Updates

by Carol A. Kemper, MD, FACP

Mystery Lung Nodule in Baker—Case Closed

Source: Ren P, et al. J Clin Micro. 2004;42(6):2840-2842.

How many times as an id Consultant have you been faced with a case with abnormal pathology suggestive of mycobacterial or fungal infection but cultures were either not obtained or were lost? This was the circumstance facing Ren and colleagues, who evaluated a previously healthy 40-year-old man who presented with an isolated ~0.7 cm pulmonary nodule, discovered on a routine chest X-ray. The man worked as an employee in a bakery, had never smoked, and was asymptomatic. Histopathology revealed a solitary, well-demarcated inflammatory mass. Hematoxylin and eosin stain revealed small spherical-to-oval organisms. Silver staining confirmed the presence of small budding yeasts, 5-15 micrometers in diameter.Unfortunately, tissue was not saved for culture.

Using a nested PCR, using first universal primers and then species-specific primers, a local mycology laboratory was able to successfully amplify DNA from paraffin-embedded tissue consistent with Saccharomyces cerevisiae. Further work-up revealed no evidence of immune deficiency. He received no specific therapy, and remained well for 2 years thereafter. Since he worked in a bakery, it is reasonable to assume that occupational exposure was the source of his infection.

Frequency of CJD in Asymptomatic Britons

Source: BBC News Online, May 21, 2004; ProMED-mail post, May 21, 2004.

Scientists in the united kingdom have discovered that 0.024% of routine surgical specimens have tested positive for variant Creutzfeldt-Jacob disease (vCJD), suggesting that up to 3800 persons in Britan may harbor the prion protein without knowing it. In this government funded study, 12,674 stored tissue samples of appendix and tonsil examined for evidence of vCJD. Most of the specimens were from the late 1990’s, and most were obtained from healthy persons in their 20’s undergoing routine procedures. Surprisingly, 3 of the specimens were positive, although the investigators cautioned that 2 of the specimens showed features somewhat atypical from those obtained from patients with confirmed vCJD.

While the significance of this data is not known, the obvious concern is that asymptomatic carriers may pose a threat to the blood supply or from contaminated specimens from elective procedures. A second larger study involving an assessment of 100,000 tonsil specimens is planned.

Prepared Infant Formula a Risk

Source: New Scientist Print Edition, June 4, 2004.

Two studies presented at the American Society for Microbiology meeting in New Orleans 2 weeks ago reported finding a surprising frequency of baby food contaminated with bacteria. Iverson and colleagues surveyed powdered infant formula, dried infant food and milk powder commonly sold within the United States, 7 European countries, Korea, and South Africa. In total, they examined 200 samples of 110 products. Eight of 82 samples of powdered infant formula (10%) and 12 of 29 samples of dried infant food (24%) were contaminated with up to 13 different bacterial species. One bacterium in particular identified in some samples was Enterobacter sakazakii, which has been implicated in outbreaks of neonatal meningitis in hospitals in Europe and the United States. One outbreak in Tennessee in 2001 cased serious infection in 9 children, including 1 death.

In a second study, the doubling time for bacterial colony counts in prepared infant formula was 10 hours in the refrigerator but only 30 minutes at room temperature. This suggests that the practice of "being prepared" with ready bottles in your day pack—or by setting up bottles in the fridge before bedtime for easy use in the middle of the night—may pose an increased risk.

Does Mefloquine Pose an Unacceptable Risk to US Soldiers?

Source: United Press International, May 31, 2004.

The continued use of mefloquine in United States soldiers stationed in Afghanistan and Iraq is becoming an increasingly hot button issue. While Military Health Officials continue to assert the safety of the drug in military personnel, and deny any connection to several murder-suicides in soldiers who received the drug, other members of the military may be having their doubts. According to doctors at the Naval Medical Center in San Diego, 6 service members are believed to be suffering from serious long-term neuropsychiatric and neurologic effects after taking melfoquine, including vestibular effects and memory loss. One of the servicemen, a Naval Reserve Commander, has filed suit against the drug’s manufacturer, Hoffmann LaRoche, claiming inadequate safety warning. Apparently this individual had suicidal ideation while receiving drug, and 1 year after discontinuation continues to be plagued with severe balance problems, trembling and memory loss.

The UPI reports that, in a letter dated May 24th to the HHS Secretary, Sen. Diane Feinstein wrote "six service members have been diagnosed with permanent brain stem and vestibular damage from being given this drug, despite the fact that alternative drugs might have been chosen to prevent infection."

Army officials and the Department of Veterans Affairs have announced plans to assess the long-term safety of mefloquine, including the risk of suicide, in military personnel. Neuropsyschiatric symptoms are known to be significantly more common and more severe in persons who receive mefloquine vs chloroquine. However, earlier data may provide some interesting clues to longer-term problems with mefloquine, even after the drug is stopped (the serum half-life is ~21 days). For example, in a survey of 1340 young travelers without a previous history of psychiatric problems, 1.2% reported ongoing neuropsychiatric symptoms more than 2 months after taking mefloquine.1,2 This included sleep disturbances, dizziness, vivid dreams and nightmares. Frank depression occurred in 0.5%. Nearly one-fourth of those surveyed admitted to the use of "recreational drugs" during their travel, including psychotropic mushrooms, speed, ecstasy, marijuana, and hashish.

It is interesting to speculate whether the concurrent use of illicit substances and alcohol—not to be underestimated in the military—may act as a co-factor in the development of neuropyschiatric problems with mefloquine. My guess is that earlier safety studies of mefloquine did not examine young military recruits, some of whom may have occult neuropsychiatric problems (or who may be at risk), who may use drugs and alcohol, and who are getting shelled somewhere on the other side of the world.

Reference

1. Potasman I, et al. J Travel Med. 2000;7:5-9;

2. Kemper CA. Infectious Disease Alert. 2000.

Adherence with HIV Vaccination Guidelines Poor

Source: Tedadi EM, et al. Clin Inf Dis. 2004;38:1478-1484.

Clinical care guidelines have recommended the routine use of hepatitis A vaccine (HAV) and hepatitis B vaccine (HBV) in HIV-infected persons for many years, especially for individuals at greatest risk for infection, such as men who have sex with men (MSM) and those with underlying liver disease. However, compliance with these guidelines varies amongst caregivers.

Tedadi and colleagues assessed the usual care practices for screening and vaccination for hepatitis in 9 HIV clinics across the United States. Surveys of laboratory tests results in 1071 patients found that 82% and 57% had been, respectively, screened for hepatitis B and A virus serologies. While 612 patients were eligible for HBV, only 32% received at least 1 dose of HBV; 17% received the full series. Of these, confirmatory follow-up serologies were obtained in 51 patients, and only 19 (3%) had evidence of a "response" documented in the medical record.

Of those patients eligible for HAV, 23% received at least 1 dose; 13% received 2 doses. Vaccine rates varied widely by site, with ranges of 4-68% for HBV, and 0-34% for HAV.

While chronic hepatitis C co-infection is considered an indication for vaccination, the prevalence of HCV co-infection was no different in those who received HBV or not. In addition, there was no significant difference in the use of antiretroviral therapy between those who did or did not receive vaccintion. Bivariate analyses found that HBV was more common in women, whites, high-risk hetersexuals, and patients with public insurance. HAV was similarly more common in women, patients with low viral loads, and individuals who did not identify as MSM.

While patients with lower CD4 cell counts (eg, < 200 CD4 cells/mm3) may have lower rates of response—a legitimate reason to possibly defer vaccination in some patients till their CD4 counts are higher—this did not appear to be the basis for non-adherence with current recommendations. Given the morbidity and mortality associated with acute hepatitis B infection, and to a lesser degree hepatitis A, clinics providing HIV care should examine their policies and procedures for improved delivery of these basic services to patients with HIV, especially those patients at greatest risk for hepatitis.

Carol A. Kemper, MD, FACP, Clinical Associate Professor of Medicine, Stanford University, Division of Infectious Diseases; Santa Clara Valley Medical Center, Section Editor, Updates, Section Editor, HIV.