Effect of cross-border migration on the healthcare system of a destination community: Insights from mathematical modelling of COVID-19 in a developing country.

The movement of persons during the pandemic has played a significant role in increasing the disease transmission rates as well as the spread of COVID-19 variants from one region to another. Although, strict restrictions on movement of persons across borders had been imposed early on in the pandemic, countries had to open up their borders to travel as a way of trying to resuscitate their economies that were declining due to closure of businesses and restriction on both local and international travel. Although the lifting of travel bans was done under strict regulations, there has since been a spike in the number of infection cases and spread of virus variants. These increases have certainly put a lot of strain on the rather limited resources allocated to fighting COVID-19 in most regions including the Eastern and Southern Africa. In this manuscript, we examine the potential role played by cross-border movements on the number of detected cases in a developing country. Here, we consider cases where persons cross borders through either designated controlled border points with proper facilitation for screening and detection of potentially infected cases, as well as border crossings through ungazatted points. The persons crossing borders are considered to be either susceptible, exposed or infected with no or mild symptom. A mathematical model was formulated to cater for the aforementioned classifications as well as additional important dynamics related to the disease. The behaviour of solutions for the model is determined and the conditions for existence of the disease free equilibrium as well as the disease persistent equilibrium ascertained. Finally, a dynamically consistent nonstandard finite difference scheme is proposed to replicate the properties of the continuous model. The baseline model was fitted to data of two waves, parameter values were determined and used to obtain numerical results. Our results show that, an increase in cross border movement can result in an increase in the number of detected cases. We observed that if the number of persons who cross-border points while positive for COVID-19 is reduced by 60%, the total number of detected cases can be reduced by up to 58%. In addition, an 83% increase in immigration of exposed persons can increase the disease burden in a destination country by at least 14%. These results justify border points closures during a pandemic or imposing very stringent measure across borders to curtail the importation of positive cases in a country.

Impact of the WHO Integrated Stewardship Policy on the Control of Methicillin-Resistant Staphyloccus aureus and Third-Generation Cephalosporin-Resistant Escherichia coli: Using a Mathematical Modeling Approach.

Methicillin-resistant Staphylococcus aureus (MRSA) and third-generation cephalosporin-resistant Escherichia coli (3GCREc) are community and hospital-associated pathogens causing serious infections among populations by infiltrating into hospitals and surrounding environment. These main multi-drug resistant or antimicrobial resistance (AMR) bacterial pathogens are threats to human health if not properly tackled and controlled. Tackling antimicrobial resistance (AMR) is one of the issues for the World Health Organization (WHO) to design a comprehensive set of interventions which also helps to achieve the end results of the developing indicators proposed by the same organization. A deterministic mathematical model is developed and studied to investigate the impact of the WHO policy on integrated antimicrobial stewardship activities to use effective protection measures to control the spread of AMR diseases such as MRSA and 3GCREc in hospital settings by incorporating the contribution of the healthcare workers in a hospital and the environment in the transmission dynamics of the diseases. The model also takes into account the parameters describing various intervention measures and is used to quantify their contribution in containing the diseases. The impact of combinations of various possible control measures on the overall dynamics of the disease under study is investigated. The model analysis suggests that the contribution of the interventions: screening and isolating the newly admitted patients, improving the hygiene in hospital settings, decolonizing the pathogen carriers, and increasing the frequency of disinfecting the hospital environment are effective tools to contain the disease from invading the population. The study revealed that without any intervention, the diseases will continue to be a major cause of morbidity and mortality in the affected communities. In addition, the study indicates that a coordinated implementation of the integrated control measures suggested by WHO is more effective in curtailing the spread of the diseases than piecemeal strategies. Numerical experiments are provided to support the theoretical analysis.

Genetic characterization of Echinococcus species in eastern Ethiopia.

Cystic echinococcosis (CE) is a neglected zoonotic disease with considerable economic and public health burden worldwide, particularly affecting developing countries like Ethiopia. To initiate effective prevention and control of CE, comprehensive data on the local lifecycles of the various species/genotypes of Echinococcus are needed. In the present study, conducted in eastern Ethiopia, a total of 1106 livestock animals were examined at three slaughterhouses, which resulted in combined prevalence of morphologically and molecularly confirmed CE of 8.4% (75/891) in cattle, 1.1% (1/95) in sheep, 0.0% (0/95) in goats and 12.0% (3/25) in camels. All cystic lesions recovered during post mortem examination were assessed for cyst condition and underwent molecular characterization by PCR and sequencing of a 1081 bp fragment of the mitochondrial cox1 gene. A total of 175 cysts belonged to E. granulosus s.s. (n = 165), E. ortleppi (n = 6) and E. canadensis G6/7 (n = 4). Of all examined cysts, only 14 were fertile and contained protoscoleces, all from the lungs of cattle: 5 were E. granulosus s.s., 6 E. ortleppi and 3 E. canadensis G6/7. In sheep, only one sterile liver cyst of E. granulosus s.s. was found, while in camels seven sterile or caseated/calcified cysts of E. granulosus s.s. and E. canadensis G6/7 were found in liver and lungs. In conclusion, the prevalence of CE was rather low compared to other regions of Ethiopia, and, based on the number of fertile cysts, three Echinococcus spp. contributed almost equally to transmission. Cattle seem to be, epidemiologically, the most important livestock species. Our data provide a substantial basis for more detailed investigations of the transmission dynamics of CE in the study area.

Mathematics of a model for Zika transmission dynamics.

Zika is a flavivirus transmitted to humans through either the bite of infected Aedes mosquitoes or sexual intercourse with infected individuals. In this paper, we present a mathematical model based on these two modes of transmission. Using the next-generation matrix method, a threshold parameter called basic reproduction number is determined. Sensitivity analysis of the basic reproduction number in terms of parameters involved in its formulation is discussed. A dynamically consistent nonstandard finite difference scheme is designed to replicate the properties of the continuous model. Numerical simulations of the nonstandard finite difference scheme that we have constructed show the number of infected humans due to sexual intercourse with Zika virus infectious individuals. The numerical simulations also support the theoretical analysis of the model.