Case of the Week 97

Blood smear from a febrile missionary who just returned from Nigeria. Diagnosis?

Interesting PodCast

Here's an interesting podcast on how a lack of biodiversity might increase the rates of human disease, including malaria.

http://www.vermontbiz.com/audio/december/biz-brief-december-7-2009

To hear the part of interest, fast forward to the 2 min, 22 second mark.

Case of the Week 96

The following was found on the scalp of a 60 year old woman. Identification?

Answer to Case 96

Answer: Pediculus humanus, Human head or body louse.

Many of you were very observant and noticed that there was a similar image on my front page: http://parasitewonders.blogspot.com/

Thanks for writing in!

Case of the Week 95

The following objects were aspirated through a fine-gauge needle along with fluid from a slowly growing cystic mass. Papanicolaou stain. No further information is available. (CLICK ON IMAGES TO ENLARGE)
Identification?




(600 times original magnification)

Answer to Case 95

Answer: Protoscoleces and hooklets of Echinococcus spp.

The fact that this is a single cystic mass, and that protoscoleces are present suggests that this is E. granulosus instead of E. multilocularis, but clinical and radiographic correlation is necessary for definitive speciation. E. granulosus typically produces a single, slowly growing cyst, that may eventually contain one or more daughter cysts - each containing protoscoleces (the so called 'cysts within a cyst' appearance) - while E. multilocularis typically produces multiple, rapidly growing cysts that expand in a invasive fashion, and are not constrained by an outer cyst wall. E. multilocularis cysts rarely contain protoscoleces in humans, but are often 'sterile'. These 2 species are the most common to infect humans, but other species rarely infect humans as well.

Thank you all for the great comments on this case! I especially enjoyed "I am hooked on Echinococcus" by Scott and Anonymous.

Case of the Week 94

The following objects were found in a Papanicolaou-stained urine specimen. The intact object measures approximately 170 µm long by 50 µm wide. Identification?



(I'd like to thank Drs. Gladwyn Leiman and Ann Berry for these beautiful images!)