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Measles (Rubeola) Virus

Paramyxoviridaegenus Morbillivirus

Enveloped single-strandedRNA virus

Reservoir Host: HumanRelated Viruses

Canine distemperRinderpestPeste des petits ruminantsPhocine distemperDolphin distemperPorpoise distemper

Phylogeny of Known Morbilliviruses

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Measles Virus Genetic Variants

Measles Virus Genetic Groups

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Measles Epidemiology

Measles EpidemiologyResurgence Associated with Group 2 Virus

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Human Measles CasesVaccination Status

Measles (Rubeola) Virus InfectionTransmission: Aerosol droplet; direct contact with

nasal or throat secretions, fomitesHighly infectious virus

Disease: Similar in humans and nonhuman primatesMost species of primates are susceptibleIncubation period 7-14 daysInfectious period 1-2 days prior to onset of prodrometo ~ 4 days after appearance of rashSubclinical infections have been documented

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Measles VirusZoonotic Transmission

Measles Virus Infection

Clinical Measles Prodrome: 7-14 days after infection

Lasts 2-3 daysFever, malaise, anorexia, coryza, cough, conjunctivitis, Koplik spots

Rash: 3-7 days post onsetMaculopapular eruptionStarts on head/face – spread to trunk/limbs

becoming generalizedPersists 3-4 days

Leukopenia - common

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Measles Virus Pathogenesis

Measles Virus InfectionComplications and Sequelae

ComplicationsPrimary viral or secondary bacterial

Otitis mediaPneumoniaEncephalitisEnteritis

SequelaeSubacute Sclerosing Panencephalomyelitis (SSPE)

(Reactivation of latent MV?)

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Primary measles interstitial pneumonia and hemorrhage

Coalescing rash and inguinal lymphadenopathy

“Morbilliform” maculopapularrash in human and rhesusmacaque

Measles Virus Infection

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Measles Virus InfectionAtypical Koplik’s Spots in NHP

Koplik’s spots – pale areas of focal necrosis usually found in buccal mucosal epithelium

Measles Virus InfectionPathologic Features

Broad Tissue Tropism

Intranuclear inclusions

Formation of multinucleated “giant cells” (Syncytia)

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Measles Virus Immune Suppression

Impaired cellular immune function

Impaired humoral immune function

CNPRC Measles Outbreak, 1987

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Human Measles CasesCNPRC Measles Outbreak 1987

Employee; animal contact3-22-8722F5

Employee; animal contact3-7-8721F4

Employee; animal contact2-25-8727F3

Household contact case 12-8-8730M2

Employee; animal contact1-28-8728F1

ExposureOnsetAgeSexCase #

CNPRC Measles Outbreak 1987Epidemiologic Evidence of Monkey-to-Human Transmission

Case 3Exposed to confirmed monkey measles on 2/16/87Onset of measles on 2/25/87 (9 days)No known exposure to human cases (CNPRC or community). Worked only weekends

Case 4Exposed to confirmed monkey measles on 2/24/87Onset of measles on 3/7/87 (11 days)No known exposure to human case 3 or other human cases

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Measles Virus InfectionAbortions/Stillbirths Outdoor-housed Macaques

CNPRC 1984-1987

45.8551201986-87*

18.1311711985-86

21.6301691984-85

%Stillbirths/AbortionsPregnanciesBirth Year

*Measles outbreak

Measles Virus InfectionNeonatal* Mortality in Macaques

CNPRC 1984-1987

35.42365Outdoor

3.5385Indoor1986-87#

5.78140Outdoor

2.3143Indoor1985-86

5.07139Outdoor

0034Indoor1984-85

%Neonatal DeathsLive BirthsHousingBirth Season**

*Neonate = < 28 days of age** Through April of each year# Measles outbreak

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Measles Virus InfectionWild Nonhuman Primates

Measles virus antibodies found in wild NHP populations having human contact (low prevalence)

Possible introduction of measles into habituated troop of Mountain Gorillas 1988, 1990

Measles Virus InfectionTreatment and Prevention

No specific treatmentSupportive carePrevention of secondary bacterial infections

Natural infection confers life-long immunityVaccine preventable disease

Attenuated live MV vaccine (Attenuvax)Canine distemper-measles vaccine provides

protection against MV challenge in NHP*Attenuated live MV vaccine may be pathogenic

in New World monkeys

* Christe KL, et al. Comp Med 52:467-472; 2002;

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