Human Immunodeficiency Virus (HIV) causes the immune system to gradually weaken, reducing your ability to protect yourself from other diseases. Acquired Immunodeficiency Syndrome (AIDS) is a late stage of HIV infection in which immunity has decreased so much that the inidividual has developed specific complications from other diseases, called opportunistic infections. The time it takes to develop AIDS varies greatly from person to person, and it can progress rapidly or take several years.

The common route of HIV infection is through semen, vaginal secretions during sexual activity, through blood, or mother-to-child infection.There are no risk in getting infection on a regular daily living, work or school routine.

Once infected with HIV, it will not be possible to eliminate the virus from the body, but if antiviral drugs (called antiretroviral therapy or ART) are taken, it can reduce the amount of virus in the blood, and by controlling this, the risk for complications will be less and the individual with HIV can live a normal lifestyle. In addition to this, it will not be possible for them to infect others anymore, because there is no virus in their blood. Therefore, treatment is strongly recommended for everyone infected with HIV. It is very important to diagnose HIV infection early and to treat it early.

How to prevent HIV infection

The most common route of infection is through sexual contact. HIV is in semen and body fluids. The use of a condom is highly effective to reduce the risk of infection. In adults, HIV transmission occurs mainly by vaginal and rectal routes but rarely via oral route. However, oral mucus can have a risk of transmission when there is a wound and the use of condom is recommended even for oral sex.

There is a method of using antiviral medications before sexual activity to prevent getting HIV infection, but in Japan, it is not currently supported by the national health insurance program and so is expensive. In addition to taking antiviral drugs, it is very important to take screening for HIV and side effects of the drugs at the same time under the guidance of a doctor with specialized knowledge about HIV.

What is U=U?

U=U means "undetectable and untransmittable"
For those who are living with HIV, if the level of virus in the blood is below the detectable range, and as long as this viral load is controlled there will be no possible transmission even through sexual contact.

U=U amplifies that detecting the HIV status early and beginning the treatment immediately to quickly suppress the viral load will be vital in ending HIV prevalence. This international campaign has become a slogan globally to reduce HIV stigma and discrimination, and shows that people living with HIV can also live a normal life including secual intercourse.

What is PEP?

PEP means "Post Exposure Prophylaxis". This is a treatment program that is used for those who are potentially exposed to HIV and/or have a high risk of getting infected. PEP must be taken within 72 hours after exposure to lessen the risk of getting HIV infection. The types of cases that PEP should be considered includes those medical professionals who have had accidental exposure to a needle injury at work, or when one finds out that their sexual partner is a person living with HIV.

Once PEP medicine is initiated, it must be continued and completed for 28 days.

Who can take PEP?

If you had sexual activities with high risk of HIV infection (e.g. Sex with no condom) with a person who has or may have HIV, you may be eligible for PEP within 72 hours after exposure.

If you are already HIV positive or if you know that your sexual partner is HIV negative and theres an assurance of no risk then you do not need to receive PEP. An HIV test is necessary prior to starting PEP.

What is the process and period of taking PEP?

PEP uses the same treatment as people who are HIV positive, called anti-retroviral therapy (ART). This treatment include 3 types of medication that must be taken for 28 days.

Upon starting PEP, you may experience side effects such as nausea and vomiting. In some cases, you may show allergic reactions or reduced liver and kidney functions. A follow up after 14 days is important to check for severe forms of side effect from the medications. After clearance, you will then be prescribed the remaining 14 days of medications.

Prescription of ART for PEP is currently not approved in Japan. It is not part of National Health Insurance subsidy, and so, to receive treatment, a patient must pay for the medications, consultation and testing fees.

What is PrEP?

Pre-exposure prophylaxis (PrEP) is a preventive measure that reduces the risk of HIV infection by taking antiviral drugs even though you are not infected with HIV.

It is not necessary for everyone to take the medicine as prevention for regular sexual activity, but it is an effective method in a very high-risk situation. It does not guarantee 100% protection from getting HIV, hence, it is also recommended to use condoms at the same time.

There are currently two types of antiviral drugs that are widely being used for PrEP. Various methods of taking PrEP and medications are still under development, and we can expect different methods in the future.

Who is PrEP recommended for?

Those who are not currently infected with HIV and are at risk of HIV infection are eligible for PrEP.

If you have a HIV partner living with HIV who has not received treatment, recently have had a STI, and do not use condoms during sexual activity you may be considered high risk of HIV infection, and suitable for PrEP.

Not everyone who is sexually active needs to take PrEP. Please start PrEP after confirming the risk with the doctor in advance.

Precautions when taking PrEP

It is necessary to take the medication before any sexual activity (before exposure). If you forget to take the medicine or take it the wrong way, you will not get a sufficient effect.
Be sure to take it under the guidance of a doctor. In addition, PrEP does not promise a 100% protection from HIV and and does not protect you from other STIs. It is recommended to use condoms during sexual activity at the same time as taking PrEP.

When you plan to stop taking PrEP, please be sure to consult your doctor. Visit a medical institution regularly to check for side effects of antiviral drugs and your HIV status. If you take a medication at your own discretion, there is a risk of missing serious complications, and/or of being exposed to a drug-resistant form of HIV, where medications become ineffective. Taking antiviral drugs for preventive purposes is not yet approved in Japan, hence, more and more people are getting PrEP medications by purchasing online or by personal import. This is not medically advisable. Please be sure to consult your doctor beforehand.

How to get HIV tests

During the first, acute stage of HIV infection, symptoms such as high fever and rash may appear in the first 2 to 6 weeks, but the symptoms soon disappear and the infection is often unnoticed. Even if you have no symptoms, it is important to have a test if you have any concerns.

The HIV test is free and anonymous at most public health centers nationwide. laboratories can carry out a "same-day test" so that the results can be known on the same day. Recently, HIV testing using mail-in test kits has become more available worldwide.

You can also get an HIV test at a medical institution. It is possible to have more than one sexually transmitted infection at once. Please actively seek care and visit a medical facility for more information.


Due to the measures taken for the current on going COVID-19 pandemic, the regular testing sites might not be operating. If you have any concerns and would like to get HIV test, please visit the public health center website and check for the operating days and hours prior to your visit.