《科学》：艾滋病1920年代起源于金沙萨

【侨报网10月3日讯】艾滋病的广泛传播可以追溯到1920年代的金沙萨，即现在的刚果民主共和国首都。

由各国科学家组成的国际研究小组说，当时金沙萨市人口激增、性行业活跃，再加上铁路网络给艾滋病的传播提供了“完美的土壤”。

科学家用“病毒考古学”，其中包括艾滋病毒的基因密码来寻找艾滋病疫情的起源，根据他们找到的证据，似乎追溯到上世纪20年代的金沙萨市。该报告发表在最新的《科学》杂志上。

该报告说，性行业的繁荣、人口激增以及卫生诊所使用不消毒的针头使病毒得到了广泛传播。

与此同时，由比利时帮助建筑的铁路为人们的交通提供了方便，每年有100万人经由金沙萨，使病毒迅速传到周围地区。

艾滋病直到1980年才开始引起世人的重视，世界上共有近7500万人感染了艾滋病毒。

而艾滋病在非洲的历史更长，但艾滋病的起源问题一直受到争议。

英国以及比利时的科学家试图建立一个艾滋病的“家谱”，找到艾滋病的“鼻祖”。

他们研究了艾滋病变异的基因密码，通过读取这些变异标志，科学家可以重建艾滋病的家谱以及它的根源。

HIV艾滋病毒是黑猩猩“猴免疫缺陷病毒”其中的一个变种，它可能是通过接触丛林动物带病毒的血液感染而致。

当时在非洲地区，人们已经知道HIV病毒可以从黑猩猩身上跨物种传播给人类。

20世纪20年代的金沙萨是比利时刚果殖民地的一部分。当时有大量的男性劳动力涌到那里，人口性别比例失调，男女比例为2：1，最终导致性行业的繁荣。

专家说，当时的诊所为人们治疗各种传染病时大量使用针头注射，这导致了病毒的广泛传播。

再就是当时交通运输的发达，使得人们更容易流动，导致病毒广泛蔓延。

到1940年代末，大约上百万人使用金沙萨的铁路运输。这种情况持续了几十年。虽然后来在金沙萨艾滋病毒传染的“完美的土壤”已经不复存在，但该病毒已经被传到了世界各地。

专家认为归根到底，是人员的大量流动、性行业、不安全的人类行为例如使用不消毒的针头以及人口增长导致了艾滋病毒的大爆发。

HIV May Have Emerged in Congo in 1920s:Study

By Randy Dotinga
HealthDay Reporter

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THURSDAY, Oct. 2, 2014(HealthDay News) -- A new study into the origins of the AIDS virus suggests onestrain of the disease appeared in the early 20th century in the western regionof Congo and spread through a swath of Africa over the next several decadeswithout notice by the rest of the world.

The researchers say thefindings support -- but don't prove -- the theory that the virus expanded itsreach in Africa due to social factors such as railroad expansion, changingsexualhabitsand unsafe medical practices.

The study adds to ourunderstanding of how a virus that is less transmissible than otherpathogens likemalariaandthecommon coldcan still become established in thehuman population and eventually grow into a devastating pandemic, saidstudy co-author Philippe Lemey, from the Rega Institute for Medical Research atCatholic University of Leuven, Belgium.

The fact thatsocial changes were critical in the rise of the virus suggests that suchchanges may also be an important factor in combating epidemic spread,Lemey said.

The origins of HIV, thesexually transmitted virus that causes AIDS, are still hazy. Scientists believevariations of the virus migrated from primates, possibly monkeys and chimps, tohumans in Africa. Then two strains of the virus, known as HIV-1 and HIV-2,developed in people.

Thenew study, published in the Oct. 3 issue in the journalScience, looks at aform of HIV-1, the prevalent strain in the world today. Scientists previouslydetermined that it existed in heterosexual populations in the first half of the20th century, but exactly where and when it appeared wasn't clear.

Now, the study authorssay analysis of virus samples suggests this form of HIV emerged in Kinshasa,the capital of what is now known as the Democratic Republic of the Congo, inthe early 1920s. The researchers relied on a molecular clock modelto determine the timing.

Its initial spreadfollowed the Democratic Republic of Congo's transport links, in particular itsrailways, that made Kinshasa one of the best connected of all central Africancities, Lemey said. This new ease of movement, coupled with prostitution-- a byproduct of development -- and use of unsterilized needles by medicalworkers treating sex workers may have boosted transmission of the virus, hesaid.

Lemey said the researchreveals a perfect storm of social changes that may have fosteredHIV's spread. This matters now, he said, because knowledge of thecircumstances that facilitated the expansion of the epidemic can assist thedevelopment of effective education and prevention programs.

According to Lemey, thevirus may have gone undetected because few people were infected at first andbecause the symptoms caused by the AIDS-related decline of the body's immunesystem were definitely not new to Africa. AIDS wasn't formallyrecognized until 1981 after it had spread across the world. Since then about 75million people have been infected, according to a United Nations report.

Lemey cautioned that thefindings don't offer insight into how a variation of the virus leaped fromanimals to people, or what might have happened if the virus had been recognizeddecades ago. There's no way to know if medical officials could have stopped itsspread.

Still, the study authorssay the findings could be a template for understanding the spread of otherblood-transmitted diseases such ashepatitisC.Currently, researchers around the world are struggling to containEbolainfectionsin Africa.

William Schneider, aprofessor who studies the history of medicine at Indiana University-PurdueUniversity Indianapolis, praised the study for providing a fascinatingand helpful framework to understand the origins of HIV/AIDS. Schneider ispart of a team of historians and anthropologists exploring the roots of thedisease in Africa.

However, Schneider saidthe authors' theories about the spread of the disease aren't convincing becausethey're based on questionable information from a time when Europeans controlledmuch of Africa. Colonial records are well-known by historians andanthropologists to be biased, selective and above all in need of broaderunderstanding of historical and cultural circumstances to evaluate their usefulness,he said.

Staying Healthy With HIV

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·HIV ComplicationsProtect your health.Understand common HIV complications. Find out what to do.

HIV/AIDS Discriminationand Stigma

If you've been diagnosed withHIV(humanimmunodeficiency virus), or know someone who has, the need for support andcompassion couldn't be greater. But all too often HIV-positive people becometargets of AIDS discrimination and stigma. On top of handling new healthchallenges, they sometimes face rejection by family and friends. They may beforced out of homes, lose jobs, or even become victims of violence. Thefollowing information can help you learn about ways to cope with AIDSdiscrimination. It can also help you better understand civil rights forHIV-positive people.

What's Behind AIDS Discrimination and Stigma?

Many factors can lead to AIDS discrimination and stigma:

·HIV is a deadly disease that manypeople fear.

·Some adults in the U.S. stillwrongly believe that they can catch HIV through casual contact, such as sharinga drinking glass or touching a toilet seat. This greatly increases their fearabout being near people who are infected.

·Many people connect HIV and AIDSwith behaviors that are already stigmatized, such as sex between men orinjectingdrugs.

·Some people believe that havingHIV or AIDS is the person's own fault. For example, they might think it's theresult of moral weakness and deserves to be punished.

Unfortunately, AIDS discrimination and stigma also fuel theepidemic. They prevent people from talking about their HIV status with sexpartners or people with whom they share needles. Fear of rejection and worriesabout confidentiality also prevent many from getting tested for HIV. This meansthey may spread HIV to others without knowing it.

How to Cope With AIDS Stigma

There is no simple answer for how to deal with the stigmasurrounding HIV and AIDS. The first step might be to seek support from peoplewho understand what you're going through.

·Ask your doctor about localHIV/AIDS support groups. Or, ask to be referred to apsychologist,psychiatrist, or clinical social worker.

·Find a hotline by looking in theyellow pages of your telephone book. Look under AIDS, HIV EducationalReferral and Support Services or Social ServiceOrganizations. Ask for practical advice or emotional support over thephone. They can also refer you to local HIV/AIDS self-help organizations.

Examples of AIDS Discrimination

What exactly is AIDS discrimination? It means you are treateddifferently than other people simply because you are infected with HIV. Forexample:

·A person denies you access tomedical care at a hospital, medical or dental office, skilled nursing facility,or drug treatment center.

·A person denies you child custodyor visitation, or the right to adopt or become a foster parent.

·An employer asks unlawfulquestions on a job application or harasses, fires, or transfers you to a lesserjob position.

·A person of authority revealsyour HIV status at school, at work, or within a health care institution.

·You are evicted from a rentalproperty.

Understanding AIDS/HIV -- Symptoms

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The Symptoms of HIV/AIDS - the First Stage

HIV infection comes inthree stages. The first stage is called acute infection or seroconversion, andit typically happens within two to six weeks after exposure or becominginfected. This is when the body's immune system puts up a fight against HIV.The symptoms of acute infection look similar to those of other viral illnessesand are often compared to those of the flu. The symptoms may last a week or twoand then completely go away as the virus goes into a non-symptomatic stage.

The initial symptoms ofacute HIV infection may include:

·Headache

·Diarrhea

·Nausea and vomiting

·Fatigue

·Aching muscles

·Sore throat

·Red rash that doesn'titch, usually on the torso.

·Fever

Call Your Doctor AboutHIV Infection If:

You think you have comein contact with HIV. Doctors can now prevent HIV from taking hold in the bodyif they act quickly after initial infection. Health care workers, police, andfirefighters who are exposed to HIV-infected blood often use a process thatinvolves taking anti-HIVdrugstoprotect themselves. These drugs must be taken within hours or days of initialexposure.

You may be tested forHIV using highly sensitive tests that detect both HIV antigen, a proteinproduced by the virus immediately after infection, and HIV antibodies. Thistest can confirm a diagnosis within days of infection. (RegularHIV testsdon'twork this soon after infection; they can only detect antibodies.) You may begiven anti-HIV drugs to take for a prescribed period of time. There may beunpleasant side effects to these drugs, but they may stop HIV from infectingyou.

Most people don't knowthey've been infected with HIV, but weeks later they may experience thesymptoms of seroconversion. These symptoms mean the body is trying to fightHIV.

The Period Without Symptoms of HIV - the Second Stage

After the firstseroconversion period, the immune system loses the battle with HIV and symptomsgo away. HIV infection goes into its second stage, which can be a long periodwithout symptoms, called theasymptomaticperiod.Thisis when people may not know they are infected and can pass HIV on to others.This period can last 10 or more years.

During this periodwithout symptoms, HIV is slowly killing the CD4 T-cells and destroying theimmune system. Blood tests during this time can reveal the number of these CD4T-cells. Normally, a person has a CD4 T-cell count between 450 and 1,400 cellsper microliter. This number changes constantly, depending on a person's stateof health. For an HIV-infected person, the number of CD4 T-cells steadilydrops, making them vulnerable to other infections -- and in danger ofdeveloping AIDS.

HIVInfection and AIDS - the Third Stage

AIDS (acquired immunedeficiency syndrome) is the advanced stage of HIV infection. When the CD4T-cell number drops below 200, people are diagnosed with AIDS.

Someone infected withHIV can also be diagnosed with AIDS if they have an “AIDS defining illness”such as Kaposi’s sarcoma (a form of skin cancer) or pneumocystis pneumonia (alung disease).

Fortunately, combinationmedications used to treat HIV -- a ''cocktail'' – can help rebuild theimmune system. These drugs can be expensive and pose challenges with sideeffects, but it is critical tonotstop taking them without talking toyour doctor. It is also important not to take part of the medicationswithout taking the others. People with low CD4 T-cells may also receivedrugs to prevent opportunistic infections. These preventative medicationsshould be taken until the CD4 count has improved.

Some people don't knowthey were infected with HIV, and only discover their HIV infection afterexperiencing some of these HIV-related symptoms:

·Being tired all of the time

·Swollen lymph nodes in the neck or groin

·Fever lasting for more than 10 days

·Night sweats

·Unexplained weight loss

·Purplish spots on the skin that don't go away

·Shortness of breath

·Severe, long-lasting diarrhea

·Yeast infections in the mouth, throat, or vagina

·Easy bruising or unexplained bleeding

Call Your Doctor AboutHIV or AIDS If:

Call your doctor if youexperience any of the above symptoms of HIV/AIDS. These are serious signs ofdisease, which could be HIV-related.

The Top 10 Myths and Misconceptions About HIV and AIDS

For nearly 30 years,HIV(human immunodeficiency virus) andAIDS(acquiredimmunodeficiency syndrome) have been shrouded in myths and misconceptions. Insome cases, these mistaken ideas have prompted the very behaviors that causemore people to become HIV-positive. Although unanswered questions about HIVremain, researchers have learned a great deal. Here are the top ten myths aboutHIV, along with the facts to dispute them.

33 Million People Now Live With HIV. How Did We Get Here?

MythNo. 1: I can get HIV by being around people who are HIV-positive.

The evidence shows thatHIV is not spread through touch, tears, sweat, or saliva. Youcannotcatch HIV by:

·Breathing the same air as someone who is HIV-positive

·Touching a toilet seat or doorknob handle after an HIV-positiveperson

·Drinking from a water fountain

·Hugging, kissing, or shaking hands with someone who isHIV-positive

·Sharing eating utensils with an HIV-positive person

·Using exercise equipment at a gym

Youcanget it from infected blood, semen,vaginal fluid, or mother's milk.

Myth No. 2: I don't need to worry about becoming HIV positive -- newdrugs will keep me well.

Yes, antiretroviraldrugsare improving and extending the livesof many people who are HIV-positive. However, many of these drugs are expensiveand produce serious side effects. None yet provides a cure. Also,drug-resistant strains of HIV make treatment an increasing challenge.

Myth No. 3: I can get HIV from mosquitoes.

Because HIV is spreadthrough blood, people have worried that biting or bloodsucking insects mightspread HIV. Several studies, however, show no evidence to support this -- evenin areas with lots of mosquitoes and cases of HIV. When insects bite, they donot inject the blood of the person or animal they have last bitten. Also, HIVlives for only a short time inside an insect.

Myth No. 4: I'm HIV-positive -- my life is over.

In the early years ofthe disease epidemic, the death rate from AIDS was extremely high. But today,antiretroviral drugs allow HIV-positive people -- and even those with AIDS --to live much longer, normal, and productive lives.

Myth No. 5: AIDS is genocide.

In one study, as many as30% of African-Americans and Latinos expressed the view that HIV was agovernment conspiracy to kill minorities. Instead, higher rates of infection inthese populations may be due, in part, to a lower level of health care.

Myth No. 6: I'm straight and don't use IV drugs -- I won't becomeHIV-positive.

Most men do becomeHIV-positive through sexual contact with other men. However, about 16% of menand 78% of women become HIV-positive through heterosexual contact.

Myth No. 7: If I'm receiving treatment, I can't spread the HIV virus.

When HIV treatments workwell, they can reduce the amount of virus in your blood to a level so low thatit doesn't show up in blood tests. Research shows, however, that the virus isstill hiding in other areas of the body. It is still essential topractice safe sex so you won't make someone else become HIV-positive.

MythNo. 8: My partner and I are both HIV positive -- there's no reason for us topractice safer sex.

Practicing safer sex --wearing condoms or using dental dams -- can protect you both from becomingexposed to other (potentially drug resistant) strains of HIV.

MythNo. 9: I could tell if my partner was HIV-positive.

You can be HIV-positiveand not have any symptoms for years. The only way for you or your partner toknow if you're HIV-positive is to get tested.

MythNo. 10: You can't get HIV from oral sex.

It's true that oral sexis less risky than some other types of sex. But you can get HIV by having oralsex with either a man or a woman who is HIV-positive. Always use a latexbarrier during oral sex.

Half of HIV-Positive Gay Men in U.S. Aren'tGetting Proper Treatment

THURSDAY, Sept. 25, 2014(HealthDay News) -- Even though gay and bisexual men make up the majority ofAmericans infected withHIV, half aren't receiving ongoing care orgetting the virus-suppressing drugs they need to stay healthy, a new reportfinds.

The study, from the U.S.Centers for Disease Control and Prevention (CDC), looked at 2010 data on morethan 400,000 male gay and bisexual Americans who were infected with HIV, thevirus that causes AIDS.

The research shows thatwhile 77.5 percent did initially get HIV medical care within three months oftheir diagnosis, only about 51 percent continued getting care on an ongoingbasis.

Experts note thatHIV infectioncan be manageable if powerfulantiviral drugs are taken on a regular basis. But the CDC report finds thatless than half of HIV-positive gay or bisexual men were prescribed such drugs,and only 42 percent achieved healthy viral suppression.

Why are so many infectedmen not getting proper treatment? The CDC researchers said many factors couldbe at play.

Lack of healthinsurance, stigma and discrimination might influence whether [gay and bisexualmen] access medical care, they wrote. Gaining access to care soon afterdiagnosis is crucial to whether or not a patient continues to getvirus-suppressing medications, the team added.

Younger men and minoritymales appear to be at highest risk of not getting the HIV-related treatmentthey need, said the team led by CDC researcher Sonia Singh.

For example, while 84percent of men aged 45 to 54 who were newly diagnosed with HIV got linked tomedical care, that proportion dropped to 71 percent for males ages 13 to 24. Asimilar age gap was seen in statistics relating to ongoingretention in HIV medical care, the CDC study found.

The gap widened when itcame to men taking HIV-suppressing medications. While nearly 68 percent ofinfected gay or bisexual men age 55 or older were on the drugs, that numberfell to just 30.5 percent for those aged 18 to 24, the study found.

Minorities were morelikely to miss out on needed care compared to white patients, the CDC added. Whileabout 83 percent of white gay or bisexual men infected with HIV got linked tocare soon after their diagnosis, the rate for blacks fell to about 72 percent.

All of these numbersfall short of targets from the CDC's National HIV/AIDS Strategy, which aims tohave 80 percent of infected gay and bisexual men retained in ongoing medicalcare by 2015.

According to the CDC,gay or bisexual males make up 2 percent of the U.S. population but comprise 52percent of Americans infected with HIV. Many are unaware they are infected.

The CDC team noted that,in 2011, the National HIV Behavioral Surveillance System in 20 citiesfound that only 49 percent of [gay and bisexual men] aged 18-24 years whotested positive were aware of their HIV infection. Young black or Hispanicmen are at much higher risk of not knowing their HIV status, the CDC said.

According to experts,early detection is crucial to getting newly diagnosed patients into care and tocurb the spread of HIV.

Persons who areaware of their HIV-positive status are less likely to engage in risky behaviorsthat increase the probability of transmitting HIV to sex partners,Singh's team noted. Knowing your infection status can also help peopleenter into care and treatment earlier, further improving health outcomes,they added.

To that end, they advisethat all sexually active but currently HIV-negative gay and bisexual men get anHIV test at least annually, and preferably every three to six months.

More outreach could helpboost treatment levels, as well. The findings from the new reporthighlight the need for continued expansion of prevention, care andtreatment efforts, particularly for younger and minority gay and bisexualmen, the authors said.

Thestudy is published in the Sept. 26 issue of the CDC journalMorbidity and Mortality WeeklyReport.

-- E.J. Mundell

What is HIV?

HIV is short forhuman immunodeficiency virus. This is thevirus that causes the acquired immunodeficiency syndrome or AIDS. HIV is acomplicated virus that uses RNA, not DNA, as its genetic messenger. Itreplicates (reproduces) primarily in specialized cells of the body's immunesystem called CD4 lymphocytes. During HIV replication, the CD4 cells aredestroyed. As more and more cells are killed, the body loses the ability tofight many infections. If the number of CD4 cells in the bloodstream fallsbelow 200 per cubic millimeter, or if some other special conditions occur, theperson is defined as having AIDS. These special conditions include infectionsand cancers that take advantage of the way that HIV suppresses the immunesystem. Regardless of the CD4 count, people withHIV infectioncarry the virus and can spread itto others through unprotected sex or contact with blood or some other bodyfluids.

Statistics show thatmore than 1.1 million Americans are currently infected with HIV. Over 250,000of these Americans are not aware that they are infected. The U.S. Centers forDisease Control and Prevention (CDC) estimates that more than 50,000 newinfections with HIV occur each year. Thus, HIV testing is important to diagnosethose who are newly infected, to identify previously unrecognized infections,and to relieve the minds of those who are not infected. HIV testing is alsoused to reduce the risk of transmission during blood transfusions and tissuetransplantation.

The CDC recommendsroutine HIV testing of adolescent and adult patients aged 13 to 64 in allhealth-care settings, of all women duringpregnancyandthe newborns of HIV positive women. Thus, HIV testing is considered part ofroutine medical practice, similar to tests that screen for other diseases.People who are at high risk for acquiring HIV should be tested at leastannually. Sometimes, doctors request or require testing as part of evaluationand treatment for other conditions, such as women undergoing treatment withassisted reproductive technologies forinfertilityortreatment of viralhepatitis. There is increasing concern thatnot enough people are being tested. Events such as National HIV Testing Dayhave been used to raise awareness and increase participation in testing.