Updates

By 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, is Associate Editor for Infectious Disease Alert.

Our Lady of 100 Victims of Norovirus

Source: Verheof L, et al. Import of norovirus infections in the Netherlands and Ireland pilgrimages to Lourdes, 2008 - following report. Eurosurveillance. 2008; Volume 13.

Lourdes has been an important Catholic pilgrimage site for the elderly and infirm since 1858. This year marks the 150th anniversary of the apparition known as the "Lady of Lourdes," which was observed on multiple occasions that year by a 14-year-old peasant girl out searching for firewood. Her sister and a friend did not share in the vision, but spoiled the spirit of the event by spilling the beans to the parents. Both kids got a beating, although the 14-year-old was later canonized by the church as a saint in 1933. By the 15th vision, over 9,000 people were present at the grotto, hoping to share in the vision with the young girl, some of whom began claiming the spring waters had miraculous healing powers. By the 18th and final vision, the French gendarmes had cordoned off the site and prohibited visitors from reaching the grotto. Controversial in its own time, some believe the spot would have not have attracted as much interest had the police acted less forcibly in restricting access.

Lourdes has become the busiest Marion shrine in the Catholic Church, and anticipates more than 8 million visitors this year. As the result of an active surveillance system established in 1999, called the Food-Born Viruses in Europe (FBVE) network, a series of norovirus outbreaks in October 2008 were quickly recognized and traced back to Lourdes. The FBVE network was first alerted about an outbreak of norovirus at a mental health institution for the elderly in the Netherlands in October. Four persons died, and one remains critically ill as of the date of this publication, underscoring the high morbidity of this infection in the elderly. Twenty-four health care workers and patients from the institution had traveled to Lourdes at the end of September. During their trip, two of the party became ill with acute gastroenteritis symptoms, including one who was too ill to leave her hotel room. A total of 119 of the 550 (22%) of the institutional patients developed gastroenteritis.

An initial alert from the FBVE network was forwarded to Municipal Health Services and microbiologists, prompting reports of three other clusters of norovirus cases involving pilgrims to Lourdes at about the same time. Genotyping demonstrated the cases were due to a common norovirus strain (genotype II.4 2006b variant). As a result of this prompt response, the cases were traced back to six local hotels in Lourdes that had been housing groups of pilgrims from Italy, France, Ireland, and Denmark, at least three of which had been coping with an outbreak of diarrhea in guests between September 28 and October 16.

Thus far, the investigation has identified 90 primary cases of norovirus within seven groups of pilgrims to Lourdes, resulting in more than a hundred cases of secondary infection in three different countries. Containment efforts appear to have brought the outbreak under control, although the source for the infection has not yet been determined. French authorities routinely check the spring water for bacteriologic quality, although this would not exclude viral contamination. Under these circumstances, with such a high density of travelers, environmental contamination and person-to-person transmission is likely. The FBVE network provided a rapid and effective response to a problem spread over multiple countries.

Viral Failure Predicted in Women with Blips

Source: Geretti A, et al. Doubled risk of failure after 1 year under 50 copies in women and steady blippers. Abstract H-1256; 48th ICAAC, October 2008.

Geretti et al tracked the risk of virologic failure (VF) in 1386 HIV-infected persons after starting their first HAART regimen (between 1996 through 2005) at two primary HIV care clinics in London and Frankfurt. Just over half (57%) were MSM; 80% were male; and 63% were Caucasian, 25% black African, and 12% other ethnic minorities. After achieving virologic suppression (plasma viral load < 50 copies/mL), 74.5% of the patients maintained complete virologic suppression for the first year of treatment, whereas 19.4% were transient one-time only "blippers" and 6.1% experienced two or more consecutive blips (defined as low-level viremia between 50-400 copies/mL).

Geretti et al examined multivariate predictors of virologic failure over the subsequent years (defined as two or more consecutive plasma viral loads > 400 copies/mL, or a viral load > 400 copies/mL that resulted in a regimen change); VF occurred in 86 (6.2%) patients at a median of 2.2 years. Multivariate analysis showed that the strongest predictor of failure was the occurrence of consecutive blips during the first year of therapy (OR 2.18, CI 1.15 to 4.10). Additional predictors of VF included the use of a boosted-protease-inhibitor-containing regimen vs a non-nucleoside containing one (OR 1.88), the use of a triple nucleoside regimen vs a non-nucleoside-containing one (OR 1.87), and female gender (OR 1.79).

Patients who were frequent "blippers" during the first year of HAART therapy were more likely to prematurely fail treatment. In addition, woman and patients who received boosted PI therapy were more likely to fail their regimen. Geretti et al concluded that patients who have trouble taking their medications, experience more side effects, or who have poor access and compliance with care, such as many of their poor West African female clients, are more likely to fail therapy.

A Rabies Update

Sources: ProMED-mail post, November 11, 2008; www.promedmail.org; ProMED-mail post, October 24, 2008.

I was attending a lovely dinner party the other evening when the 55-year-old husband of a friend merrily shared his experience rock climbing with his son three days earlier up on Lone Ridge Reserve off of Skyline in Santa Clara County. This was only his 3rd effort at rock climbing, which he described as an incredible rush. But what gave me a rush was the next part of the story: While canvassing the cliff, he put his hand in a crevice, felt something brush up against his hand, and then felt a tingle in his index finger. Seconds later, out flew a bat. Since there was no visible bite or blood, he didn't think much of it. The party was stunned when it was suggested he should receive rabies vaccine. Presumably, this bat was healthy and peacefully taking an afternoon nap, although the local health officer on-call concurred with the assessment of higher-risk contact in this case and the need for rabies prophylaxis.

My quick review found no published cases of high-risk bat exposure associated with rock climbing. In addition, a review of rock climbing websites found no reference to a risk for bat exposure nor recommendations for rabies pre-prophylaxis, although this is often suggested for spelunkers. It may be appropriate for health authorities to consider this recommendation if bat contact in rock climbers is common.

1) A remarkable survivor of rabies encephalitis is being reported by the Department of Health in Floresta Pernambuco, Brazil. A 15-year-old boy developed onset of symptoms in early October, about 29 days after having been aggressively bitten by a hematophagous bat (eg, a vampire bat). He had received four doses of rabies vaccine before the onset of symptoms. Within four days of the onset of symptoms, he was transferred to a tertiary care center, and rabies was confirmed with a hair follicle biopsy of the nape of the neck. Rabies virus consistent with that from a vampire bat was identified by RT-PCR. Within seven days of onset of symptoms, he was transferred to the ICU, intubated, and what has become known as the Milwaukee protocol was initiated. (The Milwaukee protocol was used in the 15-year-old Wisconsin girl who miraculously survived rabies in 2004, and is intended to induce coma, and control cerebral edema and cerebral artery spasm). Four weeks later, the Brazilian patient was brought out of his induced coma, and remains clinically stable. No details on his neurologic condition are yet available.

Rare survivors of rabies who received some rabies post-exposure prophylaxis and vaccination have been reported. The young Wisconsin girl remains the only survivor of rabies to date who developed symptoms prior to initiation of medical care and rabies vaccination, although her virus was never isolated for further characterization.

2) The United Kingdom has long enjoyed its human rabies-free status (the last cases of human rabies from an animal other than bats occurred in 1902), although a bat lyssavirus has been rarely found in Great Britain, known as European Bat Lyssavirus type 2 (EBLV-2). A passive surveillance system in place since 1987 screens downed bats for possible rabies virus.

Recently, the Health Protection Agency reported the 8th confirmed EBLV-infected bat, which was found dead at a heritage site in Shropshire in October.

Although there are about 17 species of bats in the United Kingdom, all eight of the EBLV-infected bats found to date have been the same species of bat, and this is the second found in Shropshire. EBLV is in the same family as rabies virus, and is found in insectivorous bats in northern Europe. While it causes symptoms in infected bats, the risk for human infection appears to be low, unless humans are directly exposed to saliva from an infected bat. A bat handler in Scotland died of EBLV infection in 2002. For this reason, it is recommended that persons in the United Kingdom who handle bats, or come in contact with a sick or dead bat, should receive rabies vaccine, although the presence of EBLV in low levels does not threaten the UK's rabies-free status.