We are NOT authorized by Govt of India for Yellow Fever Vaccination

Friday, October 6, 2017

Dengue and yellow fever: two Kenyan cities at high risk, Oct 2017

study published in PLOS One last month (17 August) shows that poor urban planning in Kenya could aid the re-emergence of dengue and yellow fever, transmitted through mosquitoes: Aedes aegypti and Aedes bromeliae.

Dengue, a viral disease spread by day-biting mosquitoes, “is the fastest spreading vector-borne viral disease” and has reached more than 100 countries, according to the WHO. Patients with the non-severe form of dengue develop high fever, flu-like symptoms and stomach pain, the severe form could result in the death of 20 per cent of patients with the disease. Meanwhile, yellow fever, a viral disease spread by infected mosquitoes could kill about 50 per cent of those infected with its severe form within seven to ten  days, says WHO.

“Our study is helping to identify areas where the vector is present in high abundance that can sustain transmission of the virus.”

Rosemary Sang, Kenya Medical Research Institute


The study was conducted in the outskirts of three Kenyan cities — Nairobi and Kisumu, which have no known history of dengue outbreak and Mombasa, which is prone to dengue outbreak — from October 2014 to June 2016 during the wet and dry seasons.
Researchers from Kenya-based International Centre of Insect Physiology and Ecology (icipe) and South Africa’s University of Pretoria measured the abundance of the mosquitoes Ae. aegypti and Ae. bromeliae.

According to the study, 7,424 Ae. aegypti and 335 Ae. bromeliae were collected from all sites, made up of 100 houses for each city and season.

Ae. aegypti remains the only known dengue vector in Kenya with sufficient abundance in the major cities to sustain transmission,” the authors note. “It is highly abundant and the risk values are indicative of high risk of dengue transmission in Kilifi and Kisumu.”

Rosemary Sang, a co-author of the study and a consultant scientist at the icipe, tells SciDev.Net that dengue outbreak in Kenya has only occurred in few specific locations in the coast and that the research team “wanted to establish the risk of spread of outbreaks to other areas”.

Sang, a principal research scientist at the Arbovirology Unit, Kenya Medical Research Institute, adds that more experiments are underway to determine if these vectors can transmit the viruses.

“Our study is helping to identify areas where the vector is present in high abundance that can sustain transmission of the virus should the disease get imported through infected travellers from outbreak countries or regions,” explains Sang, adding that this will be important for early warning and implementation of preventive measures.

Omu Anzala, a professor of medical microbiology at the University of Nairobi, lauds the study for increasing knowledge and understanding of newly emerging pathogens. “Being able to understand and predict whether there is impending epidemic is very important,” Anzala tells SciDev.Net. “We should be doing this regularly, looking at indicators of early warning so that we are better prepared [during disease outbreak].”

Anzala encourages research uptake by policy makers to enable them act quickly on outcomes of studies on emerging disease outbreaks.   
 
This piece was produced by SciDev.Net’s Sub-Saharan Africa English desk.
Source

Over 6000 receive free yellow fever vaccination in Uganda, Oct 2017

By Ritah Kemigisa:
Over 6000 people have been immunized in the three day free yellow fever campaign  organized by the National Medical Stores and the ministry of health that ends today to reward tax payers.
Speaking to Kfm at Kololo independence grounds on the last day of the URA tax payers appreciation week, the NMS General Manager Moses Kamabare says by the end of today more than 10,000 people are expected to be immunized and issued with yellow fever cards.
Kamabare says due to the overwhelming turn up of people the ministry of health together with NMS have decided to add more five days for the free services adding that come next week the services shall still be offered to the people at Kololo independence grounds.
Kamabare adds that as a government policy only people with national identification cards are allowed to access the free services.
According to the Ministry of Health and Civil Aviation Authority, all passengers traveling in and out of Entebbe International Airport are supposed to present proof of immunization against the disease inform of certificates or cards.

Experts Alarmed by Yellow Fever Cases in Asia, Oct 2017

Eleven cases of yellow fever (YF) brought to China in 2016 were quickly contained but set off fear that the disease might gain a foothold in Asia, where 1.8 billion unvaccinated people could be at risk.
The introduction, by workers returning to China from Angola, highlight the dire straits epidemiologists face in trying to contain a disease with limited vaccine supplies. Shortages of YF vaccine developed because of outbreaks and the need for mass vaccinations in Angola and Brazil. By July 24, 2017, stocks of the only YF vaccine approved in the United States had been depleted, and supplies are not expected to become available for routine civilian use again until mid-2018.
Daniel R. Lucey, MD, MPH, and Halsie Donaldson, MS, both from the Division of Infectious Diseases, Georgetown University Medical, Washington, DC, write that the new risk for YF in Asia means that "the global vaccine stockpile must contain more than the projected 1.38 billion doses needed to eliminate existing YF epidemics by 2026." They published their findings online September 25 in Annals of Internal Medicine. The authors also explain that the 80-year-old, egg-based method currently used to manufacture YF vaccine cannot be scaled up quickly enough to stop urban epidemics.
"Thus, new YF vaccines based on cell culture and DNA technologies should be developed now, rather than in the mid to long term cited in the [World Health Organization's] Global Strategy to Eliminate Yellow fever Epidemics," the authors write.
Peter Hotez, MD, PhD, dean of the National School of Tropical Medicine, professor of Pediatrics and Molecular & Virology and Microbiology, and head of Pediatric Tropical Medicine at Baylor College of Medicine, Houston, Texas, agreed that new methods for producing YF vaccine are urgently needed, even without the potential for YF outbreaks in Asia.
"With regard to Asia, it remains somewhat of a mystery as to why YF has not spread there, as has Japanese encephalitis. Some have speculated that circulating dengue and [Japanese encephalitis] strains may provide some cross-protective herd immunity, but we really don't know the answer," Dr Hotez told Medscape Medical News. "But there are 3 million Chinese working in Africa now, through their belts-and-road initiative, and there is a theoretical threat to Asia. Moreover, we can be sufficiently concerned about YF in the western hemisphere and Africa alone to raise the issue of YF vaccine shortage."
Dr Hotez said that Dr Lucy and Donaldson are right to be concerned about the potential for YF outbreaks in both Africa and the Americas, as well as the possibility of YF vaccine shortages. "In the western hemisphere, we have seen during the last few years the rise of dengue, Zika, chikungunya, and other arboviruses transmitted by Aedes aegypti, so the threat of YF is very real. This is due to shifts in poverty and climate change. The risk to other areas, including the United States, has been further heightened by increased population density in urban areas, making transmission more likely, and by the widespread presence of mosquitoes able to transmit the virus," he said.
However, Dr Hotez also echoed the comment by Seth Berkley, MD, chief executive from Global Alliance for Vaccines and Immunization, that emergency vaccine stockpiles should be the last line of defense against YF, after better mosquito control, routine YF immunization, and preemptive vaccination campaigns. According to Dr Berkley, emergency YF vaccine stockpiles are essential, but "if we have to call upon them, we have in some way already failed. They should be our last line of defense."
Dr Berkley notes that the current global emergency stockpile of YF vaccine is about 6 million doses, a supply that could be quickly exhausted if Rio (population 12 million) and one other major city had YF outbreaks.
Meanwhile, shortages in the United States are already limiting the availability of YF travel vaccinations, which are required for travelers to enter some countries.
Dr Hotez told Medscape Medical News that part of the problem is the demand for YF vaccine has not been high until recently. "There is not always a high market incentive for vaccine manufacturers to make vaccines for pandemic threats, which is why the new organization [Coalition for Epidemic Preparedness Innovations] has been established," he said.
In the United States, YF vaccination is not routinely recommended except for patients traveling to an endemic area. Containing a potential outbreak is likely to be complicated by the fact that few US physicians have ever seen a case of YF, which causes a self-limited fever in 85% of patients but black vomit; bleeding from nose, mouth, and eyes; jaundice; and renal damage in the other 15%, half of whom die from the infection.
The authors and Dr Hotez have disclosed no relevant financial relationships.
Ann Intern Med. Published online September 26, 2017. Abstract
Source (nneds free registration)

Friday, September 29, 2017

Yellow Fever Vaccine Shortages in the United States and Abroad: A Critical Issue, Annals of Internal Medicine, Sept 2017

Yellow fever (YF) virus, a flavivirus that infects the liver, causes a self-limited febrile syndrome in 85% of patients. In the other 15%, however, it causes jaundice, bleeding, and renal damage, and half of these patients die. No antiviral therapy exists. In urban settings, YF virus is transmitted between humans by Aedes aegypti mosquitoes, as are Zika, dengue, and other viruses. Outside urban settings, in the jungle or forest (“sylvatic cycle”), YF transmission occurs between monkeys and from monkeys to humans via non-Aedes mosquitoes (1).

The United States had YF epidemics in the 18th and 19th centuries. In the 20th century, epidemics occurred in sub-Saharan Africa, Latin America, and the Caribbean. The first cases in Asia were reported in 2016, when 11 workers returned home to China after having been infected in Angola (1).