Summary about Disease
Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV-8), is a gamma herpesvirus that is the causative agent of Kaposi's sarcoma (KS), a type of cancer that causes lesions in the skin, lymph nodes, internal organs, and mucous membranes. KSHV is also associated with other lymphoproliferative disorders such as primary effusion lymphoma (PEL) and multicentric Castleman's disease (MCD).
Symptoms
Symptoms vary depending on the condition caused by KSHV.
Kaposi's Sarcoma (KS): Reddish-purple or brownish lesions on the skin (often on the legs, face, or mouth), in the mouth, lymph nodes or internal organs. These lesions can be flat or raised. Swelling (edema) of the legs or other affected areas can also occur.
Primary Effusion Lymphoma (PEL): Accumulation of fluid in body cavities (pleural, peritoneal, pericardial), leading to symptoms like shortness of breath, abdominal swelling, and chest pain.
Multicentric Castleman's Disease (MCD): Enlarged lymph nodes throughout the body, fever, night sweats, weight loss, fatigue, and signs of organ dysfunction.
Causes
KSHV infection is the primary cause of these diseases. However, infection alone is not sufficient.
KS: Typically occurs in individuals with weakened immune systems, such as those with HIV/AIDS, transplant recipients taking immunosuppressants, or elderly individuals of certain ethnic backgrounds (e.g., Mediterranean, Eastern European).
PEL: Almost exclusively occurs in individuals with HIV/AIDS.
MCD: Can occur in HIV-positive or HIV-negative individuals, with KSHV being a more prominent factor in HIV-positive cases.
Medicine Used
Treatment depends on the specific condition and its severity.
Kaposi's Sarcoma (KS):
Antiretroviral therapy (ART) (for HIV-associated KS) to improve immune function.
Local therapies: Cryotherapy, excision, radiation therapy, topical retinoids, or intralesional chemotherapy (e.g., vinblastine).
Systemic chemotherapy: Liposomal doxorubicin, paclitaxel, or other chemotherapy drugs for more extensive or aggressive KS.
Primary Effusion Lymphoma (PEL): Chemotherapy regimens, often including agents like etoposide, cyclophosphamide, doxorubicin, vincristine, and rituximab. ART therapy if patient is HIV positive.
Multicentric Castleman's Disease (MCD): Rituximab (anti-CD20 antibody) or chemotherapy, as well as antiviral medications like ganciclovir. Siltuximab is also used to treat MCD.
Is Communicable
Yes, KSHV is communicable, but it is not as easily transmitted as some other herpesviruses (e.g., herpes simplex virus). Transmission routes include:
Saliva: Primary route, especially among children.
Sexual contact: Can be transmitted sexually.
Blood transfusions and organ transplantation: Rarely, can be transmitted through infected blood or organs.
Mother to child: Vertical transmission during birth is possible, but rare.
Precautions
The following may reduce the risk of transmission:
Safe sexual practices: Using condoms reduces the risk of transmission through sexual contact.
Avoid sharing items: Avoid sharing items that might be contaminated with saliva (e.g., toothbrushes, utensils, drinks).
Screening of blood and organ donations: Screening of donated blood and organs helps prevent transmission through these routes.
For individuals with HIV/AIDS: Strict adherence to antiretroviral therapy (ART) to maintain a healthy immune system and reduce the risk of KSHV-related diseases.
How long does an outbreak last?
KSHV itself is a persistent virus, remaining in the body for life after infection. Therefore, it is not really a matter of an outbreak lasting a set amount of time. However, the manifestations of KSHV-related diseases, like KS lesions, can have varying durations.
KS lesions: Can persist for weeks, months, or years if untreated. The duration depends on the extent and aggressiveness of the KS and the effectiveness of treatment.
PEL and MCD: These are chronic conditions that require ongoing management.
How is it diagnosed?
Diagnosis involves a combination of clinical evaluation and laboratory tests:
Clinical examination: Visual examination of skin lesions, lymph nodes, and other potential sites of involvement.
Biopsy: A tissue sample is taken from suspected lesions for microscopic examination (histopathology) and detection of KSHV DNA or proteins.
Blood tests: Detection of antibodies against KSHV in the blood (serology) can indicate past or current infection. PCR (polymerase chain reaction) can detect KSHV DNA in blood or other bodily fluids.
Imaging studies: CT scans, MRI, or PET scans may be used to assess the extent of disease and involvement of internal organs.
Timeline of Symptoms
Initial KSHV infection: Most people infected with KSHV are asymptomatic (show no symptoms).
Development of KSHV-related diseases: The time between initial infection and the development of KS, PEL, or MCD can vary greatly, ranging from months to years or even decades. It depends on the individual's immune status and other factors.
Progression of symptoms: Once symptoms of KS, PEL, or MCD appear, they can progress gradually or rapidly, depending on the specific condition and its aggressiveness.
Important Considerations
HIV/AIDS: KSHV-related diseases are much more common and aggressive in individuals with HIV/AIDS. Effective ART is crucial for prevention and management.
Immunosuppression: Other forms of immunosuppression (e.g., transplant recipients) also increase the risk of KSHV-related diseases.
Early diagnosis and treatment: Early diagnosis and treatment are important for improving outcomes and preventing complications.
Surveillance: Individuals at high risk (e.g., HIV-positive individuals, transplant recipients) should be monitored for signs and symptoms of KSHV-related diseases.
Not everyone infected with KSHV will develop Kaposi Sarcoma: Most people do not get Kaposi Sarcoma from having KSHV.