Climate change and viruses

Introduction

Climate is long term average of the weather condition in a given place which includes type, frequency, duration, intensity of weather and seasonal variations. Climate change develops over longer periods from decades to centuries. (APHA., 2024) [1] . International Panel on Climate Change has reported that drought, flood, melting of glaciers occurs and will affect human health and death., Greenhouse effect caused by green gases leads to Global warming. (Anubha Kaushik and C.P. Kaushik 2010) [2] Increased temperature on the earth surface led to Global warming (Melissa Denchak 2017) [3] . Warming temperature affects behavior, physiological characteristics and life history of both vectors and pathogens, behavior of reservoir and definitive hosts, And lower temperature increases the reproduction of vectors and transmission of viruses to the host. Here are some of the viruses which cause disease in human and disease are related with the climatic changes.

Climate Change and Dengue:

Nearly 390 million of dengue cases in 100 countries are reported, El Nino has caused increase in dengue fever in Asian countries (Andrew K. Githeko et al., 2000) [4] Dengue is an Arthropod borne virus belongs to family Flaviviridae and Genus Flavivirus. Dengue virus is transmitted between people by female mosquito of Ades aegypti and Ades albopictus bite which are found throughout the tropical and sub-tropical regions. (Gaurab Karki., 2017) [5] . Dengue virus causes diseases and death of human. Climate change is one of the greatest threats to human health by the World Health Organization. Dengue is rapidly spreading 30-fold increase in global incidence over the past 50 years and an estimated 100-390 million dengue infections reported worldwide. The impact on health is dependent on the socio-economic environment and can influence the resilience of the population. Poor health, poverty, and conflict are also contributing factors to the impact of drought. The stagnation of water during flood help in breeding and increasing of mosquito population and high temperature also is desirable for the mosquito and they can survive from 25 to 40 °C. During rainy season as the people stay at home in a congested place and mosquito bites spread very fast in these areas and become epidemic in the whole area. There are 5 dengue virus serotypes like DENV-1, DENV-2, DENV-3, DENV-4 and DENV-5 Four serotypes are found among the population of India. Karnataka state in the year 2024 was declared epidemic as the number of dengue cases has increased rapidly and caused death of 9 and suspected cases of 306257 in Karnataka and Bengaluru city alone is 77315 as on September 2024. Symptoms includes mild infection high fever of 104 0 F, severe headache, pain behind eyes, muscle and joint pain, nausea, swollen glands, rashes, and in severe dengue symptoms include severe abdominal pain, persistent vomiting, bleeding gums and nose, feeling thirsty, feeling pale and cold skin weakness. (WHO,2024). Dengue virus is spherical enveloped viruses with 40-60 nm in diameter. Dengue virus has single-stranded Positive-sense RNA genome of about 11 Kbp long, surrounded by a nucleocapsid and covered by a lipid envelope that contains the viral glycoproteins. and its Genome is given in the picture. given below, Structure of dengue virus picture was taken from Gaurav Karki 2017 [5] Climate change and Chicken pox virus: Chicken pox viral cases are reported in several Asian countries including India, In Japan it has been reported that the factors like temperature, relative humidity and rainfall are responsible for the bimodal cycle of virus and transmission of virus rapidly. (K. Hari Gane et al 2015). The study revealed that the 6-10 age groups children were most vulnerable, and, with peak infection between November and February. The disease is generally more common during the colder and spring months, In India recorded outbreaks were seen among the children in Anganwadis, play schools, and schools and gathering locations. (Vikram Khan et al., 2023) [21] Symptoms includes itching skin rash, small blisters, mild fever, bumps filled with milky water. Varicella-Zoster virus (VZV) is an alpha Herpes virus subfamily Herpes simplex virus (HSV) 1 and 2. It is a member of varicella virus genus.

The virion is spherical in shape with icosahedral symmetry measuring 159-200nm.The icosahedral protein capsid with average diameter 100 nm consists of 162 hollow hexagonal and pentagonal capsomeres with an electron-dense core containing the double-stranded DNA genome with 125240 kbp nucleotides together forming the nucleocapsid. The nucleocapsid is surrounded by an envelope which is lipoprotein in nature.

Varicella Zoster Virus structure picture taken from Sagar Aryal 2022 [8] .

Climate change and Measles:

The measles infection occurs between February and May and second infection occurs between September and December. Measles outbreak was seen in Maharashtra state as reported by Sunil R Vaidya., 2016 [23] . Measles virus: Structure taken by Acharya Tankeshwara 2025 [22] Climate change and Coxsackie virus is a Enterovirus, it belong to the Picornaviridae family, genus Enterovirus,.

They contain a single plus-strand of RNA protected by an icosahedral capsid exclusively constituted of proteins. The viral particle contains no enzyme and no envelope. Its size is 22-30 nm. Coxsackieviruses are divided into two subgroups: coxsackievirus A (CA) with 23 serotypes 1-24 (23 is missing) and coxsackievirus B (CB) with six serotypes 1-6.

(Bruno Pozzetto and Odette G Gaudin 2007) [13] , The Coxsackievirus circulate in the summer months having warmer weather and transmission is seen in warmer places and high humidity. less rainfall is likely for more infections.

The symptoms include poor appetite, runny nose and sore throat can appear three to five days after exposure. A blisterlike rash on the hands, feet and in the mouth The viruses can spread from person to person, usually on unwashed hands and surfaces contaminated by faeces.

Picture is taken from shutter stock Structure of Hepatitis A Virus by Nazuk Gupta Hepatitis B Virus by Sagar Arya 2022 [28] Climate change and Chandipura virus (CHPV) was identified in 1950, The fever was first found in Chandipura village in northern Maharashtra near Nagpur district, The virus belong to families of arbovirus include Toga virideae (Alpha viruses), Flaviviridae, Bunya viradeae and Reho viradeae. infection is caused by virus loaded female Aedes aegypti and Sand flies (Phlebotomus papatasi, Phlebotomus argentipes or Sergentomyia spp.) and ticks bite. The virus is a tropical pathogen (Sunil Menghani et al., 2012) [11] with massive outbreak in 2003-2004 in Maharashtra, Telangana and Gujarat with 55 to 75% fatality among children and they found out that the infection is due to climatological factors or human genetic factor or a combination of both. (A.B. Sudeep et al 2019) [14] The infection again occurred in the month of June to August 2024 in the children below 15 years of age (Morgan E Brises and Hinh Ly 2024) [29] , The manifestation of CHPV starts as an influenza-like illness, associated with abdominal pain, vomiting, altered consciousness, and impaired neurologic functions The outer envelope consists of glycoprotein (G) and hostderived lipid membrane. The viral RNA and envelope are connected through the matrix protein (M). The genome is a single-stranded RNA having a negative helical turn. The RNA genome is associated with three other viral proteins known as nucleoprotein (N), phosphoprotein (P) and large protein (L) forming the ribonucleoprotein complex (2012 Li J, Zhang Y, Sourish Ghosh 2017) [10,9] this virus has to manipulate the cellular machineries of its hosts at molecular levels through specific protein-protein interactions for its survival, replication, subsequent spread and infection.

Climate change and Viral hepatitis

(Sreejith Raja Sekharan et al., 2013) [6] the vectors were killed using pesticides in Gujrat and Rajasthan because of many children were affected.(WHO 2024)

Structure of Chandipura virus Picture from Sourish Ghosh 2017 [9] Climate change and Human Meta Pneumo Virus (HMPV) HMPV infects individuals of 5 years and adults of 65years of age, The immune compromised individuals, are susceptible populations. Disease severity increase as the immunity decreases. and infants of 5 months with prolonged stays s in the intensive care unit (ICU) are susceptible they show severe respiratory infections: Cough., Fever., Runny or stuffy nose., Sore throat. wheezing, rashes on the body. HMPV spreads through direct contact with someone who has it or from touching things contaminated with the virus Coughing and sneezing. Shaking hands, hugging or kissing. Touching surfaces or objects like phones, door handles, keyboards or toys. younger than 5) or older than 65 week with weakened immune. (Cleveland Clinic 2023) [17] .

Human Metapneumovirus structure by Pablo F Cespedes et al 2016 [31] HMPV relatively new member of the Paramyxoviridae family paramyxovirinae subfamily, and belongs to the genus Metapneumovirus hMPV is a pleomorphic, spherical, enveloped virus with a mean diameter of 209 nm, The nucleocapsid has a varying length from 200 to 1000 nm and a 17 nm diameter. The genome of hMPV is negative-sense, single-stranded, nonsegmented RNA that is about 13,000 nucleotides in length and consists of eight Structure of influenza virus is from Vincent Racaniello 2009 [32] Climate change and Pneumonia: Seasonal influenza is an acute respiratory infection caused by influenza viruses which circulate in all parts of the world. It represents a yearround disease burden. It causes illnesses that range in severity and sometimes lead to hospitalization and death. Most people recover from fever and other symptoms within a week without requiring medical attention. However, influenza can cause severe illness or death, particularly among high risk groups including the very young, the elderly, pregnant women, health workers and those with serious medical conditions. In temperate climates, seasonal epidemics occur mainly during winter, while in tropical regions, influenza may occur throughout the year, causing outbreaks more irregularly.

Influenza virus structure Sonia Bianchini et al 2020 [16] Climate change and Chikungunya: Chikungunya is caused by a virus found in Africa, the Americas, Asia, Europe, India and Pacific Oceans. The virus belongs to a group of viruses called alphaviruses. Other alphaviruses causing a similar disease include Mavaro virus and Ross River virus People are infected with chikungunya virus when mosquitoes feed on another infected person and then bite them. People infected with chikungunya virus have high enough levels of virus in their blood (viremia) during the first few days of illness to transmit the virus to mosquitoes. Prevent getting infected with chikungunya virus by preventing mosquito bites and getting vaccinated before trave spread can occur through Blood transfusion, Handling infected blood in the laboratory, Drawing blood from an infected patient The virus is not spread from person-toperson and is not spread through coughing, sneezing, or touching. Pregnancy and breastfeeding, Rarely the infection can be spread from a pregnant person to their unborn baby, mostly during the second trimester. through the bites of infected Culex species mosquitoes, particularly Culex tritaeniorhynchu bronchiolitis or respiratory syncytial virus rhinovirus or parainfluenza virus caused during rainy or winter seasons.

Structure of chikungunya by Srijan Singh, et al 2021 [20] According to a Council on Energy, Environment and Water (CEEW) study, Eighty percent of the population in India live in districts that are highly vulnerable to extreme weather events and population do not have adequate adaptive capacities, India does not have the capability and skills to make its people climateresilient because of its diverse structural challenges including inadequate infrastructure, low literacy rates, and poor disaster management planning. (Abhinash Mohanty and Shreya Wadhawan October 2021) [15] and climate change has impact on disease outbreak.

Conclusion

Viral disease outbreak, viral multiplication, viral infection, viral transmission from human to human or through vectors to human are due to climate change causing pandemic or epidemic leading to the death of human population. . .

References

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