Did You Know....
The Aspergillus Web Site, http://www.aspergillus.man.ac.uk, is designed to provide information on pathogenic Aspergillus species for clinicians and scientific researchers. The site includes DNA sequence data, a comprehensive bibliographic database, laboratory protocols, treatment information (including management algorithms), and discussion groups.
By Carol A. Kemper, MD
Antenatal HIV Screening in Ireland
Source: Birchard K. Lancet 1998; 352:796.
This news brief from the Lancet describes Ireland’s recent success in the care of HIV-infected pregnant women. Ireland provides antenatal antiretroviral therapy, presently using combinations of antiretroviral agents, to all known HIV-positive women. Since the program started in 1994, none of the children born to known HIV-positive women have been HIV infected. Based on this accomplishment, the Irish Department of Public Health is preparing draft guidelines for screening all pregnant women for HIV infection, much the same as that recently proposed for the United States. The head of the National Pediatric AIDS Program, Karina Butler, MD, acknowledged, however, that, as a result of the success of their program, some HIV-positive women are choosing to have more children.
Another Bad Cat Tale. . .
Source: Zanusso G, et al. Lancet 1998;352:1116-1117.
Neurologists at the university of Verona report on the simultaneous occurrence of clinically similar spongiform encephalopathies in a 60-year-old man and his 7-year-old previously healthy cat. The cat usually ate canned cat food (which can contain cattle remains) and slept with her owner in the same bed. The man was not known to have any unusual dietary habits—although pensioners have been known to eat pet food because it’s cheap.
The man presented with visual complaints, cerebellar ataxia, and myoclonic jerks; he rapidly deteriorated and died within two months. The cat presented with similar symptoms, and required euthanization one week after her owner’s death. This rapid disease progression differs from other reports of feline spongiform encephalopathy.
Although there is considerable controversy whether differing strains of prion-protein complexes (e.g., from differing origins) can be distinguished based on their size and morphology, examination of the brain tissue from both the man and his cat showed similar histopathological changes, as well as similar prion-protein constellations—which Zanusso and colleagues believed were similar to those observed in cases of sporadic Creutzfeldt-Jakob disease, but differed from those associated with Bovine-spongiform encephalopathy (BSE).
While it is not clear whether these two cases represent a common source of infection (e.g., the cat food) or possible horizontal transmission (in either direction), Zanusso et al believed that, based on the genetic strain typing and the similar clinical presentation, the two cases appear to be causally related but inconsistent with BSE.
Malarone for Malaria Prevention
Source: Shanks GD, et al. Clin Infect Dis 1998;27:494-499.
Current prophylactic regimens for malaria are limited by a lack of universal efficacy, convenience, and tolerance. The combination of atovaquone and proguanil (Malarone) has proven safe and effective in the treatment of drug-resistant Plasmodium falciparum and is being used with increasingly frequency in England and Europe. Although the mechanism is not well understood, atovaquone and proguanil (A/P) act synergistically against blood parasites (schizonticides).
Shanks and associates examined the safety and effectiveness of A/P as a chemoprophylactic agent in Lwak, Kenya, an area of intense disease activity in the spring and summer, when this study was conducted. Following a course of four tablets of atovaquone (250 mg) plus proguanil (100 mg) per day for three days (a regimen designed to eradicate any pre-existing infection), adult volunteers were randomized to one of three regimens for 10 weeks: two tablets daily, one tablet daily, or placebo.
None of the patients receiving either of the two treatment regimens developed P. falciparum infection, whereas more than one-half (52%) of the patients in the placebo group developed disease (P = 0.001). The frequency of side effects were comparable for all three groups, and none of the treated patients experienced dose-limiting side effects (one patient required hospitalization for repeated vomiting during the initial 3-day treatment course). Daily A/P was well tolerated and was 100% successful in preventing malaria during this 10-week trial in Kenyans at high risk for chloroquine-resistant malaria. Similarly, A/P was highly effective and well-tolerated when administered as prophylaxis to children in Gabon (Lell B, et al. Lancet 1998;351:709-713).
Malarone will be a valuable chemoprophylactic alternative to mefloquine in the United States once approved by the FDA and can safely be administered to children. The cost of a Malarone tablet in countries outside the United States is reportedly about $7, which is not cheap, but it is comparable to the cost of mefloquine in our area ($8.43 per tablet).