Media attention has been drawn to the Brazilian babies born with small heads, a neurological defect known as “Microcephaly”. Zika, a previously little known virus, is thought to be behind it. Zika was first detected in 1947 in Uganda (found in monkeys of Zika forest). It has been found sporadically in humans in limited areas. An unexpected outbreak was reported on Yap Island in the southwestern Pacific Ocean in 2007. But prior to the Brazilian outbreak, a significant correlation between Microcephaly in newborn and Zika infection had not been established. Many, therefore, wonder if Microcephaly is a new syndrome.
Zika virus is believed to be transmitted through the bite of infected Aedes mosquitos. Aedes agypti and Aedes albopictus are among the mosquito species known to transmit Zika virus to humans. Both mosquito species are found in Nepal including in Kathmandu. Travelers from Zika affected regions thus pose significant threat to Nepal. Some researchers have also pointed at possible transmission of Zika through sexual contact, though only few studies are available to confirm this. Transmission through blood transfusion has also been reported.
It is estimated that 80 percent of people infected with Zika do not display clinical symptoms, while remaining patients show rashes, joint pains and red eyes. Fever, body ache, pain behind the eyes and vomiting are other symptoms. These symptoms are similar to those of dengue and chikungunya viruses, both of which have been reported in Nepal. Therefore it is difficult to identify Zika based only on symptoms.
Symptoms usually appear between two to seven days after a person is bitten by an infected mosquito and they last for a week. No cases of death or internal bleeding have been established by previous studies. This means Zika virus may manifest in milder illnesses than dengue and chikungunya. Zika infection cannot be confirmed without laboratory investigations.
Tests like ELISA, PCR and Virus Isolation are performed to identify Zika. ELISA test can be positive only after five days of symptoms. The person who has been affected by viruses such as dengue, West Niles, yellow fever and Japanese Encephalitis (which are already known to exist in Nepal) can also show positive in ELISA test, creating the impression that it could also be Zika.
PCR test is a highly reliable method for detection of Zika. It can be detected during the first three to five days of illness. These laboratory facilities have not been set up in Nepal yet.
No specific approved antiviral drug is available for Zika in Nepal. Owing to its relatively mild symptoms, pharmaceutical companies seem reluctant to invest in the development of medicine to treat this virus. Patients suspected of Zika infection are recommended to take plenty of rest until symptoms disappear. Given the suspected link between Zika virus and Microcephaly, researchers are trying to develop Zika vaccine as early as possible.
It may make take years to find safe, effective and cost-effective vaccine in resource-poor countries like Nepal. Preventive measures are what we can take at the moment to avoid potential risk. The government has issued a travel warning for Zika affected regions. Such warnings may not be enough to prevent the public from panicking.
Thus the government, in coordination with WHO, should lead the awareness campaign against Zika using social media, education institutions and advocacy groups. Once the virus enters Nepal, it may lead to serious long-term public health consequences in areas where vector mosquitoes are active the year round.
Increasing numbers of newborns with neurological disorder has prompted widespread worldwide concerns. The majority of people with milder symptoms may not seek immediate hospital care, which could spread the virus in the community. Pregnant women are particularly at risk of giving birth to babies with underdeveloped brains. Thus the government should make Zika virus test mandatory during pregnancy tests.
Zika has now been recognized as a global threat, prompting the World Health Organization to declare Zika outbreak as a Public Health Emergency of International Concern. The WHO predicts that up to 4 million people will be infected with Zika virus over the next 12 months. The situation could be much worse if it jumps and spreads explosively to other regions of the world, especially densely populated areas where mosquito vectors are aplenty.
It is believed the Zika entered Brazil through travelers returning from Zika-affected countries. Thailand was the first country in Asia to detect Zika cases (in 2012) and has been detecting on an average five cases a year. A number of Nepalis travel to Zika affected countries like Thailand and Indonesia. So it makes sense for the government to set up Zika detection centers in hospitals.
Does Zika virus exist in Nepal? We have observed symptoms similar to Zika virus, and frequent outbreaks of viral-origin fever have been reported in different parts every year. So we cannot categorically rule out Zika.
The author is a Medical Officer and Clinical Research Coordinator at Sukraraj Tropical and Infectious Disease Hospital, Kathmandu
Related story
EDCD points out Nepal’s risk of Zika virus and Chikungunya once...
