Infection Control ofAerosol Transmissible

Diseases

The Chain Model of Communicable Diseases

�Sources of infection /Reservoirs

Portals of exit

�Modes of transmission

Portals of entry

�Susceptible hosts

The chain of infection: portals of exit of a pathogen

Portal of exit: routes by which the infectious agents escapes the human or animal reservoirs (some diseases may have several portals of exit)

Portals of exit:

� Respiratory tract (nasal/respiratory secretions)

� GI tract (saliva, vomitus, stool)

� Genital/urinary tract (urine, semen, vaginal secretions

� Breaks in skin (skin rash, needle sticks, bites of mosquitos)

Modes of Transmission

� Direct Transmission� Direct Contact

� Droplet

� Indirect Transmission� Vehicle-borne

� Vector-borne

� Airborne (sometimes claimed as vehicle-borne)

� Vertical transmission (mother to infant)

Infectious aerosols are generated when an some ill person sneezes, coughs or speaks.

Source: Department of Medical Microbiology, Edinburgh University

Transmission of Infections by Respiratory Aerosols

Expulsion of infectious material into the air through sneezing, coughing or through aerosol-generating medical procedures such as sputum induction creates large droplets and smaller aerosols.

speaking and breathing generate smaller amounts of aerosols

1. Droplets: Bacterial or viral laden droplets (10-100 µ)

• land directly on mucosal lining of nose, mouth, eyes of nearby persons or can be inhaled.

• Highest exposures within 1-2 meters

2. Airborne: aerosols become smaller by evaporation; small aerosols (≤ 10 microns) remain suspended for longer periods, if inhaled travel deep into the lungs (pl tbc).

3. Contact: Aerosols/ secretions contaminate nearby surface. Touch surfaces �can infect self or others.

Relative contribution of three routes varies with agent.

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Transmission of Infections by Respiratory Aerosols

Modes of Transmission viaInfectious Respiratory Secretions

� Airborne: tuberculosis, measles (2 hours), varicella, smallpox, SARS, avian influenza

� Droplet: meningococcal meningitis, rubella, pertussis, common cold, SARS, influenza*

� Indirect contact: (fomite) RSV, SARS, influenza (15 min hands, 2-48 hours on certain surfaces)

*Influenza traditionally droplet, increasing evidence for airborne component

Infection Control in a Health CareSetting Review

Basic Principles

� All body fluids are potentially infectious (except sweat) � blood and blood-tinged fluids including open-wounds

� respiratory secretions, saliva, stool, urine, vomit, semen, vaginal secretions, breast milk, other body fluids such as pericardial and synovial fluids

� Minimize exposure to potentially infectious body fluids

� Infection control measures designed to “break the chain” of transmission

Standard Precautions in Health Care Settings

1. Appropriate hand hygiene

2. Barrier protective equipment:� if splash, splatter, or sprays can be reasonably anticipated

� appropriate PPE (Personal protective equipment) as needed: gloves, gown, mask, eye protection (face shield, goggles)

3. Proper use and handling of patient care equipment

Standard Precautions in Health Care Settings

4. Proper environmental cleaning and disinfection

5. Proper handling of linen

6. Adherence to bloodborne pathogens standards

7. Proper patient placement

8. Respiratory hygiene/cough etiquette

9. Safe injection practices

Expanded Isolation Precautions:

� Transmission-based Standards : when standard precautions are not enough

� Additional measures based on mode of transmission

� Contact Precautions

� Droplet Precautions

� Airborne Precautions

Aerosol Transmissible Diseases in Health Care and Public Safety Settings

� Droplet

� Meningococcal meningitis

� Pertussis

� Mumps

� Rubella (German measles)

� Strep pharyngitis

� Influenza

� Airborne

� Tuberculosis

� Varicella (chickenpox)

� Measles

� SARS

� Avian influenza

� Smallpox

� Influenza

Reasons for Respiratory Protection

� Engineering controls not feasible or sufficient

� Employees must wear N95 respirators (or higher level of protection) in the following circumstances

� Entering a room with patient with suspect or confirmed airborne infectious disease

� When performing high-hazard (aerosol-generating) procedures on persons with suspect/confirmed airborne infectious disease or influenza

� When emergency response employees/others must transport in a closed vehicle, a patient with suspect/confirmed airborne infectious disease

Transmission-Based Precautions: Droplet Precautions

� Single room preferred, no special ventilation

� Patient: Mask if transport necessary. Instruct on

respiratory hygiene/cough etiquette

� HCWs wear surgical or procedure mask within 6

feet (1,8 m) of patient. Eye protection if splash,

spray anticipated

(in addition to Standard Precautions)

Transmission-Based Precautions: Airborne Precautions

� Airborne Infection Isolation Room (AIIR) - intended to prevent transmission of infectious agents suspended in the air that

remain infectious over long distances

� Patient: Mask if transport necessary (as tolerated).

� Health care workers (HCWs):

� N95 respirator prior to entry into room, discarded after exit.

� Higher level respirators for aerosol-gen procedure. Careful attention to proper putting on & taking off (don/doff) respirator, including seal check.

� Hand hygiene before & after don/doff.

� Alert others if need to transfer

(in addition to Standard Precautions)

� Facemasks

� A facemask is a loose-fitting, disposable device that creates a physical barrier between the mouth and nose of the wearer and potential contaminants in the immediate environment.

N95 respirator

N95 respirator is a respiratory protective device designed to achieve a very close facial fit and very efficient filtration of airborne particles.

Meningitis epidemicaMeningococcal Disease

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Epidemiology

Pathogen: Neisseria meningitidis

Reservoir: Humans are the only natural reservoir of meningococcus

Source of infection: Ill person and asymptomatic carrier

Transmission: by respiratory droplet spread or by direct contact with nasal or throat secretions

Up to 5%–10% of people may be asymptomatic carriers with nasopharyngeal colonization by N. meningitidis.

Incubation period: 3-4 days (range 2-10 days)

Communicability: 1-2 days before onset, until pathogens are no longer present in discharges from nose and mouth 20

Incidence of meningococcal disease peaks among persons in three age groups:

� infants and children aged

Clinical Features

Abrupt onset of fever, meningeal symptoms, hypotension, and rash

Fatality rate 10%-15%, up to 40% in meningococcemia

� Meningococcal Meningitis: most common presentation of invasive disease

Result of hematogenous dissemination

Clinical findings: fever, headache, stiff neck

� Meningococcemia

Bloodstream infection

May occur with or without meningitis

Clinical findings: fever, petechial or purpuric rash, hypotension, shock, acute adrenal hemorrhage, multiorgan failure 22

Glass test: rash that does not fade under pressure is a sign of meningococcal septicaemia

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Methods of control

Control of patient, contacts and the immediate environment:

Report to local health authority: Obligatory case report in

most countries, (in Hungary immediate report)

Respiratory isolation for 24 hours after start of AB

Concurrent disinfection: Of discharges from the nose and

throat and articles soiled therewith. Terminal cleaning.

Protection of contacts: Close surveillance of household, daycare, and other intimate contacts for early signs of illness,

Prophylactic administration of antibiotic24

Preventive measures

Meningococcal Conjugate Vaccines (MenACWY)

Meningococcal B vaccine (rekombinant) - Bexsero

Meningococcal vaccination is recommended for persons at increased risk for meningococcal disease:

� infants

� adolescents/young adults

� microbiologists who are routinely exposed to isolates of N. meningitidis

� military recruits

� persons who travel to and reside in countries in which N. meningitides is hyperendemic or epidemic, particularly areas in the Sub-Saharan African “meningitis belt”

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Scarlet fever

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Scarlet fever is a form of streptococcal disease characterized by a skin rash, occurring when the infecting strain produces a pyrogenic exotoxin (erythrogenic toxin)

Pathogen: group A Streptococcus

Reservoir: Humans

Source of infection: Ill person and asymptomatic carrier

Transmission: by respiratory droplet spread or by direct contact

Incubation period: Short, usually 1–3 days, rarely longer

Communicability: In untreated, uncomplicated cases, 10–21 days; with adequate penicillin treatment, transmissibility generally ends within 24 hours

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Clinical Features

streptococcal sore throat, strawberry tongue, fever, rush (fine erythema, felt like sandpaper)

typically, the scarlet fever rash does not involve the face, but there is flushing of the cheeks and circumoral pallor

High fever, nausea and vomiting often accompany severe infections.

During convalescence, desquamation of the skin occurs at the tips of fingers and toes

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Circumoral pallor Strawberry tongue

Poststreptococcal sequelae:

� otitis media or peritonsillar abscess

� acute glomerulonephritis (1–5 weeks, mean 10 days)

� acute rheumatic fever (mean 19 days)

� rheumatic heart (valvular) disease occurs days to weeks after acute streptococcal infection

Most cases of scarlet fever occur in children under 10 (usually between 3 and 5 years of age)

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Methods of control

Control of patient, contacts and the immediate environment:

Report to local health authority: Obligatory case report in most countries (including Hungary )

Isolation: Drainage and secretion precautions may be terminated after 24 hours’ effective antibiotherapy; AB therapy should be continued for 10 days to avoid development of rheumatic heart disease

Concurrent disinfection: Of purulent discharges and all articles soiled therewith. Terminal cleaning.

Investigation of contacts and source of infection

Prevention: aspecific (higiene) 30

Varicella/Chickenpox

Background

� Infectious agent: Varicella-Zoster virus

� Source: ill person

� Mode of transmission: respiratory or direct contact with lesions

� incubation period: 14 to 16 days (range of 10 to 21 days)

� Clinical features: fever, rash (itchy, fluid-filled blisters that eventually turn into scabs in 1 week); the rash may first show up on the face, chest, and back then spread to the rest of the body, including inside the mouth, eyelids, or genital area

� Period of communicability: 1 to 2 days before the onset of rash until lesions have formed crusts

� Preventive measures: vaccination

• > 90% of population infected by 15 yrs

• attack rates 90% for household contacts

Complications:

– bacterial skin infections

– pneumonia

– encephalitis, post varicella cerebritis

Risk of death:

lower for children than infants

increases with age for adolescents/adults– 30% for perinatally exposed infants

– 2/100,000 aged 1-14

– 2.7/100,000 aged 15-19

– 25.2/100,000 aged 30-4933

Varicella vaccine

attenuated live virus vaccine

For: susceptible children above 1 year, susceptible women planning pregnancy

Contraindications: immunedeficiency

Efficacy

• 96-100% seroconversion within 4-6 weeks post vaccination

• > 90% with high titers after 20 years

• < 2% breakthrough of varicella - mild symptoms

Varicella in pregnancy

• ~2% transmission to fetus

• intrauterine infection more common in 1st trimester

• congenital infection: scarring, limb deformities, cataracts, CNS involvement, chorioretinitis

• neonatal or childhood zoster

Varicella in neonates

• during maternal varicella 24% of fetuses get transplacentally infected

• critical times

– in 5 days before to 2 days after birth

– neonates < 28 weeks gestation or

Influenza

Importance of Influenza

� One of the most important Emerging and Reemerging infectious diseases

� Causes high morbidity and mortality in communities (epidemic) and worldwide (pandemic)

� Epidemics are associated with excess mortality

Leading Causes of Deaths in the US

� Heart Disease

� Cancer

� CVD

� Chr Obst Lung Dis

� Accidents

� Pneumonia & Influenza

� Diabetes Mellitus

� HIV

� Suicide

� Homicide

Influenza

� Influenza is an acute respiratory illness characterized by fever, headache, myalgia, coryza, sore throat and cough. Cough is frequently severe and protracted.

� Duration of illness is usually 2-7 days.

� Infectious agent: Orthomyxoviridae - Influenza A, B és C

� Reservoir: human, animals (type A only)

� Transmission

� Incubation period 1-3 days

� Transmission: from person- to- person through respiratory secretions either as droplets (close contact) or as airborne infection by droplet nuclei suspended in the air.

� Incubation period 1-3 days

� Temporal pattern

�peak December - March in temperate climate

�may occur earlier or later

� Communicability: 1 day before to 5 days after onset (adults)

Diagnosis

Influenza infection causes a clinical syndrome not easily distinguished from other respiratory infections.

Influenza-like illness (ILI) case definition

An acute respiratory infection with:

measured fever of ≥ 38 C°

and cough;

with onset within the last 10 days

Since the clinical picture of influenza is nonspecific, its specific diagnosis –in case of need – is confirmed by laboratory tests, by virus isolation, identification of specific antigens or antibody rise

Antigenic Shift

� This term denotes MAJOR changes in hemagglutinin and neuraminidase resulting from reassortment of gene segments involving two different influenza viruses.

� When this occurs, worldwide epidemics may be the consequence since the entire population is susceptible to the virus.

Antigenic Drift & Shift

Antigen drift: MINOR changes in hemagglutinin and neuraminidase of influenza virus.

This results from mutation in the RNA segments coding for either the HA or NA

This involves no change in serotype; there is merely an alteration in amino acid sequence of HA or NA leading to change in antigenicity.

Antigen shift: MAJOR changes in hemagglutinin and neuraminidase resulting from reassortment of gene segments involving two different influenza viruses.

When this occurs, worldwide epidemics may be the consequence since the entire population is susceptible to the virus.

Known flu pandemics

Name of pandemic

Date DeathsCase fatality

rateSubtypeinvolved

1889–1890 flu pandemic(Asiatic or

Russian Flu)

1889–1890 1 million 0.15%possibly H3N8

or H2N2

1918 flu pandemic

(Spanish flu)1918–1920 20 to 100 million 2% H1N1

Asian Flu 1957–1958 1 to 1.5 million 0.13% H2N2

Hong Kong Flu 1968–1969 0.75 to 1 million

Types of Vaccine

� Inactivated, consisting of (1) whole-virus, (2) subvirion, (3) purified surface antigen. Only subvirion or purified antigen should be used in children. Any of the three can be used for adults. (TIV – trivalent)

�Live attenuated (LAIV) - nasal spray

Contraindications of LAIV (nasal) fluvaccine

� Children younger than 2 years

� Adults 50 years and older

� People with a history of severe allergic reaction to any component of the vaccine or to a previous dose of any influenza vaccine

� Children 2 years through 17 years of age who are receiving aspirin therapy or aspirin-containing therapy.

� Pregnant women

� People with weakened immune systems (immunosuppression)

Inactivated Influenza Vaccine Recommendations

� children 6 months through 4 years (59 months) of age

� Persons 50 yrs or older

� Persons with heart, pulmonary, renal and metabolic diseases

� Residents of nursing homes and other chronic-care facilities

� Persons 6 mos-18 yrs old receiving aspirin therapy (Reye-sy)

� Women who are or will be pregnant during the influenza season

� Household members of persons in high-risk groups

� Health care workers and others providing essential community services

CDC Influenza Vaccine Recommendation

Seasonal Influenza in Healthcare Settings

Multi-faceted approach

� Flu vaccine for HCWs

� Implementation of respiratory hygiene and cough etiquette

� HCWs with ILI stay home

� Source Control

Seasonal Influenza in Healthcare Settings: Isolation Precautions

� Droplet precautions for all patients with suspect influenza (ILI)

� ILI Temp >37.8 C (100 F) plus new cough or sore throat

� Ideally, place patients in single room

� Surgical mask for close patient contact

� Employer may allow N95 during routine care as option

� Patient should be transported with surgical mask.

Seasonal Influenza in Healthcare Settings: Isolation Precautions

� For aerosol-generating procedures: N95 respirator + standard precautions (gown, gloves, goggles for spray/splash)

� Aerosol generated procedures

� Sputum induction, bronchoscopy, elective intubation and extubation, autopsies

� CPR, emergent intubation, open suctioning of airways

Tubercolosis

TB as a Worldwide Public Health Issue

� World population ~ 6 billion

� ~ 1in 3 people in world infected

� ~ 9.4 million new cases of active TB/year

� 1.7 million deaths/year

� US population 280 million

� ~ 3-5% infected

� ~ 11,000 cases/year

� ~ 5-7% mortality

Estimated TB incidence rates

Natural History of TB Infection

Exposure to TB

No infection

(70-90%)Infection

(10-30%)

Latent TB

(90%)

Active TB

(10%)

Untreated

Die within 2 years Survive

Treated

Die Cured

Never develop

Active disease

Tuberculosis

� Infectious agent: Mycobakterium tuberculosis

� Mode of transmission: respiratory (rarely enteral)

� Incubation period: 2-12 weeks

� Clinical Features(pulmonary TB) a bad cough that lasts 3 weeks or longer; coughing up blood or sputum; weakness or fatigue, weight loss, no appetite, chills, fever, sweating at night

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Treatment

� Four or more drugs required for the simplest regimen

� 6-9 or more months of treatment required

� Person must be isolated until non-infectious

� Directly observed therapy to assure adherence/completion recommended

� Side effects and toxicity common

� May prolong treatment

� May prolong infectiousness

� Other medical and psychosocial conditions complicate therapy

� TB may be more severe

� Drug-drug interactions common

TB – continues as a public health issue in the world

� Old public health concepts (isolation of infectious

individuals, closely monitored treatment, recognition and

preventive treatment for infected contacts,) are still

critical, but will not eradicate TB

� Early diagnosis and prompt treatment especially of pulmonary disease

� Use of observed / supervised treatment where necessary

� BCG vaccine

Recommendations for BCG in UK

� Infants living in an area of the UK with an incidence of TB of 40 / 100,000 or greater

� All infants, children and young people aged up to under 16 years of age with a parent or grandparent born in a country where the annual incidence is 40 / 100,000 or greater (Hungary 11/100,000)

� Previously unvaccinated, tuberculin negative, contacts of cases of respiratory TB (follow NICE TB Guideline)

Recommendations for BCG (con)

� Previously unvaccinated, tuberculin-negative new entrants under 16 years of age who have lived for a prolonged period (at least 3 months) in a country with a high TB incidence

� Individuals at occupational risk (page 397, TB Chapter (Nov 2007), Green Book (note advice on HCWs)

� Travellers and those going to work abroad: may be required for previously unvaccinated, tuberculin negative, individuals aged under 16 going to live or work with local people in a country with a high incidence of TB

� Where vaccine requested: assess for specific risk factors for TB

BCG vaccine is good at:

� Protection of neonates and children against serious forms of primary disease such as meningeal and disseminated TB

� Protecting against death

Immunization coverage

Targeted Screening for TB

� The CDC recommends that the following should be screened for TB:

• Close contacts to individuals with active TB disease

• HIV Infected individuals

• Injection drugs users and users of other high risk substances

• Individuals with medical conditions that are at greater risk for TB

• Individuals/Employees in high risk congregate settings

• Healthcare workers who serve high-risk clients

• Individuals born in countries with high prevalence/incidence

• Infants and children exposed to high risk adults

• WDH recommends that all healthcare facilities conduct the CDC evaluation to determine the frequency for employee screening.

Surveillance

� Tbc must be reported (symptoms, lab tests-DNA)

� Contacts must be screened (tuberculin test for thoseunder 14 years of age, or those who had an X-ray less than threen months ago.

� Screening must be repeated in three months and oneyear.

Legionella

Background

July 21st, 1976: First Discovered at the American Legion Convention.

A thin and flagellated gram-negative bacterium.

Grows best in warm water sources such as: hot tubs, cooling towers, hot water tanks, large plumbing systems, or parts of the air-conditioning systems of large buildings.

� Pathogen: Legionella genus

� Source: warm freshwater environment

� Transmission: Inhalation of mist or vapor contaminated with the bacteria - NOT spread by human-human interaction!

� Incubation period: 2-10 days

� Opportunistic Disease: underlying illness/weak immune system.

� Nosocomial infections are major concerns.

� Middle-aged, elderly, COPD, smokers and other genetic susceptible patients are primary targets.

Symptoms

� Early Symptoms

� Malaise, muscle aches, lethargy and slight headaches.

� High Fever, non-productive cough, abdominal pain, diarrhea.

� Late Symptoms

� Extreme lethargy, comatose state

� Impaired kidney and liver functioning

� Nervous System disorders

Diagnosis

� Urinary Antigen Test

� The serogroup of Legionella often times overlap with other immunocompromised diseases.

� Culture

� Lung biopsy, respiratory secretions, sputum

� Less preferable technique

Prevention

� Regularly maintain and clean cooling towers and evaporative condensers to prevent growth of Legionnaires’ disease Bacteria (LDB). This should include twice-yearly cleaning and periodic use of chlorine or other effective biocide.

� Maintain domestic water heaters at 60°C (140°F). The temperature of the water should be 50°C (122°F) or higher at the faucet.

� Avoid conditions that allow water to stagnate. Large water-storage tanks exposed to sunlight can produce warm conditions favorable to high levels of LDB. Frequent flushing of unused water lines will help alleviate stagnation.

Diphtheria

Revised March 2002

Corynebacterium diphtheriae

� Aerobic gram-positive bacillus

� Toxin production occurs only when C. diphtheriaeinfected by virus (phage) carrying tox gene

Tonsillitis Diphtheria

Diphtheria Epidemiology

� Reservoir: Human carriers (Usually asymptomatic)

� Transmission: Respiratory (Skin and fomites rarely)

� Temporal pattern: Winter and spring

� Communicability: Transmission may occur as long as virulent bacilli are present in discharges and lesions. Effective antibiotic therapy promptly terminates shedding, without antibiotics, organisms usually persist 2 weeks or less and seldom more than 4 weeks.

Diphtheria Clinical Features

� Incubation period 2-5 days (range, 1-10 days)

�May involve any mucous membrane

�Classified based on site of infection� Anterior nasal

� Tonsillar and pharyngeal

� Laryngeal

� Cutaneous

� Ocular

� Genital

Pharyngeal and Tonsillar Diphtheria

� most common sites of diphtheria infection

early symptoms: malaise, sore throat, anorexia, and low-grade fever < 38°C(101°F).

-within 2-3 days, a bluish-white membrane - varying in size from covering a small patch on the tonsils to covering most of the soft palate

- extensive pseudomembrane formation may result in respiratory obstruction.

75

Pharyngeal and Tonsillar Diphtheria

Insidious onset of exudative pharyngitis

Exudate spreads over 2-3 days and may form adherent membrane

Membrane may cause respiratory obstruction

Fever usually not high but patient appears toxic

� Complications:

Most attributable to toxin

Severity of generally related to extent of local disease

Most common complications are myocarditis and neuritis

Death occurs in 5%-10% for respiratory disease

Diphtheria Toxoid Vaccine

� Formalin-inactivated diphtheria toxin

� Schedule: Four doses + boosterBooster every 10 years!

� Efficacy: Approximately 95%

� Duration: Approximately 10 years

� Should be administered with tetanus toxoid as DTaP, DT, or Td

Pertussis

Revised August 2002

Pertussis (whooping cough)

� Bordetella pertussis - Fastidious gram negative bacteria

� Incubation period 5-10 days (up to 21 days)

� Reservoir: human

� Transmission: Respiratory droplets (Airborne rare)

� Communicability Maximum in catarrhal stage

� Secondary attack rate: up to 90%

Pertussis Pathogenesis

� Attachment to cilia of ciliated epithelial cells in respiratory tract

� Pertussis antigens allow evasion of host defenses (lymphocytosis but impaired chemotaxis)

� Local tissue damage in respiratory tract

� Systemic disease may be toxin mediated

Pertussis Clinical Features

Clinical Features: Slow onset, similar to minor upper respiratory infection with nonspecific cough

Fever usually minimal throughout course

� Primary stage 1-2 weeks

� Paroxysmal cough stage 1-6 weeks

� Convalescence Weeks to months

Pertussis Complications

ConditionPneumonia 5,2%Seizures 0,8%Encephalopathy 0,1%Death 0,2%Hospitalization 20%

Cases reported to CDC 1997-2000 (N=28,187)

83

*Cases reported to CDC 1997-2000 (N=28,187)

Acellular Pertussis Vaccine

� Purified "subunit" vaccines

� Intended to reduce adverse reactions

� Together with Diphtheria and Tetanus vaccine(DTaP)

Maesles (Morbilli)

Paramyxovirus (RNA)

One antigenic type

Hemagglutinin important surface antigen

Rapidly inactivated by heat and light

Measles Virus

Measles Epidemiology

Reservoir - Human

Transmission –Respiratory, Airborne

Temporal pattern - Peak in late winter and spring

Incubation period – 10-12 days

Communicability: 4 days before to 4 days after rash onset

Measles Pathogenesis

Respiratory transmission of virus

Replication in nasopharynx and regional lymph nodes

Primary viremia 2-3 days after exposure

Secondary viremia 5-7 days after exposure with spread to tissues

Rash: 2-4 days after prodrome, 14 days after exposure

Maculopapular, becomes confluent

Begins on face and head

Persists 5-6 days

Fades in order of appearance

ConditionDiarrhea – 8%Otitis media – 7%Pneumonia – 6%Encephalitis – 0,1%Death – 0,2%Hospitalization -18%

Measles Complications

Measles Vaccine

Composition: Live virus

Efficacy: 95% (range, 90%-98%)

Duration of Immunity: Lifelong

Schedule: 2 doses

Should be administered with mumps and rubella as MMR

For infants >12 months of age (MMR given before 12 months is noteffective enough)

Mumps

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Mumps

Paramyxovirus - RNA virus, one antigenic type

Respiratory transmission of virus

Replication in nasopharynx and regional lymph nodes

Viremia 12-25 days after exposure with spread to tissues

Multiple tissues infected during viremia

Mumps Epidemiology

Reservoir: Human

Transmission: Respiratory drop nuclei (Subclinical infectionsmay transmit)

Temporal pattern: Peak in late winter and spring

Incubation period: 12-25 days

Communicability: Three days before to four days onset of active disease

Clinical Features

Nonspecific prodrome of low-grade fever, headache, malaise, myalgias

Parotitis in 30%-40%

Up to 20% of infections asymptomatic

May present as lower respiratory illness, particularly in preschool-aged children

CNS involvement: 15% of clinical casesOrchitis: 20-50% in post-pubertal malesPancreatitis 2-5%Deafness 1/20.000Death 1-3/10.000

Vaccination: Vaccine composition: Live virus Efficacy: 95% (Range, 90%-97%)Duration of immunity: LifelongAdministered with measles and rubella (MMR)

Mumps Complications

Rubella

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Rubella Epidemiology

Pathogen: Rubella virus

Reservoir: Human

Transmission Respiratory: Subclinical cases may transmit

Temporal pattern: Peak in late winter and spring

Communicability: 7 days before to 5-7 days after rash onset

Infants with CRS may shed virus for a year or more

Rubella Pathogenesis

Respiratory transmission of virus

Replication in nasopharynx and regional lymph nodes

Viremia 5-7 days after exposure with spread to tissues

Incubation period 14 days (range 12-23 days)

Symptoms are often mild, and up to 50% of infections may be subclinical or inapparent

Prodrome of low grade fever

Maculopapular rash 14-17 days after exposure

Lymphadenopathy may begin a week before the rash and last several weeks.

Rubella Complications

Arthralgia or arthritis

children

adult female

Thrombocytopenic purpura

Encephalitis

Neuritis

Orchitis

rare

up to 70%

1/3000 cases

1/5,000+ cases

rare

rare

Congenital Rubella Syndrome (CRS)

� Placenta and fetus infected during viremia

� Infection may affect all organs

� May lead to fetal death or premature delivery

� Severity of damage to fetus depends on gestational age

� Up to 85% of infants affected if infected during first trimester

Congenital Rubella Syndrome

Deafness

Cataracts

Heart defects

Microcephaly

Mental retardation

Bone alterations

Liver and spleen damage

Vaccination

Vaccine composition: Live virus

� Efficacy: 95% (Range, 90%-97%)

� Duration of immunity: Lifelong

� Administered with measles and rubella (MMR)

Strongly recommended for susceptible women planning pregnancy

Contraindications: immunedeficiency

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References

� CDC� 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings

http://www.cdc.gov/hicpac/2007IP/2007isolationPrecautions.html

� Guideline for Hand Hygiene in Health-Care Settings MMWR 2002; vol. 51, no. RR-16 http://www.cdc.gov/mmwr/PDF/rr/rr5116.pdf

� Cal/OSHA� Aerosol Transmissible Disease Standard http://www.dir.ca.gov/Title8/5199.html

� Appendix A http://www.dir.ca.gov/Title8/5199a.html

� Seasonal Influenza Infection Control Guidelines 2010� CDC: http://www.cdc.gov/flu/professionals/infectioncontrol/index.htm

� CDPH http://www.cdph.ca.gov/programs/immunize/Documents/CDPHGuidanceFluPreventionHCS20101105.pdf

� Cal/OSHA http://www.dir.ca.gov/dosh/Cal-OSHA_influenza_guidance_11-5-10.pdf

References

Infection Control of Aerosol Transmissible Diseases. California Department of Public Health

PANDEMIC INFLUENZA PLANNING: WHAT SCHOOLS NEED TO KNOW

Influenza: epidemiology, prevention and control. Tom D. Y. Chin

Herd Protection against Influenza. W P Glezen, P A Piedra, M J Gaglani

BCG Vaccination. Lika Nehaul

Tuberculosis: An Old Disease – New Twists, a Continuing Public Health Challenge. Jane Moore

Tuberculosis. Wyoming Department of Health Communicable Diseases

Chickenpox in Children, Adults and Pregnancy: What to do? Nayyar Raza Kazmi

Legionnaires’ Disease. Asif Khan

Thank you for your attention!