Eight Zika-positive cases in Jaipur: It seems that Zika is now here to stay

Last year in May, the WHO confirmed the first three cases of laboratory-confirmed Zika virus infection in India from Ahmedabad in Gujarat. The cases then detected were a 34-year-old female patient admitted to hospital with complaints of fever following delivery of a healthy baby, who had no travel history to any Zika affected country. The other two cases include a 22-year-old pregnant woman in her 37th week of pregnancy and a 64-year-old male with 8 days history of fever.

Eight people have reportedly tested positive for Zika virus. It seems that Zika is now here to stay in India. Dengue and Chikungunya are already endemic in the country. Like Dengue and Chikungunya, Zika is a viral infection and also shares a common vector with them, the Aedes mosquitoes.

Here is an update of Zika virus disease.

• Zika is caused by the Zika virus transmitted by Aedes mosquitoes. This is the same mosquito that transmits dengue, Chikungunya and yellow fever.

Zika virus derives its name from the Zika forest in Uganda, where it was first identified in 1947 in monkeys. It was then identified in humans in 1952. The first recorded outbreak of Zika virus disease was reported from the Island of Yap (Federated States of Micronesia) in 2007. This was followed by a large outbreak of Zika virus infection in French Polynesia in 2013 and other countries and territories in the Pacific.

• In March 2015, Brazil reported a large outbreak of rash illness, soon identified as Zika virus infection, and in July 2015, found to be associated with Guillain-Barré syndrome.In October 2015, Brazil reported an association between Zika virus infection and microcephaly. Zika virus disease was declared as a Public Health Emergency of International Concern (PHEIC) by the WHO in February 2016, which was declared as ended in November 2016.

• A pregnant woman can pass Zika virus to her fetus. Infection during pregnancy can cause serious birth defects such as microcephaly and other congenital malformations, known as congenital Zika syndrome. Other complications include preterm birth and miscarriage. Pregnancy loss due to asymptomatic Zika virus infection may be a common but under-recognized adverse outcome related to maternal Zika virus infection (Nat Med. 2018 Aug;24(8):1104-1107.

• Zika virus infection is also a trigger of Guillain-Barré syndrome, neuropathy and myelitis, particularly in adults and older children.

• The incubation period is 3 to 14 days.

• Most people are asymptomatic or have mild symptoms such as fever, rash, conjunctivitis, muscle and joint pain, malaise or headache. Symptoms generally last for 2–7 days.

• Dengue or Chikungunya-like symptoms of fever with a rash or joint pain, with red eyes, should not be ignored. Such cases could be Zika. Eliciting a travel history in such patients is very important.

• At present, there is no vaccine or specific drug available to prevent or to treat Zika infection. Patients should be advised to take paracetamol to relieve fever and pain, plenty of rest and plenty of liquids. Avoid aspirin, products containing aspirin, or other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen.

• Use of measures to protect against mosquito bites is very important to prevent Zika infection such as using insect repellent, covering as much of the body as possible with long, light-colored clothing, eliminating places where mosquitoes can breed and putting screens on windows and doors.

• People traveling to high risk areas should take protections from mosquito bites. Pregnant women should avoid traveling to high risk areas.

These new cases tell us that all this time, the Zika virus has been circulating in the community and suggest low level transmission of Zika virus and the likelihood of more cases occurring in the near future. This should be of great concern to all, especially the public health authorities given India’s huge population, climate that is favourable to vector-borne diseases and India being a hotspot on the tourist map.

It has been suggested that the Zika virus in India “is distinct from the both African as well as pathogenic Asian strains; thus, it does not replicate profusely as the African and Asian prototype strains are known to do, and this is also the reason that there is low susceptibility in mosquitoes and they do not pick up and transmit the infection easily” (Indian J Med Res. 2017;146:572-5). But, if this Zika strain mutates to more efficiently infect mosquitoes, it could become a major public health problem in the future similar to Chikungunya virus, which re-emerged in India after decades of remaining dormant.

While enhanced surveillance, community-based including at international airports and ports, to track cases of acute febrile illness is the need of the hour, creating public awareness about the disease including preventive measures should be the focus. At the same time, the public should be assured that there is no need to panic.

The Author of this article is Dr KK Aggarwal