Evaluation of cross-neutralizing immunity following COVID-19 primary series vaccination during the Omicron surge in Tanzania.

COVID-19 vaccine became available in Tanzania during the first wave of the Omicron variant. During that time community seroprevalence of SARS-CoV-2 was already at 50%-80%. To date, it remains largely unknown whether ongoing vaccination with the primary series vaccines has any meaningful immune-boosting effects against newer Omicron subvariants. Therefore, we tested cross-neutralizing capacity of antibodies elicited by infection, vaccination, or both against SARS-CoV-2 Omicron subvariants BA.1, and the newer subvariants BQ.1.1 and XBB.1.5. that were unexperienced by this population. Participants who were either SARS-CoV-2 infected-only (n = 28), infected vaccinated (n = 22), or vaccinated-only (n = 73) were recruited from Dar-es-Salaam, Tanzania, between April and December 2022. Plasma 50% neutralization titers (NT50) against SARS-CoV-2 wild-type strain and Omicron subvariants were quantified by a lentiviral-based pseudo-virus assay. Percentage of participants with neutralizing activity against WT and BA.1 was high (>85%) but was reduced against BQ.1.1 (64%-77%) and XBB.1.5 (35%-68%) subvariants. The low median cross-neutralization titer was slightly higher in the infected vaccinated group compared to vaccine-only group against BQ.1.1 (NT50 148 vs. 85, p = 0.032) and XBB.1.5 (NT50 85 vs. 37 p = 0.022) subvariants. In contrast, vaccine-boost among the infected vaccinated did not result to increased cross-neutralization compared to infected-only participants (BQ.1.1 [NT50 of 148 vs. 100, p = 0.501] and XBB.1.5 [NT50 86 vs. 45, p = 0.474]). We report severely attenuated neutralization titers against BQ.1.1 and XBB.1.5 subvariants among vaccinated participants, which marginally improved in the infected vaccinated participants. Our findings call for further studies to evaluate effectiveness of the primary series vaccines in preventing severe infection and mortality against the newer variants.

Drivers of irrational use of antibiotics among children: a mixed-method study among prescribers and dispensers in Tanzania.

BACKGROUND: Misuse of antibiotics has been associated with poor knowledge, attitude and practice (KAP). Therefore, this study aimed to assess if KAP of prescribers and dispensers could drive irrational use of antibiotics among children in Tanzania. METHODS: A convergent parallel mixed-methods study design that employed quantitative and qualitative approaches was conducted in 14 regional referral hospitals (RRHs). A total of 108 participants, prescribers [54] and dispensers [54] working with the pediatric population in the respective regions participated in a quantitative survey, by filling the standard questionnaire while 28 key informant interviews were conducted with in-charges of units from the pharmacy and pediatric departments. Two key informants (prescriber and dispenser) were selected from each RRH. RESULTS: Overall, among prescribers and dispensers, there was adequate knowledge; 81.5% and 79.6%, p = 0.53, those with positive attitudes were 31.5% and 81.5%, p < 0.001 and poor practices were among 70.4% and 48% p = 0.0312 respectively. Among prescribers, 14.8% agreed and strongly agreed that prescribing antibiotics that a patient did not need does not contribute to resistance. Moreover 19% disagreed to prescribe antibiotics according to local guidelines. Among dispensers, a-quarter of the dispensers thought individual efforts to implement antibiotic stewardship would not make a difference, 17% agreed and strongly agreed that antibiotics can treat viral infection and 7% agreed and strongly agreed antibiotics can be stopped upon resolution of symptoms. From qualitative interviews, both participants displayed an adequate understanding of multi-contributors of antibiotic resistance (AR) including polypharmacy, community self-medication, among others. Regardless, both professions declared to prescribed and dispensed antibiotics according to the antibiotics available in stock at the facility. Furthermore, prescribers perceived laboratory investigation took a long time, hence wasting their time. On the other hand, Dispensers reported not to provide adequate instruction to the patients, after dispensing antibiotics. CONCLUSIONS: Both prescribers and dispensers had adequate knowledge, few prescribers had positive attitudes and the majority had poor practices. Few dispensers had poor attitude and practice. These findings highlight the need to provide adequate training on antimicrobial stewardship and enforce regulation that foster appropriate medical practice.

Profiling of antimicrobial dispensing practices in accredited drug dispensing outlets in Tanzania: a mixed-method cross-sectional study focusing on pediatric patients.

BACKGROUND: The emergency of antimicrobial resistance due to irrational antimicrobial use has put public health under threat. Accredited Drug Dispensing Outlets (ADDOs) play an important role in enhancing availability and accessibility of antimicrobials, however, there is a scarcity of studies assessing antimicrobial dispensing practices in these outlets, focusing on children in Tanzania. OBJECTIVE: This study was conducted to assess the antimicrobial dispensing practices among ADDO dispensers and explore the factors influencing the use of antimicrobials for children in Tanzania. METHODS: A community-based cross-sectional study utilizing both qualitative (interviews) and quantitative (simulated clients) methods was conducted between June and September 2020 in seven zones and 14 regions in Tanzania. RESULTS: The study found inappropriate dispensing and use of antimicrobials for children, influenced by multiple factors such as patient's and dispenser's knowledge and attitude, financial constraints, and product-related factors. Only 8% (62/773) of dispensers asked for prescriptions, while the majority (90%) were willing to dispense without prescriptions. Most dispensers, 83% (426/513), supplied incomplete doses of antimicrobials and only 60.5% (345/570) of the dispensers gave proper instructions for antimicrobial use to clients. Over 75% of ADDO dispensers displayed poor practice in taking patient history. CONCLUSION: ADDO dispensers demonstrated poor practices in dispensing and promoting rational antimicrobial use for children. Training, support, and regulatory interventions are required to improve antimicrobial dispensing practices in community drug outlets.

C - reactive protein and interleukin - 6 levels among human immunodeficiency virus -infected patients with dysglycemia in Tanzania.

BACKGROUND: Chronic inflammation has been associated with dysglycemia among people living with HIV (PLHIV). There is however, limited data regarding this phenomenon in sub-Sahara Africa (SSA). Therefore we assessed the levels of C-reactive protein (CRP) and Interleukin 6 (IL-6) on a cohort of PLHIV and its associations with dysglycemia in Tanzania. METHODS: We conducted a cross-sectional study at the Infectious Disease Clinic (IDC) in Tanzania from March to May 2018. Purposive sampling was used to identify participants who had an undetectable viral load, were on 1st line anti-retroviral therapy (ART) and had an overnight fast. The WHO stepwise approach for non-communicable disease (NCD) surveillance was used to collect data. Fasting blood glucose and blood glucose after 75 g oral glucose load was measured, and Enzyme-linked immunosorbent assay (ELISA) was used to test for inflammatory markers (IL-6 and CRP). Associations were explored using the Chi square test and binary logistic regression was performed to estimate the odds ratios. A p-value less than 0.05 was considered statistically significant. RESULTS: A total of 240 participants were enrolled. Forty two percent were overweight/obese (> 25 kg/m2), 89% had a high waist to height ratio. The median ART duration was 8(5-10) years. The prevalence of dysglycemia among our cohort of PLHIV was 32%. High CRP was associated with a 2.05 increased odds of having dysglycemia OR 2.05 (1.15-3.65) (p = 0.01). Taking stavudine was associated with a 1.99 odds of having dysglycemia OR 1.99 (1.04-3.82) (p = 0.03).We did not find a significant association between IL-6 and dysglycemia. CONCLUSION: High CRP and taking stavudine were significantly associated with dysglycemia among PLHIV with undetectable viral load.

Neutralizing immunity against coronaviruses in Tanzanian health care workers.

The ongoing vaccination efforts and exposure to endemic and emerging coronaviruses can shape the population's immunity against this group of viruses. In this study, we investigated neutralizing immunity against endemic and emerging coronaviruses in 200 Tanzanian frontline healthcare workers (HCWs). Despite low vaccination rates (19.5%), we found a high SARS-CoV-2 seroprevalence (94.0%), indicating high exposure in these HCWs. Next, we determined the neutralization capacity of antisera against human coronavirus NL63, and 229E, SARS-CoV-1, MERS-CoV and SARS-CoV-2 (including Omicron subvariants: BA.1, BQ.1.1 and XBB.1.5) using pseudovirus neutralization assay. We observed a broad range of neutralizing activity in HCWs, but no neutralization activity detected against MERS-CoV. We also observed a strong correlation between neutralizing antibody titers for SARS-CoV-2 and SARS-CoV-1, but not between other coronaviruses. Cross-neutralization titers against the newer Omicron subvariants, BQ.1.1 and XBB.1.5, was significantly reduced compared to BA.1 and BA.2 subvariants. On the other hand, the exposed vaccinated HCWs showed relatively higher median cross-neutralization titers against both the newer Omicron subvariants and SARS-CoV-1, but did not reach statistical significance. In summary, our findings suggest a broad range of neutralizing potency against coronaviruses in Tanzanian HCWs with detectable neutralizing immunity against SARS-CoV-1 resulting from SARS-CoV-2 exposure.

Implementation research for promoting access and rational use of antibiotics for children: lessons learnt from Tanzania.

Implementation research (IR) has proved to be a potential catalyst in facilitating the uptake of evidence-based innovations into routine practices and thereby maximizing public health outcomes. IR not only focuses on the effectiveness of the innovations but also identifies and addresses the barriers and facilitators to maximize their uptake into routine practices. This article describes the processes undertaken to implement a research project aimed at promoting access and rational use of antibiotics for children (PARAC). It also provides an overview of the lessons learnt during its implementation in Tanzanian hospital and community settings.

Seroprevalence and risk factors of Toxoplasmosis among HIV infected women of child-bearing age attending care and treatment clinics in Dar es Salaam, Tanzania.

Background: Toxoplasmosis in HIV-infected women of child-bearing age (HIV-WCB) increases the risk for congenital toxoplasmosis, leading to many complications. However, its magnitude is unknown in this population. Objectives: The study aimed to determine the prevalence and factors associated with toxoplasmosis among HIV-WCB. Methods: This was a cross-sectional study conducted from July to August 2020 among HIV- WCB attending care and treatment clinic (CTC) at Muhimbili National Hospital and Mnazi Mmoja hospital. Questionnaire and TORCH rapid test were used to obtain data and serological testing respectively. Data analysis was done using statistical package for social sciences (SPSS) version 20. Results: Overall, 29.7% of the study participants were positive for anti-T. gondii IgG, whereas none tested positive for IgM. Multivariate analysis showed that the probability of being infected with T. gondii increased by 57.1% for participants who consumed raw vegetables (p=0.005, aOR=0.43, 95%CI = 1.24-8.77). Other common risk factors such as undercooked meat consumption, source of drinking water, and cat ownership at home showed no association. Conclusion: A high number of HIV-WCB have not developed immunity to T. gondii in the study area. Introduction of routine screening during antenatal visits for pregnant women and further epidemiological studies are warranted in the country.

Impaired fasting glucose levels among perinatally HIV-infected adolescents and youths in Dar es Salaam, Tanzania.

Objective: This study assessed impaired fasting glucose and associated factors among perinatally HIV-infected adolescents and youths in Dar es salaam Tanzania. Background: Impaired fasting glucose is a marker of heightened risk for developing type 2 diabetes among perinatally HIV-infected individuals. Therefore, identifying individuals at this stage is crucial to enable early intervention. Therefore, we assessed impaired fasting glucose (IFG) and associated factors among perinatally HIV-infected population in Dar es salaam Tanzania. Methods: A cross-sectional study was conducted among 152 adolescents and youth attending HIV clinic at Muhimbili National Hospital and Infectious Disease Centre from July to August 2020. Fasting blood glucose (>8 hours) was measured using one-touch selects LifeScan, CA, USA. We also examined C-Reactive Protein and interleukin-6 inflammatory biomarkers in relation to impaired fasting glucose (IFG). Associations between categorical variables were explored using Chi-square, and poison regression with robust variance was used to calculate the prevalence ratios. Results: Of the 152 participants, the majority were male (n=83[54.6%]), and the median age was 15(14-18) years. Overweight or obesity was prevalent in 16.4%, while more than one in ten (13.2%) had high blood pressure (≥149/90mmHg). All participants were on antiretroviral therapy (ART); 46% had used medication for over ten years, and about one in three had poor medication adherence. Among the recruited participants, 29% had impaired fasting glucose. The odds of IFG were two times higher in males compared to females (PR, 2.07, 95% CI 1.19 -3.59 p=0.001). Moreover, we found with every increase of Interleukin 6 biomarker there was a 1.01 probability increase of impaired fasting glucose (PR, 1.01, 95% CI 1.00 - 1.02 p=0.003). Conclusion: About one in three perinatally HIV-infected youths had impaired fasting glucose in Dar es Salaam, Tanzania, with males bearing the biggest brunt. Moreover, with every increase of 1.101 of the probability of having IFG increased. This calls for urgent measures to interrupt the progression to diabetes disease and prevent the dual burden of disease for this uniquely challenged population.

Implementation of antibiotic stewardship programmes in paediatric patients in regional referral hospitals in Tanzania: experience from prescribers and dispensers.

Background: In 2017, Tanzania launched the National Action Plan for Antimicrobial Resistance (NAPAR), 2017-2022 and implementation of antibiotic stewardship programmes (ASPs) was one of the agendas. Since the launch of the National Action Plan, no study has been done to assess its implementation. Objectives: To explore the experiences of prescribers and dispensers on implementing ASPs among paediatric patients attending Regional Referral Hospitals (RRHs) in Tanzania. Methods: An exploratory qualitative study was conducted among key informants, in 14 RRHs in Tanzania between July and August 2020. A total of 28 key informants, 14 dispensers in charge of pharmacies and 14 medical doctors in charge of paediatric departments (prescribers), were interviewed. A hybrid thematic analysis was conducted on the gathered information. Results: Most of the study participants were not conversant with the term 'antibiotic stewardship'. Some had heard about the programmes but were not aware of the activities involved in the programme. Those who were knowledgeable on ASPs mentioned the lack of existence of such programmes in their settings. They further added that absence or limited knowledge of the stewardship concepts may have influenced the current poor practices. Barriers to the implementation of ASPs mentioned were lack of laboratory facilities to support culture and susceptibility tests, lack of materials and reagents, management pressure to prevent loss or to generate income, patients' influence and limited training opportunities. Conclusions: Despite launching the NAPAR in 2017, we found limited implementation of ASPs in the management of paediatric patients. This study highlighted some barriers and identified possible intervention points.

Determinants of misuse of antibiotics among parents of children attending clinics in regional referral hospitals in Tanzania.

Parents are the important implementers on appropriate/inappropriate use of antibiotics, especially in the pediatric population. Limited studies have associated poor knowledge, attitude, and practice (KAP) among parents with antibiotics misuse. Therefore, this study was conducted to determine the parents' KAP and factors associated with inappropriate use of antibiotics among Tanzanian children. A hospital-based cross-sectional study was conducted in 14 regional referral hospitals (RRHs) in Tanzania between June and September 2020. KAP was estimated using a Likert scale, whereas KAP factors were determined using logistic regression models. A total of 2802 parents were enrolled in the study. The median age (interquartile range) of parents was 30.0 (25-36) years where 82.4% (n = 2305) were female parents. The majority of the parents had primary education, 56.1% (n = 1567). Of 2802 parents, only 10.9% (n = 298) had good knowledge about antibiotics, 16.4% (n = 455) had positive attitude whereas 82.0% (n = 2275) had poor practice on the appropriate use of antibiotics. Parents' education level, i.e., having a university degree (aOR: 3.27 95% CI 1.62-6.63, p = 0.001), good knowledge (aOR: 1.70, 95% CI 1.19-2.23, p = 0.003) and positive attitudes (aOR: 5.56, 95% CI 4.09-7.56, p < 0.001) were significantly associated with the appropriate use of antibiotics in children. Most parents had poor knowledge, negative attitude, and poor practice towards antibiotics use in children. Parents' education level, employment status, knowledge on antibiotic use, and good attitude contributed to the appropriate use of antibiotics in children attending clinics at RRHs.