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http://www.thenews.com.pk/print1.asp?id=29652
<TABLE cellSpacing=0 cellPadding=0 width=778 align=center border=0><TBODY><TR><TD vAlign=top width=37></TD><TD vAlign=top width=611><TABLE cellSpacing=0 cellPadding=0 width="96%" align=center border=0><TBODY><TR><TD align=middle height=20><TABLE cellSpacing=0 cellPadding=0 width="100%" align=center border=0><TBODY><TR><TD></TD><TD></TD><TD class=small_txt vAlign=bottom align=right>Editor-in-Chief: Mir Shakil-ur-Rahman </TD></TR><TR><TD width=206></TD><TD width=368></TD><TD width=204></TD></TR></TBODY></TABLE><TABLE id=Table_01 cellSpacing=0 cellPadding=0 width="100%" align=center border=0><TBODY><TR><TD class=small_txt width=349></TD><TD width=75></TD><TD class=small_txt align=right width=354></TD></TR></TBODY></TABLE></TD></TR><TR><TD bgColor=#efefef>
</TD></TR><TR bgColor=#f4faff><TD class=heading_txt height=20> Asian tiger mosquito may be behind fever outbreak</TD></TR><TR><TD></TD></TR><TR><TD bgColor=#efefef></TD></TR><TR><TD></TD></TR><TR><TD class=small_txt height=20> </TD></TR><TR><TD class=small_txt>KARACHI: Local health experts find a reason to worry as they feel that another virus with symptoms similar to those of dengue fever have caused the fever outbreak after realising that more than 60 percent of the suspected Dengue fever cases failed to prove positive.
Aedes Aegypti, the mosquito that is believed to spread dengue may not be the sole culprit for the present outbreak because another breed of mosquito called Aedes Albopictus (the Asian tiger mosquito) is also quite abundant in Karachi and is a vector for Chikungunya Virus or the CHIK Virus (CHIKV), a disease with symptoms similar to those of Dengue viral fever.
Dr. Rafiq Khanani, Associate Professor of Pathology at the Sindh Medical College, said that there is enough reason for the health circles to believe the incidence of this new kind of virus in the current epidemic as a large number of cases have not been established as those of Dengue fever.
?Firstly, the virus typically follows the rainy season and its notorious epidemics are reported during the last quarter of the year, while Dengue only breeds in very high temperatures, and secondly, India has received more than 1.25 million patients with CHIKV during February up until October 2006,? he said.
The clinical manifestations of Chikungunya fever have to be distinguished from dengue fever. Co-occurrence of both fevers has also been observed in Maharashtra state of India. In early illness, the clinical features of CHIK fever can be similar to those of Dengue and malaria, especially in patients without joint symptoms. Its habitat is also almost the same as Aedes Aegypti?s.
Because no specific drug therapy is available, treatment of CHIK fever is supportive. Chikungunya fever is a self-limiting condition and is not a life- threatening infection. Symptomatic treatment for mitigating pain and fever using anti-inflammatory drugs along with rest usually suffices. Prevention is entirely dependent upon taking steps to avoid mosquito bites and elimination of mosquito breeding sites. Special care should be provided to infected persons as mosquitoes become infected when they bite people who are sick with Chikungunya.
While recovery from Chikungunya is the expected outcome, convalescence can be prolonged (up to a year or more), and persistent joint pain may require analgesic (pain medication) and long-term anti-inflammatory therapy. Chloroquine is gaining ground as a possible treatment for the symptoms associated with Chikungunya and as an anti-viral agent to combat the Chikungunya virus.
According to scientific reports, most CHIKV infections are symptomatic. ?Silent? CHIKV infections (infections without illness) do occur; but how commonly this happens is not yet known. Human CHIKV infections include a transient, high-titered viremia (typically detectable during the first two days of illness, ranging up to 6 days after illness onset) that is adequate to infect feeding mosquitoes. In clinical infections, the incubation period typically is 2-4 days.
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Chikungunya is characterized by sudden onset of fever, headache, malaise, arthralgias or arthritis (pain and swelling of joints) involving the wrist, ankle, knee and small joints of the extremities, myalgias (muscular pain), and low back pain.
Some patients have prolonged fatigue lasting several weeks. The term ?Chikungunya? is derived from Swahili dialect which means ?that which bends up.? As due to severe joint pains patient may assume a stooping posture.
Skin rash occurs in approximately half of cases. Although CHIK fever typically lasts 3-7 days and full recovery is the usual outcome, certain patients experience persistent joint symptoms for weeks or months and occasionally years after illness onset. Serious complications (e.g., neuro-invasive disease) are rare. Acute Chikungunya fever typically lasts a few days to a couple of weeks. No deaths, neuro-invasive cases, or hemorrhagic cases related to CHIKV infection have been conclusively documented in the scientific literature.
The most important differentiating features from Dengue infection is that Chikungunya is a relatively mild condition, joint involvement is more common, reduction in platelets is less common and less marked, abdominal pain is less common and patients do not progress to circulatory shock or coma. One attack of CHIKV infection is believed to confer life-long immunity. No effective vaccine exists.
The CHIK fever was first recognized in epidemic form in East Africa during 1952?1953. Chikungunya virus (CHIKV) which is a member of the genus Alphavirus, in the family Togaviridae is transmitted by the bite of infected mosquito Aedes Aegypti which is the primary CHIKV vector in Asia, but Ae. albopictus (the Asian tiger mosquito) may also transmit the virus.
In Asia, CHIKV epidemics involve a human-mosquito cycle, with humans serving as the sole vertebrate amplifying hosts. In Africa, sylvatic cycles involving nonhuman primates and forest-dwelling Aedes species (e.g., Ae. Furcifer) also occur. Mosquitoes become infected when they feed on a person infected with CHIKV.
Monkeys, and possibly other wild animals, may also serve as reservoirs of the virus. Most CHIKV epidemics occur during the tropical rainy season and abate during the dry season. Because CHIK fever epidemics are sustained by human-mosquito-human transmission, the epidemic cycle is similar to those of Dengue.
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<TABLE cellSpacing=0 cellPadding=0 width=778 align=center border=0><TBODY><TR><TD vAlign=top width=37></TD><TD vAlign=top width=611><TABLE cellSpacing=0 cellPadding=0 width="96%" align=center border=0><TBODY><TR><TD align=middle height=20><TABLE cellSpacing=0 cellPadding=0 width="100%" align=center border=0><TBODY><TR><TD></TD><TD></TD><TD class=small_txt vAlign=bottom align=right>Editor-in-Chief: Mir Shakil-ur-Rahman </TD></TR><TR><TD width=206></TD><TD width=368></TD><TD width=204></TD></TR></TBODY></TABLE><TABLE id=Table_01 cellSpacing=0 cellPadding=0 width="100%" align=center border=0><TBODY><TR><TD class=small_txt width=349></TD><TD width=75></TD><TD class=small_txt align=right width=354></TD></TR></TBODY></TABLE></TD></TR><TR><TD bgColor=#efefef>
</TD></TR><TR bgColor=#f4faff><TD class=heading_txt height=20> Asian tiger mosquito may be behind fever outbreak</TD></TR><TR><TD></TD></TR><TR><TD bgColor=#efefef></TD></TR><TR><TD></TD></TR><TR><TD class=small_txt height=20> </TD></TR><TR><TD class=small_txt>KARACHI: Local health experts find a reason to worry as they feel that another virus with symptoms similar to those of dengue fever have caused the fever outbreak after realising that more than 60 percent of the suspected Dengue fever cases failed to prove positive.Aedes Aegypti, the mosquito that is believed to spread dengue may not be the sole culprit for the present outbreak because another breed of mosquito called Aedes Albopictus (the Asian tiger mosquito) is also quite abundant in Karachi and is a vector for Chikungunya Virus or the CHIK Virus (CHIKV), a disease with symptoms similar to those of Dengue viral fever.
Dr. Rafiq Khanani, Associate Professor of Pathology at the Sindh Medical College, said that there is enough reason for the health circles to believe the incidence of this new kind of virus in the current epidemic as a large number of cases have not been established as those of Dengue fever.
?Firstly, the virus typically follows the rainy season and its notorious epidemics are reported during the last quarter of the year, while Dengue only breeds in very high temperatures, and secondly, India has received more than 1.25 million patients with CHIKV during February up until October 2006,? he said.
The clinical manifestations of Chikungunya fever have to be distinguished from dengue fever. Co-occurrence of both fevers has also been observed in Maharashtra state of India. In early illness, the clinical features of CHIK fever can be similar to those of Dengue and malaria, especially in patients without joint symptoms. Its habitat is also almost the same as Aedes Aegypti?s.
Because no specific drug therapy is available, treatment of CHIK fever is supportive. Chikungunya fever is a self-limiting condition and is not a life- threatening infection. Symptomatic treatment for mitigating pain and fever using anti-inflammatory drugs along with rest usually suffices. Prevention is entirely dependent upon taking steps to avoid mosquito bites and elimination of mosquito breeding sites. Special care should be provided to infected persons as mosquitoes become infected when they bite people who are sick with Chikungunya.
While recovery from Chikungunya is the expected outcome, convalescence can be prolonged (up to a year or more), and persistent joint pain may require analgesic (pain medication) and long-term anti-inflammatory therapy. Chloroquine is gaining ground as a possible treatment for the symptoms associated with Chikungunya and as an anti-viral agent to combat the Chikungunya virus.
According to scientific reports, most CHIKV infections are symptomatic. ?Silent? CHIKV infections (infections without illness) do occur; but how commonly this happens is not yet known. Human CHIKV infections include a transient, high-titered viremia (typically detectable during the first two days of illness, ranging up to 6 days after illness onset) that is adequate to infect feeding mosquitoes. In clinical infections, the incubation period typically is 2-4 days.
.
Chikungunya is characterized by sudden onset of fever, headache, malaise, arthralgias or arthritis (pain and swelling of joints) involving the wrist, ankle, knee and small joints of the extremities, myalgias (muscular pain), and low back pain.
Some patients have prolonged fatigue lasting several weeks. The term ?Chikungunya? is derived from Swahili dialect which means ?that which bends up.? As due to severe joint pains patient may assume a stooping posture.
Skin rash occurs in approximately half of cases. Although CHIK fever typically lasts 3-7 days and full recovery is the usual outcome, certain patients experience persistent joint symptoms for weeks or months and occasionally years after illness onset. Serious complications (e.g., neuro-invasive disease) are rare. Acute Chikungunya fever typically lasts a few days to a couple of weeks. No deaths, neuro-invasive cases, or hemorrhagic cases related to CHIKV infection have been conclusively documented in the scientific literature.
The most important differentiating features from Dengue infection is that Chikungunya is a relatively mild condition, joint involvement is more common, reduction in platelets is less common and less marked, abdominal pain is less common and patients do not progress to circulatory shock or coma. One attack of CHIKV infection is believed to confer life-long immunity. No effective vaccine exists.
The CHIK fever was first recognized in epidemic form in East Africa during 1952?1953. Chikungunya virus (CHIKV) which is a member of the genus Alphavirus, in the family Togaviridae is transmitted by the bite of infected mosquito Aedes Aegypti which is the primary CHIKV vector in Asia, but Ae. albopictus (the Asian tiger mosquito) may also transmit the virus.
In Asia, CHIKV epidemics involve a human-mosquito cycle, with humans serving as the sole vertebrate amplifying hosts. In Africa, sylvatic cycles involving nonhuman primates and forest-dwelling Aedes species (e.g., Ae. Furcifer) also occur. Mosquitoes become infected when they feed on a person infected with CHIKV.
Monkeys, and possibly other wild animals, may also serve as reservoirs of the virus. Most CHIKV epidemics occur during the tropical rainy season and abate during the dry season. Because CHIK fever epidemics are sustained by human-mosquito-human transmission, the epidemic cycle is similar to those of Dengue.
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