红细胞前体内的粉红色核内包涵体是微小病毒感染的典型特征。微小病毒或“ 第5 疾病”是一种自限性感染，在儿童能产生似面部被打的皮疹，在成年人往往不被注意。然而孕妇可将病毒传给胎儿，并且导致胎儿严重贫血、水肿及宫内死胎。

The pink intranuclear inclusions in the erythroid precursors seen here are characteristic for parvovirus infection. Parvovirus, or "fifth disease" is a self-limited infection that can produce a "slapped cheek" appearance of a rash in children, and often goes unnoticed in adults. However, pregnant mothers can pass the virus to the fetus, and a severe anemia with fetal hydrops and intrauterine demise can result.

可见巨细胞散在分布。右上的插图显示的是巨细胞内的粉红色圆形胞浆内包涵体，它在呼吸道合胞病毒( RSV )感染中很典型，在婴儿和2 岁下面的的儿童中是引起肺炎一个常见的病因。

Scattered giant cells with a scant mononuclear interstitial infiltrate are seen. The pink, rounded intracytoplasmic inclusion in the giant cell of the inset at the upper right is typically seen with respiratory syncytial virus (RSV), a common cause for pneumonia in infants and children under 2 years of age.

成年人结肠取出的蛔虫团，为重度感染。尽管这些幼虫看起来很恶心，但对大多数感染者只产生轻度病变。

This is a ball of Ascaris lumbricoides worms removed from the colon of an adult. This is a heavy infection. Though these worms are disgusting, they produce minimal disease in most infected persons.

鞭虫大量侵袭使结肠粘膜表面出现红斑。

This colonic mucosal surface is erythematous because of the enormous infestation by Trichuris organisms (whipworms).

微丝蚴随血液循环，不同种属在临床症状上稍有不同，但是它们均由蚊子传播。这些微丝蚴是班氏吴策线虫（斑氏丝虫）的幼体。

Here are microfilaria. These tiny worms circulate in the bloodstream. There are several species with slightly different clinical characteristics, but they are spread by mosquitos. These microfilaria happen to be Wuchereria bancrofti.

疟疾病人外周血涂片, 此为间日疟原虫感染。箭头所指为红细胞内的环形疟原虫。涂片上另外三个红细胞也被环状滋养体感染，在左边远处为配子体。

This peripheral blood smear comes from a patient with malaria. This infection happens to be with Plasmodium vivax. At the arrow on the left is a RBC with a malarial parasite in the shape of a ring. Three other RBC's in this smear are also infected with a ring trophozoite. At the far left is a gametocyte of this species.

疥疮，学名疥螨。表皮的皮损可表现为小隧道，通常出现在手上，有时也会在其它地方,并且沿着隧道发痒。这些损害因为发痒经常被抓破。

This is a scabies mite. The official name is Sarcoptes scabiei. These little critters burrow in the epidermis, usually on the hands but sometimes elsewhere, and produce itching along the linear burrows. These lesions are often excoriated because of the itching.

芝麻大小黝黑小虱在头发中散布。头虱相对更常见,特别多见于儿童，并引起骚痒,表皮抓破脱落处有时可继发感染。虱和它们的卵容易通过共用的梳子、毛巾及其它用品传播给他人。

Small tan sesame seed-sized lice are seen scattered amongst the hairs of the head. Head lice are relatively common, particularly among children, and can cause itching, sometimes to the point of excoriation with risk for secondary infection. The lice and their eggs can easily be passed from one person to another with close contact or from sharing combs, towels, etc.

虱是昆虫纲中的节肢动物，它生存于宿主的毛发中，并以宿主的血为食。左边是头虱，右边是耻阴虱。

Lice are arthropods of the class Insecta which generally inhabit hair and bite the human host for a blood meal. At the left is the head louse (Pediculus humanis capitis) and at the right is the crab (pubic) louse (Phthirus pubis).