most common communicable diseases with communicability, incubation period, prevention and control, and treatment strategies

1. FARHAT NAZ
Miss ABDUR REHMAN
PAKISTAN.

2. DIPHTHERIA
Cornybacterium diphtheriae
 Word derived from Greek diphthera means “leather hide”.
 Recognized by Hippocrates in 5th century BCE
 Epidemics described in 6th century
 First observed in diphtheritic membranes by Klebs in 1883
and cultivated by Löffler in 1884.
 Toxoid developed in 1920s.
TOXIGENICITY:
 C. diphtheriae is an aerobic gram-positive bacillus.
 Toxin production (toxigenicity) occurs only when the bacillus
is itself infected (lysogenized) by a specific virus
(bacteriophage) carrying the genetic information for the toxin
(tox gene).
 Only toxigenic strains can cause severe disease.
PERIOD OF INFECTIVITY:
Unless treated, the period of infectivity vary from 14 to 28
days from the onset of the disease, but carriers may remain
infective for much longer periods.
INCUBATION PERIOD:

3. Incubation period 2-5 days (range, 1-10 days)
COMMUNICABILITY
1.Transmission may occur as long as virulent bacilli are present
in discharges and lesions.
2.The time is variable, but without antibiotics, organisms
usually persist 2 weeks or less and seldom more than 4 weeks.
3.Chronic carriers may shed organisms for 6 months or more.
4.Effective antibiotic therapy promptly terminates shedding.
CONTROL AND PREVENTION OF
DIPHTHERIA
Cases and Carriers detection:
 Cases are diagnosed clinically and by Schick test.
 Carriers can be detected only by culture method.
 Swabs should be taken from both the nose and throat and
examined by cultural methods.
Isolation:
 All cases, suspected and carriers should be isolated, preferably
in a hospital, for at least 14 days or until proved free of
infection.
 At least 2 nose and throat swabs, taken 24 hours apart.
TREATMENT
Cases:
 In case of diphtheria antitoxin should be given without delay.

4.  I/M or I/V in doses ranging from 10,000 to 80,000 units or
more.
 The antibiotics of choice are erythromycin (500 mg PO Q6H
for 14 days) Or
 Procaine penicillin G (300,000 units Q12H for patients ≤10
kg and 600,000 units Q12 H for patients >10 kg IM) until the
patient can take oral medicine,
 Followed by oral penicillin V (250 mg Q6H) for a total
treatment course of 14 days.
 The disease is usually not contagious 48 hours after antibiotics
are instituted.
Carrier:
The carriers should be treated with 10 days course of
erythromycin
Contacts:
They should be throat swabbed and their immunity status
determined by Schick test.
Where primary course or booster dose received >2 years before,
only a booster dose of toxoid need to be given.
Where dose was received within previous 2 years no further
action should be needed.
Non-immunized contacts should receive prophylactically
penicillin or erythromycin. They should be given 1000-2000
units of antitoxin and actively immunized against diphtheria.
COMMUNITY IMMUNIZATION
The only effective control is by active immunization with
diphtheria toxoid of all infants as early as possible, as scheduled
with subsequent booster doses every 10 years thereafter.
Single-antigen diphtheria toxoid is not available.

5. COMBINATION FORMS:
Diphtheria toxoid is available in combination forms:
a) With tetanus toxoid:
a. pediatric diphtheria-tetanus toxoid (DT) or
b. adult tetanus-diphtheria (TD),
b) with tetanus toxoid and acellular pertussis vaccine:
a. DTaP and
b. TDaP.
c) Diphtheria toxoid is also available as
a. DTaP-HepB-IPV (Pediarix) and
b. DTaP-IPV/Hib (Pentacel).
Pediatric formulations (DT and DTaP) contain a same amount of
tetanus toxoid as adult TD, but contain 3 to 4 times as much
diphtheria toxoid.
Children <7 years of age should receive either DTaP or pediatric
DT.
Children of 7 years of age or older should receive the adult
formulation (adult TD), even if they have not completed a series
of DTaP or pediatric DT.
Two brands of TDaP are available—
a. Boostrix (approved for persons 10 years of age or older) and
b. Adacel (approved for persons 10 through 64 years of age).
DTaP and TDaP vaccines do not contain thimerosal as a
preservative.

6. VACCINATION SCHEDULE AND USE
TRIPLE ANTIGEN DTaP
The vaccine of choice for children 6 weeks through 6 years of
age.
The usual schedule is a primary series
DOSE AGE INTERVAL
Primary 1 2 months ---
Primary 2 4 months 4 wks
Primary 3 6 months 4 wks
Primary 4 15-18 months 6 months
If a child is contraindicated to pertussis vaccine, pediatric DT
should be used to complete the vaccination series.
If the child was <12 months old when the first dose of DT was
administered (as DTP, DTaP, or DT), the child should receive a
total of four primary DT doses.
If the child was ≥12 months at the time the first dose of DT was
administered, three doses (third dose 6-12 months after the
second) complete the primary DT series.
If the fourth dose of DT, DTP or DTaP is administered before
the fourth birthday, a booster (fifth) dose is recommended at 4
through 6 years of age. The fifth dose is not required if the
fourth dose was given on or after the fourth birthday.
Vaccines containing reduced diphtheria (i.e., TD and TDaP) are
indicated for children ≥ 7 years and for adults.

7. A primary series is three or four doses, depending on whether
the person has received prior doses of diphtheria-containing
vaccine, and the age these doses were administered.
For unvaccinated persons 7 years and older (including persons
who cannot document prior vaccination), the primary series is
three doses.
The first two doses should be separated by at least 4 weeks, and
the third dose given 6 to 12 months after the second.
ACIP recommends that one of these doses (preferably the first)
be administered as TDaP. A booster dose of Td should be given
every 10 years. Persons who have never received TDaP should
be given a booster dose.
CONTRAINDICATIONS TO VACCINATION
 Severe allergic reaction to vaccine component or following a
prior dose
 Moderate or severe acute illness
ADVERSE REACTIONS
 Local reactions (erythema, induration) are common
 Fever and systemic symptoms not common
 Exaggerated local reactions (Arthus-type) occasionally
reported
Other control measures
 Notification of disease.
 Health education
 Encourage high rates of vaccination coverage.

9. PLAGUE
INCUBATION PERIOD OF YERSINIA PESTIS
Bubonic Plague----------- 2 to 7 Days
Septicaemic Plague-------- 2 to 7 Days
Pneumonic Plague--------- 1 to 3 Days
COMMUNICABILITY:
 Fleas may remain infective for months,
 Bubonic plague is not usually transmitted from person to
person.
 Pneumonic plague may be highly communicable under
appropriate climatic conditions (overcrowding facilitates
transmission).
 Patients are usually no longer infectious after receiving 72
hours of appropriate antibiotic treatment.
PREVENTION AND CONTROL
1. CONTROL OF CASES
A. EARLY DIAGNOSIS:
During epidemic situations, diagnosis can be made on clinical
grounds. In other situation, “rat falls” provide a useful warning

10. of possible outbreaks. Plague suspected humans and rodents
must be examined bacteriologically to confirm the presence of
plague.
B. NOTIFICATION:
Case notification is required by international health regulations.
C. ISOLATION
Although most bubonic plague patients are non-infectious.
Isolation is recommended whenever possible.
Pneumonic plagues patients whether suspected should be
isolated.
D.TREATMENT:
Drug of choice is Streptomycin – 30mg/kg body weight daily
IM in 2 divided doses for 7 to 10 days.
Tetracycline, orally, 30-40mg of body weight daily in an
alternative drug and sometimes given in combination with
streptomycin.
Gentamycin, 2mg/kg of body weight loading dose, then
1.7mg/kg body weight every 8 hours IV.
Sulphonamides, used if other drugs are not available
E. DISINFECTION
Disinfection OF sputum, discharges and articles soiled by the
patients should be carried out.

11. Dead bodies should be handled with aseptic preparations.
2. CONTROLOF FLEAS
■ Most effective method to break the chain of transmission is
destruction of rat fleas by insecticides
■ DDT (10%) and BHC(3%), used as dust
■ In areas of resistance to one or both of these, dust of carbaryl
(2%) or malathion (5%) is used.
3. CONTROL OF RODENTS
■ Continuous mass destruction of rodents is an important
plague preventive measure
4. VACCINATION
To be effective, vaccination should be carried out at least a
week before an anticipated outbreak and the vaccine should be
given in 2 doses.
5.CHEMOPROPHYLAXIS

12.  Highly recommended
 Should be offered to all plague contacts, medical, nursing, and
public health personnel exposed to the risk of infection
 Drug of choice is tetracycline
 For adult dose is 500mg, 6 hourly for 5 days
 Cheaper alternative is sulphonamide , 2-3g daily for 5-7 days
6. SURVEILLANCE
■ In areas where natural plague foci exist, or where there is
history of past infection, surveillance is essential.
7. HEALTH EDUCATION.
■ Emphasis must be placed on the need for the prompt reporting
of dead rats and suspected human cases.
■ Medical practitioners should keep plague in mind for
differential diagnosis of any cases of fever with
lymphadenopathy, or when multiple cases of pneumonia occur.
SMALL POX
Smallpox is derived from the Latin names Variola or Variol a
vera, varius ("spotted") or varus ("pimple").

13. It refers to the raised bumps that appear on the face and body of
an infected person.
RESERVOIR
Human
TRANSMISSION
 Person to person
 Respiratory tract secretions
 Direct contact with lesions
TEMPORAL PATTERN
Peak in winter and early spring.
INCUBATION PERIOD
12-14 days.
VACCINE ADMINISTRATION
JET GUN
• Rapid
• High maintenance
BIFURCATED NEEDLE
 High efficacy, sterilizable , and rapid.
 Uses less vaccine

14.  It is a needle not an injection
 Bifurcated needle is dipped into the vaccine and then used
to prick the skin 15 times in about 3 seconds in a 5mm radius
area
 Administered into the superficial layer of the skin
 Mainstay for the WHO eradication campaign
COURSE OF VACCINATION
 If vaccination is successful a red, itchy bump develops at
the vaccine site in 3-4 days; a papule surrounded by erythema
 In the first week the bump becomes a blister, fills with pus,
and begins to drain
 During the second week the blister begins to dry and a scab
forms; the scab then falls off leaving a scar
 It is given on the right side universally
CONTROL AND PREVENTION:
• 1958: Soviet Union proposed to the WHO that a global
smallpox eradication program be undertaken
• The campaign was based on a two-fold strategy.
– 1. Mass vaccination campaigns in each country using a
vaccine of ensured potency and stability that would reach at
least 80% of the population
– 2. Surveillance-Containment- isolation of patients and the
vaccination of family members and other contacts in the
immediate vicinity

15. • Ring vaccination:
• Incorporated into the current CDC Smallpox Plan
• The strategy involves the following steps:
– Rapid identification and isolation of all smallpox cases
– Identification and vaccination of contacts of smallpox cases
– Monitoring contacts for development of fever and isolating
them if fever occurs
– Vaccination of household members of contacts if there is no
contraindications.
MANAGEMENT OF AN OUTBREAK
 Surveillance is easier because of the distinctive rash.
 Containment involves efficient detection of cases and
identification and vaccination of contacts.
 Patients diagnosed with smallpox should be physically
isolated.
 All specimen collectors, care givers and attendants coming
into close contact with patients should be vaccinated.
 Medical care givers, attendants, and mortuary workers should
wear gloves, caps, gowns, and surgical masks.
 Contaminated clothing and bedding, if not incinerated, should
be autoclaved or washed in hot water containing bleach.
 Fumigation of premises with formaldehyde.
 Airborne and Contact Precautions in addition to Standard
Precautions should be implemented for patients with suspected
smallpox.

16. FACTORS THAT LED TO
ERADICATION
• Epidemiological factors:
– No known animal reservoir
– No long-term carrier of the virus
– Life-long immunity after recovery from the disease
– Detection of cases, the rash was so characteristic
– Sub-clinical infection did not transmit the disease
– Vaccine highly effective
– International co-operation
CHICKEN POX
Chicken pecked skin appearance, chickpea appearance

17. EPIDEMIOLOGICAL DETERMINANTS
– Agent: Human (alpha)herpes virus3
– Primary infection causes chicken pox
– Recovery followed by latent infection
– Reactivation results in zoster- a painful, vesicular, pustular
eruption in distribution of one or more sensory nerve roots
– Can be grown in tissue culture
• INCUBATION PERIOD:
14-16 days (10-21 days)
• PERIOD OF COMMUNICABILITY:
1-2 days before the appearance of rash, and 4-5 days thereafter
• It tends to die out before the pustular stage
• Patient ceases to be infectious once the lesion have crusted
• Secondary attack rate: About 90% in household contacts
CONTROL
• No specific treatment for chicken pox
• Notification of cases.
• Isolation of cases for about 6 days after onset of rash
• Disinfection of articles soiled by nose and throat discharges
• Antiviral drugs provide effective therapy for varicella
(acyclovir, valaciclovir, famiciclovir and foscarnet).

18. PREVENTION
• Varicella zoster immunoglobulin (VZIG)
• VZIG given within 72 hours of exposure has been
recommended for prevention.
– Dosage: 1.25-5ml IM up to a maximum of 625 units, with a
repeat dose in 3 weeks, if high risk patient remain exposed.
– Used for immunosuppressed contacts of acute cases or
newborn contacts.
– Provide improvement in high risk children with varicella.
VACCINE
• Live attenuated vaccine (Japan)
• Mild local reaction at inoculation site is 1%
• A general reaction mainly rash or mild varicella may occur
• Sero-conversion in healthy sero-negative children is over 90%
• Age shift of peak incidence due to vaccinations is a major
concern
– Monovalent vaccine
• One or two dose schedule (0.5 ml subcutaneous injection)
• For children between 12-18 months
• Two dose schedule for persons aged >13 years
• Minimum interval between doses 6 weeks for children from
12 month to 12 years of age.

19. • 4 or 6 weeks dose interval for adolescents and adults ≥13
years.
• Combination vaccines (MMRV) for children 9 months to 12
years
• Duration of immunity probably 10 years
TYPHOID (Commonly s. Typhi).
Typhoid fever, also known as enteric fever, is a potentially fatal
multisystemic illness transmitted by the ingestion of
contaminated food or water by Salmonella enterica serovar
Typhi (Salmonella Typhi).
INCUBATION PERIOD:

20. From 3 days to over 60 days; usual range is 8-14 days depending
on innoculum size and on host factors.
PERIOD OF COMMUNICABILITY:
Typhoid is communicable as long as S. Typhi is being excreted
in stools or urine, usually from one week after symptom onset,
through convalescence, and for a variable period thereafter.
About 10% of untreated typhoid fever cases have detectable
bacteria in their stool for three months after onset of symptoms;
2-5% become chronic carriers (carriage for more than one year
following illness).
The frequency of long-term carriage is higher for women, those
older than 50 years, and patients with cholelithiasis, carcinoma
of the gall bladder, other gastrointestinal malignancies, persons
with biliary abnormalities, or concurrent bladder infection with
Schistosoma haematobium.
In cases treated with appropriate antibiotics, fewer than 2%
become carriers, or relapse.
1-TREATMENT PLAN:
Another third-generation cephalosporin [e.g., cefotaxime, 2 g
q8h(iv); or cefixime, 400 mg bid (PO)].
Ofloxacin, 400 mg bid (PO) for 2–5days
or 1 g on day 1 followed by 500 mg/d PO for 6 days
Optimal therapy Alternative

21. Susceptibil
ity
drug therapy
Antibiotics Dail
y
dose
mg/k
g
Days Antibiotic
s
Dail
y
dose
Mg/
kg
Da
ys
Fully
sensitive
Floroquinol
ones
E.g.
15 5-7
Chloramph
enicol
50-
75
14-
21
Ofloxacin
or
Amoxicilli
n
75-
100
14
Ciprofloxaci
n
TMP-SMX 8-40 14
Multidrug
resistance
Floroquinol
ones
15 5-7 Azithromy
cin
8-10 7
Cefixime 15-
20
7-14 Cefixime 15-
20
7-
14
Quinolones
resistance
Azithromyci
n or
Ceftriaxone
8-10
75
7
10-
14
Cefixime 20 7-
14
2-SURGICAL CARE
• Surgery is usually indicated in cases of intestinal perforation.

22. • Small-bowel resection is indicated for patients with multiple
perforations. If antibiotic treatment fails to eradicate the
hepatobiliary carriage, (carrier state)
• The gallbladder should be resected.
• Cholecystectomy is not always successful in eradicating the
carrier state because of persisting hepatic infection.
PREVENTION AND CONTROL
There are generally three lines of defense.
1. Control of reservoir.
2. Control of sanitation.
3. And, immunization.
 Travelers to developing countries should be advised to
monitor their food and water intake carefully
 Wash your hands frequently and thoroughly.
 Practice proper body hygiene.
 Drink purified water (boiled or un-tampered bottled water)
 Only eat well cooked foods.
VACCINATION
– There are two types of vaccines available;
(1) Ty21a, an oral live attenuated S.typhi vaccine (given on
days 1, 3, 5, and 7, with a booster every 5 years);
(2) Vi CPS, a parenteral vaccine consisting of purified Vi
polysaccharide from the bacterial capsule (given in 1 dose, with
a booster every 2 years).

23. HEPATITIS
HEPATITIS A

24. Hepatitis A (formerly known as ―infectious hepatitis or
epidemic jaundice) is an acute infectious disease caused by
Hepatitis A virus (HAV).
PERIOD OF INFECTIVITY:
The risk of transmitting HAV is greatest from 2 weeks before to
1 week after the onset of jaundice.
INCUBATION PERIOD
10-50 days (usually 25 to 30 days).
PREVENTION AND CONTROL
 Hygienic measures and sanitation
 Attention should be paid for complete bed rest.
 Disinfection of feces and fomites.
 The use 0.5% sodium hypochlorite is strongly
recommended as disinfectant.
 Passive immunization (human immunoglobulin gamma
globulin given before exposure to virus or early during the
incubation period, will prevent or attenuate a clinical illness.
 Active immunization several inactivated or live attenuated
vaccines against hepatitis a have been developed.
CONTROLOF TRANSMISSION
The best means of reducing the spread of infection is by
promoting simple measures like,

25.  Personal and community hygiene. e.g., hand washing
before eating and after toilet.
 The sanitary disposal of excreta.
 Filtrationand adequate chlorination ofdrinking water.
 Distributionsystem should be improved.
CONTROL OF SUSCEPTIBLE POPULATION
1. FormaldehydeInactivatedvaccine:
Primary dose:
At the age of 1 year and older, 0.5 ml below 18 years and 1ml
beyond.
Booster dose:
6-12 months after the primary dose.
2. Live attenuated vaccine;
Administer as a single subcutaneous dose.
PROPHYLACTIC USE OF
IMMUNOGLOBULIN
Use of normal human immunoglobulins(IG) to induce passive
Immunity.
It is recommended for:
i) Preprophylaxis:
Susceptible persons travelling to highly endemic areas.

26. ii) Postprophylaxis:
Close personal contacts of patients. When given within 1to2
weeks of exposure prevents illness in 80 to 90 percent of the
contacts.
TREATMENT:
No specific, dietary food and long rest.
HEPATITIS B
(formerly known as ―serum hepatitis)
PERIOD OF COMMUNICABILITY:
Period of communicability is usually several months
(occasionally years in chronic carriers).
INCUBATION PERIOD:
6 weeks to 6 months
►5 to 15 percent of the cases, infection fails to resolve and the
affected individuals then become persistent carriers of the virus
PREVENTION AND CONTAINMENT
Since there is no specific treatment, prevention has been the
major aim in managing viral hepatitis B.

27. The following measures are available:
HEPATITIS B VACCINE
This is based on the surface antigen (HBs Ag).
The vaccine is given in 3 doses at 0,1and 6 months. An effective
antibody response is generally attained in 95% of vaccines.
Immunity continues at protective levels for approximately 3-5
years.
Booster doses may be given after 3-5 years.
HEPATITIS B VACCINE FOR GENERAL
POPULATION:
IMMUNIZATION SCHEDULE
HEPATITIS B VACCINATION IN EPI SCHEDULE:
►1st
Dose, HBV 0.5ml IM right thigh at birth.
►2nd
Dose, combine vaccine as PENTAVALENT at 6 weeks.
0,5ml IM right thigh
►3rd
Dose, combine vaccine as PENTAVALENT at 10 weeks,
0.5ml IM left thigh
►4th
Dose, combine vaccine as PENTAVALENT at 14weeks,
0.5ml IM right thigh

28. HEPATITIS B AND PREGNANCY:
►Hepatitis B screening of mother during first trimester:
If negative = No intervention
If positive, give immunoglobulins,1 injection IV
►At 28 weeks give another injection of IG
►At delivery, give IG to the newborn IV and hepatitis B IM
vaccine to the baby at birth.
►If mother was negative during 1 trimester, then after delivery
vaccinate mother for hepatitis B at 0, 1, and 6 months.
VACCINATION FOR AT RISK GROUP
►Both pre-exposure and post-exposure administration has been
recommended.
►Classical examples of post exposure prophylaxis are
protection of newborn infants born to carrier mothers,
Individuals accidentally exposed to HBV infection through
transfusion, cuts, injuries and needle sticks.
HEPATITIS B IMMUNOGLOBULIN
(HBIG)
For immediate protection, HBIG is used for those acutely
exposed to HBs Ag-positive blood, for example,
a. Surgeons, nurses or laboratory workers
b. New born infants of carrier mothers,
c. Sexual contacts with acute hepatitis B patients.
The HBlG should be given ideally within 6 hours and preferably
not later than 48 hrs.

29. started immediately and a full course given. If the test is positive
for surface antibody, no further action is needed.
Two doses should be given 30 days apart. It provides short-term
passive protection which lasts approximately 3 months.
a.Passive-active immunization
The simultaneous administration of HBIG and hepatitis B
vaccine is more efficacious than HBIG alone. HBIG(0.05-
0.07ml/kg) should be given as soon as possible and within 24
hours if possible.
Hepatitis B virus vaccine1.0ml (20mcg/1,0ml) should be given
intramuscularly within 7 days of exposure and second and third
doses given one and six months, respectively, after the first
dose.
b. Other measures
All blood donors should be screened for HBV infection, and
those positive for Australia antigen should be rejected. Positive
Australian antigen means
recent infection.
Carriers should be told not to share razors or tooth brushes and
use barrier methods of contraception; they should not donate
blood.
HEPATITIS C

30. INCUBATION PERIOD:
2 weeks to 6 months
More than 50% change to chronic hepatitis, which may lead to
cirrhosis of liver or liver cancer.
Liver cancer is more likely in men than in women, and in
alcohol consumers.
TREATMENT
Acute Infection:
American Association for the Study of Liver Diseases (AASLD)
recommend considering treatment for patients with acute HCV
infection with peg-interferon. The addition of ribavirin has not
been studied and as such there is no specific recommendation
for or against its use in acute infection.
Combination therapy with pegylated interferon (long-acting
interferon with once-weekly dosing) plus ribavirin is the current
optimal treatment for chronic HCV infection.
PREVENTION AND CONTROL
PRIMARY PREVENTION:
There is no Hepatitis C vaccine and IG, so post-exposure
prophylaxis not effective. Risk of infection can be reduced by
avoiding,
►Unnecessary and unsafe injections.
►Unsafe blood products
►Unsafe sharp waste collection and disposal
►Sharing of injection equipment
►Unprotected sex with hepatitis C-infected persons

31. ►Tattoos, piercings, and acupuncture performed with
contaminated equipment.
►Infected razors with beauty saloons and barbers.
►Standard precautions in healthcare and laboratory settings.
►Education regarding low risk of sexual transmission
►HCV- positive women do not need to avoid pregnancy or
breast feed
SECONDARY AND TERTIARY PREVENTION
For people infects with the hepatitis c virus, WHO
recommends:
Education and counseling for care and treatment.
Immunization with hepatitis A and B vaccines to prevent
co-infection from these viruses.
Early and appropriate medical management including
antiviral therapy if appropriate,
Regular monitoring for early diagnosis of chronic liver
disease
COUNSELING
A. HCV-positive persons should be advised to:
1. Avoid drinking alcohol.
2. Avoid starting any new medications
B. To reduce the risk for transmission to others, HCV-positive
persons should be advised to:
1. Avoid donating blood, body organs.
2. Cover cuts and sores.

32. 3. Avoid sharing any personal items e.g., tooth brushes, razors,
etc.
HEPATITIS E (HEV)
INCUBATION PERIOD:
Incubation period of 3 to 8 weeks (mean 40 days).
PERIOD OF COMMUNICABILITY:
Unknown.
TREATMENT
Recovery from hepatitis E is always complete. No vaccine or
specific immunoglobulin prophylaxis is available.
PREVENTION AND CONTAINMENT
CONTROL OF RESERVOIR
Control of reservoir is difficult because of the following factors:
►The occurrence of large number of subclinical cases.
►Fecal shedding of the virus is at its height during the
incubation period and early phase of illness.
►Absence of specific treatment.
CONTROL OF TRANSMISSION
The best means of reducing the spread of infection is by
promoting simple measures like

33. Personal and community hygiene. e.g., hand washing
before eating and after toilet use.
The sanitary disposal of excreta.
Filtration and adequate chlorination of drinking water.
Water distribution system should be improved.
Travelers to highly endemic areas are recommended to take
the elementary food hygiene precautions.
HEPATITIS D
INCUBATION PERIOD:
2-12 weeks
PREVENTION:
It can be prevented by vaccinating HBV susceptible
persons with hepatitis B vaccine. But it doesn’t
protect hepatitis B carriers from super-infection by
HDV.
References:
Park’stextbookof social andpreventivemedicines
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