explained | Nipah, a highly pathogenic paramyxovirus

Story so far: Kerala has reported death from a case Kozhikode’s northern district brings back memories of chaos due to Nipah virus infection May-June 2018 When 18 confirmed cases were reported in the same district, of which 17 were laboratory-confirmed deaths. It is the high death rate associated with the virus that caused panic throughout the state and country and when it was controlled the state’s health surveillance system came in for praise, although, as it turned out, it was only one for the 2020 pandemic. There was a test-run. .

What do we know about the Nipah virus outbreak?

Human Nipah virus, as it is called, is classified as an “emerging zoonotic disease”, which means it can transfer to people after incubation in other species. It was first identified in a large outbreak of 276 cases in Malaysia and Singapore from September 1998–1999.

Prior to the 2018 Kerala outbreak, there have been several Nipah virus outbreaks with outbreaks in India, particularly in Siliguri and Nadia in West Bengal in 2001 and 2007. During the outbreak in Siliguri, 33 health workers and hospital visitors became ill after coming in contact with patients suffering from Nipah virus disease. At least 70 people died in the outbreak in these two districts. In the 2018 outbreak in Kerala, family of four The first person to confirm the infection succumbed to the viral disease.

How does Nipah virus originate and spread?

Nipah virus (NIV) is classified as a “highly pathogenic paramyxovirus” and requires the highest-grade facilities, called BS-IV, to handle the virus. The natural reservoir for the virus is the large fruit bats of the Pteropus genus. From here the virus can spread to pigs who can become infected after eating fruit bitten by infected bats.

Initial outbreaks were reported among pig breeders, while in Bangladesh it was suspected that the virus had jumped to humans who directly consumed fruits that may have been contaminated with bat saliva or urine. It takes 6-21 days for the virus to develop and manifest as a disease.

Drinking raw date palm juice contaminated with NiV and close physical contact with Nipah infected patients are believed to be the two main ways of spreading. Person-to-person transmission can occur by close physical contact, particularly through contact with body fluids.

Unlike in the case of the novel coronavirus, which is more airborne and can spread over great distances, the Nipah virus is not a very efficient spreader. Exposure to body fluids and respiratory droplets of an infected person, which is not expected to travel very far, is said to be the main source of spread which suggests that close family members in a household are most at risk with infection. Why is it said to be spreading among patients in hospital settings.

In most Nipah outbreaks in South Asia, the virus has displayed a “stuttering chain of transmission”, meaning that once the virus has spread from fruit bats to humans, it is mainly in close proximity to patients. People in contact, such as family, hospital staff and caregivers, in this picture show the nursing staff of Kozhikode Medical College wearing masks.

A duty doctor wears protective gear in the line of duty at Kozhikode Medical College. Caregivers are at higher risk, because the more sick patients are, the more viruses they secrete.

The natural host of the virus is the fruit bat. In this image, experts set traps for bats that were found inside a well near Soppikada in Changaroth, Kozhikode on Monday.

Bat experts secured a bat procured from a well near Soppikada to test whether bats were actually responsible for the Nipah viral infection at Changaroth in Kozhikode.

Lini, a staff nurse at Perambra Taluk Hospital, passed away on May 21 due to suspected infection with Nipah virus. She was on duty when one of the deceased was undergoing treatment there. Here a health worker is seen collecting blood samples from Lini’s younger sister.

A two-wheeler rider wears a mask at the Medical College, Kozhikode. The death of two members of the same family due to Nipah virus infection at the Government Medical College Hospital in Kozhikode has raised alarm bells.

A mask seller at the gate of the Medical College in Kozhikode. Mask sales outside the hospital were brisk as all visitors were advised to wear protective masks.

A boy injured in an accident in the casualty department of Kozhikode Medical College wears a mask as a precaution, on Monday. Visitors to the campus including students, doctors and teachers besides patients, spectators, visitors are wearing surgical masks as a precautionary measure.

The usually overcrowded computerized outpatient (OP) counter at Kozhikode Medical College looked deserted on Wednesday amid fears of Nipah virus infection.

People wearing masks at a one way lottery shop in Kozhikode. Tension prevailed in Soppikkada from where the deceased cheered and many residents have left the village.

A masked fruit vendor at his fruit shop in Kozhikode. The fear of Nipah virus has led to a decrease in the sale of fruits in the district.

A security personnel wearing a mask at a mall in Palazhi in Kozhikode city. One case of Nipah virus infection has been reported in Palazhi.

Central team member discussing the situation with Kerala Health Minister KK Shailaja at Kozhikode Medical College on May 21, after Nipah virus (NIV) infection claimed three lives in Kozhikode district.

As a precautionary measure, the Coimbatore Medical College Hospital has prepared a 20-bed isolation ward for patients with symptoms of Nipah virus infection.

What are the symptoms of the disease and how is it diagnosed?

Fever, delirium, severe weakness, headache, shortness of breath, cough, vomiting, muscle pain, convulsions, diarrhea are the main associated symptoms. In infected people, Nipah virus causes severe disease characterized by inflammation of the brain (encephalitis) or respiratory diseases, which is why it is associated with high mortality. Due to the lethality of the virus, very few laboratories such as the Pune-based National Institute of Virology are equipped to isolate and confirm the virus.

Antibody tests that detect the presence of antibodies in the serum of the cerebrospinal fluid can be used to detect infection or the RNA of the virus can be detected from respiratory secretions, urine, or cerebrospinal fluid.

Does treatment exist?

There is currently no known treatment or vaccine available for people or animals. According to a fact sheet by the National Center for Disease Control, ribavirin, an antiviral, may have a role in reducing mortality in patients with encephalitis caused by Nipah virus disease.

The emphasis of treatment depends on the management of symptoms.

However, immunotherapeutic therapies (monoclonal antibody therapy) for the treatment of NiV infection are currently under development and evaluation. One such monoclonal antibody, m102.4, has completed phase 1 clinical trials and has been used on a compassionate basis. In addition, according to the US Centers for Disease Control, the antiviral treatment remdesivir has been effective in nonhuman primates when given as post-exposure prophylaxis. There are no approved vaccines or even test-vaccines as part of human trials for the virus.