Thursday, April 24, 2008

Goodbye to Vellore

Well folks,
I am about to embark on the "after" part of my Vellore - n -after trip. Goodbye shreiking giant mutant bats that wake me every morning. Goodbye crazy Vellore town. Goodbye CMC, which I got to know from a variety of viewpoints! I got to see and do and learn a lot. Some disappointments, but I'm still very very happy with my experience overall.

So now I head up to Delhi this evening. Felicia already got there this AM. She called to let me know that the hotel there we had been corresponding with regularly, which had arranged to pick her up at the airport when she got in at 5AM 1) did not pick her up 2) had no rooms available when she got there. Stupid Hotel Tara Place. You will get some bad on-line reviews from us.
The last I hear, she had found another place, but could not check in until noon, so I guess she's hanging out in Delhi for a few hours. In theory they will pick me up too.....let see what happens.

We'll spend 2 day in Delhi, and take a day trip to Agra to see the Taj Mahal. Then we fly down to Cochin in Kerala, stay there a day (hopefully wash some elephants), go down to Alleppey, back on a house boat, then down to Varkala for a night, then to the very bottom and Trivandrum (Thiruvanathapuram). From there, fly up to Mumbai for a few days, and finally head home on the 9th of May. Wow. I am going to need a vacation after this trip.

Internet access may be spotty. I'll post text whenever I can. Pics will depend on many things, but I shall try. Felicia's going to post on here too.

2 more weeks of wacky fun! Wish us luck!

Chikungunya Virus

CHIKUNGUNYA - A Problem for Vellore, Tamil Nadu, India, and the World

Overview

Chikungunya fever is a re-emerging viral disease, especially in South India, characterised by abrupt onset of fever with severe arthralgia followed by generalized fatigue, fever, chills, nausea, vomiting, lower back pain and rash lasting for 1-7 days. The disease is usually self-limiting, and rarely fatal. The virus (CHIKV) is an RNA virus beloning to family Togaviridae, genus Alhpavirus, and derived its name from the Makonde word meaning "that which bends up", referring to the stooped posture developed as a result of the arthritic symptoms of the disease.

History
There are apparently two distinct lineages in Africa and Asia. This arbovirus shows some diversity between these two strains. In Africa, the disease cycle is maintained between monkeys and wild mosquitos in the forest. In contrast, the Asian lineage cycles between humans and our old friends the Aedes aegypti (also the vector for yellow fever, Dengue, and other fun diseases. Basically, they are jerks) mosquito. These like to bite during the daylight hours.







The first recorded epidemic was in the early 1950s, in Tanzania. Shortly after that, CHIKV was noted in Bangkok, Thailand in 1958, with viral transmission continuing up until 1964. There followed a period of quiescence, a hallmoark of this disease, followed by a second period of activity in Bangkok in the mid 1970s, finally declining in 1976.


In India, there have been well documented outbreaks in 1963 and 1964 in Kolkata (Calcutta) and southern India. This 1964 outbreak was very well documented, as it was focused on Vellore (home to the CMC), Chennai, and Puducherry. As the rainy season turned to summer, moquito populations bloomed, and as temps dropped and things dried out, the mosquito polulations shrank, with a resultant decline in human cases. A small outbreak was reported in Maharashtra (around Mumbai/Bombay) in 1973. One of the most publicized ourbreaks was among several islands in the southwest Indian Ocean, namely La Reunion, Mauritius, and the Seychelles, apparently ongoing now since 2005.










In keeping with its pattern of activity-quiescence-activity, the disease has also reappeared throughout southern India since December 2005, in the states of Andrha Pradesh, Karnataka, Maharashtra, Madhya Pradesh, and Tamil Nadu (where I am right now). This outbreak continues to the present day. In June 2007 there were 7000 confirmed Chikungunya patients in southern India, and it appeares to have spread from Kerala and Tamil Nadu to Sri Lanka around this time. As of Jan 2008, at least 8 people had been diagnosed with CHIK in Melbourne, Australia, and in Singapore authorities were given legal power to detain any Chikungunya cases.








Clinical Features


As stated above, this is an acute infection with abrupt onset of fever and severe arthralgia, followed by other constitutional signs, with a rash lasting for a total of 1-7 days. The incubation period is usually 2-3 days. Fever often rises rapidly to 39-40 C, and shaking chills, with this acute phase lasting 2-3 days. The temperature me wane for 1-2 days, then return, in a "saddleback" fever curve.


Arthralgias are polyarticular, migratory, and predominately in the small joints of the wrists, ankles and feet. They usually progress in a specific order, actually. Knee, then ankle, then wrist, then phalanges, then elbow. Patients in acute stage are incredibly reluctant to move, prefering to remain in the flexed position, often confined to bed.


Patients do not exhibit any active bleeding, but do evidence hypotension and GI distress.


Cutaneously, patients present with flushing over the face and trunk, followed by a maculopapular rash, occasionally extending to the face, palms, and soles of the feet.



Other signs and symptoms can include headache, photophobia with retroorbital pain, conjunctival redness, sore throat, and pharyngitis.


Neurologically, encephalopathy is the most common sequela, with alterred sensorium and ataxia. An EEG within normal limits offers a good prognosis and decreased likelihood of mortality. CSF shows increased proteins, increased activated lymphocytes. On MRI, multiple high-density dots are seen (similar to those seen in Nipah virus). There are no spinal cord changes seen. Other than encephalopathy, the other common neurologic manifestations are myelopathy, polyradiculopathy, neuropathy (early > late), and carpal tunnel syndrome (2/2 excess synovial fluid and swelling).



Dangerous sequalea may occur in neonates, who are prone to developing meningo-encephalitis. This disease can be transmitted vertically from mother to fetus. Similar complications occur in the immunosuppressed as well.


The tricky thing is that symptoms of CHIK infection are almost identical to those opf Dengue fever, and dual infections of these two have been reported.





Prognosis varies with age. Younger patients tend to revover completely within 5-15 days, while the middle aged take 1 to 2.5 months. The elderly can take even longer.



Detection



A serological test has been developed and is in wide use throughout affected regions. This is employed via am IgM card test. There are also rt-PCR assays. The actual virus has only been isolated from CSF twice.


Management


At present, as with many viral infections, there are no specific treatments for Chikungaya fever. Luckily it tends to be self-limiting and resolve with time. Stiffness and morning arthralgia can be improved with movement and mild exercise, but heavy activity appears to exacerbate the problem. Many medicatons have been tried. IV Methylprednisone, plamapheresis, IVIg, and others, alone and in combinations, have had poor responses. NSAIDs are recomended, and Chloroquine has been reported as useful on arthritides refractory to NSAIDs.



Otherwise, one should keep infected people away from mosquitos to reduce further transmission.


Prevention


There is no vaccine currently available. A Phase II vaccine trial sponsored by the US in 2000 used a live attenuated virus and showed 85% resistance at 1 year.


Other measures recomended are the same as for all mosquito-born illnesses. Cover yourself, use DEET, eliminate breeding sites by dumping, covering, or draining stagnant water etc etc.






This might work too.




Follow-up


Why Chikunganya exhibits its active-rest-active cycle is as yet unclear. Recent outbreaks have been more severe, and sequencing indicates that the virus may have altered its virus coat protein, aloowing it to replicate in mosquitos more rapidly. The recent vaccine trials are promising, but wide-spread use has been postponed pending the outcome of long-term studies.