Kenya - Sh991m to fight cholera, says Ministry | Cholera bacteria show adaptability to changing environments
Campbell, Dan
Kenya - Sh991m to fight cholera, says
Ministry
December 9 2009 at 16:25
http://www.nation.co.ke/News/-/1056/820054/-/vo1k18/-/
The Health Ministry has said it requires Sh991million to fight the
cholera outbreak in the country.
Public Health and Sanitation Assistant
minister Dr James Gesami added that the situation was grim.
Some 131
deaths have been recorded in the last month due to acute water diarrhoea out of
4,842 cases.
The House heard that eleven districts are seriously affected
in Turkana, East Pokot, Kamukunji, Starehe and Kasarani in Nairobi, Ruiru,
Chalbi in Eastern and Lamu and Malindi in Coast province.
New cases
continue to arise and according to the Assistant minister, this is due to
insufficient access to safe drinking water and poor hygiene.
Since last
year, some 11,307 cases of cholera have been reported countrywide and 259 deaths
recorded from the same, according to the assistant minister.
Dr Gesami
was responding to a question by Turkana Central MP Ekwe Ethuro (PNU) who sought
to know why the cases were recurring in about 70 districts.
The member
wondered why the government has not declared the outbreak a national disaster.
Mr Ethuro said this should be done urgently to enable government mobilise
resources required to confront the health problem.
Kinagop MP David Ngugi
(Sisi kwa Sisi) accused the government of playing a reactive role instead of
investing in a system that would enable early detection and prevention of a
crisis.
The Assistant minister, responding to members’ concerns said the
government was concentrating on urgent intervention measures which involve case
management, medical supplies and diseases surveillance.
The outbreak
sweeping across the country has been described one of the worst cholera
outbreaks in a decade.
A shortage of cholera kits and other essential
medical supplies, rehydration supplies, antibiotics, gloves and other assorted
supplies has been reported and the amount being sought by government is expected
to boost their supply.
In October, the Metrological Department had warned
of the possible escalation of cholera and waterborne disease and advocated
sustained water chlorination campaigns.
Cholera bacteria show
adaptability to changing environments
Dec 7,
2009
http://www.ucsc.edu/news_events/press_releases/text.asp?pid=3429
Cholera bacteria can live as free-swimming individuals (above) or
form colonies called
biofilms.
The deadly bacterium
behind cholera epidemics spends only a fraction of its life infecting humans.
Most of the time, Vibrio cholerae lurks in estuaries and other semisalty aquatic
habitats.
Understanding the pathogen's behavior between epidemics and its
transitions between different environments could help public health officials
prevent outbreaks, according to microbiologist Fitnat Yildiz.
"If you
know the mechanisms by which an organism can survive in the environment, you can
better devise systems to prevent its transmission," said Yildiz, an associate
professor of microbiology and environmental toxicology at the University of
California, Santa Cruz.
The optimal salt concentration for growth and
survival of V. cholerae is similar to that found in brackish water and
estuaries. But the bacteria experience fluctuations in salinity both in their
aquatic habitat and during human infections.
A recent analysis by Yildiz
and graduate student Nick Shikuma revealed that changes in salinity affect the
activity of a wide range of the pathogen's genes. Among these is a gene the
researchers called OscR, which appears to play an important role in managing the
pathogen's response to fluctuating salt levels in the environment. (More
precisely, it responds to changes in osmolarity, a measure of the concentration
of dissolved substances.) Yildiz and Shikuma described their findings in a
recent paper in the Journal of Bacteriology.
Cholera outbreaks occur when
environmental conditions allow the bacteria to contaminate sources of drinking
water. "Cholera is a disease of disaster," Yildiz said. "Whenever there's a
breakdown in public health, like during the Iraq War or in refugee camps, when
people don't have access to clean drinking water, cases of cholera
increase."
In areas of Africa and South Asia where cholera is endemic,
outbreaks occur seasonally. Two peaks coincide with the dry season and the
monsoon rains, according to Paul Dunlap of the University of Michigan, who wrote
a commentary accompanying the paper in the Journal of Bacteriology. During the
dry season, freshwater sources become more salty, opening them to colonization
by V. cholerae. Flood conditions during monsoons can also lead to contamination
of drinking water sources.
Yildiz and Shikuma found more than 300 cholera
genes that respond to changes in salinity, many of which Yildiz and others had
previously linked to the pathogen's deadliness. In medium salt environments
similar to the human body, for instance, genes controlling virulence rev
up.
The researchers found that OscR is a regulatory gene that switches on
under low salt conditions and controls the activity of other genes. OscR
increases bacterial motility and decreases the formation of sticky cell
groupings called biofilm, Yildiz said.
Biofilm colonies form when
individual cells secrete matrices of sugar chains and proteins that help them
glom on to neighbors and to surfaces. Many kinds of bacteria form biofilms,
which act as bacterial shields, making cells harder to kill and more tolerant of
environmental fluctuations. Within biofilms, V. cholerae is more resistant to
antimicrobial and chlorine-based disinfectant treatments, Yildiz
said.
"What we learn with respect to the mechanisms of biofilm formation
in V. cholerae could be applicable to other organisms because biofilm formation
is so prevalent and it is so important for clinical, environmental, and
industrial processes," she said.
V. cholerae forms biofilms both in
infected hosts and in the environment. During cholera infection, biofilms cling
to intestinal walls, releasing a steady stream of debilitating toxins.
Scientists have even found biofilms riding through the water on tiny crustaceans
called copepods, as well as in stool samples from cholera
patients.
Yildiz has been investigating the network of genetic
interactions that regulates biofilm formation. This network, in which
environmental cues regulate genes that control other genes, works like a complex
domino chain in which one piece knocks down several others.
OscR blocks
the toppling dominos that lead to biofilm formation. Why the pathogen prefers
being a mobile single cell in freshwater remains a mystery but is the topic of
future study, Yildiz said. Knowing how the pathogen passes through freshwater
versus salty water may help to expose the dynamics of cholera infections, she
said.
But shifts in environmental dynamics rarely occur in isolation.
Changes in salinity go hand-in-hand with changing temperatures and nutrient
levels. A holistic model of V. cholerae behavior, Yildiz said, will include how
these factors work in tandem.
"We are analyzing environmental
fluctuations singly, but the goal is to eventually combine them," she said.
"When you combine multiple stresses, you get a different
response."
Yildiz collaborates with scientists in Bangladesh who help her
re-create South Asian estuary or freshwater conditions in the lab. Eventually,
however, she wants to study V. cholerae in the field.
Cholera is readily
treated, but without treatment it causes rapid and often fatal dehydration from
severe diarrhea. The World Health Organization estimates that 120,000 people die
from cholera every year. Yildiz said that her work is just one step in a wide
effort to predict and curb cholera epidemics.
Yildiz and Shikuma's
research was funded in part by a grant from the National Institutes of Health,
the ARCS Foundation, the Coastal Environmental Quality Initiative, the STEPS
Institute at UCSC, and the Friends of the Long Marine Lab.
Dan Campbell, Web
Manager
Environmental Health at USAID
1611 North Kent St., Suite 300
Arlington, VA 22209
Ph:
703-247-8722
Email: dcam...@usaid.gov
Environmental Health at USAID: http://www.ehproject.org
Indoor Air Pollution Updates: http://iapnews.wordpress.com
Sanitation Updates: http://sanitationupdates.wordpress.com
Urban Health Updates: http://urbanhealthupdates.wordpress.com
Cholera Google Group: http://groups.google.com/group/cholera-control
Household Water Treatment Google Group: http://groups.google.com/group/household-water-treatment