inadequate:
Vaccine booster, recheck
titre after 1 month

7. • HbIg must be administrated in the fisrt 24 hours, after 7 days unkown effect.
• When vaccine is indicated is given as soon as possible.
• Vaccine + HBIg give 85-95% protection.
• Multiple doses of HBIg alone or vaccine alone give 70-75% protection.
• Follow up: post vaccination testing after 1-2 months after completion of 3 doses.
Management of hepatitis c:
Antiviral, immunoglobulin are not recommended
follow up recommendations:
1- For the source perform testing for HCV, if positive:
a- Perform baseline testing for HCV ab and ALT activity.
b- Follow up for HCV ab and ALT at 4-6 months
NB: if early diagnosis is desired: HVC RNA after 4-6 weeks.
c- Confirm positive results by RIBA.
counseling:
1- Refrain from donating blood and plasma.
2- Practice sex as usual, lactation and pregnancy.
3- No need to restrict professional activities.
4- Follow infection control practice.

8. Management of HIV:
Percutaneous injury:
Exposure type HIV +ve
Class 1
HIV +ve
Class 2
Unknown HIV
state
Unknown source HIV -ve
Less sever Basic 2 drug PEP Expanded 3 drugs
PEP
No PEP
warranted,
however consider
2 drug PEP for
source with HIV
risk factor
No PEP
warranted,
however consider
2 drug PEP in
setting where
exposure to HIV
infected person is
likely
No PEP warranted
More sever
(larg bore hollow
needle, deep
puncture, visible
blood on device,
needle used in
patient artery or
vien)
Expanded 3 drug
PEP
Expanded 3 drug
PEP
No PEP
warranted,
however consider
2 drug PEP for
source with HIV
risk factor
No PEP
warranted,
however consider
2 drug PEP in
setting where
exposure to HIV
infected person is
likely
No PEP warranted

9. Mucous membrane:
Exposure type HIV +ve
Class 1
HIV +ve
Class 2
Unknown HIV
state
Unknown source HIV -ve
Small volume Basic 2 drug PEP Basic 2 drugs PEP No PEP
warranted,
however consider
2 drug PEP for
source with HIV
risk factor
No PEP
warranted,
however consider
2 drug PEP in
setting where
exposure to HIV
infected person is
likely
No PEP warranted
Large volume Basic 2 drug PEP Expanded 3 drug
PEP
No PEP
warranted,
however consider
2 drug PEP for
source with HIV
risk factor
No PEP
warranted,
however consider
2 drug PEP in
setting where
exposure to HIV
infected person is
likely
No PEP warranted

10. - Basic 4 week regimen is 2 drugs : zidovudine + lamivudine twice daily.
If taken before 36 hours reduce the risk of HIV infection by 81%.
- Expanded: addition of third drug indinavir.
Follow up:
1-Perform HIV ab at least 6 months after exposure ( baseline, 6 weeks, 3 months, 6 months)
2-Use precaution to prevent secondary transmission during follow up period
3-Evaluate the exposed person taking PEP after 72 hours after exposure and monitor for
drug toxicity at least 2 weeks

11. Case ( 2): A patient has arrived with a chief complaint of animal bite, he
was holding his right arm and his forearm has a piece of gauze covering it.
This is not the first time he has bitten by an animal as he was volunteering
at an animal shelter.
1- what are the organisms we are fear from?
2- How to manage this case?
3- what are the preventive measures?

12. 1- Rabies virus, tetanus.
2- According to the risk category:
Category I – touching or feeding animals, licks on intact skin (i.e. no exposure)
None
Category II – nibbling of uncovered skin, minor scratches or abrasions without bleeding
Immediate vaccination and local treatment of the wound
Category III – single or multiple transdermal bites or scratches, licks on broken skin;
contamination of mucous membrane with saliva from licks, exposures to bats.
Immediate vaccination and administration of rabies immunoglobulin; local treatment of the
wound
He is most likely to be classified as category 3

13. 1- Care of the wound:
A- immediate local treatment of the animal bite and scratch by repeated flushing and
cleaning of the wound with soap and water.
B- the wound should not be sutured then wound is dressed.
C- tetanus prophylaxis, antibacterial treatment.
2- vaccine:
a- If immunized before > 3 years : 4 doses of the vaccine, 1ml each, IM in the deltoid at
0,3,7,14
b- If immunized within 3 years: 3 booster doses at 0,3,7.
3- Immunoglobulin:
Human immunoglobulin: 20IU/KG or Equine immunoglobulin 49IU/kg, infiltrated at the bite
site and the reminder intramuscular.
Types of vaccine:
1- Human diploid cell vaccine
2- Rabies vaccine adsorbed
3- Duck embryo vaccine
4- Purified chick embryo vaccine

14. C) Primary prevention:
Measures for the animal:
1- Destruction of stary dogs
2- Vaccination of domestic animals by vaccine every 2 years and giving license
3- Quarantine of imported animals to prevent introduction of rabies
Measures for man:

15. Secondary prevention:
Measures for cases:
1- Notification to local health authority
2- Isolation
3-Disinfection of saliva and solid articles
4- Treatment: no effective treatment, only symptomatic.
Measures for contact:
No specific measures but avoid contamination of skin wound by patient saliva.

16. Case (3): 53 years old male farmer presents for evaluation of growth on his
arm.
About a week previously, he noticed some mildly itchy red lumps on his
arm. They started to blister a day or two later then ruptured. During this
time he had a low grade fever, but otherwise feel well. He has cows, horses,
goat, sheep and chicken in his farm.
a) What is your provisional diagnosis?
b)How can you confirm the diagnosis?
c) What measures would be done for this case?
d)What is the prevention of this disease?

17. a)Anthrax ( bacillus anthracis)
b)1- gram stained smear from skin lesion
2- blood culture
c)Measures for this case:
1- Notification to local health authority
2- Isolation at hospital
3- Disinfection of discharges from lesions & solid particles
4- Chemotherapy with penicillin or tetracyclin, erythromycin and chloramphenicol.
d) Primary prevention:
I- Protection of population at risk:
1-Health education
2- Disinfection of raw wool and hair
3-Quarantine measures for raw wool & hair
4- Vaccination with anthrax vaccine for those with occupational exposure.
II- control of reservoir:
1- Eradication of anthrax in animals by: a- sanitary clean environment
b- veterinary care
c- vaccination: annual vaccination of all domestic animals in endemic areas
2- Control of diseased animals: a- Isolation of diseased animals
b- Disinfection of discharges
c- Carcasses of dead animals should be incinerated or buried in deep pit
Secondary prevention: measures for cases: as above

18. Case (4): A 55 years old man coming to the emergency room with
crush injury in his upper left extremity. This arm was very tender on
palpation, had decreased range of motion with finding crepitation. A
radiograph of his arm revealed gas in soft tissue.
a) What is your provisional diagnosis?
b)What are the causative agents for that condition?
c) What are the preventive measures?

19. a) Gas gangrene
b) Two groups of anaerobic spore-forming clostridia:
1- primary organisms: saccharolytic and toxigenic. They include:
a- clostridium welchii
b- clostridium oedematients
c- clostridium septicum
2- secondary invaders: which are proteolytic. They include:
a- clostridium histolyticum
b- clostridium sporogenes
c) Primary prevention:
1-Surgical care of injuries, removal of any foreign matter and excision of damaged tissues.
2-Aseptic techniques in surgery and chemoprophylaxis with antibiotics.
3-Sero-prophylaxis by polyvalent antitoxin I.M.
Measures for cases:
1-Early diagnosis and surgical management.
2-Penicillin in massive doses
3-Sero-therapy in proper dose.
4-Sterilization of any used object or material.

20. Case (6): a 13 years old child was injured in his foot with sharp object, when he
played in the garden. He was transferred to the emergency room to receive the
appropriate treatment.
a) What is the organism we are fear from?
b) How can you treat this case?
c) How to prevent this condition?

21. a) Clostridium tetani
b) 1-Prevent further toxin production by:
Cleaning & local debridement of the wound by removing foreign matters & necrotic
tissues, then application of local antiseptic solution.
Suturing & dressing of the wound.
Chemoprophylaxis: Antibiotic (e.g. penicillin or tetracycline) & metronidazole.
2- immunization: according to immunization state
TetanusImmunization
No record of
immunization or less
than 3 doses
1st dose TT +
HIG
2nd dose after 4
weaks
3rd dose after 6
months
vaccinated
<5 years: no
further
>5 years: DT
Types of vaccine:
1-DTap: from 6 weeks to 6 years
2,4,6, 15-18, 4-6 years
Fewer side effects and safe version of
DPT
2- Tdap: 10-64 years
Low concentration of dyphteria and
pertussis that Dtap
Given at 11-12 years.
3-Td: every 10 years
Givem for 7 years and older.
HIG: 500U, IM, protection 2-3 months.
tetanus antitoxin: 1500-5000 IU, IM, protection 2 weeks.

22. Pteventive measures: General measures:
1- cleanliness of the environment.
2- control of animal reservoir
Prevention of special form of tetanus:
1. Neonatal tetanus (tetanus neonatorum):
Aseptic cutting & dressing of the umbilical cord
Training & health education of birth attendants for sound health behavior.
Preconceptional or prenatal active immunization of mothers in high risk areas.
2. Surgical infection:
•Proper sterilization of catgut & instruments and asepsis in care of surgical wounds.
•Clean hospital environment & surrounding.
3. Puerperal infection:
• Active immunization of pregnant in high risk areas.
• Proper asepsis & sterilization in labor or abortion.
• Chemoprophylaxis after labor or abortion.

23. Specific measures:
1. A-Active immunization by tetanus toxoid vaccine
Infants:
DPT (Diphtheria, Pertussis and Tetanus), compulsory, at 2, 4 & 6 months, 0.5 ml, I.M.,
then booster dose at 18 months. DT is used instead of DPT after 4 years.
. Pregnant mothers: to prevent neonatal tetanus. 5 doses of tetanus toxoid
1st dose: 1st contact with the health service (in 1st pregnancy)
2nd: At least 4 weeks after 1st dose.
3rd: 6-12 months after 2nd dose or during subsequent pregnancy.
4th: 5 years after 3rd dose or during subsequent pregnancy.
5th: 10 years after 4th dose or during subsequent pregnancy.
3-High risk groups: e.g. Military forces, soldiers, farmers, night guards and pregnant.
It gives immunity for 10 years, so booster dose is given every 10 years.
1st and 2nd doses 0.5ml, 1 month apart, while 3rd 1ml after 6 months.

24. II-Control measures for cases:
Notification to the LHO.
Isolation in a quiet room.
Treatment: Human immunoglobulin (3000-6000 I.U.) or equine antitoxin (30,000
I.U.) I.M. with precautions for serum reaction.
Surgical care of the wound.
Chemoprophylaxis (e.g. penicillin & metronidazole).
Sedatives to avoid stimuli.
Tracheostomy is performed if needed.
Active immunization should be initiated concurrently with therapy.

25. Case (5): a 20 years old man presents for evaluation of a rash that he thought was an
allergic reaction. For the past 4-5 days he had flu with fever, chills, headache and body
aches. He has been taking flu medications without any symptomatic relief. Yesterday
he developed a diffuse rash made up of red, slightly raised lumps. It cover his whole
body, and he says that it must be an allergic reaction to the medication. He has no
history of allergies and takes no other medication. On further questioning he denies
dysuria or urethral discharge and any genital lesions now, but says that he had a sore
on his external genitalia a few months ago that never hurt and went away on its own
after a few weeks so he didn’t think much about it. Upon examination, he has
palpable cervical, axillary and inguinal adenopathy. His skin is erythematous,
maculopapular eruption covering his whole body including his palms and soles of the
feet. No vesicles noted. His genital examination is normal.
a) What is the provisional diagnosis?
b) What are the differential diagnosis?
c) How can you confirm the diagnosis?
d) How can you prevent & control the disease?

26. Viral
AIDS
Genital
herpes
simplex
Genital warts
(HPV)
Molluscum
contagiosum
Bacterial
Syphilis
Gonorrhea
Non-gonorrheal
urethritis
Chancroid
Non-specific
vaginitis
Granuloma
inguinale
chlamydia
Parasitic
Trichomonus
vaginitis &
urethritis.
Scabies
Pediculosis
pubis.
Fungal
Vaginal
thrush
Valvovaginitis.
Balanitis
a) Syphilis (Treponema pallidum)
b)Sexually transmitted diseases

27. c) Lab investigations:
Dark field microscopic exam
Serologic testing
1-Non-treponemal test (non-specific): for screening e.g. Wassermann Reaction (WR) &
Venereal Disease Research Laboratory test (VDRL) “↑false +ve”.
• 2-Treponemal tests (specific test): Use treponema Ag. e.g. fluorescent treponema
antibody absorption test.
d) General measures: 1-Avoidance of sexual promiscuity.
2-Health education to increase awareness.
3- Religious & social guidance especially of youth.
4- Convenient family life & supervision of youth
5- Suitable places for leisure time & development of hobbies.
6- Socioeconomic development & provide facility for marriage
Specific: Chemoprophylaxis: 1 dose of 2.4 million units of long acting penicillin
I.M. soon after exposure.

28. . For Cases:
1. Early case finding: during survey & on health appraisal:
•Premarital & prenatal examination & Suspected attendants of medical services.
•Exam of food handlers, blood donors, army recruits, child nurses.
•Diagnosis of congenital syphilis when mother is syphilitic.
2. Measures for cases:
•Notification: LHO.
•Isolation: not needed but avoid sexual contact till elimination of infectivity.
•Disinfection: non but precautions with blood & body fluids.
•Specific ttt: Long acting penicillin 2.4 million units in a single dose
I.M.
Penicillin sensitive patients: doxycycline 100 mg twice daily for 14 days.
•Re-examination after treatment.

29. Case (7): 25 years old male complaining of dysuria and purulent
urethral discharge. He gave history of being sexually active with 3
partners in the last 9 months.
a) What is your provisional diagnosis?
b)What are the differential diagnosis?
c) What is the epidemiology of the causative agent?
d)How can you manage this case?

30. a) Gonohhrea
b) From other sexually transmitted diseases
c) Reservoir: Man: case “infectious for months or years if not treated, while ttt eliminates infection
within days”.
Exit:Discharges of infected mucous membranes.
Transmission :Direct sexual contact only.
d) 1- Diagnosis by:
A- History & C/p
B-Lab investigations:
Acute case: demonstration of causative organism from film of pus taken from cervix or urethra.
Chronic case: serologic test such as complement fixation test
2- measures for case:
Notification: LHO.
Isolation: not needed but avoid sexual contact till elimination of infectivity.
Disinfection: non but precautions with blood & body fluids.
Treatment:oAmoxicillin: 3 gm orally as a single dose.
Penicillin resistant strains: Ceftrioxone 250 mg as a single dose.
Re-examination after treatment.
organism from film of pus taken from cervix or urethra.
Chronic case: serologic test such as complement fixation test

31. Case (8): a patient 53 years old male, have 2 children with a history of exposure to
armadillo, his clinical history was significant for diabetes with peripheral neuropathy,
he presented to his dermatologist complaining of slowly growing enlarging diffuse
nodular bilateral ear lesion, his only dermal symptom was a 4cm hypo pigmented rash
on the left flank. A routine biopsy was performed. The skin biopsy revealed numerous
acid fast bacilli.
a) What is the provisional diagnosis?
b)How to manage this case?
c) What are the measures for his children?

32. a) Provisional diagnosis : lepromatous leprosy
b)1- Notification to local health authority
2- Isolation until therapy is established
3- Disinfection for nasal discharges
4- Treatment: combined chemotherapy
Rifampicin 600mg once monthly + dapsone 100mg/ day +
clofazimine 50mg once a day & 300mg once a month for 12 month or
until skin smear is negative.
c) Periodic examination at 12 months intervals for at least 5 years.
Dapsone: not recommended as it only give 50% protection.
Booster dose of BCG vaccine reduce the incidence of tuberculoid
leprosy.

33. Case (9): a 36 years old farmer from sharkia governorate presented to
urologist complaining of episodic gross hematuria, he described his
hematuria as intermittent, occurring 2 -3 times / week, usually at the end of
urination, he also complained of right flank pain that began several years ago.
a) What is your provisional diagnosis and its causative agent?
b) What are the factors which favor endemic spread of this disease in Egypt?
c) How to prevent this condition?

34. a) Bilharziazis, schistosoma heamtobium
b) factors affecting its spread:
Host factors (the most important):
1- Age: highest age affected is 10-20 years due to swimming in infected canals in summer
2- sex: male are more affected due to more exposure during farming and irrigation.
3- Education: less in educated person as they can avoid polluted water and sake medical care early.
4- Occupation: affect those exposed to water as farmer, fisherman, worker in irrigation and drainage
network.
5-Habits and behavior: defecation and urination in canal water make infectious cycle completed and
infection is endemic
6- Underutilization and reluctance to seek medical care for diagnosis and early treatment.
Agent factors:
1- Continuous flow of snail intermediate host from Nile resources.
2- Perennial irrigation favors development of snails
3- Cercaria characteristics: big number, survive 2-3 days, thermotropic, phototropic, have great affinity to
man, swim freely in water
Environmental factors:
1- Unsanitary environment.
2- Lack of safe water supply for bathing and washing
3- Unavailable latrines.
4- Suitable climate( temperature and humidity for development of cercaria and snails)

35. c) A - protection of susceptible host or population at risk:
1- Community development in all aspects of life:
a- Socioeconomic development
B- Satisfactory education and culture of the public.
C- Upgrading quality and utilization of health services with proper discovery and treatment of cases.
D- Sanitary water supply and availability of latrines in rural areas.
E- Mechanization of agriculture including irrigation and drainage system to minimize human contact with
water.
F- Provision of recreational centers in rural areas which would attract rural children to spend their time.
2- Health education for the public:
To prevent water pollution by eggs and human exposure to cercaria and to seek medical care by:
A- Follow clean habits by prohibiting defecation and urination in water canals ( the sure single preventive
measure that can eradicate infection if strictly followed by the public).
B- To avoid unnecessary exposure to water canals.
C- To dry up the body after getting out of the water so give no chance for the cercaria to penetrate the skin.
D- To seek medical treatment when infected.
E- Wearing protective clothes on exposure to infected water.

36. 3- Snail control:
A- Periodic drying of canals and clearance from vegetation.
B- Trapping of snails by special methods.
C- Application of effective mollucides to canal water.
The ideal molluscicide must be:
1- Lethal to snail, eggs and cercaria.
2- Not poisonous to man, animal and fish.
3- Cheap and easy to supply.
4- Not affected by heat and sun and vegetation in water.
5- Having persistent effect in water for long time.
niclosamine is the molluscicide of choice at present
Value of snail control:
A suitable molluscicide can be applied in mass anti-schistosomiasis campaign especially for hyper endemic
area but of limited practical value in the general anti-schistosomiasis program due to:
1- Practical unfeasibility of extensive application and maintenance of lethal doses of molluscicude.
2- Continuous flow of snails from Nile resources.
3- Potential chemical risk of continued application of molluscicide.
No specific or international measures

37. Secondary prevention:
Control of cases:
1- case finding: by routine urine and stool examination for viable schistosoma egg on the different
occasion of health appraisal:
A- All attendants of the rural health unit
B- All persons undergoing preplacement examination and periodic check up of employees
C- All school children on their first attendance to school and at periodic check up
D- Army recruits
E-Field surveys especially in hyper endemic areas.
2- Management of cases:
A- Treatment of diagnosed cases.
B- Reexamination to be sure of cure and retreatment if necessary.
C- Health education to prevent reinfection.
Treatment: early treatment eliminate the disease and prevent the irreversible sequale
Mass chemotherapy is of community value as it control the reservoir of infection ( cases) so limit
spread of infection.
Requirement of ideal drug:
1- Give absolute cure rate.
2- Least number of doses needed.
3- Easy administration, the oral route is the best.
4- No or minimal toxicity.

38. 1- Praziquantel: drug of choice in egypt, tablets of 600 mg
dose: 30mg/kg body weight with maximum 2400mg (4 tablets)
orally either in one dose or divided into 2 doses to be taken within one day.
2- Mirazid: 300mg, 2 capsules daily on empty stomach
Measures for contact:
No special measures as there is no man to man transmission
Stool and urine examination for early detection of cases
Health education to avoid infection
Mass treatment by praziquantel