NEWS SCAN: Dengue vaccine progress; cholera vaccine study; polio in Myanmar; TB linked to substance abuse, elephants

Feb 17, 2011

World getting closer to dengue vaccine, experts say
The world's first vaccine for dengue fever may become available within the next few years, US health officials said at a press teleconference at a dengue meeting in Puerto Rico today. Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases (NIAID), noted that one dengue vaccine is now in phase 3 clinical trials. "If that turns out to be successful, then you're just a few years away," he said. "If not, I can't really predict." Sanofi Pasteur launched the first phase 3 trial of its dengue vaccine candidate last November in Australia. Fauci said a number of other dengue vaccine candidates are in phase 1 trials. "All of us are very optimistic that we're heading in the right direction and should not be too far away," he added. Harold Margolis, MD, director of the dengue branch at the Centers for Disease Control and Prevention (CDC), seconded him, saying, "I think there's been tremendous progress in the last 5 years. We're finally getting into the home stretch." Fauci said the NIAID spent $44.4 million on dengue research in 2010, compared with $30 million in 2005. He also commented that 1.5 million dengue infections were reported in Latin America in 2010. The purpose of the Puerto Rico conference, hosted by the NIAID, CDC, and Pan American Health Organization, is to build collaborative dengue research efforts, he said.
Feb 17 press conference transcript
Nov 4, 2010, Sanofi news release on launch of phase 3 trial

Bangladesh to launch massive study of oral cholera vaccine
Bangladesh is preparing to launch the world's largest trial of an inexpensive oral cholera vaccine, according to an Agence France-Presse (AFP) story today. Starting tomorrow, researchers will administer the India-made vaccine to 160,000 people living in Mirpur, one of Dhaka's poorest suburbs. Another 80,000 people will not receive the vaccine, and both groups will be monitored for 4 years to test the vaccine's effectiveness. The World Health Organization (WHO) estimates that up to 5 million people contract cholera each year around the globe, with as many as 120,000 of them dying.

Rare polio strain triggers vaccine effort in Myanmar
A rare vaccine-derived poliovirus strain has re-emerged in Myanmar after a 3-year absence, spurring a campaign to vaccinate children, according to a report today from the United Nations (UN)-based Integrated Regional Information Networks (IRIN). A case in a 7-month-old in December was confirmed by lab testing, and two more cases were detected last month but are not yet lab-confirmed, according the local UN Children's Fund (UNICEF) office. "But one case is enough [to require] an emergency response," said Marinus Gotink, UNICEF's chief of health and nutrition in Myanmar. Myanmar's Department of Health has already vaccinated 10,000 children living near the 7-month-old, and UNICEF and the WHO plan to immunize more than 3 million children in 109 of the country's 325 townships. The vaccine-derived poliovirus comes from a strain used in the oral polio vaccine that can mutate into a form that can paralyze, according to the report, which also underscores that vaccine is the only way to combat it and the more common wild strain.
Feb 17 IRIN report

TB outbreaks strongly linked to substance abuse
A federal review of recent US tuberculosis (TB) outbreaks showed substance abuse to be a leading factor in disease spread, along with misdiagnosis and inability to do a full contact investigation, according to a study released yesterday in Emerging Infectious Diseases (EID). CDC investigators identified 27 outbreaks from 2002 through 2008 in which the agency was involved that included at least three cases linked by genotype and epidemiology. Twenty-four of the 27 outbreaks involved US-born patients, and 17 were linked to a drug house. Other places associated with outbreaks were homeless shelters (5 outbreaks), prisons (4), households (4), and workplaces (4). In addition, 58% of the 398 patients involved in the outbreaks reported substance abuse, most commonly alcohol. The following factors were identified in TB transmission: delayed diagnosis related to providers (12 outbreaks), inappropriate treatment (2), delayed diagnosis on part of patient (6), not adhering to treatment (5), mistrust of public health (6), incomplete contact investigation, often because of hard-to-reach populations (10), and a crowded at-risk setting (7). The authors conclude, "Substance abuse remains one of the greatest challenges to controlling tuberculosis transmission in the United States."
Feb 16 EID study

TB transmitted from captive elephants to caretakers
Another EID study reports that nine employees working on an elephant refuge in Tennessee contracted TB from a resident elephant. After receiving positive tuberculin skin tests in 2009, officials from the Tennessee Department of Health conducted a cohort study and on-site assessment. In 2006, the refuge had accepted eight elephants from an exotic animal farm that had been exposed to TB and were therefore quarantined. The investigators' study of 46 refuge employees identified 9 who had positive tuberculin skin tests between 2006 and 2009. They found that employees who worked more than 4 hours in the quarantine barn during 2009 were 20 times more likely to have TB, and that those who worked in adjacent offices were also at increased risk of infection. The researchers concluded that the indirect exposure to aerosolized Mycobacterium tuberculosis—TB's causative agent—and delayed or inadequate infection control practices likely contributed to transmission.
Feb 16 EID study

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