Papillomavirus: HPV and Warts

Papillomavirus

• Papillomavirus belongs to the Papovavirus group
• Can induce tumors in susceptible hosts
• Possess the longest (slowest) growth cycle of the DNA viruses
• Causative organisms of benign papillomatous lesions of the skin and squamous mucosa, such as common and plantar warts, flat warts, cervical flat warts, and oral papillomas
• Laryngeal papillomas are dangerous in young children due to acute respiratory obstruction and recurrence
• Infections may be subclinical
• Cause Condylomata acuminata (anogenital warts)
• Infections occur throughout the lower female genital tract, often involving multiple sites like the cervix, vagina, and vulvar region
• Lesions called cervical intraepithelial neoplasia are associated with human papillomavirus infection
• Prevention includes avoiding sharing towels, shower shoes, and dressings to prevent cross-infection
• Sterilization of instruments used for examining and treating patients is crucial
• General STD control principles apply, including health education to avoid casual sex, use condoms, and seek medical attention for lesions
• Most warts regress spontaneously, but treatment may be sought for cosmetic purposes or discomfort
• Locally destructive techniques include cautery, surgical excision, and cryotherapy with liquid nitrogen

Alphaviruses

• Cause various syndromes ranging from benign febrile illnesses to severe systemic diseases with hemorrhagic manifestations or major organ involvement
• Viruses like Chikungunya, Mayaro, and Ross River, cause painful arthritis that can persist for weeks or months after the initial febrile illness
• Cause markedly different disease patterns
• Chikungunya virus causes acute (3- to 7-day) febrile illness with malaise, rash, severe arthralgias, and sometimes arthritis
• Mayaro and Ross River viruses cause similar or identical clinical manifestations as Chikungunya
• The virus is introduced by the bite of an infected mosquito, replicates, and causes a viremia
• Viremia coincides with abrupt onset of fever, chills, malaise, and joint aches
• Viremia subsides in 3 to 5 days, and antiviral antibodies appear in the blood within 1 to 4 days of the onset of symptoms
• A macular-papular rash typically develops around the third to fifth day of illness, when defervescing
• Migratory arthralgia mainly involves the small joints and occurs more prominently in adults than children
• In severe cases, the involved joints are swollen and tender, and rheumatic signs and symptoms may persist for weeks or months following the acute illness

Coronaviruses

• Coronaviruses are found in avian and mammalian species and cause various diseases in animals by invading different tissues
• In humans, they are only proven to cause mild upper respiratory infections such as common colds
• Infection waves pass through communities during winter months, causing small outbreaks
• Usually transmitted via inhalation of contaminated droplets but may also be transmitted by the hands to the mucosa of the nose or eyes
• Treatment remains symptomatic, though antiviral therapy has been attempted
• The likelihood of transmission can be reduced by practicing hygienic measures

Filoviruses

• Ebola hemorrhagic fever was first reported from northern Zaire and southern Sudan in 1976 when two distinct subtypes were isolated during simultaneous epidemics
• Classified as "Biological Level 4" agents (WHO; Risk Group 4) due to their high mortality rate, person-to-person transmission, aerosol infectivity, and absence of vaccines and chemotherapy
• Symptoms include sudden onset of fever, chills, headache, myalgia, and anorexia, followed by abdominal pain, sore throat, nausea, vomiting, cough, arthralgia, diarrhea, and pharyngeal and conjunctival vasodilatation
• A non-pruritic, maculopapular centripetal rash develops, associated with varying degrees of erythema, which desquamates by day five or seven of the illness
• Hemorrhagic manifestations develop at the peak of the illness, including bleeding into the gastrointestinal tract, petechiae, and hemorrhages from puncture wounds and mucous membranes
• In fatal cases, clinical signs occur early, and the patient dies between day six and 16, from hemorrhage and hypovolemic shock
• The mortality rate is between 30 and 90% (Ebola Zaire)

Flaviviruses

• Cause various syndromes, ranging from benign febrile illnesses to severe systemic diseases with hemorrhagic manifestations or major organ involvement
• Dengue fever causes fever-arthralgia-rash syndrome
• Viral replication occurs in macrophages at the site of the mosquito bite, in regional lymph nodes, and then throughout the reticuloendothelial system
• Viremia is concurrent with clinical illness
• Three clinical syndromes include dengue fever, dengue hemorrhagic fever, and dengue shock syndrome
• Dengue fever causes sudden onset of systemic toxicity, fever, headache, vomiting, and severe myalgia or bone pain of escalating intensity, lasting 3 to 9 days, is self-limiting, and is rarely associated with serious sequelae
• Following remittance of fever on days 3 to 5 of the illness, there appears a maculopapular or morbilliform rash on the trunk which spreads to the limbs and face
• Accompanied by recrudescence of fever, lymphadenopathy, granulocytopenia, and thrombocytopenia
• Minor mucocutaneous bleeding is occasionally manifested by petechiae, epistaxis, menorrhagia, and tourniquet test-positive
• Dengue hemorrhagic fever begins with an initial stage of fever, rash, and anorexia (lasting 3 to 5 days) followed by a shock phase in which hepatomegaly, hypotension, and a hemorrhagic diathesis occur
• Dengue shock syndrome is decreased plasma volume resulting from increased vascular permeability causes clinical shock that, if uncorrected, may lead to acidosis, hyperkalemia, and death

Orthomyxoviruses

• The classic influenza syndrome is a febrile illness of sudden onset, characterized by tracheitis and marked myalgias-headache, chills, fever, malaise, myalgias, anorexia, and sore throat appear suddenly
• The fever rapidly climbs to 101 to 104°F (38.3 to 40.0°C), and respiratory symptoms ensue including nonproductive cough, sneezing, rhinorrhea, pharyngeal inflammation, and nasal obstruction
• Other symptoms include photophobia, hoarseness, nausea, vomiting, diarrhea, and abdominal pain
• Symptoms predominantly include common cold-sneezing, nasal obstruction, and nasal discharge, upper respiratory illness - nasal obstruction, discharge, and sore throat, pharyngitis-sore throat with erythema, laryngitis-hoarseness, tracheobronchitis - cough and fever may be absent
• Respiratory and systemic symptoms generally last 1 to 5 days
• Complications include influenza pneumonia and secondary bacterial pneumonia
• Prevention includes the use of inactivated influenza virus vaccines while live attenuated vaccines are being developed as alternatives to inactivated vaccine