Viral Skin Infections PDF - Microbiology & Parasitology

MICROBIOLOGY AND PARASITOLOGY 09/03/2024. MOD 5: VIRAL SKIN INFECTIONS Ma. Teresa...

MICROBIOLOGY AND PARASITOLOGY 09/03/2024. MOD 5: VIRAL SKIN INFECTIONS Ma. Teresa A Barzaga, M.D., FPSP Trans Group: 9A, 10A I. INTRODUCTION ○ When culturing, ask the patient which lesions are Skin infections are caused by a wide variety of the newest. organisms and symptoms can vary from mild to serious. Viral skin infections are different from skin infections HERPES VIRUSES AFFECTING THE INTEGUMENTARY caused by bacteria or fungi but some of their symptoms SYSTEM may be similar. A major difference between viral skin infections and Designation Common (official name) Disease bacterial or fungal skin infections is that viral skin Name infections CAN’T be treated with antibiotics or antifungal drugs. Oral (fever blisters), Herpes simplex HHV-1 ocular lesions, virus 1 II. HERPESVIRIDAE encephalitis The members of the Herpesviridae family are large, *Genital, anal lesions; DNA-containing enveloped viruses. Herpes simplex HHV-2 severe neonatal OUTSTANDING CHARACTERISTICS: virus 2 infections, meningitis ○ Ability to establish lifelong persistent infections in their hosts (persist indefinitely in infected hosts) *Chickenpox (primary Varicella zoster ○ Undergo periodic reactivation (frequently HHV-3 infection) virus reactivated in immunosuppressed hosts) Shingles (reactivation) ○ Induce lifelong latent infections in natural hosts. An incompletely understood process. *Roseola in infants The virus resides in infected ganglia in a (primary infections) Human herpes nonreplicating state and only very few viral HHV-6 Infections in allograft virus 6 genes are expressed during this time. recipients (pneumonia, In 2006, a small RNA, called microRNA, was marrow failure) discovered to be encoded by a latency associated viral gene. This works to prevent III. HERPES SIMPLEX VIRUS cell death, maintaining the latent infection. Viral persistence in latently infected ganglia Among the most common infections affecting humans lasts for the lifetime of the host. Often annoying and troublesome ○ Some are cancer causing. Occasionally life threatening “Herpes” is derived from the greek word meaning “to creep” A. EPIDEMIOLOGY AND TRANSMISSION Clinical descriptions of herpes labialis go back to the Herpesviruses are fragile and do NOT survive for time of Hippocrates prolonged periods in the environment. Transmission generally requires inoculation of fresh virus – containing body fluid of an infected person HSV 1 HSV 2 directly onto the susceptible tissues (oral, ocular, genital Usual Etiologic Herpes Labialis Herpes Genitalis or anal mucosa, respiratory tract and bloodstream) of a Agent of Ocular Herpes previously uninfected person. Gingivostomatitis Viruses are transmitted when there is active viral Pharyngitis replication or during the course of primary infection or during reactivation. Age Specificity Frequently in Most frequently in of Primary infancy and early ages 14-29 B. DIAGNOSIS Infections childhood Can be made clinically Can be diagnosed by viral culture, serology, Transmission Close contact, Sexual or close polymerase chain reaction, Tzanck smear, or direct usually of face contact fluorescent antibody tests Serologic tests are used for diagnosing recent or Latency Occurs in Occurs primarily confirming past infections trigeminal in sacral ganglia Serial serologic tests of little value in chronic or recurrent ganglion infection Most are best diagnosed by virus culture Skin Lesions Skin lesions In internal, ○ Viral culture: standard diagnostic method external Tzanck smear: most rapid and inexpensive test genitalia; thighs; ○ CANNOT differentiate between herpes viruses buttocks including the Varicella zoster virus Detection of viral antigen or DNA These two viruses have some similarities: Vesicles contain the highest titer of virus in the first ○ Both have worldwide distribution 24-48 hours ○ Humans are the only natural reservoir Microbio and Para - Mod 5 Viral Skin Infections 1 of 10 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  ○ Transmission is promoted by direct exposure to be observed in 24-48 hours. secretions containing the virus ○ Virus remains infectious in moist secretions and Fluorescent inanimate objects for a few hours Antibody or Confirmatory Tests ○ Persons with active lesions are the most DNA Probe significant source of infection ○ Asymptomatic carriers can shed small numbers of Useful only for primary the virus infections and for those with Serology asymptomatic HSV-2 infections Recurrent infections have a TRANSMISSION 10% increase in titers. Mucocutaneous Person to person when active Herpes (HSV 1) lesions are present because fever PREVENTION blisters are contagious and through contact with contaminated objects Avoid contact Asymptomatic shedding may occur with individuals and be transmitted from saliva, Genitoherpes Occur when there are: with lesions urethra, and cervix by individuals with (HSV 2) Active lesions; or no evident lesions. In asymptomatic intravaginal lesions through: Safe sex practices Sexually Via semen Cesarean section for infected pregnant females Perinatally Passage in an infected birth canal IV. VARICELLA ZOSTER VIRUS In utero Through a small hole in the amniotic Causes two distinct clinical entities: membranes, in premature rupture of membranes or in congenital viremia of pregnancy VARICELLA ZOSTER Causative Agent Varicella-zoster virus Varicella or Herpes zoster or Disease chickenpox shingles Reactivation of a Follows primary latent virus within Infection contact with the dorsal root virus Lesions caused by HSV 1 with vesicles on denuded skin on ganglia the lips in Herpes labialis and stomatitis and buccal mucosa redness in Gingivostomatitis. Occurs in all ages Age Group Occurs in Affected Children persons seropositive for the virus Respiratory droplets Direct contact with (airborne) virus filled fluid of Direct Lesions caused by HSV 2 with vesicles in clusters in the Transmission skin lesions in contact with genital area of a female and penile head of a male in genital susceptible virus filled herpes. individuals fluid of skin lesions DIAGNOSIS OF HSV-1 and -2 Low-grade fever, To visualize the presence of Unilateral malaise, multinucleated giant cells and vesicular eruption Giemsa/ Wright/ pruritus; rash intranuclear eosinophilic Clinical with a dermatomal PAP stain of Manifestations (maculopapules, scrapings from inclusion bodies. distribution vesicles and base of lesions Tzanck Smear is indicative but (thoracic and scabs in varying (TZANCK SMEAR) NOT diagnostic of Herpes lumbar) stages) Simplex Viruses. Uses primary cell lines such as A. VARICELLA monkey kidney cells inoculated More commonly called chicken pox with specimens from the lesions, Primary infection and results from exposure of a Culture throat, washings, cerebrospinal susceptible individual to the virus fluid and stool. Characterized clinically by a generalized vesicular Cytopathogenic effects should eruption of the skin and the mucous membranes Microbio and Para - Mod 5 🏠 Viral Skin Infections 2 of 10 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  Occur chiefly on children ○ Isolation in cell culture Initial symptoms include: ○ Tzanck smear (showing ○ Sudden onset of fever multinucleated giant cells in ○ Headache scrapings from base of lesion) ○ Feeling tired ○ Direct fluorescent antibody ○ Itchy blister-like rash usually starting on the face stain of scrapings from lesions The rash spreads to the chest or back 1-2 ○ Serology of acute and days later. convalescent serum samples The rash then spreads to the rest of the body and new blisters continue to appear for about Prevention Live attenuated virus vaccines 3-4 days. and Control Avoid direct contact with infected Generally, within 1 week the blisters dry out person and scabs form and fall off. Cover the rash Vesicles in varicella or chickenpox occur in different Avoid touching or scratching the stages of evolution at the same time including intact rash vesicles, ruptured vesicles, and crusts. Clean hands often ○ Vesicles are often on an irregular area of Rigid isolated precautions for erythema leading to dew drop on a rose petal hospitalized cases appearance. B. ZOSTER V. HUMAN HERPES VIRUS 6 Also called shingles “Roseola rash” Reactivation of primary infection Infections typically occur in early childhood Characterized by a rash histopathologically identical Transmission: saliva (epidemiologically proven source) to those of Varicella ○ The virus replicates in the salivary gland and is Limited in distribution to skin innervated by a single secreted in the saliva sensory ganglion Causes exanthem subitum (roseola infantum or Common infection among the elderly “Sixth disease”) characterized by: Initial symptoms include: ○ A generalized benign (maculopapular) rash on ○ Tingling feeling on the skin trunk and neck of infants and young children within ○ Itchiness or stabbing pain 48 hours ○ After several days, a rash appears beginning as a ○ Accompanied with 3-5 days high fever band or patch of raised dots on the side of the ○ With or without mild upper respiratory tract infection trunk or face or other areas of the body. and cervical lymphadenopathy It develops into small fluid-filled blisters ○ The classic rash of Roseola is rose colored as the which begin to dry out and crust over within a name implies and is distinctive. few days. It begins as discrete, small, 2-5 mm, ○ When the rash is at its peak, symptoms can range slightly-raised pink lesions on the trunk, from mild itching to extreme and intense pain. The and usually spreads on neck, face, and rash and pain usually disappear within 3-5 weeks. proximal extremity. It is not usually pruritic with no vesicles or pustules developed. Produces latent infection in T cells ○ HHV-6 genome persists in host cells in a latent state after resolution of primary infection. ○ This makes it an important pathogen in organ transplant recipients as a serologic reactivation. Varicella or chickenpox (Left) & Herpes Zoster or Shingles (Right). Classic rash of Roseola. Herpes Zoster or Shingles vesicular rash which is VI. HUMAN PARVOVIRUS B19 dermatomal in distribution, most often thoracic, CN V, and CN VII. This viral disease is transmitted from person to person ○ If there is ophthalmic distribution, cornea should that usually occurs around late winter to early spring. be examined. ○ Local outbreaks tend to be cyclical. ○ Affects all ages and ethnic groups Targets cells that mature into RBCs VARICELLA ZOSTER Most common manifestation: erythema infectiosum (“Fifth Disease”) Diagnosis Clinically: history & physical ○ A mild rash illness that commonly affects children examination of early school age and occasionally affects adults. Laboratory Microbio and Para - Mod 5 🏠 Viral Skin Infections 3 of 10 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  ○ Blotchy or raised red rash or a “slapped cheek” appearance on the face and a lacelike rash on the limbs and trunk which fades after 2-4 days Rashes usually occur on the cheeks or chin Modes of transmission ○ Respiratory route — through respiratory secretions such as saliva, sputum or nasal mucus, when an infected person coughs or sneezes ○ Blood transfusion — through blood or blood product ○ Vertically — pregnant mother to baby Warts produced by papillomavirus. B. MODES OF TRANSMISSION 1 Direct contact with warts Slapped Cheek Red Rash. 2 Indirect contact with fomites VII. PAPILLOMAVIRUSES 3 By autoinoculation A. EPIDEMIOLOGY AND PATHOLOGY Widespread throughout the population Produces epithelial tumors of the skin and mucous C. DIAGNOSIS membranes Have been closely associated with genital tract 1 Clinical diagnosis is possible due to the distinctive malignancies character of warts. They cause infections at cutaneous and mucosal sites sometimes leading to the development of various 2 Biopsy and histologic examination may be needed in types of warts including: some ambiguous cases. 1 common Painless, elevated rough growths or seed on the fingers D. TREATMENT warts Represents 71% of all cutaneous warts 1 Chemical Podophyllin Occurs frequently among school application of Fluorouracil (5FU) aged children cytotoxins Trichloroacetic acid (TCA) 2 plantar Painful deep papillomas at the 2 Electrocautery Used for cervical lesions warts soles of the feet Less common Observed frequently among Recurrences are common after cessation of treatment adolescents and young adults due to the survival of the virus in the basal layers of the epidermis. 3 flat or Smooth, skin-colored lesions on juvenile the face, trunk, elbows and knees E. PREVENTION AND CONTROL warts Least common For prevention and control of cervical cancer Occur predominantly in children 1 Papanicolau Detection of precancerous cellular 4 genital Prevalent sexually transmitted smear changes allowing for lesion removal warts disease linked to some types of prior to cancer cancer Also known as Condylomata 2 HPV vaccine Recommended to be given to acuminata adolescent and young adult Most common viral sexually males transmitted disease in the United Consists of non-infectious States recombinant virus-like The virus invades the internal and particles composed of HPV external genital membranes prone proteins to friction such as vagina and penile head. TYPES OF HPV VACCINES 1 Bivalent Contains type 16 and 18 Microbio and Para - Mod 5 🏠 Viral Skin Infections 4 of 10 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  2 Quadrivalent Contains type 6, 11, 16, and 18 ○ Scientific advances have made it possible to create smallpox in the lab 3 Ninevalent Contains type 6, 11, 16, 18, 31, 33, ○ Led to concerns that it may be used as a 45, 52, and 58 bioweapon someday Initial targets are adolescent young females and males. 1. TRANSMISSION Directly from person to person ○ Coughing, sneezing, or talking VIII. POXVIRUSES ○ Skin-to-skin contact Indirectly from an infected person A. CLASSIFICATION AND STRUCTURE ○ Rarely, spread through the air inside buildings The largest and most complex of the animal viruses Through contaminated item (fomites) They are brick-shaped or ovoid, enveloped, ○ Clothing and beddings double-stranded DNA viruses ○ Least likely to get smallpox this way Multiply in the cytoplasm in well-defined sites called As a terrorist weapon, potentially (unlikely threat) factory areas which appear as inclusion bodies called ○ Releasing the virus could spread quickly which is Guarnieri’s bodies why the government is preparing for this possibility Poxviruses produce eruptive skin pustules called pocks or pox which leave small, depressed scars 2. CLINICAL MANIFESTATIONS ○ These infections typically result in the formation of Flu-like symptoms: fever, muscle aches, headache, lesions, skin nodules, or disseminated rash. severe fatigue, severe back pain Common feature of all poxvirus infections: specificity ○ Occurs suddenly after the incubation period for the cytoplasm of epidermal cells and Rash begins in pharynx, spreads to face then subcutaneous connective tissue extremities (happens a few days later) The poxvirus family includes a large number of related ○ Mouth and tongue → skin of the face, arms, and DNA viruses that infect various vertebrate hosts. legs first → torso, hands, and feet Initially macular → papular → vesicular → pustular → GENUS SPECIES HUMAN DISEASE crusting over → nonpigmented sites pitted with scar ○ Within a day or two, many of the spots turn into Ortho- Variola (variola major) Smallpox small blisters filled with clear fluid, then later it is poxvirus filled with pus Monkeypox Smallpox-like Pustules: sores/blisters filled with pus (Zoonotic monkeypox virus) ○ Scabs form 8-9 days later and eventually, fall-off Vaccina leaving deep-pitted non pigmented scars Local pox lesions Cowpox Mollusci- Molluscum contagiosum poxvirus Para- Contagious poxvirus pustular Orf dermatitis, local pox lesions Pseudocowpox Milker’s nodule Yata- Tanapox Local pox lesions poxvirus Lesions of Smallpox. After the incubation period, sudden flu-like symptoms occur. A few days later, flat, red spots Infections with orthopoxviruses: smallpox or variola appear on the body. major virus and the zoonotic monkeypox virus, can result in systemic, potentially lethal human disease Other poxvirus infections cause primarily localized skin SMALLPOX RASH PROGRESSION disease in humans The genus Orthopoxvirus contains a number of Macular Flat, red spots species that can affect animals and humans Papular Raised, red spots B. SMALLPOX (VARIOLA) Most well-known from the genus Orthopoxvirus Vesicular Raised, containing clear fluid sores/blisters Serious, contagious, and sometimes, fatal infectious disease Pustular Raised, pus-containing sores/blisters One of the deadliest infectious diseases Considered to be a disease of the past 3. TREATMENT & PREVENTION ○ It has affected humans for thousands of years ○ But was wiped out worldwide by 1980 with the help There is no specific treatment for smallpox disease of smallpox vaccines and the ONLY PREVENTION is vaccination ○ No longer found naturally in the world Smallpox vaccines can provide protection: ○ Last naturally occurring case in the world was in ○ Lasting for 10 years Somalia in 1977 ○ Against similar viral infections (e.g. monkeypox Now presently exist only in research labs as samples and cowpox) Microbio and Para - Mod 5 🏠 Viral Skin Infections 5 of 10 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  Vaccine is no longer given and not required for travel because: ○ Fatigue/exhaustion ○ Smallpox is no longer a threat ○ Intense headaches ○ Vaccine complications especially in the ○ Swelling of lymph nodes immunocompromised and allergic person ○ Muscle aches and backache (encephalitis, fever, headache, gangrene, rashes, ○ Sore throat and sometimes, paralysis) ○ Nasal congestion ○ Cough Swelling of lymph nodes aka IX. OTHER POXVIRUS INFECTIONS lymphadenopathy ○ Prominent feature of monkeypox A. MONKEYPOX (ZOONOTIC INFECTION) ○ Distinguishes it from other Important current infection that we have worldwide illnesses that appear similar to it Named after the animal from which it was originally such as chicken pox, measles, isolated and smallpox (WHO) It first caused a smallpox-like disease in monkeys in 1958, in which the virus was also later found in rodents 2 Second Starts 1 to 3 days after the but the latter did not manifest any disease Stage appearance of fever Primary viral reservoir: rodents Infected person develops a rash, ○ Rodents: mammals (examples: rats, mouse, which is concentrated on the face hamsters, prairie dogs, guinea pigs, squirrels) and extremities Human infections with monkeypox virus typically occur in Africa Mnemonic: First Fever, Second raSh 1. TRANSMISSION Mainly by direct contact with an infected 2.1 Flu-Like Symptoms as Monkeypox Manifestation animal/person or their fluids Sometimes people have flu-like symptoms BEFORE the rash MONKEYPOX MODE OF TRANSMISSION The first stage does not only include a fever but also upper respiratory tract manifestations Contact By scratching or biting of an with infected animal 2.2 Rashes of Monkeypox infected By preparing or eating meat from 1 Characterized by a systemic illness and a vesicular animals an infected animal By using products from an rash (rash similar to variola or smallpox) infected animal In the majority of cases, the virus affects the following: ○ Face Close, Direct contact with monkeypox ○ Palms of the hands personal, rash, scabs, or body fluids from a ○ Soles of the feet skin to person with monkeypox May be located on or near the genitals (penis, skin Touching objects or fabrics (e.g. testicles, labia, and vagina) or anus (butthole) 2 contact clothing, beddings, towels) and ○ Could also be on other areas like the hands, feet, surfaces used by an infected chest, face, or mouth person During past outbreaks, the rash typically started on the Contact with their respiratory face and spread to many areas of the body. secretions ○ During this outbreak in 2022, the rash may start on the groin, genital region, or around the anus and Direct Oral, anal, or vaginal sex sometimes stay in the spot where it started instead contact Touching the genitals or anus of spreading. (i.e. Hugging, massaging, kissing, and People may have only one or two bumps on their skin intimate prolonged face to face contact ○ These bumps may look like a blister, pus-filled sexual Touching fabrics and objects bump or open sore 3 Monkey-pox rash can be mistaken for chickenpox, contact) during sex that were used by a person with monkeypox and that shingles or herpes. have not been disinfected ○ There are differences in the pattern on the skin and ○ e.g. beddings, towels, fetish where the rash appears gear, sex toys ○ Compared to the lesions of herpes virus infection and varicella zoster virus infection, monkey pox Vertical A pregnant person can also spread the lesions tend to be more uniform (i.e. in the same 4 stage of development), diffused, and peripheral in virus to their fetus through the placenta distribution. 2. MANIFESTATIONS One may experience all or only a few symptoms MONKEYPOX MANIFESTATIONS 1 First Lasts for up to 5 days Stage Patients experience: ○ Fever/chills Microbio and Para - Mod 5 🏠 Viral Skin Infections 6 of 10 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  5.1 Transmission (From Technical Report) Monkeypox can spread between people through close contact, skin to skin contact including sexual contact with infected persons, or contact with contaminated fomites (e.g., shared linens). Anyone can catch monkeypox if they have close contact with someone who has the virus regardless of gender, identity, or sexual orientation. ○ However, most of those affected in the current global outbreaks are gay, bisexual, or other men who have sex with men. 5.2 Features (From Technical Report) Lesions of monkeypox. Note the sharply raised lesions filled with opaque yellowish fluid on the hands and Distinguishing features in the current outbreak include: extremities. ○ Papules ○ Vesicles 3. LABORATORY DIAGNOSIS ○ Pustules Procedures and materials used for collecting ○ Scabs that are deep-seated, firm, or rubbery with specimens may vary depending on the phase of the well-defined round borders rash (e.g. swab of lesion’s surface or crust from healing ○ Lesions can sometimes be umbilicated (i.e., have lesion). a dent in the middle) These features may be painful, painless, or itchy 3.1 Initial Laboratory Testing of Monkeypox Virus People with monkeypox may develop symptoms, Specimen including: ○ Fever Recommended specimen: lesion material, such as: ○ Headache ○ Dry swabs of lesion material ○ Muscle aches ○ Swabs of lesion material in viral transport media ○ Exhaustion ○ Crust from healing lesions is also acceptable ○ Swollen lymph nodes Reference laboratory testing requires that specimens be placed on dry ice. B. MOLLUSCUM CONTAGIOSUM Preferred laboratory test (molecular detection tests): Primary pox virus that affects humans Polymerase Chain Reaction (PCR) testing of samples Distributed throughout the world with highest incidence from skin lesions in certain Pacific islands ○ Polymerase Chain Reaction Blood Tests are Primarily an infection of children usually inconclusive because the virus remains in blood only at a short time. 1. TRANSMISSION To interpret test results, the following information is required: Often transmitted sexually or via contact sports ○ Date of onset of fever ○ Sexual intercourse in adult with lesions occurring on ○ Date of onset of rash the pubic and genital region ○ Date of specimen collection It is spread by skin-to-skin contact and fomites or via ○ Current stage of the rash autoinoculation (e.g., sharing of towels) ○ Patient’s age 2. CLINICAL MANIFESTATIONS 4. TREATMENT NO specific treatment The typical lesions are a papular rash or pearly, waxy, Monkeypox is genetically similar to smallpox viruses, umbilicated nodules in the skin or mucosa which hence antiviral drugs and vaccines developed to protect results from epidermal hyperplasia. against smallpox may be used to prevent and treat it ○ A cheesy material may be expressed from the ○ Antiviral drugs such as Tecovirimat (TPOXX) may pore–at the center of each lesion be recommended for people who are more likely to ○ Nodular, pale, firm (pearl-like) painless and get severely ill (e.g., patients with weakened umbilicated lesions immune systems) Lesions can occur anywhere in the body with the EXCEPTION on the palms or soles. 5. TECHNICAL REPORT: MULTI-NATIONAL MONKEYPOX ○ Most are commonly found on the neck, trunk, OUTBREAK, UNITED STATES, 2022 genital areas, and thighs. On July 23, 2022, the World Health Organization (WHO) 3. TREATMENT declared the escalating global monkeypox outbreak as a public health emergency of international concern. Generally self-limiting ○ Currently, the vast majority of reported cases are in ○ Lesions may disappear in 2-12 months without the WHO European Region. treatment. As of July 25, 2022, scientists at the US Centers for If treatments are needed or desired, options are Disease Control and Prevention (CDC), along with state cryotherapy, curettage, laser or photo or beam and local public health partners, are tracking 3,487 therapies, and topical treatments cases of monkeypox in the United States. ○ The CDC is also tracking multiple clusters of 4. PREVENTION monkeypox that have been reported globally in 69 countries that do not normally report monkeypox. Keeping your hands clean; which is the best way to avoid Molluscum infection. Microbio and Para - Mod 5 🏠 Viral Skin Infections 7 of 10 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  Don’t scratch or pick at molluscum lesions. 6 Sore throat It is best to keep the area of lesion/s clean and covered with clothes or bandages so others won’t be 7 Headache able to touch the lesion and become infected. Don’t share personal items, such as unwashed 8 Lymphadenitis clothes, hairbrushes, wristwatches and bar soap with others. The rash starts at the head and spreads to the chest, If there are lesions on or near the penis, vulva, vagina, trunk, and limbs or anus–avoid sexual activities. Appear as light pink discrete maculopapules that coalesce to form blotches becoming brownish in 5-10 days. The rash shows up first with a red flat rash, starting on the face and neck. It then begins to appear more solid and spreads to the trunk and arms in 2-3 days. 2.2 Signs KOPLIK’S SPOTS: pathognomonic for measles ○ Koplik spots (on lateral buccal mucosa) appear as a prelude to the red maculopapular exanthem that erupts on the head which progresses to the trunk and extremities. ○ Tiny white spots, often on a reddened background that occur on the inside of the cheeks early in the course of measles (2-3 days after symptoms begin) Typical spots of Molluscum contagiosum on the face and ○ The lower left image shows the rash in measles genital areas. which shows up first with a red, flat rash starting on the face and neck, then begins to appear more solid C. MEASLES VIRUS and spreads to the trunk and arms in 2-3 days. Also called red measles and RUBEOLA Entirely UNRELATED to rubella (German measles) Rare under 6 months of age: transplacental IgG Epidemic spread favored by crowding, a prevalence of nonimmune children, and malnutrition NO reservoir other than humans Measles has been recognized as a disease for some two-thousand years but the infectious nature of the illness was not recognized until about 150 years ago It is a highly infectious disease that is usually seen in children, and is caused by the rubeola virus. The illness is characterized by cough, coryza, fever, and a maculopapular rash. 1. TRANSMISSION Gain access to the body via the respiratory tract Koplik’s Spots. ○ Transmitted principally by direct contact with respiratory aerosols 3. COMPLICATIONS ○ Remain infective in droplet form in air for several hours (especially under conditions of low In most instances, measles is a self-limited infection, humidity) but may be severe enough to cause death in about 1 Person is considered infectious during periods of in 500 children. incubation, prodrome, and skin rash Single attack confers lifelong immunity 1 Laryngitis 2. CLINICAL MANIFESTATIONS 2 Bronchopneumonia Characterized by maculopapular eruption, URTI, 3 Bronchitis conjunctivitis Incubation period: 2 weeks 4 Pneumonitis 2.1 Symptoms 5 Bacterial secondary infections 6 Sinusitis 1 Rash 2 Dry cough 7 Bacterial pneumonia 3 Runny nose 8 Otitis media 4 Eye irritation/Conjunctivitis 9 Post-infectious encephalitis 5 Fever Subacute Sclerosing Panencephalitis (SSPE) Microbio and Para - Mod 5 🏠 Viral Skin Infections 8 of 10 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  ○ A rare complication in the CNS 1. IMMUNITY ○ Manifests 5-7 years after initial infection, due to Persons who have received the rubella vaccine do failure of viral replication which is related to NOT transmit rubella to others mutations of the gene encoding the M protein There is lifelong immunity for most persons but reinfections may occur 4. DIAGNOSIS 2. REINFECTIONS Made clinically by: ○ Age and history of recent exposure to measles Documented by a significant boost in rubella (which are useful tools for diagnosis) antibody titer in naturally immune persons ○ Cough, coryza, conjunctivitis, Koplik’s spots, and a reexposed to rubella maculopapular rash beginning on the face More common in vaccinated people than in persons In the laboratory, diagnosis of measles is done via: who had natural rubella ○ Virus isolation ○ Identification of measles antigen in infected B. CLINICAL MANIFESTATIONS tissues Prodrome of body malaise, fever, and anorexia for ○ Immunofluorescence using nasal exudates or several days urine sediments ○ May be accompanied by mild coryza and ○ Reverse transcriptase PCR conjunctivitis ○ Demonstration of a specific serologic response Maculopapular rash that begins on the face and moves down the body 5. PREVENTION AND CONTROL Adenopathy of posterior auricular, posterior cervical, and suboccipital node Symptomatic treatment is done for most cases Forscheimer spots: lesions on the soft palate but is ○ Antibiotics may be given for bacterial NOT diagnostic of rubella (unlike Koplik spots in complications Measles) ○ Large doses of immunoglobulin may be ○ Small, red spots or petechiae on the soft palate therapeutic in 20% of patients with rubella Prevention involves vaccination, which is the most practical, economical, and enduring strategy to combat measles X. RUBELLA VIRUS A contagious viral infection best known by its distinctive red rash It is also called German Measles or 3-Day Measles While this infection may cause mild- to no symptoms (in most cases), it can cause serious problems for unborn babies whose mothers became infected during pregnancy Link between maternal rubella and certain congenital defects were recognized in 1941 Common in ages 5-9 years old Maculopapular Rash (Left) & Forscheimer Spots (Right). ○ Now being seen with increasing frequency in the older age group because of the widespread use of 1. CONGENITAL RUBELLA SYNDROME rubella vaccine Rubella virus can be disastrous in early gestation Can lead to fetal death, premature delivery, and an A. TRANSMISSION array of congenital defects Occurs in a developing fetus of a pregnant woman who has contracted rubella RUBELLA VIRUS MODE OF TRANSMISSION The younger the fetus = the more severe the illness ○ Severity of illness depends on the timing of infection 1 Droplet Via respiratory secretion of Infection infected persons CONGENITAL RUBELLA SYNDROME MANIFESTATIONS Most contagious point: when rash is erupting 1 2-month 65 - 85% chance of fetus either being: Shed the virus from the throat AOG Spontaneously aborted; or from 10 days before onset of Developing multiple congenital rash to 15 days after defects 2 Can occur with subclinical illness 2 3rd month 30 - 35% chance of developing a Patients with subclinical illness may transmit the disease of fetal life single defect such as: Deafness 3 Transmitted Infants with congenital rubella shed Cataract or glaucoma by congenital large quantities of virus from Congenital heart disease rubella body secretions for many months patients (may transmit virus to those who 3 4-month 10% risk of single congenital defect care for them) AOG CLASSIC TRIAD OF CONGENITAL RUBELLA SYNDROME Microbio and Para - Mod 5 🏠 Viral Skin Infections 9 of 10 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.  1 Sensorineural deafness ○ More common in adult females over 25 yrs ○ 40% of vaccines may develop this complication but 2 Eye abnormalities (retinopathy, cataract, glaucoma, they are transient microphthalmia) 3 Congenital heart disease (pulmonary artery stenosis, patent ductus arteriosus) Common manifestations of Congenital Rubella: ○ low birth weight ( temporary) ○ deafness ○ cataract or glaucoma ○ congenital heart disease ○ mental retardation Pathologic mechanisms to explain manifestations: a. Persistent infection with rubella virus leads to mitotic arrest of cell leading to inhibition of cell growth → retarded organ growth b. Increased frequency of chromosomal breakage in cultured cell from children with congenital rubella c. Infection of various types of cells during gestation interferes with normal balance of growth and differentiation → defective organogenesis d. Lymphocytic abnormalities in patients may predispose them to organ-specific autoimmunity C. DIAGNOSIS Done by virus isolation from (acceptable methods for diagnosis): ○ Throat swab ○ Urine ○ Synovial Fluid ○ Other body secretions Diagnosis is usually made serologically (IgM or IgG), either by: ○ Acute rubella infection may be diagnosed either by: Demonstration of specific IgM in one serum sample; or A 4-fold greater increase in rubella antibody titer in acute and convalescent specimens assayed in the same test. Diagnosis of congenital rubella: virus isolation ○ From throat swabs, urine, synovial fluid and other body secretions ○ From amniotic fluid ○ Drawback of isolation method: time-consuming and expensive. Hence, reserved only for special circumstances (e.g. investigation of arthritis,and complications of postnatal rubella) D. PREVENTION AND CONTROL A live attenuated vaccine has been in use since 1969 ○ Available as a single antigen or combined with measles and mumps vaccines. ○ Induces life-long immunity (seroconversion rate) in at least 95% of recipients. ○ Rationale for its use: Prevent congenital rubella by controlling postnatal rubella ○ Caused a decline in the number of reported cases of clinical rubella ○ The risk of acquiring congenital rubella in vaccinated pregnant women is 2%. It is advised that women who are vaccinated against rubella should not become pregnant for at least three months after the vaccine has been administered. COMPLICATIONS ○ May cause viremia: fever, adenopathy, arthritis and arthralgia Microbio and Para - Mod 5 🏠 Viral Skin Infections 10 of 10 The use of trans, practice questions, and evals ratio must be used discreetly and social media/public exposure of the aforementioned shall be strictly prohibited.