Prevalence, genetic characteristics and economic losses of Foot-and-Mouth Disease Virus (FMD) in global and Bangladesh context: A Review

Foot and Mouth disease virus (FMD) is a transboundary animal disease (TAD) affecting global cloven-hooved wild and domesticated animals. It is recognized as a significant economic infectious disease in the livestock business. Domesticated animals such as goats, sheep, cattle, pigs, and buffalo are vulnerable hosts for FMD. This RNA virus is classified as a member of the Aphthovirus genus in the Picornaviridae family. It encompasses around 60 subtypes and is divided into seven serotypes: C, O, A, SAT1, SAT2, SAT3, and Asia1. There is no cross-protection across different serotypes, and occasionally, the effectiveness of vaccination may be restricted, even when targeting the same serotype. Therefore, it is crucial to identify and classify the viruses currently in circulation, mainly when vaccination is employed for disease management. Hence, it is necessary to administer multivalent vaccines with genetically matching vaccines in circulation to ensure adequate protection through immunization. Bangladesh has a high cattle population, and FMD leads to significant economic losses for farmers. Sero-types A, O, and Asia 1 are circulating in Bangladesh. The most common serotype is O, although Bangladesh has reported multiple serotype infections. Strategic vaccination, immunity screening, and outbreak surveillance are being examined for FMD management in Bangladesh. This review analyses FMD epidemiology, genetics, diagnostics, economic impacts, and prevention-control efforts worldwide, emphasizing Bangladesh. Finally, the study recommends FMD management advice for endemic settings.


Introduction
Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals, including cattle, swine, sheep, and goats.FMD causes significant socioeconomic losses worldwide, potentially causing substantial economic losses due to its rapid spread and impact on animal health (Giasuddin et al., 2019;Ali & Giasuddin, 2020).Agriculture is the backbone of Bangladesh's economy, and the livestock sector contributes significantly to the national GDP and plays a crucial role in the socioeconomic development of rural areas, providing employment and food security to thousands (Giasuddin et al., 2020).Given these stakes, understanding the prevalence and genetic diversity of the FMD virus (FMDV) is crucial for effective control and eradication strategies (Ali et al., 2019).FMD threatens Bangladesh's animal health, food security, and socioeco-nomic stability.Few studies have been done on the prevalence of FMD in Bangladesh; many studies have been conducted to elucidate the epidemiology, genetic characterization, and impact of FMD virus strains circulating in the country (Ali et al., 2019;Rahman et al., 2020).This review aims to provide a critical synopsis of the prevalence, genetic characterization, and implications of FMDV in Bangladesh based on recent studies.Recent studies have suggested that the genetic landscape of FMDV in Bangladesh is complex and continuously evolving, with multiple serotypes circulating within the region (Ali & Sultana, 2012;Hossain et al., 2023).This genetic variability complicates the development of effective vaccines and makes timely diagnosis challenging.
Moreover, the epidemiological impact of these variations needs to be better understood, necessitating a thorough review and synthesis of the available research to inform policy and practice (Jamal & Belsham, 2013).We begin by examining the prevalence rates reported in various studies.Then, we analyze the genetic characterization efforts that have helped identify the dominant strains of the virus in local livestock populations.The discussion then shifts to the broader implications of these findings, including the economic burdens imposed by FMD outbreaks and the potential for future disease management interventions.In addition to providing a comprehensive overview of the scientific literature, this article discusses the strengths, limitations, and potential areas for future research.By integrating these diverse pieces of information, we aim to offer a detailed and nuanced picture of FMD's role within Bangladeshi livestock health management and its broader socioeconomic dimensions.

Etiology
The FMDV infects animals of the Suidae family, which belongs to the suborder Ruminantia, order Artiodactyla, and Camelus bactrianus (Grubman & Baxt, 2004).The virus is an RNA virus with a diameter of 26 nm and lacks an outer covering.The FMD virus, belonging to the Aphthovirus genus and Picornaviridae family, is the causative agent of the disease.It is classified into seven known serotypes, namely O, A, C, SAT-1, SAT-2, SAT-3, and Asia-1, with over 60 sub-serotypes (Hirsh et al., 2004;Ding et al., 2011).The currently prevalent FMDV serotypes in Bangladesh, as detected by Reverse Transcription Polymerase Chain Reaction (RT-PCR), are O, A, and Asia-1 (Grubman & Baxt, 2004;Giasuddin et al., 2016).Protection against one serotype does not confer immunity against another (OIE, 2009).

Structure of FMDV
This virus bears a genome of about 8.2 kb long, including a single-strand positive sense of RNA.As an outcome of other RNA viruses, it has a high rate of genetic mutation.The significant variability of antigens of this virus, together with the existence of large and neutralizing sites on its surface, gives its account (Belsham, 2005).The FMDV particle is approximately spherical, 25 to 30 nm diameter.It contains the RNA genome enclosed by a protein shell or capsid.The capsid contains 60 copies of the capsomers.Every capsomer forms four structural polypeptides: VP1, VP2, VP3, and VP4.Of the four proteins, VP1, VP2, and VP3 are surfaceexposed, whereas VP4 is internal.The protein coat contains a single-stranded positive-sense RNA genome of about 8400 nucleotides (nt) in length.RNA consists of three separate parts: the five ′ untranslated region (5′ UTR), an extended coding region, and the 3′ untranslated region (3′ UTR) (Thomas et al., 1988) (Figure 1).(Jamal & Belsham, 2013).

FMD Virus Serotypes
The FMDV is categorized into seven clearly defined serotypes: O, A, C, SAT 1, SAT 2, SAT 3, and Asia 1 (Vallée & Carré, 1922).Only three serotypes, A, O, and Asia 1, are present in Bangladesh.Serotype O is the dominant strain, exceeding the others in circulation (Nandi et al., 2015;Ullah et al., 2015;Ali et al., 2019).Since the discontinuation of immunization in 1990, there have been no documented instances of serotype C epidemics in Europe.The last outbreak of an epidemic caused by serotype C FMDV was recorded in Bangladesh in 1996 (Kitching, 1998) and Ethiopia in 2005(WAHID, 2009).Serotype C viruses may have been extinct in the natural environment and are now limited to laboratory settings (Paton et al., 2021).

FMD Virus Topotypes
Different topotypes of the FMD Virus have been identified till now, as described in Table 1.

Host species
FMD is a highly infectious disease that impacts animals possessing divided hooves, such as pigs, cattle, goats, sheep, and buffalo.It can also be transmitted to indigenous animals possessing divided hooves, such as antelope, wild pigs, elephants, camelids, and deer.Old-world camels may resist certain strains of the disease, whereas llamas and other South American camelids show minimal susceptibility.Cattle can be affected by the same strain of FMDV, which infects deer and wild pigs.Guinea pigs, rats, mice, and armadillos can be intentionally infected in laboratory experiments (OIE, 2011).However, horses, dogs, and cats are not vulnerable to FMD, although they can harbor the virus in their hair.Bangladesh has detected The FMD virus in several animals, such as cattle, buffalo, goats, sheep, and pigs.

Carrier state
Van Bekkum's study in 1959 showed that live FMDV may be successfully extracted from cows' esophageal and pharynx fluids during the recovery stage of the disease (Van Bekkum et al., 1959).The carrier stage of the virus in dairy cows might last for a maximum duration of three and a half years.In addition, the carrier status in sheep and goats has been determined (Alexandersen et al., 2002).The duration of infection in an African buffalo can extend for a maximum of five years (Borrego et al., 1995).The carrier's fluids in the esophagus and pharynx show modest levels of viruses and occasional detection of viruses in individual animals.The current most effective method for detecting carrier animals is virus isolation from esophageal-pharyngeal secretions.However, there are ongoing efforts to improve sensitivity by developing RT-PCR.Considering that the pharynx is the primary source of continuous infection in cattle, it is likely that the virus originates from this area (Van Bekkum et al., 1959).

Mode of Transmission of FMDV
During the early phase of infection, the virus can be easily transmitted by releasing particles from ruptured blisters and through physiological fluids such as saliva, milk, and semen (Alexandersen et al., 2003) (Figure 2).Ruminants that are vulnerable can infect the virus by inhaling minuscule quantities.This can occur either through direct exposure to the exhalation of other sick animals or indirectly through inhalation of aerosols that the virus has contaminated.When inhaled, pigs exhibit a notable degree of immunity to infection with FMDV (Alexandersen et al., 2003).Other infection methods, such as consuming or entering through skin abrasions, require more virus.The FMDV can endure in the environment and animal products, such as meat, for different lengths, ranging from a few days to many months.The duration of persistence is contingent upon the prevailing conditions (Sellers, 1971).The immunological response to infection with FMDV is rapid and results in the eradication of the virus.Nevertheless, specific ruminant hosts continue to harbor the virus and serve as carriers.The quantities of FMDV in specific nasal and throat locations and lymphoid tissues diminish gradually in these carriers.
The model utilizes a straightforward S (susceptible), E (exposed), I (infected), and R (recovered) framework to depict the cycles of FMDV replication and transmission in livestock (Figure 3).Vulnerable animals can contract the infection through direct contact with infected animals, consumption of infected animal products, exposure to contaminated objects (fomites), or ingestion or contact with aerosolized infected animal products.The period of infectiousness typically aligns with the onset of clinical symptoms.Nevertheless, experimental research has revealed that the precise timing of these processes varies depending on the host species, infection models, and serotypes of the FMDV (Paton et al., 2018).

Global distribution of FMD
Research on FMD has revealed that the spread of the FMDV serotypes varies worldwide.Africa has documented the occurrence of six out of the seven serotypes of FMDV(O, A, C, SAT-1, SAT-2, SAT-3).In comparison, Asia and Europe have confirmed the presence of four serotypes (O, A, C, Asia 1).Conversely, South America has recorded the existence of three serotypes (O, A, C).The Middle East, commonly recognized as the region most severely impacted by FMD, has FMD virus serotypes O and A (Jamal & Belsham, 2013).The geographical location of the Middle East and North Africa poses a possible threat to other regions, mainly Europe (Aidaros, 2002).The predicted geographic spread of viral pools in the 2010 FMD situation is depicted in the Annual OIE/FAO FMD Reference Laboratory Network Report.The collection of FMD viruses globally can be classified into seven distinct "regional pools" based on geographic regions.These pools are defined as follows: Pool 1-Eastern Asia, Pool 2-Southern Asia, Pool 3-Euro-Asia, Pool 4-Eastern Africa, Pool 5-Western Africa, Pool 6-Southern Africa, and Pool 7-South America.These pools contain viral strains that exhibit genetic and antigenic variations from one another and are usually localized to specific locations.Diseases might be transmitted from swimming pools to uninhabited places (Jamal & Belsham, 2013).
Currently, there is no presence of FMDV serotype C on Earth.The last occurrence of a type C outbreak took place in East Africa and Asia in 1996.Serotype C is often regarded as the primary contender for global eradication, notwithstanding the unknown factors contributing to its elimination from different regions (Kitching, 2005).The serotype O is the most prevalent serotype globally, including in India, and it is the leading serotype accountable for recent outbreaks in several nations that were previously free of the disease.Serotype A has a more comprehensive geographical range than other serotypes.
Furthermore, it is essential to mention that this specific serotype, widespread in Eurasia, demonstrates the utmost antigenic variation.This diversity can be detected through-out Asia, Africa, and South America, as documented by (Araujo et al., 2002) and (Tosh et al., 2002).A recent study clarified the global diversity of FMDV serotype A (Mohapatra et al., 2011).The serotype Asia1 virus was identified outside Asia on a single occasion during a brief outbreak in Greece in 2000 (Kitching, 2005).It has the most minor genetic variation compared to the other serotypes (Ansell et al., 1994;Valarcher et al., 2009).The African buffalo is the primary serotype SAT 1-3 host, distinguished by its notable antigenic diversity.The three serotypes of the SAT virus are solely present in Africa.While there have been documented cases of SAT1 and two serotype events in the Middle East, these incidents did not result in a lasting presence in the region (Aidaros, 2002).The behavior of several serotypes of the FMD virus poses several mysteries, many of which are yet unexplained (Kitching, 2005).

Clinical signs
FMD symptoms encompass fever, heightened salivation, despondency, reduced appetite, and the development of blister-like sores on different body areas, including the mucous membrane, gum tissue, tongue, dental pad, udder teats, muzzle, coronary band, and interdigital gaps (Figure 5) (Hirsh & Zee, 1999;Blowey & Weaver, 2003;Azeem et al., 2020).Clinical symptoms usually manifest between 3 to 5 days after contact with infected animals, but the incubation period for a naturally acquired infection might range from 2 to 14 days.The clinical signs of the disease's severity are influenced by factors such as the level of immunity, the host species, the viral strain, and the age and breed of the animal.While tongue sores typically take a few days to heal, lesions on the foot and nasal cavities can cause a subsequent bacterial infection.This illness can lead to the excretion of mucus and pus from the nasal cavity and persistent impairment in walking (Knipe & Howely, 2001).Young animals suffering from necrotizing myocarditis may die before any cysts develop.Mastitis, a disorder marked by the development of vesicles on the udder and teats of breastfeeding cows, reduces milk output (Hirsh & Zee, 1999).

Post Mortem Finding
The postmortem examination demonstrates the presence of vesicular lesions and erosion caused by FMD on the mouth, food, and udder.After the vesicle bursts, the damaged area experiences initial erosion, characterized by a red appearance and followed by the creation of gray, fibrous tissue.The process of coting entails transforming from its initial hue to either green or yellow and then replacing the old epithelium with new tissue.Sometimes, blisters may not form, leading to the escape of fluid from the epidermis.These "Dry" lesions have a necrotic appearance instead of a vesicular one.The pig's mouth often shows dry sores (Fiebre, 2018).Following a bacterial infection, the erosions advance and develop into ulcers.To conduct a thorough histopathological investigation, it is crucial to include tissue samples that comprise oral mucous membranes and skin with blisters or recent erosions.Additionally, it is imperative to consider the cardiovascular system, mammary gland, and pancreatic organ.Cattle and buffalo affected by FMD may have pneumonia and respiratory distress as a result of infection by the bacteria Clostridium perfringens (Elgioushy et al., 2019).

Confirmatory diagnosis of FMD
FMD diagnosis is determined by evaluating the patient's clinical symptoms and analyzing laboratory test results (Aitken, 2007).The FMD virus is identified using the following protocols.
Performing serological assays The FMDV virus's presence can be identified by analyzing a specific immunological response in antibodies.Frequently employed diagnostic tests include solid-phase ELIZA (Enzyme-Linked Immunosorbent Assay), CFT (Complement Fixation Test), RT-PCR (Reverse Transcription Polymerase Chain Reaction), PCR (Polymerase Chain Reaction), and various non-structural protein antibody tests, such as enzyme-linked immune electron transfer blot assay (Hughes et al., 2002).ELIZA is the primary technique used to detect viral antigens of FMD and determine their serotypes (Stear, 2005).

Examining the direct complement fixation:
Before developing virus isolation techniques, Bachrach demonstrated that a direct complement fixation test could detect FMDV and serotype isolates (Bachrach, 1968).The fundamental idea behind this strategy was that virusantibody complexes stick to complement produced from guinea pigs.Suppose an antibody that targets sheep red blood cells is present, and the virus cannot attach to the antibody.In that case, the unbound complement activates the lysis process, losing sheep red blood cells.The direct complement fixation test effectively distinguished between various serotypes of FMDV due to the specificity of FMDV antibodies (Traub, 1983).

ELISA
The enzyme-linked immunosorbent assay (ELISA) is the most efficient technique for identifying and measuring the presence of antibodies in a sample (Birhanu et al., 2015).Several methodologies can be employed to validate a positive diagnosis, including virus isolation, nucleic acid detection in tissue samples, identification of FMD viral antigen, or culture products.The ELISA technique is the most recommended approach for identifying FMD viral antigens.This method makes use of serological reagents that are specific to different types of the virus.The sandwich ELISA is a highly efficient method for quickly identifying viral antigens, albeit it has a restricted level of sensitivity.Many studies are concentrating on developing alternative assay techniques that expedite the confirmation of clinical diagnoses.These systems can also be employed for "Pen side" tests.

RT-PCR (Reverse Transcription Polymerase Chain Reaction)
Reverse transcription-PCR (RT-PCR) is used to precisely detect the presence of the FMDV with a high level of specificity.This method can identify viral RNA by examining various animal samples.This technique can also amplify FMDV genome segments in milk, serum, epithelial, and OP samples (Sáiz et al., 2003).As Thomas et al. (1988) mentioned, specific primers are available for each of the seven serotypes.

VP1 gene sequencing
Sequencing the VP1 region of the virus genome is an additional method to confirm the identification of Foot-and-Mouth Disease (FMD).Knowles et al. (2016) created primer sets for this purpose.The phylogenetic relationship of three serotypes, including A, O, and Asia 1 isolated in Bangladesh, are shown in Figure 6.

Fig. 6. Phylogenetic trees showing the relationships of FMDV serotypes isolated in Bangladesh
Virus isolation ELISA can be used to detect the presence of vesicular FMDV antigen material.However, when the virus concentration is not enough for ELIZA to detect, it becomes necessary to grow the virus by utilizing a culture of receptive cells (Stear, 2005).The pig kidney cells are initially exposed to suspensions that are thought to contain the FMD virus.Subsequently, they are transferred to an incubator set at a precise temperature of 37 °C.After 24 to 48 hours, the cells are analyzed for CPE (cytopathic effect) indications.They occur due to a bacterial or viral invasion (Kitching & Hughes, 2002).The inability of the virus isolation process to propa-gate the virus on a particular cell type suggests that the lack of virus growth does not necessarily mean that the virus is not present in the collected sample.Other constraints of this method encompass the potential for contamination in cell culture, the requirement for ELIZA to verify virus growth, and the necessity for frequent maintenance of the cell supply (Jamal & Belsham, 2013).

Prevention and Control of FMD
Efficient preventative strategies are required for FMD at national and worldwide scales.Countries not affected by FMD should implement stringent controls regarding import-ing animals and animal products from countries afflicted with FMD (Aitken, 2007).Vaccination programs can hinder the spread of FMD (Hirsh et al., 2004).During periods of national disease-free status, it is imperative to prohibit the importation of animals and animal products from countries with a high prevalence of FMD.During an outbreak, it is essential to implement preventive measures such as swiftly euthanizing infected animals and strictly enforcing separation between affected and healthy animals (James & Rushton, 2002).

Investigation of disease outbreaks
Outbreak investigation and surveillance of FMD virus in cattle are vital for early detection, control, and prevention of this highly contagious viral disease.Rapid identification of outbreaks enables prompt implementation of control measures, limiting their spread within and across borders (Ali et al., 2019).Surveillance facilitates the monitoring of disease trends, aiding in developing effective vaccination strategies and policy interventions.Timely response reduces economic losses, preserves food security, and safeguards public health.A study by Knight-Jones et al. (2016) underscores the crucial role of surveillance in FMD control, emphasizing its significance in preventing devastating outbreaks and mitigating global trade disruptions.

Population reduction of diseased animals
According to the OIE (2014), when animals suspected of having FMD are killed in the affected herd or in other herds that have come into contact with the FMD virus directly or indirectly through other animals, the disease is highly likely to be transmitted.

Disinfection
The virus is susceptible to a 3 % concentration of regular household bleach.It is crucial to avoid using this solution to clean equipment and pathways, although the premises should still be cleansed.When diluted, a 4 % to 5 % quantity of vinegar can effectively neutralize the virus.In recent years, new disinfectants like Virkos S have been created.Virkos S is composed of a blend of surfactants, organic acids, and peroxygen molecules.These disinfectants exhibit high efficacy against FMDV and other pathogens (Depa et al., 2012).Owen (1995) proposes using a disinfectant solution of 4 % sodium carbonate, 2 % sodium hydroxide, 0.5 % citric acid, 0.2 % hydrochloric acid, and 2 % formalin to disinfect FMDV.However, these disinfectants are mainly used on environmental surfaces, such as contaminated places or automobiles, rather than on persons.Harada et al. (2015) evaluated the efficacy of thirteen commercially available treatments in eradicating viruses.The researchers discovered that acidic ethanol disinfectants, alkaline cleaners, and sodium hypochlorite were highly efficient, reducing more than 3.0 log10 in the titer of FMDV.Nevertheless, neutral ethanol disinfectants, hand soaps, and quaternary ammonium compound sanitizers had restricted efficacy against FMDV.Therefore, acidic ethanol disinfectants are generally believed to be effective in humans, while alkaline cleaners are suitable for managing an FMD outbreak in contaminated surroundings.
The virus did not show significant aerosol transmission, particularly from sick sheep, so movement was limited (Donaldson & Alexandersen, 2002).The veterinary team was required to adhere to a three-day waiting period before visiting another farm following any interaction with diseased animals.

Vaccine of FMD
The increasing prevalence of various antigenic strains has led to a notable shift towards developing vaccines utilizing locally sourced viruses.Nevertheless, trivalent vaccinations comprising serotypes C, A, and O are frequently employed (Jamal & Belsham, 2013).To ensure proactive safeguarding in areas with a high prevalence of illness, it is advisable to receive at least two doses.The latest FMD vaccination protects for six months.The mice that were administered vaccines reached their peak level of antibody response within 21 to 28 days.Vaccination can safeguard particular animals of certain species (Hirsh & Zee, 1999).During an outbreak, emergency vaccines can efficiently and decisively stop the transmission of FMD.Ongoing endeavors are being undertaken to create novel immunizations.
Nevertheless, the procedure is laborious and demands substantial exertion each time a novel virus emerges (Mahapatra et al., 2017;Mahapatra & Parida, 2018;Ko et al., 2019).Therefore, multiple research efforts have been undertaken to create cutting-edge vaccines that may effectively combat the virus's changing strains (Park et al., 2016;Caridi et al., 2017;Mahapatra et al., 2017).The difficulties related to FMD vaccines include the loss of antigens during the purification process, difficulty maintaining antibodies, insufficient ability to induce an immune response, and limited protection against antigens (Mahapatra et al., 2017).Novel viral strains emerge and manifest periodically, resulting in subsequent outbreaks that may occasionally extend to places unaffected by FMD.The widespread use of inactivated vaccines is prevalent.However, the resulting immunity is restricted and targeted towards specific serotypes and occasionally strains.
Most vaccinations now in use are produced by replicating the highly contagious FMDV using baby hamster kidney-21 (BHK21) cells.Subsequently, the substance is deactivated using binary ethyleneimine (BEI), partially purified, and mixed with a suitable adjuvant such as oil or aluminum hydroxide/saponin.FMDV vaccinations can be categorized as monovalent or multivalent, with each variety containing distinct serotypes.Typically, these vaccinations are more efficient in combating genetically similar serotypes, as they promote the generation of many neutralizing antibodies.Studies have shown that administering doses with a potency greater than six times the protective dosage (PD50) can be effective within four days following vaccination (Barnard et al., 2005;Horsington et al., 2015).Using the inactivated FMDV vaccine has successfully managed and prevented FMD epidemics globally.This vaccination has effectively eliminated FMD in Western Europe and some areas of South America.Consequently, vaccination is no longer conducted in South America (Brown, 2003).

Economic impact of FMD
The FMD virus causes significant economic losses due to export trade restrictions and a high disease incidence.The rapid transmission of FMD to susceptible species threatens small-scale producers and global livestock enterprises (Arzt et al., 2010;Pacheco et al., 2016).While FMD has diminished in prominence in numerous affluent nations, it continues to be a substantial concern in countries classified as middle-income and low-income (Robinson et al., 2016).The considerable reduction in productivity resulting from FMD offsets the comparatively low mortality rate, potentially giving rise to substantial economic consequences (Di Nardo et al., 2011).Although attempts have been made to determine the effects of the FMD virus through research (Lyons et al., 2015;Duchatel et al., 2019).Previous research has established that introducing the FMD virus into FMD-free nations significantly negatively impacts their respective economies (Sissay et al., 2017;Ali et al., 2020).FMD is characterized by direct and indirect economic effects, which fall into two discrete classifications.The main ramifications include stunted growth of livestock, decreased milk production, difficulties in reproduction, and elevated mortality rates among juvenile animals.On the other hand, the secondary consequences encompass additional financial outlays, including costs associated with vaccinations and restrictions on movement (Paton et al., 2018).Certain governments have investigated the feasibility of FMD being utilized in bioterrorism due to the significant economic losses that FMD-free countries may incur and the ease with which highly contagious material can be obtained from countries where epidemics are shared (Farsang et al., 2013;Knight-Jones et al., 2016).Although FMD is prevalent throughout most of Africa, other nations have adopted control strategies (Naranjo & Cosivi, 2013).Disease transmission may arise as a result of the regular animal-to-animal contact observed in commercial marketplaces, as well as the cattle's migration through shared grazing areas and watering holes (Wondwossen & Tariku, 2000;Ayelet et al., 2009;Sissay et al., 2017).
Knight-Jones and Rushton (2013) estimate that the annual economic influence of FMD in countries where it is frequently detected ranges from $6.5 billion to $21 billion.This estimation incorporates the costs associated with production losses and vaccinations.Furthermore, they estimated yearly losses surpassing $1.5 billion in nations devoid of FMD.In various global regions, the economic consequences of FMD appear to differ.FMD has a wide-ranging impact, encompassing numerous facets, including diminished production, setbacks in breeding, compromised food security, disruptions in international commerce, and escalated expenses related to reestablishing FMD-free status.
According to a report, the FMD incidence in Bangladesh caused an estimated financial loss of Taka 53172067 (equivalent to Tk 53.17 million or US$ 0.63 million) for the 850 affected households.The mortality rate of impacted livestock constituted the most significant proportion of losses (63.47 %), followed by veterinary expenditures (10.71 %), weight reduction in maturing cattle (10.68 %), milk production decline (9.17 %), and personnel absences due to the provision of care for affected livestock (5.98 %).The annual financial loss resulting from the FMD outbreak in Bangladesh is estimated to be Taka 18856.96crore (Tk 188.57 billion or $2.22 billion), per the calculation (Giasuddin et al., 2020).

Conclusions
FMD poses a significant risk to the global livestock industry, as emerging sublineages can develop into new strains that can overcome vaccine immunity, leading to outbreaks.To effectively manage the disease, ongoing monitoring, matching vaccines to specific strains, and ensuring vaccine quality are crucial.Animal identification sys-tems and movement controls are necessary to prevent animal movement.Most Asian and African nations lack understanding of FMDV sub-types due to inadequate sampling and lack of specificity in the PCP's non-descriptive approach.Countries should have diagnostics, epidemiology, and economics expertise to enhance knowledge.Support is needed for developing research studies, risk assessment, risk management, and socioeconomic studies.Integrating laboratory data with field epidemiology information is essential for gaining insights.Effective control requires regional collaboration, timely information on FMD outbreaks, and rapid data sharing.Early diagnosis and prompt responses are necessary for adequate control.Access to high-quality FMD vaccinations with appropriate serotypes is also required for herd immunity.

Table 1
Foot-and-mouth disease viral topotypes have been identified both internationally and in Bangladesh

Table 2
The lineages and sub-lineages of the FMD virus identified in Bangladesh