As the world gets more accessible and we travel for business, pleasure, eleemosynary or political reasons we are exposed to more than divergent cultural mores. Our global travel allows us to become hosts to viruses, parasites, bacteria and heretofore (at least in LA), unknown microbes that cause difficult to diagnose diseases.
As many of you know, I am a trustee of Save the Children. Next month, several active members and myself will travel to Ethiopia to visit some of our projects in that part of Africa…I’m very excited. Like other travelers to distant lands, I did my due diligence and went on the CDC website to check on the immunizations I would need and then proceeded to the office of an infectious disease specialist to acquire said immunizations and prophylactic medications. It turns out that I was up-to-date on my Yellow Fever, hepatitis A, and tetanus shots, so all I needed was another typhoid immunization. (I had received all the other shots when I went to India a few years ago.) Subsequent to the shot, the specialist wanted to discuss malaria prophylaxis. The easiest she said, was Malarone, a single pill which should be taken 2 days before arriving in an endemic area and 5 days after leaving. Pretty simple…only when I took Malarone during a trip to India, I developed terrible hives. “Oh,” she said, “you’re the only one I have ever heard of who had an allergic reaction” (Actually, I met a documentary film maker who frequently travels to Africa who has experienced this same reaction.) The other anti-malarial prophylactic medication that is effective for Ethiopian travel is doxycycline. Unfortunately this antibiotic needs to be continued 4 weeks after the trip; can cause severe photosensitivity as well as (at least for me) GI symptoms. So I though I might simply pass on these meds and use oodles of DDT on my skin and clothes.
Sorry abut this long intro, but now I’ll get to the crux of this week’s newsletter; When I opened JAMA this week, there was an article under “Clinician’s Corner” titled Does This Patient Have Malaria? It obviously caught my eye. And here are some of the facts that were presented:
- Malaria imperils more than 3 billion (that is a “b”) people and clinically infects 250 million people every year. It kills nearly 1 million people annually, mostly children in sub-Saharan Africa. Although malaria was irradiated in the US in the mid-20th century, clinicians continue to see “imported” malaria from travelers and it accounts for almost 30% of travel-related fevers.
- In 2008, 1300 cases of malaria were reported in the US (it’s felt however that the true incidence may be higher). In that year, imported malaria (sounds like something expensive!) was due to 2 species of the malarial parasite called Plasmodium falciparum and Plasmodium vivax, mostly acquired in Africa and Asia.
Now, just so you understand what happens: Malaria involves the life cycle of mosquitoes and humans. The Anopheline mosquito transmits the malaria parasite (the plasmodia) from an infected person to an uninfected person. After this very unwelcome inoculation, the parasites pass from the skin to the liver cells (hepatocytes) where it multiplies; the liver cells then rupture and “liberate” scores of parasites that re-infect red blood cells. Since the parasites need to get to and divide in the liver to create the disease, the clinical (or blood) stage and symptoms are delayed 7 to 14 days after the bite of the mosquito. That’s when the parasites multiply within the blood cells cause them to rupture and are released. This massive rupture of the blood cells is clinically manifested as fever, shaking, anemia, pallor and jaundice. The damaged red blood cells then engorge the spleen and liver causing enlargement of these organs. This can all result in nausea, vomiting, headache, renal failure, low blood sugar and low platelets and bleeding. Malaria in children can cause cerebral malaria and coma. (OK by now I am truly concerned!)
The article dealt with the prevalence of malaria in returning travelers from endemic areas. One sentence stood out… “Compared to travelers returning from nonmalarious (great word) or very low risk areas in a database of more than 30,000 patients, the relative risk (RR) of malaria was most elevated by travel to sub-Saharan Africa (it was 208 or 208% higher), Oceana (77) and less elevated by travel to South Asia (RR, 54), Central America (RR, 38) and Southeast Asia (RR, 12). The most likely symptom for malaria in returning travelers was fever, headache, and chills. And for doctors, the diagnostic tests that were most useful for diagnosis were elevation of bilirubin (showing liver function damage and correlated with jaundice) and low platelet count as well as the clinical finding of an enlarged spleen.” Oi!
Bottom line: The prevalence of malaria in travelers who develop fevers after they return from malaria-endemic areas is approximates 30%. This may not be information that most of you will need. But as the world contracts (travel wise), you might want to put this fact in the recesses of your list of “may need to know”. Right now, I am debating between long term doxycycline with all its side effects, and long sleeved clothes, impenetrable slacks, high socks, long pajamas as well as an embedded net to sleep under (I already purchased it). I will certrainly use huge amounts of DDT. I’ll let you know how I feel after the trip.