220
Views
0
CrossRef citations to date
0
Altmetric
Research Article

A novel fractionalized investigation of tuberculosis disease

ORCID Icon, ORCID Icon, ORCID Icon, ORCID Icon, ORCID Icon & ORCID Icon
Article: 2351229 | Received 24 Nov 2023, Accepted 29 Apr 2024, Published online: 14 May 2024

ABSTRACT

In this study, we investigate novel fractional tuberculosis model with Caputo fractional derivative. The computational solution of the fractional tuberculosis disease is obtained with the help of the generalized Euler's method (GEM). This article considers two treatment strategies: protective treatment for latent populations and main treatment for infected ones. The compartmental structure of the six-dimensional model includes the susceptible, latent, infected, recovered, and treatment classes. To examine the nature of differential equations of fractional order that arise in biological illness, the findings produced utilizing the method under consideration are more accurate and straightforward. Additionally, the stability of the equilibrium point is also investigated. The fractional model has been graphically simulated using MATLAB22.

MATHEMATICS SUBJECT CLASSIFICATIONS:

1. Introduction

For millennia, humans have struggled against epidemics, resulting in the deaths of countless individuals. These epidemics occasionally take the shape of diseases like smallpox, HIV, plague, avian flu, and seasonal flu. Tuberculosis (TB) is one of these epidemics that has gained widespread recognition. Annually, millions succumb to airborne infectious TB, causing mortality. Mycobacterium tuberculosis (MTB) causes tuberculosis, a chronic bacterial and infectious disease. A TB patient's sputum or Bacillus-laden droplets spat while coughing are the most common means of transmission. Although TB is a multi-organ illness, it most commonly affects the lungs and the lymph nodes in the chest cavity (mediastinum). The sickness has been in the population for a very long time, dating back to ancient Egypt, China, and India [Citation1]. There are two main categories of tuberculosis infection:

Latent TB infection: The immune system controls germs, preventing illness. Latent TB infection is asymptomatic and cannot spread. If the immune system is impaired, the bacteria can become active and develop TB.

Active tuberculosis: This condition develops when the immune system is unable to keep the bacteria under control, enabling them to grow and lead to active illness. Individuals who have active TB experience symptoms and can transmit the germs to others.

TB is conveyed by airborne droplets laden with bacteria and is passed from one sick person to another. When a person spits, talks, coughs, or sneezes while carrying active TB germs that spread into air. Getting TB from relatives and friends is simple. When someone inhales a few TB bacterium germs, they get infected extremely quickly. Ninety percent of those with TB infection stay latent, whereas only around ten percent develop active TB infection. People who are latently infected do not spread the TB virus. People with TB infection might be identified using skin or blood testing. People who have immune-compromised illnesses (such as HIV patients and diabetics) are more susceptible to TB disease. Symptoms indicative of active TB encompass persistent cough exceeding three weeks, elevated body temperature, hemoptysis, chest unease, weariness, and nocturnal perspiration. Although TB is a disease that may be treated with medication, taking the wrong medication or administering it insufficiently might be cause a TB condition that is strictly resistant to treatment. Furthermore, the BCG vaccine is an easy way to prevent tuberculosis, but its usefulness is still up for debate, with only a 50% testified success rate [Citation2]. Despite significant efforts in TB prevention and treatment, a latent TB infection afflicts roughly 25% of the global populace, ensuring a persistent wellspring for active TB cases.

Every year on March 24, ‘World Tuberculosis Day’ is observed to honour Robert Koch's discovered of MTB Bacillus, which put a stop to the world's TB pandemic and paved the path for identification and treatment of the illness. The danger of TB is growing globally along with the rate of HIV infection. Every day, 4,500 people die from TB, which affects 30,000 people worldwide. Since 2000, TB has been decreased by 42 percent globally and 54 million lives have been spared. The World Health Organization had put into effect both its ‘European Region Tuberculosis Action Plan 2016–2020’ and its ‘Worldwide Tuberculosis Eradication Plan’, which outline the actions to be performed after 2015. The goal in this situation is to decrease TB incidence by 90 percent worldwide by 2030.

Fractional calculus expands the realm of applied mathematics by accommodating fractional orders beyond integer calculus. This extension enriches mathematical modelling approaches, particularly in capturing complex dynamics in various fields. Its versatility offers insights into intricate phenomena, enhancing our understanding and predictive capabilities. In engineering, water resources management, machine learning, cryptography, and epidemiology, fractional calculus has recently attracted substantial interest in the scientific community [Citation3–6]. Memory effect is present in fractional calculus, which plays a vital role in understanding various phenomena. The application of fractional derivatives has gained significant importance in epidemiological modelling. Adnan et al. [Citation7] investigated time-varying COVID-19 mathematical models with singular kernels, Qu et al. [Citation8] investigated a fractal-fractional mathematical model of tuberculosis, and Bhatter et al. [Citation9] investigated calcium buffering using Hilfer fractional derivatives, among others.

Mathematical models have a crucial role in analyzing disease propagation behaviour and the formation of effective methods for the control of infectious diseases. Mathematical modelling is a significant tool for understanding and eventually managing such diseases [Citation10–12]. The genesis, propagation, and decay of waves are studied by a wide variety of models, many of which centre on transmission dynamics. In the study of infectious illnesses, mathematical models are crucial instruments that offer essential insights into disease transmission and management. Researchers have created a plethora of models to investigate the dynamics of tuberculosis. These models may aid in the search for measures that can stop the spread of tuberculosis and lessen its influence on society at large. Mathematical models can analyze data on TB transmission and illness development to forecast TB incidence and direct public health actions. These models are crucial for comprehending the intricate dynamics of TB and creating evidence-based TB prevention strategies.

The potential of first mathematical model introduced by Waaler et al. [Citation13] showcased through three illustrative instances that these examples elucidate its utility in forecasting the propensity of tuberculosis within a specific region, be it through abrupt and spontaneous emergence or through the implementation of specific control initiatives. These specific cases illustrate the model's utility in assessing diverse control approaches while showcasing TB's impact on its innate predisposition. Castillo-Chavet and Feng [Citation14] demonstrated discrepancies between two TB patients with drug-resistant TB and those without. Liu and Zhang [Citation15] investigated the influence of therapy and vaccination on the spread of TB using a newly developed deterministic mathematical model. In the research of children in 22 countries with the highest rates of tuberculosis cases, Dodd et al. [Citation16] established a baseline for the country-level rates of tuberculosis cases and created guidelines to avoid TB cases at these rates. A model was constructed in another study and compared with data from Senegal to describe the effects of a public health education program for TB. The authors of [Citation17] took into account two distinct therapeutic approaches. One emphasizes addressing latent tuberculosis infection in the elderly alongside existing tuberculosis control strategies, while the other involves providing anti-TB medications to individuals already infected, whereas Schulzer et al. [Citation18] proposed a mathematical model to explore the accelerating impact of HIV infection on TB illness. It was claimed in another investigation that the impact of exogen on the qualitative dynamics of TB was excessive [Citation19]. The probability that 10,000 clinical patients receiving various doses of moxifloxacin would achieve or surpass the level of exposure necessary to reduce their moxifloxacin resistance in TB was calculated using Monte-Carlo simulations [Citation20]. Furthermore, it was determined that improved TB diagnostic methods had a significant influence on t-related illness and mortality rates in HIV endemic settings, and it was emphasised that as TB rates continue to rise, sophisticated diagnostic techniques should be taken into account as TB control measures [Citation21].

Important findings over the next ten years have been obtained through analysis of the mathematical model used in research on multidrug resistant (CID) and common drug-resistant (YID) strains in South Africa, the area with the highest TB incidence globally. It shown that from 2008 to 2017, more than 7.000 instances of CID-TB might have been avoided and more than 47.000 lives may have been saved in South Africa by increasing medication sensitivity and TB awareness among adults. This results in a 47% drop in CID-TB mortality and a 17% drop in overall TB deaths [Citation22]. According to Bowong and Tewa's [Citation23] research, the TB system they analyzed has a single stable equilibrium and is asymptotically globally stable. They also demonstrated that, depending on the basic reproduction rate, this stable structure may exist in either disease-free or disease-affected regions. Liu and Zhang [Citation15] examined the impact of vaccination and therapy on the spread of TB using a newly developed deterministic mathematical model. Tewa et al. [Citation24] used the Lyapunov function to demonstrate the existence-uniqueness of linked endemic balances in quadratic forms while taking into consideration the possibility of TB-sensitive people switching from one section to another. Trauer et al. [Citation25] the model introduced by simulated program-based responses to TB in highly endemic nations in the Asia-Pacific area and claimed that it could not be changed in accordance with the projected rate of a hit without permitting reinfection during the delay. In a different research, it was attempted to infect the fewest vulnerable individuals and to reduce the number of infected persons by using vaccination characteristics in the mathematical model [Citation26].

January 2005–December 2012 in mathematical model created with a focus on data related to tuberculosis in China [Citation27] fitted the pertinent data, and using the chi-square test, they determined the model's optimal parameter values. Using these parameters, they calculated the effective number of disease reproduction each year. In light of the findings, it was proposed that additional variables, such as chronological age and/or geographical structure, which takes into account sensitivity by age, be included to the model in order to evaluate the differences in how people in rural and urban regions approach TB. A mathematical model to combine several data sources and examine the dynamics of TB was investigated in this work. This research, which details the dynamics of tuberculosis in HCMC from 1996 to 2005, was the first comprehensive study on the disease there. The authors of [Citation17] took into account two alternative treatment modalities; one of them highlights the need of treating latent TB infection (LTBI) in the elderly in addition to current TB control measures. The second is the administration of anti-TB medications to those who are infected.

The article is arranged as follows: The essential definitions are covered in the second Section. Section 3 formulates the fractionalized model based on the variables and parameters. Section 4 investigates the solution's non-negativity and the equilibrium points. Section 5 examines the stability analysis. A numerical simulation of the model is included in Section 6. Finally, Section 7 presented the main research findings.

2. Preliminaries

This section commences with a review of essential mathematical tools employed in subsequent sections.

Definition 2.1

The usual definition of the Caputo fractional derivative (CFD) of order 0<δ<1 is defined [Citation28] as follows: (1) cDtδ(ϕ(t))=1Γ(rδ)0tϕr(s)(ts)δr+1ds,(1) where r=[δ]+1.

Definition 2.2

The usual definition of Laplace transform (LT) [Citation29] is defined as follow: (2) L[ϕ(t);P]=ϕ¯(P)=0ePtϕ(t)dt,t0,(P)>α.(2) The inverse LT for the function ϕ¯(P) is given as follow: (3) L1[ϕ¯(P);t]=ϕ(t)=12πiϰiϰ+iePtϕ¯(P)dP,(3) where ϰ is real number.

Definition 2.3

The LT of Equation (Equation1) is define by (4) L[0cDtδϕ(t)](P)=PδL[ϕ(t)](P)j=0m1Pδj1ϕj(0),m1<δ<1,mN.(4)

Definition 2.4

The Mittag-Leffler functions of one and two parameters are defined as follows [Citation30, Citation31]: Eδ()==0Γ(δℓ+1);(,δC,(δ)>0),and Eδ,ρ()==0Γ(δℓ+ρ);(,δ,ρC,(δ)>0,(ρ)>0).

3. Mathematical model

The mathematical model for TB introduced in reference [Citation32] delineates six distinct population compartments: susceptible (S), latent (L), latently infected individuals under treatment (T1), infected (I), actively infected individuals under treatment (T2), and recovered (R) so that at any time t, the total human population is define by N(t)=S(t)+L(t)+T1(t)+I(t)+T2(t)+R(t). The parameters in the model Equation (Equation5) are comprehensively detailed below.

The mathematical equations are (5) dSdt=Θ(αI+βL+ς)S,dLdt=βSL(γI+ς+f)L,dT1dt=fL(ς+m+ϰ)T1,dIdt=γLI+αSI(θ+ς+z+ϰ)I,dT2dt=θI(ϵ+ϰ+ς)T2,dRdt=mT1+ϵT2+zIςR,}(5)

where

Θ=

is recruitment rate,

α=

is the transmission rate of susceptible individuals to infected compartment,

β=

is the proportion of susceptible populations to enter the latent TB class,

θ=

is the proportion of individuals treated with infected individuals,

ς=

is normal mortality rate,

f=

is the proportion at which latent TB populations enter the consciousness class,

γ=

is the proportion of hidden TB individuals entering the infected class,

ϰ=

is the disease related mortality,

m=

is the proportion of individuals recovering with preventive treatment,

ϵ=

is the proportion of individuals recovering by treating infected individuals,

z=

is the proportion of infected people recovering without treatment,

A=

is saturated incidence force of latent from S,

B=

is saturated incidence force of infection from S,

C=

is saturated incidence force of infection from L.

3.1. The fractional model

Here we are introducing the fractional derivative to the TB infection model given as follows (6) cDtδS(t)=Θ(αI+βL+ς)S,cDtδL(t)=βSL(f+γI+ς)L,cDtδT1(t)=fL(ς+ϰ+m)T1,cDtδI(t)=γLI+αSI(θ+z+ς+ϰ)I,cDtδT2(t)=θI(ϵ+ϰ+ς)T2,cDtδR(t)=mT1+ϵT2+zIςR,}(6) with initial conditions S(0)=S0, L(0)=L0, T1(0)=T10, I(0)=I0, T2(0)=T20, R(0)=R0.

4. Qualitative analysis

This segment discusses the existence, uniqueness, positivity, and boundness of the system's solution (Equation6).

4.1. Existence and uniqueness

The symbol R+ indicates the set of all non-negative real numbers and presumes that Λ={(S,L,T1,I,T2,R)R+:S,L,T1,I,T2,R0;max(|S|,|L|,|T|,|T1|,|T2|,|R|)N}.In the region Λ×(0,T], it is demonstrated [Citation33] that the fractional order model (Equation6) solution exists and is unique.

Theorem 4.1

If ð0=(S(0),L(0),T1(0),I(0),T2(0),R(0))Λ is a starting condition, then the fractional order model (Equation6) solution ð=(S,L,T1,I,T2,R)Λ is unique for t0.

Proof.

G1(ð)=Θ(A+B+ς)S,G2(ð)=AS(f+C+ς)L,G3(ð)=fL(ς+m+ϰ)T1,G4(ð)=CL+BS(z+θ+ς+ϰ)I,G5(ð)=θI(ς+ϵ+ϰ)T2,G6(ð)=zI+mT1+ϵT2ςR.Where, A=βL, B=αI and C=γI.

Here, for ð,ð¯Λ, one obtains G(ð¯)G(ð)=G1(ð¯)G1(ð)+G2(ð¯)G2(ð)+G3(ð¯)G3(ð)+G4(ð¯)G4(ð)+G5(ð¯)G5(ð)+G6(ð¯)G6(ð),(2A+2B+ς)|S¯S|+(2C+2f+ς)|L¯L|+(2m+ς+ϰ)|T¯1T1|+(2θ+2z+ς+ϰ)|I¯I|+(2ϵ+ϰ+ς)|T¯2T2|+ς|R¯R|Mð¯ð,where M=max{(2A+2B+ς),(2C+2f+ς),(2m+ς+ϰ),(2θ+2z+ϰ+ς),(2ϵ+ϰ+ς),ς}.

As a result, G(ð) fulfills the Lipschitz condition, implying that the solution to model (Equation6) exists and is unique.

4.2. Non-negativity and boundness of solution

Theorem 4.2

Suppose the primary solution of our model is {S(0),L(0),T1(0),I(0), T2(0),R(0)0}Λ. It follows that the solution set {S(t),L(t),T1(t),I(t),T2(t),R(t)} for the system (Equation6) remains non-negative for all t0.

Proof.

The first equation of (Equation6) yields cDtδS(t)=Θ(A+B+ς)S(t),cDtδS(t)(A+B+ς)S(t).Applying Laplace transformation, PδS(P)k=0n1Pδk1Sk(0)(A+B+ς)S(P),S(P)k=0n1Pδk1Pδ+(A+B+ς)Sk(0),S(P)k=0n1L[tkEδ,k+1((A+B+ς)tδ)]Sk(0),forn=1S(P)L[Eδ,1((A+B+ς)tδ)]S(0).Taking inverse LT S(t)Eδ,1((A+B+ς)tδ)S(0),δ1S(t)exp((A+B+ς)t)S(0)0,S(t)0.Similarly L(t)0,T1(t)0,I(t)0,T2(t)0,R(t)0.

As a result, for any t0, the solution set {S(t),L(t),T1(t),I(t),T2(t),R(t)} of system (Equation6) is positive.

Theorem 4.3

The model (Equation6) has uniformly bounded solution begins in Λ+={(S,L,T1,I,T2,R)Λ;0S+L+T1+I+T2+RΘς}.

Proof.

In equation N(t) symbolizes the overall population at time t,

N(t)=S(t)+L(t)+T1(t)+I(t)+T2(t)+R(t).

By applying a direct sum to the equations in TB model (Equation6) of fractional order, we obtain cDδN(t)=Θ(ςS(t)+ςL(t)+(ϰ+ς)T1(t)+(ϰ+ς)I(t)+(ς+ϰ)T2(t)+ςR(t))=ΘςN(t)ϰ(I(t)+T1(t)+T2(t))ΘςN(t).Thus cDδN(t)+ςN(t)Θ.Following to [Citation34], we get 0N(t)N(0)Eδ(ςtς)+Θς(1Eδ,1(ςtδ)).In accordance with [Citation34], one gets 0N(t)Θς,t,As a result, the solution to the TB model (Equation6) remains uniformly bounded in the region Λ+, starting in Λ+.

5. Stability analysis

The fundamental reproductive number R0 has been determined in this section. The infectious-free equilibrium point's, local asymptotic stability is also investigated.

5.1. The infectious-free-equilibrium (IFE) point

To determine the fractionalized TB model (Equation6) equilibrium points, we choose to: (7) Θ(αI+ς+βL)S=0,βSL(f+γI+ς)L=0,fL(ς+m+ϰ)T1=0,γLI+αSI(ς+z+θ+ϰ)I=0,θI(ϵ+ς+ϰ)T2=0,mT1+ϵT2+zIςR=0.}(7) Model (Equation6) is stable when no TB exists in the population under investigation. That is when L0=I0=0.

Hence, the IFE denoted by 0, of the model (Equation6) is produced by replacing L0=I0=0 in above system. ΘςS0=0.Therefore, S0=Θς.We can easily obtain the IFE 0=(Θς,0,0,0,0,0).

5.2. The basic reproductive number

In the conventional meaning, the fundamental reproductive number is the anticipated number of secondary infected transmitted by one infectious individual in a completely susceptible population throughout the individual duration of infectiousness. This is a state quantity acquired from the conventional ‘next-generation matrix approach’ [Citation35].

(S(t),L(t),T1(t),I(t),T2(t),R(t)) remains in the biologically significant region Λ, which is positively invariant for model (Equation6). The model equations are rewritten, beginning with potentially infective classes. cDtδL(t)=βS(t)L(t)(ς+γI(t)+f)L(t),cDtδI(t)=γL(t)I(t)+αS(t)I(t)(θ+ϰ+z+ς)I(t).Then, using the next-generation matrix concept, we can gain for the model (Equation6), the disease component is x=(L,I)T and the non-disease component y=(S,T1,T2,R)T, then we have cDtδx=F(x)V(x),where F(x,y)=[βSLαSI]T,V(x,y)=[(γI+f+ς)L(θ+ς+ϰ+z)IγLI]T.The Jacobian matrix of F(x) and V(x) with regard to L and I at the IFE 0=(Θς,0,0,0,0,0) is obtained next. We assigned F(x) and V(x) in the following manner in order to streamline our work: F(x,y)=[F1F2]TV(x,y)=[V1V2]T,where F1=βSL,F2=αSI,V1=(γI+f+ς)L,V2=(θ+z+ς+ϰ)IγLI.At the IFE point 0, F, and V respectively receive the Jacobian matrix of F(x) and V(x); F=[βΘς00αΘς],andV=[ς+f00(θ+ς+z+ϰ)].Where the matrix F is nonsingular and the matrix V is non-negative, the next-generation matrix FV1 is defined as using the next-generation matrix approach. This matrix's FV1 spectral radius is evaluated at the equilibrium point 0 to compute the basic reproductive number of the disease within the system (Equation6), explained by two distinct cases as R01 and R02. R01=βΘς(ς+f),R02=αΘς(θ+ς+z+ϰ)in which R0=max[R01,R02].

5.3. Local stability of the IF steady state

Theorem 5.1

The IFE 0=(Θς,0,0,0,0,0) is locally asymptotically stable if R0<1 and unstable if R0>1.

Proof.

For the model (Equation6) at 0=(Θς,0,0,0,0,0), the Jacobian matrix J0 is provided by J0=[ςβΘς00βΘς(ς+f)00f(ς+ϰ+m)00000000mαΘς00000000αΘς(z+θ+ς+ϰ)00θ(ϵ+ς+ϰ)0zϵς]The eigen values of Jacobian matrix J0 are λ1=ς, λ2=βΘς(ς+f), λ3=(ς+m+ϰ), λ4=αΘς(θ+z+ς+ϰ), λ5=(ϵ+ϰ+ς), λ6=ς.

It is obivious that λ1,λ3,λ5,λ6 are negative and remaining eigen values, λ2=βΘς(f+ς)=(R011)(f+ς)ifR01<1thenλ2isnegative,andλ4=αΘς(θ+ς+z+ϰ)=(R021)(θ+ς+ϰ+z)ifR02<1thenλ4isnegative.It can be observed that eigen values λ1,λ2,λ3,λ4,λ5,λ6 are negative, which means the IFE point is locally asymtotically stable if R0=max[R01,R02]<1.

6. Application of GEM

We analyze the following problem in the impression of Odibat and Momani [Citation36], which is a generalization of Euler's classical technique. (8) cDtδZ=f(t,Z),t[0,T],0<δ1.(8) The interval [0,b] over which we wish to locate the solution to the problem (Equation8) can be subdivided into k subintervals [ti,ti+1] of similar width h=bk, by utilizing the nodes ti=ih for i=0,1,2,,k. Expand Z pertaining to t=t0=0 and utilizing the generalized Taylor's formula [Citation37]. Assume that Z,cDδZ,cD2δZ are continuous on [0,b]. As a consequence, there is an a1 value for every t value, meaning that (9) Z(t)=Z(t0)+(cDtδZ(t))(t0)tδΓ(δ+1)+(cDt2δZ(t))(a1)t2δΓ(2δ+1).(9) When (cDtδY(t))(t0)=f(t0,Z(t0)) and h=t1 are subsituted into Equation (Equation9), the outcome is an expression for Y(t1): Z(t1)=Z(t0)+f(t0,Z(t0))tδΓ(δ+1)+(cDt2δY(t))(a1)t2δΓ(2δ+1).The solution can be achieved by neglecting the second-order term (involving h2δ) when the step size h is sufficiently small. Z(t1)=Z(t0)+f(t0,Z(t0))tδΓ(δ+1).Repeat the procedure until the solution Z(t) is approximated by a series of points. When ti+1=ti+h, the formula for (10) Z(ti+1)=Z(ti)+hδΓ(δ+1)f(ti,Z(ti)),(10) for i=0,1,2,,k1. It is evident that if δ=1, then the GEM (Equation10) simplifies to the typical Euler's technique. Hence S(ti+1)=S(ti)+hδΓ(δ+1)[Θ(βL(ti)+αI(ti)+ς)S(ti)],L(ti+1)=L(ti)+hδΓ(δ+1)[βS(ti)L(ti)(γI(ti)+f+ς)L(ti)],T1(ti+1)=T1(ti)+hδΓ(δ+1)[fL(ti)(m+ς+ϰ)T1(ti)],I(ti+1)=I(ti)+hδΓ(δ+1)[γL(ti)I(ti)+αS(ti)I(ti)(θ+z+ς+ϰ)I(ti)],T2(ti+1)=T2(ti)+hδΓ(δ+1)[θI(ti)(ϵ+ς+ϰ)T2(ti)],R(ti+1)=R(ti)+hδΓ(δ+1)[mT1(ti)+ϵT2(ti)+zI(ti)ςR(ti)].In doing so, one obtains (11) Sn+1=Sn+[Θ(βLn+αIn+ς)Sn],Ln+1=Ln+[βSnLn(γIn+f+ς)Ln],T1n+1=T1n+[fLn(m+ς+ϰ)T1n],In+1=In+[γLnIn+αSnIn(θ+z+ς+ϰ)In],T2n+1=T2n+[θIn(ϵ+ς+ϰ)T2n],Rn+1=Rn+[mT1n+ϵT2n+zInςRn],(11) where 0<=hδΓ(δ+1)<1 is the step size and is dependent on the initial circumstances, S0, L0, T10, I0, T20, R0. We have Sn+1=Sn=S,Ln+1=Ln=L,T1n+1=T1n=T1,In+1=In=I,T2n+1=T2n=T2,Rn+1=Rn=R at a fixed point.

7. Discussion of results

This section discusses the pivotal role of numerical data for the considered TB model with the inclusion of the consciousness component. We employed the parameters from Table  for the simulations in our current paper, treating them as the ‘year’ parameter. These parameter values are utilized as ‘years’ in all our simulations and graphs. The fractional model has been graphically simulated using MATLAB22 software [Citation38].

Table 1. Parameter values.

Figure  demonstrates for integral value of δ, the number of susceptible class decreases with time. Meanwhile, for fractional orders, it can be observed that the growth of the susceptible population is slower than the integral value one. In Figure  one can observe that the latent class increases rapidly at different fractional operators in beginning then decline fastly as compared to integer order but after some years become stable. In Figure  the same behaviour occurs for the treatment of latently infected individuals as latent class at different fractional operators.

Figure 1. Dynamical behaviour of susceptible population S(t) for δ.

Figure 1. Dynamical behaviour of susceptible population S(t) for δ.

Figure 2. Dynamical behaviour of latent population L(t) for δ.

Figure 2. Dynamical behaviour of latent population L(t) for δ.

Figure 3. Dynamical behaviour of latently infected treatment population T1(t) for δ.

Figure 3. Dynamical behaviour of latently infected treatment population T1(t) for δ.

In Figure  it is evident that, in the absence of therapy and preventative measures, TB infection rises first at different fractional orders. However, with treatment and care, the infection decreased, demonstrating the stability and convergent behaviour of various fractional orders to integer orders. Figure  suggests that as the illness progresses, the treatment must also be increased in early phases at varied arbitrary sequences. Applying care and treatment will help decline the disease from society, as the number of afflicted people declines, so will the need for therapy. In Figure  shows that as the infected population decreases at different fractional order the recovered cases increases at various fractional order.

Figure 4. Dynamical behaviour of infected population I(t) for δ.

Figure 4. Dynamical behaviour of infected population I(t) for δ.

Figure 5. Dynamical behaviour of actively infected treatment population T2(t) for δ.

Figure 5. Dynamical behaviour of actively infected treatment population T2(t) for δ.

Figure 6. Dynamical behaviour of recovered population R(t) for δ.

Figure 6. Dynamical behaviour of recovered population R(t) for δ.

The effectiveness of parameter β is demonstrated in the Figure , which shows the rate of sensitive individuals enter the latent class. According to Figure , it is clear that the latent population grows at a fractional order relative to the integral value one as the parameter increases from 0.0005 to 0.0020. In Figure , we observe the influence of the parameter α, which illustrates the rate of transition of susceptible population to the infected class. If we look at Figure , we can deduce that when parameter increases from 0.0006 to 0.0014, then the infected population declines at fractional order as compared to integeral value. According to the Figure , we show that as parameter f grows from 0.55 to 0.75, in compared to an integer value, the number of TB-infected people declines more rapidly at fractional order. This finding is pivotal for discerning a parameter that helps in reducing TB incidence. Figure  illustrates the population density of the R class concerning parameter z. The graphic representation unmistakably demonstrates a rise in the R class density as the parameter values grow from 0.3 to 0.7. Figure  illustrates the population density of treatment for hidden infected individuals (T1) and actively infected individuals (T2) at varied fractional orders. Figure  shows the graphical relation of latent class and infected class at δ=(1.00,0.90,0.80). The comparison of integer value and fractional value of densities and behaviours of the model's population is illustrated in Figure  as population dynamics.

Figure 8. The infected class population density, I(t), for various values of α=0.0006,0.0008,0.00012,0.0014 for δ=0.90,1.00.

Figure 8. The infected class population density, I(t), for various values of α=0.0006,0.0008,0.00012,0.0014 for δ=0.90,1.00.

Figure 9. The infected class population density I(t), for various values of consciousness parameter for δ=0.90,1.00.

Figure 9. The infected class population density I(t), for various values of consciousness parameter for δ=0.90,1.00.

Figure 10. The population density of recovered class R(t) for various values of z for δ=0.90,1.00.

Figure 10. The population density of recovered class R(t) for various values of z for δ=0.90,1.00.

Figure 11. The densities of T1(t) and T2(t) for δ=0.80,0.90,1.00.

Figure 11. The densities of T1(t) and T2(t) for δ=0.80,0.90,1.00.

Figure 12. The proportions of infected I(t) and latent L(t) individuals for δ=0.80,0.90,1.00.

Figure 12. The proportions of infected I(t) and latent L(t) individuals for δ=0.80,0.90,1.00.

Figure 13. Population densities in the TB model vary for δ values of 0.80 and 1.00.

Figure 13. Population densities in the TB model vary for δ values of 0.80 and 1.00.

Figure 7. The hidden TB population density L(t), for various values of β=0.0005,0.0010,0.00015,0.0020 for δ=0.90,1.00.

Figure 7. The hidden TB population density L(t), for various values of β=0.0005,0.0010,0.00015,0.0020 for δ=0.90,1.00.

8. Conclusion

In this article, we studied at a TB model (SLT1IT2R) under CFD that has a useful consciousness method for the tuberculosis pandemic disease. We have emphasized the value and varied elements of consciousness with the aid of the aforementioned model. Numerous theoretical properties of the model, including its existence and uniqueness as well as its positivity, equilibria, and reproduction ratio, have been researched. For a numerical analysis utilizing the GEM, the fractionalized TB model is examined. Infection rates among the community dropped as a result of the treatment. Additionally, lowering the incidence of harmful contacts and taking preventative measures would aid in the eradication of the TB illness. The ability of the Caputo fractional derivative to accurately model key biological phenomena inherent to tuberculosis dynamics, such as non-locality, memory effects, and anomalous diffusion, which are crucial for capturing the complex dynamics of the disease spread within populations. As can be seen from the depicted figures, in comparison to the comparable integer order,the presented fractional order model in terms of the Caputo operator yields more flexible results. As a result, it is clear that the CFD provides more biologically plausible behaviour about the dynamics of the tuberculosis disease. Thus, we can conclude that CFD is a reliable technique for simulating physical occurrences. Overall, we can state that the fractional order differential equation has produced comparably better predictions than the classical derivatives. It should be highlighted that this model can be further investigated in the future by performing a comparative study using actual data and making use of various forms of fractional derivatives.

Author Contribution

Each author made an equal contribution to this paper. All authors have read and approved the final manuscript.

Acknowledgments

The authors express their sincere thanks to the editor and reviewers for their valuable comments and suggestions that improved the quality of the manuscript.

Data Availability and Access

All data generated or analyzed during this study are included in this article. Further, we declare that no human data or participants have been involved in the study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

References

  • Morse D, Brothwell DR, Ucko PJ. Tuberculosis in ancient Egypt. Am Rev Respir Dis. 1964;90(4):524–541.
  • Colditz GA, Brewer TF, Berkey CS, et al. Efficacy of BCG vaccine in the prevention of tuberculosis: meta-analysis of the published literature. JAMA. 1994;271(9):698–702. doi: 10.1001/jama.1994.03510330076038
  • Bhatter S, Jangid K, Kumawat S, et al. A new investigation on fractionalized modeling of human liver. Sci Rep. 2024;14(1):1636. doi: 10.1038/s41598-024-51430-y
  • Podlubny I. Fractional differential equations: an introduction to fractional derivatives, fractional differential equations, to methods of their solution and some of their applications. Cambridge, Massachusetts: Elsevier; 1998.
  • Venkatesh A, Manivel M, Baranidharan B. Numerical study of a new time-fractional Mpox model using caputo fractional derivatives. Phys Scr. 2024;99(2):025226. doi: 10.1088/1402-4896/ad196d
  • Zhang L, Ur Rahman M, Ahmad S, et al. Dynamics of fractional order delay model of coronavirus disease. AIMS Math. 2022;7(3):4211–4232. doi: 10.3934/math.2022234
  • Adnan A, Shah Z, Kumam P. Investigation of a time-fractional COVID-19 mathematical model with singular kernel. Adv Contin Discrete Models. 2022;2022(1):34. doi: 10.1186/s13662-022-03701-z
  • Qu H, Ur Rahman M, Arfan M, et al. Investigating fractal-fractional mathematical model of tuberculosis (TB) under fractal-fractional caputo operator. Fractals. 2022;30(5):2240126. doi: 10.1142/S0218348X22401260
  • Bhatter S, Jangid K, Kumawat S, et al. A generalized study of the distribution of buffer over calcium on a fractional dimension. Appl Math Sci Eng. 2023;31(1):2217323. doi: 10.1080/27690911.2023.2217323
  • Mahmood T, Ur Rahman M, Arfan M, et al. Mathematical study of algae as a bio-fertilizer using fractal–fractional dynamic model. Math Comput Simul. 2023;203:207–222. doi: 10.1016/j.matcom.2022.06.028
  • Meena M, Purohit M, Shyamsunder, et al. A novel investigation of the hepatitis B virus using a fractional operator with a non-local kernel. Partial Differ Equ Appl Math. 2023;8:100577. doi: 10.1016/j.padiff.2023.100577
  • Ur Rahman M, Alhawael G, Karaca Y. Multicompartmental analysis of middle eastern respiratory syndrome coronavirus model under fractional operator with next-generation matrix methods. Fractals. 2023;31(10):2340093–12360. doi: 10.1142/S0218348X23400935
  • Waaler H, Geser A, Andersen S. The use of mathematical models in the study of the epidemiology of tuberculosis. Am J Public Health. 1962;52(6):1002–1013. doi: 10.2105/AJPH.52.6.1002
  • Castillo-Chavez C, Feng Z. To treat or not to treat: the case of tuberculosis. J Math Biol. 1997;35:629–656. doi: 10.1007/s002850050069
  • Liu S, Wang S, Wang L. Global dynamics of delay epidemic models with nonlinear incidence rate and relapse. Nonlinear Anal Real World Appl. 2011;12(1):119–127. doi: 10.1016/j.nonrwa.2010.06.001
  • Dodd PJ, Sismanidis C, Seddon JA. Global burden of drug-resistant tuberculosis in children: a mathematical modelling study. Lancet Infect Dis. 2016;16(10):1193–1201. doi: 10.1016/S1473-3099(16)30132-3
  • Chong KC, Leung CC, Yew WW, et al. Mathematical modelling of the impact of treating latent tuberculosis infection in the elderly in a city with intermediate tuberculosis burden. Sci Rep. 2019;9(1):4869. doi: 10.1038/s41598-019-41256-4
  • Schulzer M, Radhamani MP, Grzybowski S, et al. A mathematical model for the prediction of the impact of HIV infection on tuberculosis. Int J Epidemiol. 1994;23(2):400–407. doi: 10.1093/ije/23.2.400
  • Feng Z, Castillo-Chavez C, Capurro AF. A model for tuberculosis with exogenous reinfection. Theor Popul Biol. 2000;57(3):235–247. doi: 10.1006/tpbi.2000.1451
  • Gumbo T, Louie A, Deziel MR, et al. Selection of a moxifloxacin dose that suppresses drug resistance in mycobacterium tuberculosis, by use of an in vitro pharmacodynamic infection model and mathematical modeling. J Infect Dis. 2004;190(9):1642–1651. doi: 10.1086/jid.2004.190.issue-9
  • Dowdy DW, Chaisson RE, Moulton LH, et al. The potential impact of enhanced diagnostic techniques for tuberculosis driven by HIV: a mathematical model. AIDS. 2006;20(5):751–762. doi: 10.1097/01.aids.0000216376.07185.cc
  • Dowdy DW, Chaisson RE, Maartens G, et al. Impact of enhanced tuberculosis diagnosis in south africa: a mathematical model of expanded culture and drug susceptibility testing. Proc Natl Acad Sci. 2008;105(32):11293–11298. doi: 10.1073/pnas.0800965105
  • Bowong S, Tewa JJ. Mathematical analysis of a tuberculosis model with differential infectivity. Commun Nonlinear Sci Numer Simul. 2009;14(11):4010–4021. doi: 10.1016/j.cnsns.2009.02.017
  • Tewa JJ, Bowong S, Noutchie SO. Mathematical analysis of a two-patch model of tuberculosis disease with staged progression. Appl Math Modell. 2012;36(12):5792–5807. doi: 10.1016/j.apm.2012.01.026
  • Trauer JM, Denholm JT, McBryde ES. Construction of a mathematical model for tuberculosis transmission in highly endemic regions of the asia-pacific. J Theor Biol. 2014;358:74–84. doi: 10.1016/j.jtbi.2014.05.023
  • Mishra BK, Srivastava J. Mathematical model on pulmonary and multidrug-resistant tuberculosis patients with vaccination. J Egypt Math Soc. 2014;22(2):311–316. doi: 10.1016/j.joems.2013.07.006
  • Zhang J, Li Y, Zhang X. Mathematical modeling of tuberculosis data of China. J Theor Biol. 2015;365:159–163. doi: 10.1016/j.jtbi.2014.10.019
  • Kilbas AA, Srivastava HM, Trujillo JJ. Theory and applications of fractional differential equations. Vol. 204. Amsterdam, Netherlands: Elsevier; 2006.
  • Sneddon IN. Fourier transforms. Massachusetts: Courier Corporation; 1995.
  • Mittag-Leffler GM. Sur la nouvelle fonction Ea(x). C R Acad Sci Paris. 1903;137(2):554–558.
  • Wiman A. Über den fundamentalsatz in der teorie der funktionen Ea; 1905.
  • Yavuz M, Ozköse F, Akman M, et al. A new mathematical model for tuberculosis epidemic under the consciousness effect. Math Model Control. 2023;3(2):88–103. doi: 10.3934/mmc.2023009
  • Li H-L, Zhang L, Hu C, et al. Dynamical analysis of a fractional-order predator-prey model incorporating a prey refuge. J Appl Math Comput. 2017;54:435–449. doi: 10.1007/s12190-016-1017-8
  • Kumawat S, Bhatter S, Suthar DL, et al. Numerical modeling on age-based study of coronavirus transmission. Appl Math Sci Eng. 2022;30(1):609–634. doi: 10.1080/27690911.2022.2116435
  • Van den Driessche P, Watmough J. Reproduction numbers and sub-threshold endemic equilibria for compartmental models of disease transmission. Math Biosci. 2002;180(1-2):29–48. doi: 10.1016/S0025-5564(02)00108-6
  • Odibat ZM, Momani S. An algorithm for the numerical solution of differential equations of fractional order. J Appl Math Inform. 2008;26(1):15–27.
  • Odibat ZM, Shawagfeh NT. Generalized Taylor's formula. Appl Math Comput. 2007;186(1):286–293.
  • The-MathWorks-Inc.; 2022. Matlab version: 9.13.0 (r2022b).