Volume 17, Number 9—September 2011

Haemophilus influenzae type b (commonly called Hib) has gone from being a major cause of childhood illness to being almost nonexistent in children, thanks to a Hib vaccine. In adults, however, a different type of Haemophilus influenzae infection is increasing. This type of invasive disease can be fatal, especially for those older than 65, and there is no vaccine. Reasons for the increase might be changes in the organism, more people at high risk, or decreasing immunity. A vaccine against the invasive form in adults is needed.

Americans are living longer than ever, which means they can continue to travel and enjoy outdoor activities. However, the downside of breathing in all that fresh outdoor air is risk for fungal disease. Fungal infections are more common in older people, whose immune systems may be weakened by age, other disease, or immunosuppressive drugs. Examination of Medicare claims showed that 3 types of fungal infections in older populations occurred mostly in the midwestern and western parts of the United States. Prevention efforts should focus on these areas, and doctors in these areas should consider fungal infections in older patients with respiratory disease.

Prophylactic antiviral agents lower the odds of acute respiratory infection but not serologic infection.

Modestly increased rates of admission or emergency department visits would have caused substantial overcrowding.

Accurate identification of these organisms is needed.

Before deploying soldiers to areas with malaria, the US military instructs them on malaria protection and supervises their uses of protective measures. Why, then, are rates of malaria 44 times higher among US military members who were born in West Africa? Findings of a recent study suggest that malaria risk is high when military members travel to their birth countries to visit friends and family in West Africa. While on leave in West Africa, nobody makes military members take antimalarial drugs, sleep under bednets, or take other actions to prevent mosquito bites. When growing up in their malarious homelands, current military members may not have worried about malaria; and when they return home as soldiers, they may assume that they still don't need to worry. However, childhood immunity to malaria wanes over time. As a result, US military members who are born in countries with malaria are susceptible when they return home; protective measures should be emphasized before such persons return to their homelands.

Cattle and goats as protection against Lyme disease? A study of risk along a hiking trail in Germany found that risk was much lower on the parts of the trail that passed through cattle or goat pasture than through meadow or abandoned land. Not only were there fewer ticks in the pasture, but fewer ticks from those areas carried the bacterium that causes Lyme disease. Proposed reasons are that grazing decreases the tick habitat and that ticks lose Lyme disease bacteria when they feed on these animals. Thus, using land as cattle and goat pasture might also minimize Lyme disease risk for people on that land. Particular methods of landscape management also appear to support public health.

Like canaries in a mine, dogs can indicate Lyme disease risk in humans. The bacterium that causes Lyme disease is spread by ticks, and whether a dog (sick or healthy) has been exposed to infected ticks can be detected by blood testing. A comparison of data from humans and dogs shows strong agreement between these 2 independent measures of Lyme disease risk. In addition, however, data from dogs may help predict areas of Lyme disease emergence. Combining data from humans and dogs could help health officials focus Lyme disease prevention efforts and help doctors interpret clinical and laboratory findings.

Cosmetic surgery, body piercing, and tattooing can lead to infection, particularly in people with weakened immune systems. Although tattooing is not a sterile procedure, measures should be taken to minimize risk for infection including properly training tattoo artists and using sterile equipment. Two newly reported infections after tattooing stand out because they occurred in people with healthy immune systems and because they were caused by a type of bacterium, Mycobacterium haemophilum, not previously found in tattoo infections. The infection might have come from the tap water used to dilute the ink. Because these bacteria are not usual suspects in tattoo infections and because testing for them is difficult and takes a long time, labs don’t routinely run these tests. From now on, however, doctors should consider Mycobacterium haemophilum as a possible cause of tattoo infection and should ask labs to test for it.