Bacterial vs Viral Infections: Causes and Treatments细菌与病毒感染：原因和治疗对比

By a physician from a reliable website, Translated by Shadow

Bacterial and viral infections have many things in common. Both types of infections are caused by microbes -- bacteria and viruses, respectively -- and spread by things such as:

Coughing and sneezing.Contact with infected people, especially through kissing and sex.Contact with contaminated surfaces, food, and water.Contact with infected creatures, including pets, livestock, and insects such as fleas and ticks.

Microbes can also cause:

Acute infections, which are short-lived.Chronic infections, which can last for weeks, months, or a lifetime.Latent infections, which may not cause symptoms at first but can reactivate over a period of months and years.

Most importantly, bacterial and viral infections, can cause mild, moderate, and severe diseases.

Throughout history, millions of people have died of diseases such as bubonic plague or the Black Death, which is caused by Yersinia pestis bacteria, and smallpox, which is caused by the variola virus. In recent times, viral infections have been responsible for two major pandemics: the 1918-1919 “Spanish flu” epidemic that killed 20-40 million people, and the ongoing HIV/AIDS epidemic that killed an estimated 1.5 million people worldwide in 2013 alone.

Bacterial and viral infections can cause similar symptoms such as coughing and sneezing, fever, inflammation, vomiting, diarrhea, fatigue, and cramping -- all of which are ways the immune system tries to rid the body of infectious organisms. But bacterial and viral infections are dissimilar in many other important respects, most of them due to the organisms' structural differences and the way they respond to medications.

The Differences Between Bacteria and Viruses

Although bacteria and viruses are both too small to be seen without a microscope, they're as different as giraffes and goldfish.

Bacteria are relatively complex, single-celled creatures, many with a rigid wall, and a thin, rubbery membrane surrounding the fluid inside the cell. They can reproduce on their own. Fossilized records show that bacteria have existed for about 3.5 billion years, and bacteria can survive in different environments, including extreme heat and cold, radioactive waste, and the human body.

Most bacteria are harmless, and some actually help by digesting food, destroying disease-causing microbes, fighting cancer cells, and providing essential nutrients. Fewer than 1% of bacteria cause diseases in people.

Viruses are tinier: the largest of them are smaller than the smallest bacteria. All they have is a protein coat and a core of genetic material, either RNA or DNA. Unlike bacteria, viruses can't survive without a host. They can only reproduce by attaching themselves to cells. In most cases, they reprogram the cells to make new viruses until the cells burst and die. In other cases, they turn normal cells into malignant or cancerous cells.

Also unlike bacteria, most viruses do cause disease, and they're quite specific about the cells they attack. For example, certain viruses attack cells in the liver, respiratory system, or blood. In some cases, viruses target bacteria.

Diagnosis of Bacterial and Viral Infections

You should consult your doctor if you think you have a bacterial or viral infection. Exceptions include the common cold, which is usually not life-threatening.

In some cases, it's difficult to determine whether an illness is viral or bacterial because many ailments -- including pneumonia, meningitis, and diarrhea -- can be caused by either. But your doctor may be able to determine the cause by listening to your medical history and doing a physical exam.

If necessary, he or she also can order a blood or urine test to help confirm a diagnosis, or a "culture test" of tissue to identify bacteria or viruses. Occasionally, a biopsy of affected tissue may be required.

Treatment of Bacterial and Viral Infections

The discovery of antibiotics for bacterial infections is considered one of the most important breakthroughs in medical history. Unfortunately, bacteria are very adaptable, and the overuse of antibiotics has made many of them resistant to antibiotics. This has created serious problems, especially in hospital settings.

Antibiotics are not effective against viruses, and many leading organizations now recommend against using antibiotics unless there is clear evidence of a bacterial infection.

Since the beginning of the 20th century, vaccines have been developed. Vaccines have drastically reduced the number of new cases of viral diseases such as polio, measles, and chickenpox. In addition, vaccines can prevent such infections such as the flu, hepatitis A, hepatitis B, human papillomavirus (HPV), and others.

But the treatment of viral infections has proved more challenging, primarily because viruses are relatively tiny and reproduce inside cells. For some viral diseases, such as herpes simplex virus infections, HIV/AIDS, and influenza, antiviral medications have become available. But the use of antiviral medications has been associated with the development of drug-resistant microbes.

细菌与病毒感染：原因和治疗

翻译： 影SHADOW

细菌和病毒感染有很多共同点。两种类型的感染都是由微生物引起的,并通过以下方式传播：

•咳嗽和打喷嚏。

•与感染者接触，尤其是通过亲吻和性行为。

•接触被污染的表面，食物和水。

•与受感染的生物接触，包括宠物，牲畜和跳蚤和壁虱等昆虫。

微生物也会引起：

•急性感染，是短暂的。

•慢性感染，可能持续数周，数月或一生。

•潜伏感染，起初可能不会引起症状，但可以在几个月和几年的时间内重新激活。

最重要的是，细菌和病毒感染可导致轻度，中度或重度疾病。

纵观历史，数百万人死于诸如鼠疫或黑死病（由鼠疫耶尔森菌引起）和天花（由天花病毒引起）等疾病。近年来，病毒感染已导致死亡的两大流行事件是：一次1918-1919年的“西班牙流感”流行病导致20-40百万人死亡，仅在2013年，持续的HIV / AIDS流行病在全球造成150万人死亡。

细菌和病毒感染可引起类似的症状，例如咳嗽和打喷嚏，发烧，发炎，呕吐，腹泻，疲劳和抽筋-所有这些都是免疫系统试图清除体内感染性生物的方法。但是细菌和病毒感染在许多其他重要方面是不同的，大多数是由于生物体的结构差异以及它们对药物的反应方式不同。

细菌与病毒感染：原因和治疗

翻译： 影SHADOW

细菌和病毒感染有很多共同点。两种类型的感染都是由微生物引起的,并通过以下方式传播：

•咳嗽和打喷嚏。

•与感染者接触，尤其是通过亲吻和性行为。

•接触被污染的表面，食物和水。

•与受感染的生物接触，包括宠物，牲畜和跳蚤和壁虱等昆虫。

微生物也会引起：

•急性感染，是短暂的。

•慢性感染，可能持续数周，数月或一生。

•潜伏感染，起初可能不会引起症状，但可以在几个月和几年的时间内重新激活。

最重要的是，细菌和病毒感染可导致轻度，中度或重度疾病。

纵观历史，数百万人死于诸如鼠疫或黑死病（由鼠疫耶尔森菌引起）和天花（由天花病毒引起）等疾病。近年来，病毒感染已导致死亡的两大流行事件是：一次1918-1919年的“西班牙流感”流行病导致20-40百万人死亡，仅在2013年，持续的HIV / AIDS流行病在全球造成150万人死亡。

细菌和病毒感染可引起类似的症状，例如咳嗽和打喷嚏，发烧，发炎，呕吐，腹泻，疲劳和抽筋-所有这些都是免疫系统试图清除体内感染性生物的方法。但是细菌和病毒感染在许多其他重要方面是不同的，大多数是由于生物体的结构差异以及它们对药物的反应方式不同。

细菌和病毒之间的差异

尽管细菌和病毒都太小而无法在显微镜下看到。

细菌是相对复杂的单细胞生物，许多细菌具有坚硬的壁，并且围绕细胞内部的流体有一层薄的橡胶膜。他们可以自己繁殖。记录表明，细菌已经存在了大约35亿年，并且细菌可以在不同的环境中生存，包括极热和极冷，放射性废物以及人体。

大多数细菌是无害的，有些实际上可以帮助消化食物，破坏引起疾病的微生物，与癌细胞抗争并提供必需的营养。不到1％的细菌会引起人类疾病。

病毒更细小：最大的病毒小于最小的细菌。他们所拥有的只是蛋白外壳和遗传物质（RNA或DNA）的核心。与细菌不同，病毒没有宿主就无法生存。它们只能通过将自身附着在细胞上来繁殖。在大多数情况下，他们会对细胞进行重新编程以产生新病毒，直到细胞破裂并死亡。在其他情况下，它们会将正常细胞转变为恶性或癌细胞。

与细菌不同的是，大多数病毒的确会引起疾病，并且它们对攻击的细胞非常有特异性。例如，某些病毒会攻击肝脏，呼吸系统或血液中的细胞。在某些情况下，病毒以细菌为目标。

细菌和病毒感染的诊断

如果您认为自己患有细菌或病毒感染，应咨询医生。例外情况包括普通感冒，通常不会危及生命。

在某些情况下，很难确定疾病是病毒性疾病还是细菌性疾病，因为许多疾病（包括肺炎，脑膜炎和腹泻）可能是由这两种疾病引起的。但是，您的医生可以通过听您的病史并进行身体检查来确定原因。

如有必要，他或她还可以下令进行血液或尿液检查以帮助确认诊断，或下令进行组织“培养试验”以鉴定细菌或病毒。有时可能需要对受影响的组织进行活检。

细菌和病毒感染的治疗

发现用于细菌感染的抗生素被认为是医学史上最重要的突破之一。不幸的是，细菌具有很好的适应性，并且抗生素的过度使用已使许多细菌对抗生素产生抗药性。这造成了严重的问题，尤其是在医院环境中。

抗生素对病毒无效，因此，除非有明显的细菌感染证据，许多领先的组织现在建议不要使用抗生素。

自20世纪初以来，已经开发了疫苗。疫苗已大大减少了新的病毒性疾病病例，例如小儿麻痹症，麻疹和水痘。另外，疫苗可以预防此类感染，例如流感，甲型肝炎，乙型肝炎，人乳头瘤病毒（HPV）等。

但是事实证明，病毒感染的治疗更具挑战性，主要是因为病毒相对较小，并且可以在细胞内繁殖。对于某些病毒性疾病，例如单纯疱疹病毒感染，HIV / AIDS和流行性感冒，已经可以使用抗病毒药物。抗病毒药物的使用与耐药微生物的发展有关。