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Viral Infections in HIV Disease
Published in Clay J. Cockerell, Antoanella Calame, Cutaneous Manifestations of HIV Disease, 2012
Wei Su, Cindy Berthelot, Clay J. Cockerell
Molluscum contagiosum (MC) is a viral infection almost universally encountered in sexually active individuals with HIV. Although most lesions are self-limiting, patients with weakened immune systems have increased difficulty clearing lesions, which may persist for prolonged periods. The association between MC and HIV was first noticed in 1983 through an autopsy study of 10 patients with AIDS.22 MC has surfaced as one of the three most common reasons nondermatologists referred HIV patients to a university-based immunosuppression skin clinic.23 Molluscum contagiosum virus (MCV) is present worldwide and is passed by direct skin-to-skin contact to produce cutaneous, and rarely, mucosal lesions. It occurs predominately in preadolescent children, sexually active adults, participants in sports with skin-to-skin contact, and in individuals with impaired cellular immunity.
Other Sexually Transmitted Diseases of the Vulva and the Vagina
Published in William J. Ledger, Steven S. Witkin, Vulvovaginal Infections, 2017
William J. Ledger, Steven S. Witkin
Molluscum contagiosum is a disease caused by the molluscum contagiosum virus (MCV), a member of the poxvirus family. It is a double-stranded DNA virus enclosed in a lipoprotein coat. The virus solely infects keratinocytes in the skin. Although transmission between individuals by direct skin-to-skin contact is common and may occur at a variety of sites including the genital tract in healthy individuals, its lesions are most prevalent and increased in size in immunosuppressed people. MCV infection can be a problem in HIV-infected individuals who have not received an adequate retroviral regimen. Four known types of MCV have been identified, with MCV-1 most prevalent in healthy humans and MCV-2 most common in HIV-infected individuals.7 The typical lesions are small projections with a waxy appearance and exhibit little or no inflammation. They can persist for varying periods of time ranging from weeks to months to years. Many individuals with no known exposure to this virus and with no apparent lesions have been shown to be positive for MCV antibodies. The presence of high antibody titers in individuals with persistent infections suggest that the antibodies are not protective. The increased rate of MCV appearance in immunocompromised individuals strongly suggests that the host immune response limits infection. MCV induces production of antiviral type 1 interferons.8 Other immune compounds known to be present in MCV lesions include β-defensin 3, tumor necrosis factor-α,9,10 and toll-like receptors 3 and 9.10 MCV proteins have been shown to inhibit apoptosis of infected cells, block phagocytic cells from migrating to the site of infection, and inhibit interleukin-1811 and interferon gene12 activation. There is no FDA-approved treatment for MCV infection.
Eyelid and Orbital Involvement in HIV Infection – An African Perspective
Published in Ocular Immunology and Inflammation, 2020
MC is caused by a virus belonging to the family Poxviridae which is referred to as the molluscum contagiosum virus (MCV). The family is genetically subdivided into four subtypes, but in developed countries, the genotype 1 predominates.11 Other genotypes are more common in HIV-infected persons, but the clinical manifestations are similar. Transmission is by direct skin contact, is specific to humans, has been reported globally and is more prevalent in sexually active persons and contact sports participants. In healthy immunocompetent subjects, MCV causes an eruption with small, raised, white or pearly colored lesions with a pit in the center which is mostly mild and benign. The eruption is often asymptomatic or at worst irritating, itchy and red. It may occur anywhere on the body in discrete singular or multiple papules. Mucosal lesions are rare. In this group of individuals, the eruption typically abates within 6–12 months.11 The incidence peaks in pre-school children. In a group of 302 non-HIV infected pediatric patients seen over a 6–8 month period, 80% of the patients were younger than 8 years of age and the majority (63%) had more than 15 lesions.12
A comparative study of topical cantharidin and intralesional PPD to treat molluscum contagiosum
Published in Journal of Dermatological Treatment, 2020
Fathia M. Khattab, Mohamed M. Nasr
Molluscum contagiosum is a skin or sometimes mucous membrane viral infection. It is triggered by a molluscum contagiosum virus (MCV) called a DNA poxvirus (1). There is no reservoir of animals in the virus (infecting only humans). There are four types of MCV, MCV-1 to -4; the most common is MCV-1, and MCV-2 is generally seen in adults (2).
Monkeypox: a new face of outbreak
Published in Expert Review of Vaccines, 2022
Vivek P. Chavda, Lalitkumar K. Vora, Vasso Apostolopoulos
The name monkeypox derives from the initial discovery of the virus in monkeys in a Danish laboratory in 1958. The first human case was reported in a child in the Democratic Republic of the Congo in 1970 [12]. The monkeypox virus is an orthopoxvirus, which is a virus genus that contains the smallpox-causing variola virus. Monkeypox is a zoonosis, a disease transferred to individuals from sick animals [13]. Poxviruses are a type of DNA virus with numerous genes that replicate in the host cell cytoplasm and not the nucleus and are super stable in the environment. Although large DNA viruses have a low mutation rate, this is not truly a hindrance for poxviruses when they encounter a new environment, as they already harbor genetic diversity and can recombine and adapt by amplifying gene numbers. The most well-known poxvirus outbreak was the devastatingly lethal, unbearable, and history-changing smallpox disease in humans. After killing over 500 million people since 1880, the variola virus came under control using an original ‘Jennerian’ vaccine based on inoculation with a related virus (vaccinia) found in animals, which provided cross protection against the variola virus, but was less likely to cause significant disease [14]. In 1980, the variola virus was eradicated, leaving humans with only a single endemic poxvirus, the relatively benign molluscum contagiosum virus, which is distantly related to the variola-like ‘orthopox’ viruses. Given their significant diversity and generalist predisposition, poxviruses frequently jump from one host species to another (particularly from rodents). One of the best-known examples is monkeypox or cowpox, both of which are rodent-borne [15]. Vaccinia viruses have caused bovine vaccinia (BV) in Brazil and India, following the end of vaccination [16]. The lack of investment in research, the unreadiness of health professionals and agencies to cope with the illness, and the propensity of dairy products as alternate routes of infection pose the issue of how BV should be addressed going forward. The highest limit R0 of 1.0 for the Central African clade shows that the viruses can continue human-to-human transmission and remain in human populations. Further studies are required to determine whether the unusual spread of the virus has a genetic foundation [17]. The genome of the monkeypox virus is much larger than the genomes of the SARS-CoV-2 and hepatitis B viruses, which are six and sixty times larger, respectively [17]. As databases include limited nucleotide sequences, numerous ambiguities persist. People with monkeypox may develop symptoms including fever, headache, muscle aches, exhaustion, or swollen lymph nodes.