Browsing by Author "Mfinanga, Sayoki"

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A Mathematical Model for Transmission of Taeniasis and Neurocysticercosis
(Hindawi, 2024-03-11) Rwabona, Gideon; Masanja, Verdiana; Mfinanga, Sayoki; Degoot, Abdoelnaser; Mirau, Silas
In this study, we present a mathematical model for the codynamics of taeniasis and neurocysticercosis and rigorously analyze it. To understand the underlying dynamics of the proposed model, basic system properties such as the positivity and boundedness of solutions are investigated through the completing differential process. The basic reproduction number was calculated using the next-generation matrix method, and the analysis showed that when R0 < 1, the disease in the community eventually dies out, and when R0 > 1, the diseases persist. Local stability of the equilibria was analyzed using the Jacobian matrix, and Lyapunov function techniques were used to determine the global analysis, which showed that the endemic equilibrium point was globally stable when R0 > 1. On the other hand, the disease-free equilibrium was determined to be globally stable when R0 < 1. To identify the most influential parameters of the proposed model, partial correlation coefficient techniques were used. The numerical results depict that the model aligns well with the transmission dynamics, which goes through two populations: humans and pigs, whereby the model system stabilizes after some time, showing the validity of the proposed model. Furthermore, the simulations of the proposed model revealed that the shedding habit of infected humans with taeniasis and the bad cooking habit or eating of raw or undercooked pork products have a higher impact on the spread of neurocysticercosis and taeniasis in the community. Hence, this study proposes that in order to control taeniasis and neurocysticercosis, effective disease control measures should primarily prioritize hygienic behaviour and proper cooking of pork meat to the required temperature.
Mathematical model to assess the impact of contact rate and environment factor on transmission dynamics of rabies in humans and dogs
(Heliyon, 2024-06-15) Masanja, Verdiana; Charles, Mfano; Torres, Delfim; Mfinanga, Sayoki; Lyakurwa, GA
This paper presents a mathematical model to understand how rabies spreads among humans, free-range, and domestic dogs. By analyzing the model, we discovered that there are equilibrium points representing both disease-free and endemic states. We calculated the basic reproduction number, using the next generation matrix method. When , the disease-free equilibrium is globally stable, whereas when , the endemic equilibrium is globally stable. To identify the most influential parameters in disease transmission, we used the normalized forward sensitivity index. The simulations revealed that the contact rates between the infectious agent and humans, free-range dogs, and domestic dogs, have the most significant impact on rabies transmission. The study also examines how periodic changes in transmission rates affect the disease dynamics, emphasizing the importance of transmission frequency and amplitude on the patterns observed in rabies spread. To reduce disease sensitivity, one should prioritize effective disease control measures that focus on keeping both free-range and domestic dogs indoors. This is a crucial factor in preventing the spread of disease and should be implemented as a primary disease control measure.
Meta-narrative review of molecular methods for diagnosis and monitoring of multidrug-resistant tuberculosis treatment in adults
(PubMed Central, 2019-06-04) Mbelele, Peter; Mohamed, Sagal; Sauli, Elingarami; Mpolya, Emmanuel; Mfinanga, Sayoki; Addo, Kennedy; Heysell, Scott; Mpagama, Stellah
Early and accurate diagnosis and rigorous clinical and microbiological monitoring of multidrug-resistant tuberculosis (MDR-TB) treatment can curb morbidity and mortality. While others are still under evaluation, the World Health Organization has recommended few novel molecular methods for MDR-TB diagnosis only. We present current molecular methods for diagnosis and monitoring of MDR-TB treatment in TB-endemic settings. A systematic meta-narrative review was conducted according to the RAMESES recommendations. Electronic databases were searched for relevant articles published in English language from January 2013 to June 2018. Based on predefined criteria, two independent reviewers extracted the key messages from relevant articles. Disagreement between them was resolved through discussion and the involvement of a third reviewer, if needed. Key messages were synthesized to create the meta-narratives for method's accuracy, drug-susceptibility capability, and laboratory infrastructure required. We included 33 articles out of 1213 records retrieved, of which 16 (48%) and 12 (36%) were conducted in high- and low-TB-endemic settings, respectively. Xpert® MTB/RIF, GenoType MTBDRplus, GenoType MTBDRsl, FlouroType™ MTBDR, TB TaqMan® array card, and DNA sequencers can accurately guide effective treatment regimens. Molecular bacterial load assay quantifies mycobactericidal impact of these regimens. Although they present inherent advantages compared to the current standard of care, they carry important limitations to implementation and/or scale-up. Therefore, considerable effort must now be directed to implementation and health systems research to maximize these forecasted benefits for individual patient's health outcomes.
Mycobactericidal effect of different regimens measured by molecular bacterial load assay among people treated for multidrug-resistant tuberculosis in Tanzania.
(American Society for Microbiology, 2021-02-03) Mbelele, Peter M; Mpolya, Emmanuel A; Sauli, Elingarami; Mtafya, Bariki; Ntinginya, Nyanda E; Addo, Kennedy K; Kreppel, Katharina; Mfinanga, Sayoki; Phillips, Patrick P J; Gillespie, Stephen H; Heysell, Scott K; Sabiiti, Wilber; Mpagama, Stellah G
Rifampicin or multidrug-resistant-tuberculosis (RR/MDR-TB) treatment has largely transitioned to regimens free of the injectable aminoglycoside component despite the drug class' purported bactericidal activity early in treatment. We tested whether () killing rates measured by molecular bacterial load assay (TB-MBLA) in sputa correlate with composition of the RR/MDR-TB regimen. Serial sputa were collected from patients with RR/MDR- and drug-sensitive TB at day 0, 3, 7, 14, and then monthly for 4 months of anti-TB treatment. TB-MBLA was used to quantify viable 16S rRNA in sputum for estimation of colony-forming-unit per mL (eCFU/mL). killing rates were compared among regimens using nonlinear-mixed-effects modelling of repeated measures. Thirty-seven patients produced 296 serial sputa: 13 patients received an injectable-containing but bedaquiline-free reference regimen, 9 received an injectable and bedaquiline-containing regimen, 8 received an all-oral bedaquiline-based regimen, and 7 patients were treated for drug-sensitive TB with conventional rifampin/isoniazid/pyrazinamide/ethambutol (RHZE). Compared to the adjusted killing of -0.17 (95% CI; -0.23 to -0.12) for the injectable-containing but bedaquiline-free reference regimen, the killing rates were -0.62 (95% CI; -1.05 to -0.20) log eCFU/mL for the injectable and bedaquiline-containing regimen (p = 0.019), -0.35 (95% CI; -0.65 to -0.13) log eCFU/mL for the all-oral bedaquiline-based regimen (p = 0.054), and -0.29 (95% CI; -0.78 to +0.22) log eCFU/mL for RHZE (p = 0.332). killing rates from sputa were higher among patients who received bedaquiline but were further improved with the addition of an injectable aminoglycoside.
Mycobactericidal Effects of Different Regimens Measured by Molecular Bacterial Load Assay among People Treated for Multidrug-Resistant Tuberculosis in Tanzania
(American Society for Microbiology, 2021-02-03) Mbelele, Peter; Mpolya, Emmanuel; Sauli, Elingarami; Mtafya, Bariki; Ntinginya, Nyanda; Addo, Kennedy; Kreppel, Katharina; Mfinanga, Sayoki; Phillips, Patrick; Gillespie, Stephen; Heysell, Scott; Sabiiti, Wilber; Mpagama, Stellah
Rifampin or multidrug-resistant tuberculosis (RR/MDR-TB) treatment has largely transitioned to regimens free of the injectable aminoglycoside component, despite the drug class’ purported bactericidal activity early in treatment. We tested whether Mycobacterium tuberculosis killing rates measured by tuberculosis molecular bacterial load assay (TB-MBLA) in sputa correlate with composition of the RR/MDR-TB regimen. Serial sputa were collected from patients with RR/MDR- and drug-sensitive TB at days 0, 3, 7, and 14, and then monthly for 4 months of anti-TB treatment. TB-MBLA was used to quantify viable M. tuberculosis 16S rRNA in sputum for estimation of colony forming units per ml (eCFU/ml). M. tuberculosis killing rates were compared among regimens using nonlinear-mixed-effects modeling of repeated measures. Thirty-seven patients produced 296 serial sputa and received treatment as follows: 13 patients received an injectable bedaquiline-free reference regimen, 9 received an injectable bedaquiline-containing regimen, 8 received an all-oral bedaquiline-based regimen, and 7 patients were treated for drug-sensitive TB with conventional rifampin/isoniazid/pyrazinamide/ethambutol (RHZE). Compared to the adjusted M. tuberculosis killing of −0.17 (95% confidence interval [CI] −0.23 to −0.12) for the injectable bedaquiline-free reference regimen, the killing rates were −0.62 (95% CI −1.05 to −0.20) log10 eCFU/ml for the injectable bedaquiline-containing regimen (P = 0.019), −0.35 (95% CI −0.65 to −0.13) log10 eCFU/ml for the all-oral bedaquiline-based regimen (P = 0.054), and −0.29 (95% CI −0.78 to +0.22) log10 eCFU/ml for the RHZE regimen (P = 0.332). Thus, M. tuberculosis killing rates from sputa were higher among patients who received bedaquiline but were further improved with the addition of an injectable aminoglycoside.
Mycobacterium bovis in rural Tanzania: Risk factors for infection in human and cattle populations
(Elsevier Ltd., 2007-01) Cleaveland, Sarah; Shawa, Darren; Mfinanga, Sayoki; Shirima, Gabriel; Kazwala, Rudovick; Eblatee, Ernest; Sharp, Michael
Although bovine tuberculosis is widespread throughout Africa, very little is known about risk factors for Mycobacterium bovis infection in either human or cattle populations. A human case–control study was conducted in northern Tanzania, comparing risk factors and prevalence of cattle interdermal test positives of cases (cervical adenitis cases from which M. bovis was isolated) with age- and sex-matched controls (selected at random from potential hospital attendees within the community). A cattle cross-sectional study was also set-up involving 27 villages selected at random in four districts, with 10,549 cattle and 622 herds tested, and questionnaire surveys conducted in 239 households. M. bovis was confirmed in seven of 65 (10.8%) human cervical adenitis cases, of which only one came from a household owning infected cattle. M. bovis in human patients was associated with families in which a confirmed diagnosis of tuberculosis had previously been made (p<0.001) and with households far (>100 m) from neighbours (p=0.003). In cattle, overall prevalence of intradermal test positives was low at 0.9% (0.70–1.06%), but widespread, with 11.8% (8.44–13.17%) herds containing at least one reactor. Prevalence of intradermal test positives increased significantly with cattle age (p<0.001). Herds with the following risk factors had a significantly greater prevalence of intradermal test positives: >50 cattle in the herd (p=0.024); herds housed inside at night (p=0.021) and herds in contact with wildlife (p=0.041). Furthermore, villages that experienced annual flooding had a higher prevalence of infection (p=0.043).
One Health: a concept led by Africa, with global benefits
(BMJ Publishing Group, 2015-05-09) Kamani, Titus; Kazwala, Rudovick; Mfinanga, Sayoki; Haydon, Dan; Keyyu, Julius; Lankester, Felix; Buza, Joram
One Health evolved from the recognition that an interdisciplinary approach is required to understand complex health problems, and that the health of humans and animals are inextricably linked. Through closer cooperation between the human, veterinary and environmental health sectors, added value, in terms of health metrics, cost savings and environmental services is achievable. Although the One Health concept has been recognised for many years, particularly since the seminal work of Calvin Schwabe (Schwabe 1984), many challenges remain in making it operational.
Shauri et al. BMC Infect Dis (2021) 21:911 https://doi.org/10.1186/s12879-021-06549-y RESEARCH Seroprevalence of Dengue and Chikungunya antibodies among blood donors in Dar es Salaam and Zanzibar, Tanzania: a cross-sectional study
(BMC Infectious Medical, 2021-09-06) Shauri, Haliya; Ngadaya, Esther; Senkoro, Mbazi; Buza, Joram; Mfinanga, Sayoki
Background: The potential shift of major causes of febrile illnesses from malaria to non-malarial febrile illnesses, including arboviral diseases such as chikungunya and dengue, is of concern. The last outbreaks of these infections were reported in 2018 and 2019 for chikungunya in Zanzibar and dengue in Dar es Salaam. We conducted a cross- sectional study that involved serological testing of stored blood samples from the blood banks in Temeke Referral Hospital in Dar es Salaam and the National Blood Bank Unit in Zanzibar. The samples were collected from Zanzibar and Dar es Salaam donors in May and June 2020, respectively. A total of 281 samples were included in the study, and their demographic information extracted from the registers. The samples were then transported to Muhimbili Univer- sity of Health and Allied Sciences at the Microbiology Laboratory. They were subjected to an indirect ELISA to detect IgG and IgM against dengue and chikungunya viruses. Results: Seropositive IgM samples from Dar es Salaam were 3/101 (2.97%) for chikungunya and 1/101 (0.9%) for dengue, while samples from Zanzibar were all IgM negative for both viruses. Chikungunya IgG seropositivity was significantly higher (p ≤ 0.05) in Dar es Salaam 21/101 (21.2%) than Zanzibar 22/180 (12.2%). There was no difference in dengue IgG seropositivity between Dar es Salaam 44/101 (43.5%) and Zanzibar 68/180 (37.8%). Similarly, dual IgG seropositivity for both dengue and chikungunya viruses were not different between Dar es Salaam 13/101 (12.9%) and Zanzibar 11/180 (6.1%). Conclusion: Detection of IgM for dengue and chikungunya in Dar es Salaam indicates recent or ongoing transmis- sion of the two viruses in the absence of a reported outbreak. These findings suggest the possibility of transmission of the two infections through blood transfusion. Detection of IgG antibodies for dengue and chikungunya viruses might be contributed by both; the ongoing infections and residual responses caused by preceding infections in the country. Results from blood banks may represent the tip of the iceberg. Further studies are needed to gain insight into the actual burden of the two diseases in Tanzania.
TB or not TB? Definitive determination of species within the Mycobacterium tuberculosis complex in unprocessed sputum from adults with presumed multidrug-resistant tuberculosis
(Tropical Medicine and International Health, 2021-06-09) Mbelele, Peter; Sauli, Elingarami; Mpolya, Emmanuel; Mohamed, Sagal; Addo, Kennedy; Mfinanga, Sayoki; Heysell, Scott; Mpagama, Stellah
Objectives Differences among Mycobacterium tuberculosis complex (MTC) species may predict drug resistance or treatment success. Thus, we optimised and deployed the genotype MTBC assay (gMTBC) to identify MTC to the species level, and then performed comparative genotypic drug-susceptibility testing to anti-tuberculosis drugs from direct sputum of patients with presumed multidrug-resistant tuberculosis (MDR-TB) by the MTBDRplus/sl reference method. Methods Patients with positive Xpert® MTB/RIF (Xpert) results were consented to provide early-morning-sputum for testing by the gMTBC and the reference MTBDRplus/sl. Chi-square or Fisher’s exact test compared proportions. Modified Poisson regression modelled detection of MTC by gMTBC. Results Among 73 patients, 53 (73%) were male and had a mean age of 43 (95% CI; 40–45) years. In total, 34 (47%), 36 (49%) and 38 (55%) had positive gMTBC, culture and MTBDR respectively. Forty patients (55%) had low quantity MTC by Xpert, including 31 (78%) with a negative culture. gMTBC was more likely to be positive in patients with chest cavity 4.18 (1.31–13.32, P = 0.016), high-quantity MTC by Xpert 3.03 (1.35–6.82, P = 0.007) and sputum smear positivity 1.93 (1.19–3.14, P = 0.008). The accuracy of gMTBC in detecting MTC was 95% (95% CI; 86–98; κ = 0.89) compared to MTBDRplus/sl. All M. tuberculosis/canettii identified by gMTB were susceptible to fluoroquinolone and aminoglycosides/capreomycin. Conclusions The concordance between the gMTBC assay and MTBDRplus/sl in detecting MTC was high but lagged behind the yield of Xpert MTB/RIF. All M. tuberculosis/canettii were susceptible to fluoroquinolones, a core drug in MDR-TB treatment regimens.
TB or not TB? Definitive determination of species within the Mycobacterium tuberculosis complex in unprocessed sputum from adults with presumed multidrug-resistant tuberculosis
(Wiley, 2021-06-09) Mbelele, Peter; Sauli, Elingarami; Mpolya, Emmanuel; Mohamed, Sagal; Addo, Kennedy; Mfinanga, Sayoki; Heysell, Scott; Mpagama, Stellah
Objectives Differences among Mycobacterium tuberculosis complex (MTC) species may predict drug resistance or treatment success. Thus, we optimised and deployed the genotype MTBC assay (gMTBC) to identify MTC to the species level, and then performed comparative genotypic drug-susceptibility testing to anti-tuberculosis drugs from direct sputum of patients with presumed multidrug-resistant tuberculosis (MDR-TB) by the MTBDRplus/sl reference method. Methods Patients with positive Xpert® MTB/RIF (Xpert) results were consented to provide early-morning-sputum for testing by the gMTBC and the reference MTBDRplus/sl. Chi-square or Fisher’s exact test compared proportions. Modified Poisson regression modelled detection of MTC by gMTBC. Results Among 73 patients, 53 (73%) were male and had a mean age of 43 (95% CI; 40–45) years. In total, 34 (47%), 36 (49%) and 38 (55%) had positive gMTBC, culture and MTBDR respectively. Forty patients (55%) had low quantity MTC by Xpert, including 31 (78%) with a negative culture. gMTBC was more likely to be positive in patients with chest cavity 4.18 (1.31–13.32, P = 0.016), high-quantity MTC by Xpert 3.03 (1.35–6.82, P = 0.007) and sputum smear positivity 1.93 (1.19–3.14, P = 0.008). The accuracy of gMTBC in detecting MTC was 95% (95% CI; 86–98; κ = 0.89) compared to MTBDRplus/sl. All M. tuberculosis/canettii identified by gMTB were susceptible to fluoroquinolone and aminoglycosides/capreomycin. Conclusions The concordance between the gMTBC assay and MTBDRplus/sl in detecting MTC was high but lagged behind the yield of Xpert MTB/RIF. All M. tuberculosis/canettii were susceptible to fluoroquinolones, a core drug in MDR-TB treatment regimens
TB or not TB? Definitive determination of species within the Mycobacterium tuberculosis complex in unprocessed sputum from adults with presumed multidrug-resistant tuberculosis
(John Wiley & Sons, Inc., 2021-06-09) Mbelele, Peter; Sauli, Elingarami; Mpolya, Emmanuel; Mohamed, Sagal; Addo, Kennedy; Mfinanga, Sayoki; Heysell, Scott; Mpagama, Stellah
objectives Differences among Mycobacterium tuberculosis complex (MTC) species may predict drug resistance or treatment success. Thus, we optimised and deployed the genotype MTBC assay (gMTBC) to identify MTC to the species level, and then performed comparative genotypic drugsusceptibility testing to anti-tuberculosis drugs from direct sputum of patients with presumed multidrug-resistant tuberculosis (MDR-TB) by the MTBDRplus/sl reference method. methods Patients with positive Xpert MTB/RIF (Xpert) results were consented to provide earlymorning-sputum for testing by the gMTBC and the reference MTBDRplus/sl. Chi-square or Fisher’s exact test compared proportions. Modified Poisson regression modelled detection of MTC by gMTBC. results Among 73 patients, 53 (73%) were male and had a mean age of 43 (95% CI; 40–45) years. In total, 34 (47%), 36 (49%) and 38 (55%) had positive gMTBC, culture and MTBDR respectively. Forty patients (55%) had low quantity MTC by Xpert, including 31 (78%) with a negative culture. gMTBC was more likely to be positive in patients with chest cavity 4.18 (1.31– 13.32, P = 0.016), high-quantity MTC by Xpert 3.03 (1.35–6.82, P = 0.007) and sputum smear positivity 1.93 (1.19–3.14, P = 0.008). The accuracy of gMTBC in detecting MTC was 95% (95% CI; 86–98; j = 0.89) compared to MTBDRplus/sl. All M. tuberculosis/canettii identified by gMTB were susceptible to fluoroquinolone and aminoglycosides/capreomycin. conclusions The concordance between the gMTBC assay and MTBDRplus/sl in detecting MTC was high but lagged behind the yield of Xpert MTB/RIF. All M. tuberculosis/canettii were susceptible to fluoroquinolones, a core drug in MDR-TB treatment regimens.