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Lab Day

Lab work excites me a lot. I'm sorry if that makes me really lame and boring. But it makes my day spent at PML's clinical lab pretty exciting.

PML's lab is very small and they do very limited testing. What they are able to do, however, is some parasitology and mycology of organisms like malaria, schistosomiasis, and several other organisms. They also perform tests for sickle cell anemia and tuberculosis sputum. The lab allowed me to do several simple tests for malaria and sickle cell.

Ghana is one of the top countries that contribute to 80% of the world's malaria burden (http://apps.who.int/iris/bitstream/handle/10665/259492/9789241565523-eng.pdf;jsessionid=E1F26C7443BCA1D8A439B7BE03ED347E?sequence=1). There are four malaria parasites that cause disease in humans: P. falciparum, P. malariae, P. ovale, and P. vivax, all four of these are present in Ghana. PML tests for malaria with the rapid tests as well as extensive lab screening. Blood samples are fixed to slides and contrast dyed to lyse red blood cells and visualize the parasite. If there is even one parasite on the entire slide, the test is positive for malaria. Then they quantify the infection by counting how many parasites are on the slide and the ratio to white blood cells is quantified. High white blood count may indicate a much more extensive infection. I was tasked with finding the parasites. They are really, really, really small. Under a microscope it still only looks like a speck of dust. If you focus on the dust you can see the purple chromatin dot and a pinkish comma-shaped tail.

(Try and find the parasites, the blue cells are white blood cells.)

Sickle-cell anemia is also at a very high prevalence in Ghana. Previously being a carrier of sickle-cell provided some immunity to malaria but the parasite has since evolved to still infect these individuals. Therefore, the sickle-cell genotype is no longer advantageous to the population and only causes a crippling disease. The lab prepares a sickling test by adding a reducing agent to a blood sample and preparing a wet mount slide. The reducing agent removes oxygen from the sample and in normal blood cells the shape stays the same "bowl" like morphology. In sickle cell patients the red blood cells collapse into the typical sickling shape which is how they determine a positive or negative for sickle cell anemia.

Regular red blood cells

Sickle cells

The lab was very efficient but they do the same tests over and over and over since the capacity to do more is not within the bounds of the lab. The hospital outsources many routine tests such as PCR for viral loads. To put it bluntly, there is just not enough money. They don't even supply different glove sizes since it is more cost effective to just provide large and extra large gloves since everyone can fit these gloves. These tests are so much harder to do when they are not in-house and makes providing effective care that much more difficult and this needs to change. But, it's always much easier said than done.