Dengue virus transmission is more likely when mosquitoes feed on the blood of infected persons who are anemic and iron deficient. Thus, iron supplementation in dengue-prone areas might help reduce the transmission of the deadly mosquito disease.
Highlights:
- Dengue virus transmission is more likely when
mosquitoes feed on the blood of infected persons who are anemic and iron
deficient - When mosquitoes bite and feed on the blood of a dengue
virus infected person who is rich in iron, the gut cells of the mosquito
take up the ingested iron to produce reactive oxygen. This reactive oxygen
kills the dengue virus within the mosquito and prevents further transmission - Dengue fever is a life-threatening illness prevalent in
Central America and northern South America, sub-Saharan Africa, Southeast Asia and the Caribbean.
Mass iron supplementation programs in these regions may reduce dengue
transmission
Dengue virus transmission is more likely when mosquitoes
feed on the blood of infected persons who are anemic and iron deficient,
according to a recent study conducted at the University of Connecticut together
with teams at
King Mongkut’s Institute of Technology Ladkrabang in Bangkok, Tsinghua
University and State Key Laboratory of Infectious Disease Prevention and
Control in Beijing and the 920 Hospital Joint Logistics Support Force in
Kunming.
Quality of Blood Influences Dengue Virus
Transmission
The study team including immunologist Penghua Wang from the University
of Connecticut wanted
to check if the quality of blood might play a part in
the transmission of dengue virus since the levels of various chemicals and
substances vary drastically from person to person. They wanted to then see
whether this parameter can be modified to reduce dengue
transmission.
Although
a vaccine exists, it is dangerous to give the vaccine to someone who has never
been previously infected. Health experts and public health officials are
actively looking for ways to reduce the prevalence of dengue fever and
reduce transmission. The
findings of the study appear in the journal Nature Microbiology.
Role
of Blood Quality In Dengue Virus Transmission
- They
team obtained fresh blood from healthy human volunteers, and added dengue
virus to each and every sample collected - Following
this, blood from the different samples were fed
to different groups of mosquitoes and the rate of infection in each group
estimated - The
team found the infection rate among the mosquito groups varied widely and this variation very closely
matched to the level of iron in the blood sample
“The
more iron in the blood, the fewer mosquitoes were infected,” says Wang. The team
found it held true in a mouse model, too: mosquitoes feeding on mice infected
with dengue were much more likely to acquire the virus if the mice were anemic.
Thus, the findings of the study suggest that iron deficiency can contribute to the spread of
deadly dengue fever.
How Adequate Iron Levels Prevent Dengue Virus
Transmission
When mosquitoes bite and feed on the blood of a dengue
virus-infected person who are not anemic, the gut cells of the mosquito take up
the ingested iron to produce a toxic chemical called reactive oxygen. This reactive
oxygen kills the dengue virus inside the mosquito and prevents further
transmission.
Interestingly, the prevalence of iron deficiency in
dengue-endemic areas is high and might explain the increased virus
transmission. Thus supplementing iron to the general population through health
programs may reduce dengue transmission, but the team found that there is a
huge catch to iron supplementation.
Caution Needed while Supplementing Iron in
Dengue Endemic Areas
Malaria tends to be prevalent in areas similar to
dengue. Paradoxically, plasmodium, the parasite causing malaria, grows well in
iron-rich environment and can, therefore,
cause severe infection in persons having adequate amounts of iron. Thus, mass iron supplementation programs need to be weighed carefully for risk-benefit balance before being introduced
in such areas.
About
Dengue Fever in Brief
- Dengue
fever is an infectious disease caused by the dengue virus and spread by
mosquitoes in the tropical areas including primarily Central America and
northern South America, sub-Saharan Africa, Southeast
Asia and the Caribbean - Dengue
is associated with high fever, headaches, rash, severe muscle and joint pains and extreme fatigue. Severe
bleeding may occur in some patients with shock and death - About
60 million cases are reported annually across the world with 18% having
severe infection needing hospitalization with nearly 14000 deaths annually
Scope
of the Study
Understanding
how disease transmission occurs may help public health authorities take proper
preventive measures in place, not only for dengue virus but other infections such
as Zika virus
and West Nile virus.
In
summary, in areas where iron deficiency anemia is prevalent the
rates
of dengue virus transmission is higher.
Therefore,
public health officials should consider mass iron supplementation after
weighing the risks and benefits to prevent this devastating
mosquito-borne disease.
Reference:
- Anemia May Contribute to the Spread of Dengue Fever – (https://today.uconn.edu/2019/09/anemia-may-contribute-spread-dengue-fever/)
Source-Medindia
Leave a Reply