Friday, March 11, 2016

Zika Virus Infection

During my recent trip to Haiti I was bitten by a mosquito that carried Zika virus and I developed clinical symptoms.

On the day after Christmas I woke up with a generalized rash. The rash was on my chest, back, arms, and legs. There was no rash on my face, palms, or soles. The rash consisted of small flat irregular-shaped spots less than 5 mm in diameter. My skin felt a bit itchy.The whites of my eyes were red (conjunctivitis). I had a headache and felt a somewhat achy generally. I otherwise felt well and I worked that day and the next.

The rash and the red eyes lasted about a week. I measured my temperature every night for the first 3 or 4 nights and the highest I recorded was 37.8 degrees.

I did not have a sore throat, runny nose, or cough. I did not have specific pains in my large or small joints.

During the day before the rash developed (Christmas) I had two watery poops and after the second liquid poop I decided to take Cipro just in case this might be the start of a bacterial gastroenteritis. My poops stayed fine thereafter. I have never taken Cipro before and when the rash developed the next day I wondered if perhaps this might be an allergic reaction to the antibiotic.

The rash and the other symptoms slowly resolved over about a week and during this time I decided the rash was either a viral infection or an allergic reaction to the Cipro.

After I returned home I had blood, urine and poop tests done, and I had a TB skin test. I routinely get checked out when I return from working abroad. My sedimentation rate test (ESR) was elevated and this suggested inflammation somewhere in the body. This test does not imply a specific infection or disease. The other tests were normal.

By the time the lab results were available the rash and other symptoms had long resolved but I was keen to track down the cause. By this time Zika was in the news and my reading from the Center for Disease Control suggested this was a likely cause for the symptoms. I had another blood test to look for Zika virus and for other viruses that might cause the symptoms. These tests take time. In early March I was notified that my Zika virus IgM studies were positive. IgM is an antibody protein that increases after a recent infection with the virus. This test implies my symptoms were due to Zika virus.

I had done my very best to avoid insect bites in Haiti. I set up a mosquito net and I routinely slept under the canopy every night. I was careful to tuck the net in around the bed. The mosquito that transmits Zika virus usually feeds (bites) during the daytime. I left for work at dawn and was usually back in the dormitory at nightfall. I wore long pants, shoes with socks, and a t-shirt. My arms, neck and face were therefore exposed during the daytime. I did not see mosquitoes in the hospital but I did see a few in the dormitory. I do not recollect a bite.

Even though I saw very few mosquitoes, and even though I took good precautions, I was still bitten and infected with Zika virus. Based on this, my sense is that infection with Zika Virus is likely inevitable for travellers to endemic areas. If the virus is proved to cause congenital malformations, this is indeed a serious public health problem for pregnant women.

Zika Virus was first discovered in 1947 and until recently was only reported in tropical Africa, Southeast Asia, and the Pacific Islands. In May 2015 the Pan American Health Organization (PAHO) confirmed the first case of Zika virus in Brazil and on February 1, 2016 the World Health Organization (WHO) declared Zika virus to be a public health emergency of international concern. 

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