Q:

你好，

本人已閱讀網站內有關口交感染風險的大部分資料。雖說口交插入者的風險較低，但部分本地或外國網站聲稱需要在口腔內/性器官上有傷口才可感染，但羅醫師在有關口交風險的文章回應欄中強調無需傷口，只要任何一方有hiv口腔粘膜和性器官粘膜有接觸，即有機會造成感染，是theoretical risk 和possible risk 的分別嗎？還是當中需要含病毒體液交換，例如血液/精液/前列腺液/母乳？口交中所接觸的體液主要不是唾液嗎?是否因應不同情況，無套口交可以是低至中度風險？

但本人（1月25日曾留言）擔心的是早前和一個剛證實感染艾滋病毒的男友進行無套口交。我是插入方，雖然對方口中並沒有什麼流血跡象，但在網路文獻指出急性感染期的病毒量極高。這會增加對方口水內的病毒量做成感染嗎? 因為有研究指出急性感染期間（感染後2-3星期）口水的病毒量有機會比精液的病毒量還高。這是否正確？感染率又會增加多少？

1.Aidsmap website-saliva
http://mobile.aidsmap.com/Saliva/page/1322841#ref1323188

For example, one study found that saliva was detectable in 91% of people during primary infection and 82% of people in untreated, chronic infection. Viral loads were comparable to those in semen, and were correlated with those in blood plasma,3 although a French study found only a weak correlation with plasma.

In another study, 42% of subjects had detectable HIV in saliva, and this was more common in people with periodontal disease, severe gingival inflammation or no combination therapy. Studies have reported individuals who have had higher viral loads in saliva than in blood.

2. Compartmentalization of HIV-1 according to antiretroviral therapy: viral loads are correlated in blood and semen but poorly in blood and saliva
AIDS 26 January 2001 Vol. 15 – Issue 2: pp 284-285

http://mobile.journals.lww.com/aidsonline/_layouts/oaks.journals.mobile/articleviewer.aspx?year=2001&issue=01260&article=00025

The mean level of HIV RNA was significantly influenced by the number of antiviral drugs, both in the blood (P < 0.001) and seminal plasma (P < 0.05). Conversely, the viral load in saliva was poorly influenced by the intensity of ART. A couple of consecutive samples were available for six patients. In semen, the viral load decreased dramatically in four cases and remained undetectable in two cases, suggesting a great sensitivity of this compartment to ART, even when the therapy showed a poor efficacy in blood. Conversely, in saliva, the viral load collapsed only in the three patients receiving ART and exhibiting a decrease of more than two log10 of their blood viral load; in the three other patients, the viral load in the saliva was close to the value observed in the blood.

3. Analysis of HIV-1 load in blood, semen and saliva: evidence for different viral compartments in a cross-sectional and longitudinal study.
Liuzzi G. AIDS. 1996 Dec;10(14):F51-6
http://www.ncbi.nlm.nih.gov/m/pubmed/8970677/

RESULTS: HIV-1 RNA was detected in 26 out of 26 samples of plasma, in 25 out of 26 samples of semen and in 24 out of 25 samples of saliva. The median number of HIV-1 copies in plasma was 14 817/ml (range: 167-254 880), in semen was 515/ml (range: 0-196 050) and in saliva was 162/ml (range: 0-72 080).

4. REVIEW ARTICLE
Oral transmission of HIV, reality or fiction? An update
Oral Diseases (2006) 12, 219–228. doi:10.1111/j.1601-0825.2005.01187.x

http://www.ip.usp.br/portal/images/stories/Nepaids/oral_transmi.pdf

Shugars and Wahl (1998) detected measurable viral RNA levels in 56% of whole saliva samples and 100% of plasma samples from seropositive patients, with five patients showing HIV-1 RNA levels in saliva up to 62-fold higher than those in blood. Filtration of the saliva significantly reduced the HIV-1 load, indicating that the maximum viral load in oral secretions is predominantly associated with the presence of infected cells or with large cell aggregates that contain the virus. These high concentrations of viral RNA in saliva strongly suggest that cells already carrying the virus penetrate the oral cavity and/or that their active replication takes place in the oral cavity or upper gastrointestinal tract (Shugars and Wahl, 1998).

讀了這些研究結果後令自己更擔心了。整個農曆新年都在網路上閱讀不同的文獻，真的越看越慌。

已知狀況:
1.對方是近期一月證實感染1月2日
2.一次有套肛交11月10日，一次無套口交12月3日
3. 我在1月3日做過快速測試Alere Determine hiv 1/2，陰性，當時距離兩次接觸4週多及7週多

擔心問題：
對方不知那時感染，我害怕在急性感染期被感染的機會。另，1月3日的測試準確度有多高？

 

 

A:

“黏膜”跟皮膚不同, 黏膜不用傷口就可以被HIV感染, “口腔/性器官有傷口才可感染”是錯誤的說法, 正確的說法是”黏膜有傷口會增加感染的機率,但就算黏膜無傷口, 仍可以被感染”. 口水有抑制HIV傳染的物質, 也就是一物剋一物, 所以你不要再管口水的病毒量研究了, 算盡天機也無法不靠空窗期過完就告訴你有沒有中獎. 數饅頭有數過嗎? 每天揪著心也是數, 放空過日子也是數, 你需要抽離昇華, 而不是歸納分析, 科學現在解決不了你的眼前問題, 只能交給時間, 用美學/宗教/哲學等等度過這等待的日子.