Japanese Encephalitis Class Notes

Japanese encephalitis (JE) Japanese encephalitis (JE) is an acute infectious disease of the central nervous system (CNS) which is transmitted through mosquitoes infected with the JE virus. JE virus belongs to the flavivirus family. This disease was first known in 1871 in Japan and was known to infect around 6,000 people in 1924. The JE virus was first isolated in 1934 from the brain tissue of an encephalitis sufferer who died. The first extraordinary incident (KLB) occurred in 1935 and almost every the year the outbreak occurred, from 1946 to 1950. This JE virus belongs to the Arbo virus group of the genus Flaviviridae, has 5 genotypes based on phylogenetic analysis of the virus E gene. This virus has also been proven to have the ability to agglutinate the red blood grains of one-day-old geese and chicks. If the JE virus is passaged in tissue culture, it will reduce agglutination power, but if it is passaged in the brain of white mice it will increase agglutination power, virulence and hemophilic activity. This disease is zoonotic and is transmitted to animals and humans not directly but through the bite of a vector in the form of the Culicine mosquito: However, the mosquito most often found as a vector is Culex tritaeniorhynchus which can transmit the JE virus to both humans and other pets. Hosts that can be infected are pigs, ruminants, horses, rabbits, poultry, bats and humans. Virus activity will naturally be maintained through the mosquito's life cyclePoultry and pigs are important hosts for the virus to propagat. Animals that act as reservoirs for the JEvirus are pigs, while humans and horses are the final targets of the transmission cycle or also known as dead -end because viraemia occurs very briefly so it is difficult to transmit from human to human. JE infection in animals generally does not cause clinical symptoms. Clinical signs of encephalitis can be seen in horses and donkeys as they do in human pandas. However, horses are not an obvious source for mosquito transmission. In other livestock these symptoms are not visible. Although pigs are the best reservoir for JE, symptoms of encephalitis in pigs are very rare.The neurological manifestations of JE caused by flaviviruses vary, ranging from slight changes in behavior to serious problems including blindness, ataxia, weakness, and movement disorders. Newcastle disease (ND) Newcastle disease (ND) is caused byAvian Paramyxovirus type - 1 genus Avulavirus family Paramyxoviridae, is an RNA virus with a single stranded (ss) genome and negative polarity . ND in Indonesia, commonly known as Tetelo disease, is a disease of poultry, especially in chickens, which is very contagious. Symptoms of ND disease are characterized by abnormalities in the respiratory tract, digestive tract and central nervous system. Clinical signs of ND disease depend on the virus strain, host species, host age, environment and immune status of the chicken.In chickens, the general symptoms of ND are loss of appetite, lethargy, decreased egg production, inflammation of the trachea and inflammation of the conjunctiva. ND disease can infect various species of domestic and wild birds, but the severity of the disease varies greatly, ranging from peracute disease with a mortality rate of almost 100% to subclinical disease without lesions. The incidence of the disease is acute to chronic, and can attack all types of poultry, especially chickens, both purebred and non -breed chickens. ND disease isendemic in Bali and is not only found in purebred chicken farms, free-range chickens which are generally on smallholder farms as well.often affected by this disease. ND viruses have a wide host range, including approximately 241 species, 27 orders out of the 50 known orders of birds. Based on their virulence, ND viruses are grouped into 3 strains, namely: velogenic, mesogenic and lentogenic. The ND virus has the specific property of being able to agglutinate chicken red blood cells, this occurs due to the presence of a protein found in the virus envelope called hemagglutinin. The process of hemagglutination occurs due to the bond between the ND virus hemagglutinin and cell receptors, namely mucoproteins found on the surface of erythrocytes. Nipah Disease This virus was originally discovered in the Nipah river basin in the state of Negri Sembilan in Malaysia, so it is known as the Nipah virus. The Nipah virus can cause illnesses ranging from mild to death in pigs, but can also infect other animals such as cats and dogs as well as humans. close contact with pigs infected with this virus.Nipah disease is caused by the Nipah virus, from the genus Morbilivirus, family Paramyxoviridae. Pigs and bats (Pteropus spp.) have been proven to play a very important role in the Nipah outbreak in Malaysia. Nipah infection in bats is subclinical. Where bats act as a reservoir for the Nipah virus, while pigs act as virus multipliers that amplify the Nipah virus so that it is ready to be transmitted to pigs or other animals or humans. Transmission of the Nipah virus is through air and inhalation where Nipah virus particles are carried out of the body of infected pigs through very loud coughing. Transmission can also be through direct contact with blood, body fluids or excretory fluids such as urine or saliva, liquid foam that comes out through breathing rne transmission is the most effective because the virus, among other things, attacks and develops in the mucosa of the pig's respiratory tract and causes mucosal cells to be damaged and the virus is secreted in the foam of respiratory fluid or exhaled air when the pig coughs hard, the virus is also excreted with urine or blood fluid and spread and infect other animals or humans.