Infectious Disease Alert: Updates
By Carol A. Kemper, MD, FACP
Fit for a king, but not a parasite
Piers D, et al. The intestinal parasites of King Richard III. The Lancet, early online publication, September 4, 2013. Doi:10.1016.S0140-6736 (13)61757-2.
"History is a myth that men believe" Napoleon Bonaparte
With a nose for solving a mystery, members of the Richard III Society in England, in conjunction with researchers at the University of Leicester, have discovered the remains of Richard III, King of England, under what is now a city parking lot, in the location of the ancient ruins of Greyfriars Priory, 20 miles outside of Leicester. The story was described in the New York Times, February 4th of this year. Richard III, who was killed at the Battle of Bosworth Field August 22, 1485 was immortalized as a demonic figure of epic proportions by Shakespeare for having usurped the throne and murdered his two young nephews. The king’s supporters theorize the case against him may have been a political smoke and mirrors maneuver by the Tudors, and hope the identification of his remains will prompt a more just reassessment of his reign, and suitable burial with honor as a king.
In a fun ID twist to the story, samples taken from the sacral area where the intestines would have been show evidence of roundworm eggs, consistent with Ascaris lumbricoides. Samples of earth from the sacral area were collected, microsifted, and analyzed, and the eggs were identified by light microscopy. They measured 55 to 70 micrometers in length. There was no evidence of other parasite eggs. Control samples taken from the skull and surrounding earth were also negative (the authors indicate that minimal environmental soil contamination with parasites was found, as expected).
Since several other species of intestinal parasites were common in England at the time, including fish, pork and beef tapeworms, whipworm, and the liver fluke, Fasciola hepatica, the authors argue King Richard must have eaten very well-cooked meat. Investigation of his remains also revealed the extent of his scoliosis, photos of which are available in the Times’ article.
Popsicles with fungal antigen?
Guigue N, et al. False positive galactomannan test after ice-pop ingestion. New Engl Jrl Med 2013;369:1:97-98.
Positive galactomannan blood tests by enzyme immunoassay are taken as proof of Aspergillus antigenemia — and generally prompt specific antifungal therapy. However, a few published reports suggest there may occasionally be false-positive test results, possibly as the result of cross contamination or cross reaction with certain food substances. The actual basis for the false positive results has not been elucidated.
A 42-yearold bone marrow transplant candidate had multiple negative serial galactomannan blood tests for 30 days post-transplantation. On days 32 and 34 post- transplant, her tests became positive. Extensive work up with CT scans, cultures, and a PCR on blood for Aspergillus were all negative. She was presumptively started on voriconazole. She had been suffering from graft vs host disease, and not eating anything — except apparently 3-4 flavored popsicles a day (sans stick), which she started on day 29 post-transplantation.
Popsicles from the same batch were tested for galactomannan, and surprisingly came up positive! Within 7 days of not eating any more popsicles, her blood tests became negative. Sadly, she went on to die of her GVH disease, but developed no evidence of fungal infection.
High levels of galactomannan were observed in 37 samples of different flavored ice-pops from 3 brands. No evidence of Aspergillus was found by PCR or culture of any of the 37 different pops. Three of the cultures grew penicillium, possibly from cross-contamination from the paper wrapping. Broad based fungal DNA multiplex PCR of the pops were negative. The galactomannan tests actually exhibited a prozone effect, and were negative when the popsicles were straight tested, but positive on serial dilutions. The source of the galactomannan in the ice-pops is not known, but food additives or thickeners are suspected to possibly cross with the assay.
Should MSM receive meningococcal vaccine?
Simon MS, et al. Invasive meningococcal disease in men who have sex with men. Ann Intern Med 2013;159(4):300-301.
A question we’ve been asking ourselves in our HIV clinic is whether to administer meningococcal vaccine to which, if any, of our HIV+ patients in Santa Clara County, California. Since 2010, 22 cases of invasive meningococcal disease have been reported in men who have sex with men (MSM) by the New York City Public Health authorities. The estimated incidence of invasive meningococcal disease in MSM in 2012 in New York City was approximately 50-fold higher than that of the general population (0.3 cases per 1000,000) (age-adjusted). The mean age of these men was 34 years, and the fatality rate was 32%. Twelve (54%) were HIV +, and their mean CD4 count was 525 cells/mm3; 70% were virologically suppressed on their most recent blood work. Four additional cases in MSM have been reported by Los Angeles health authorities during the same time period. Many of these cases occurred after hanging out in crowded bars or large social gatherings. Previous outbreaks of meningococcal meningitis were reported in Toronto in 2001 and in Chicago in 2003, resulting in a total of 12 cases, with a case fatality rate of 42%. Molecular studies suggest these outbreaks were each caused by a common strain of bacterium.
In response, the NYC Department of Health and Mental Hygiene (NYC DOHMH) began in October 2012 aggressively promoting vaccination of all MSM, and even offering free vaccine, especially for those participating in Gay Pride events. The advisory also recommended offering vaccine to all MSM, regardless of HIV status, with close or intimate contact with men met either through an online website, digital application, or at a party or bar. Since then, it is estimated more than 11,000 men in New York have received vaccine, and since February 2013, no similar cases have been reported in NYC. Health departments in other major urban areas including San Francisco, Los Angeles, and Toronto, as well as the Commonwealth of Massachusetts, also began similarly recommending immunizing MSM if they plan to travel to NYC or plan to "socialize with New Yorkers" (or anyone who could potentially be from New York). (I’m not sure how this would really work — since some of my patients don’t even know the names of their sexual contacts, let alone where they are from.) Concern remains that hard to reach groups of MSM, such as African Americans, and those who do not identify as gay, may not be easily reached by these advisories.
The question remains whether all MSM — especially those who are HIV+ - should be candidates for meningococcal vaccine. Although there is limited evidence regarding the risk of invasive infection in HIV+ individuals, it follows that HIV-positive individuals may be at increased risk for invasive meningococcal infection, similar to their increased risk for pneumococcal infection (another encapsulated organism). And it is known that the meningococcal quadravalent vaccine is immunogenic in HIV+ individuals, at least in HIV+ adolescents. Two doses seems to improve the immunogenicity of vaccine.
While the risk of invasive meningococcal disease in MSM seems low, and clearly episodic, it seems no less significant than the risk of someone traveling to the Hajj, or going off to college to live in a dorm — both current indications for vaccination. Vaccination is also recommended for microbiologists, where the attack rate has been estimated to be 13 cases per 100,000, less than that described above. While the ACIP has made no formal recommendations, it seems reasonable to at least offer vaccination to my HIV+ patients. I cannot predict when they may wake up one day and take off for New York, or decide to participate in a Gay Pride event, or a picnic on the back forty with friends. But isn’t the point of vaccination prevention?