Bacterial aetiology, antimicrobial susceptibility patterns, and factors associated with urinary tract infection among under-five children at primary health facility, North-Western Tanzania.

BACKGROUND: Urinary tract infections (UTI) are common in under-five children, with significant consequences leading to bacteremia, dehydration, kidney scarring, and renal failure. The incidence of UTI varies with patients' demographics and geographic location. Limited studies have addressed UTI issues, particularly in children. We determined the proportion of UTI, bacterial aetiology, and antimicrobial susceptibility patterns and associated factors among under-five children at the district hospital between March and April 2023. METHODS: We conducted a cross-sectional study using a convenient non-probability sampling technique to collect urine samples from participants with signs and symptoms of UTI. Written informed consent was obtained from parents or guardians. We collected Participants' information using a pretested structured questionnaire. Urine samples were processed at the Regional Referral Hospital. All analyses were conducted using STATA version 15.0. We determined the factors associated with UTI using a modified Poisson model multivariable analysis of the modified Poisson model. The results were presented as a prevalence ratio and 95% confidence interval. The level of significance was specified at 0.05. RESULT: The study recruited 368 under-five children; 194 (52.7%) were males, and the median age (interquartile range) was 24 (13-36) months. Of all, 28.8% (95% CI-24.3-33.6) had culture-confirmed UTI. One hundred and six pathogens were isolated, the majority being Escherichia coli (E. coli), 37 (34.9%), and Staphylococcus aureus (S. aureus), 26 (24.5%). The susceptibility of E. coli to cefepime, piperacillin-tazobactam, nitrofurantoin, and meropenem ranged from 81.1% to 97.3%. S. aureus was most susceptible to nitrofurantoin (96.2%) and ciprofloxacin (92.3%). Multidrug resistance was observed in 33.0% of isolates. The proportion of Methicillin-resistant S. aureus and extended-spectrum beta-lactamases was 23.1% and 25%, respectively. UTI was observed more in patients presenting with vomiting, dysuria, and abdominal pain, patients below 24 months of age, nappy users, and uncircumcised males. CONCLUSION: Our study found a relatively high proportion of UTI among under-five children associated with vomiting, dysuria, abdominal pain, nappy use, and uncircumcision in males. The pathogens were least susceptible to (trimethoprim-sulfamethoxazole, gentamycin, ampicillin, and penicillin) the commonly used antibiotic. We advocate a thorough clinical analysis to detect the predictors of UTI and a periodic review of empirical treatment of UTI based on the antibiotic susceptibility pattern.

Polymicrobial bloodstream infections a risk factor for mortality in neonates at the national hospital, Tanzania: A case-control study.

BACKGROUND: Polymicrobial bloodstream infections (BSI) are difficult to treat since empiric antibiotics treatment are frequently less effective against multiple pathogens. The study aimed to compare outcomes in patients with polymicrobial and monomicrobial BSIs. METHODS: The study was a retrospective case-control design conducted at Muhimbili National Hospital for data processed between July 2021 and June 2022. Cases were patients with polymicrobial BSI, and controls had monomicrobial BSI. Each case was matched to three controls by age, admitting ward, and duration of admission. Logistic regression was performed to determine independent risk factors for in-hospital and 30-day mortality. RESULTS: Fifty patients with polymicrobial BSI and 150 with monomicrobial BSI were compared: the two arms had no significant differences in sex and comorbidities. The most frequent bacteria in polymicrobial BSI were Klebsiella pneumoniae 17% (17/100) and Enterobacter species 15% (15/100). In monomicrobial BSI, S. aureus 17.33% (26/150), Klebsiella pneumoniae 16.67% (25/150), and Acinetobacter species 15% (15/150) were more prevalent. Overall, isolates were frequently resistant to multiple antibiotics tested, and 52% (130/250) were multidrug resistance. The 30-day and in-hospital mortality were 33.5% (67/200) and 36% (72/200), respectively. On multivariable analysis, polymicrobial BSIs were independent risk factors for both in-hospital mortality (aOR 2.37, 95%CI 1.20-4.69, p = 0.01) and 30-day mortality (aOR 2.05, 95%CI 1.03-4.08), p = 0.04). In sub-analyses involving only neonates, polymicrobial BSI was an independent risk factor for both 30-day mortality (aOR 3.13, 95%CI 1.07-9.10, p = 0.04) and in-hospital mortality (aOR 5.08, 95%CI 1.60-16.14, p = 0.006). Overall, the median length of hospital stay post-BSIs was numerically longer in patients with polymicrobial BSIs. CONCLUSION: Overall, polymicrobial BSI was a significant risk for mortality. Patients with polymicrobial BSI stay longer at the hospital than those with monomicrobial BSI. These findings call for clinicians to be more aggressive in managing polymicrobial BSI.

Bacterial Aetiology of Neonatal Sepsis and Antimicrobial Resistance Pattern at the Regional Referral Hospital, Dar es Salam, Tanzania; A Call to Strengthening Antibiotic Stewardship Program.

The diagnosis of neonatal sepsis in lower-income countries is mainly based on clinical presentation. The practice necessitates empirical treatment with limited aetiology and antibiotic susceptibility profile knowledge, prompting the emergence and spread of antimicrobial resistance. We conducted a cross-sectional study to determine the aetiology of neonatal sepsis and antimicrobial resistance patterns. We recruited 658 neonates admitted to the neonatal ward with signs and symptoms of sepsis and performed 639 automated blood cultures and antimicrobial susceptibility testing. Around 72% of the samples were culture positive; Gram-positive bacteria were predominantly isolated, contributing to 81%. Coagulase-negative Staphylococci were the most isolates, followed by Streptococcus agalactiae. Overall, antibiotic resistance among Gram-positive pathogens ranged from 23% (Chloramphenicol) to 93% (Penicillin) and from 24.7% (amikacin) to 91% (ampicillin) for Gram-negative bacteria. Moreover, about 69% of Gram-positive and 75% of Gram-negative bacteria were multidrug-resistant (MDR). We observed about 70% overall proportion of MDR strains, non-significantly more in Gram-negative than Gram-positive pathogens (p = 0.334). In conclusion, the pathogen causing neonatal sepsis in our setting exhibited a high resistance rate to commonly used antibiotics. The high rate of MDR pathogens calls for strengthening antibiotic stewardship programs.

Molecular Characterization and Phylogenetic Analysis of Dengue Fever Viruses in Three Outbreaks in Tanzania Between 2017 and 2019.

BACKGROUND: Dengue is a disease of public health interest, and Tanzania experienced major outbreaks in 2014 and 2019. Here, we report our findings on the molecular characterization of dengue viruses (DENV) that circulated during two smaller outbreaks (2017 and 2018) and one major epidemic (2019) in Tanzania. METHODOLOGY/PRINCIPAL FINDINGS: We tested archived serum samples from 1,381 suspected dengue fever patients, with a median age of 29 (IQR:22-40) years, referred to the National Public Health Laboratory for confirmation of DENV infection. DENV serotypes were identified by reverse transcription polymerase chain reaction (RT-PCR), and specific genotypes were identified by sequencing the envelope glycoprotein gene and phylogenetic inference methods. DENV was confirmed in 823 (59.6%) cases. More than half (54.7%) of patients with dengue fever infection were males, and nearly three-quarters (73%) of the infected individuals were living in Kinondoni district, Dar es Salaam. DENV-3 Genotype III caused the two smaller outbreaks in 2017 and 2018, while DENV-1 Genotype V caused the 2019 epidemic. DENV-1 Genotype I was also detected in one patient in 2019. CONCLUSION/SIGNIFICANCE: This study has demonstrated the molecular diversity of dengue viruses circulating in Tanzania. We found that contemporary circulating serotypes did not cause the major epidemic of 2019 but rather due to a serotype shift from DENV-3 (2017/2018) to DENV-1 in 2019. Such a change increases the risk for patients previously infected with a particular serotype to develop severe symptoms upon potential re-infection with a heterologous serotype due to antibody-dependent enhancement of infection. Therefore, the circulation of serotypes emphasizes the need to strengthen the country's dengue surveillance system for better management of patients, early detection of outbreaks, and vaccine development.

Predominance of Multidrug-Resistant Gram-Negative Bacteria on Contaminated Surfaces at a Tertiary Hospital in Tanzania: A Call to Strengthening Environmental Infection Prevention and Control Measures.

The spreading of multidrug resistance (MDR) strains in the hospital settings via contaminated surfaces have been increasingly reported where Gram-negative bacteria have been implicated in causing most nosocomial infections. This study aimed to determine the rate of contamination with multi-resistant gram-negative bacteria in the hospital environment. A cross-sectional study was conducted at Muhimbili National Hospital paediatric department, between July and August 2020. Non-repetitive surface swab samples were collected from predefined surfaces and medical device surfaces, and cultured on MacConkey agar with and without antibiotics. Isolates were identified using biochemical test and tested for antibiotic susceptibility using the Kirby-Bauer disk diffusion method. The rate of hospital contamination with Gram-negative bacteria across the Pediatrics units was 30%, with a high rate observed in oncology units (34.8%) and the malnutrition/diarrhoea ward (32.1%). Sink/washing basin had the highest frequency of bacterial contamination (74.2%). We observed a high rate of ESBL (32.5%), with Acinetobacter baumannii, Klebsiella pneumoniae, and E. coli being the predominant ESBL-producing Gram-negative bacteria, while carbapenemase-producing Gram-negative bacteria was detected at 22.8%. Highest resistance rates (63-100%) were observed against ceftriaxone and trimethoprim-sulfamethoxazole. Up to 51% of the Gram-negative bacteria showed resistant to meropenem. MDR strains were detected in 61.4% of Gram-negative bacteria isolated. In conclusion, we observed a high rate of MDR bacteria contaminating hospital surfaces. The higher rate of MDR calls for a need to strengthen infectious prevention control measures, including cleaning practices in the hospital environment, to reduce the risk of transmission of resistant strains to patients and healthcare workers.

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.

Genetic relatedness, virulence factors and antibiotics susceptibility pattern of Vibrio cholerae isolates from various regions during cholera outbreak in Tanzania.

BACKGROUND: Cholera continues to cause morbidity and mortality in developing countries, including Tanzania. Since August 2015, Tanzania Mainland has experienced cholera outbreaks affecting 26 regions and a 1.6% case fatality rate. The current study determined the virulence factors, genetic relatedness and antimicrobial susceptibility patterns of the Vibrio cholerae isolated from different regions in Tanzania. METHODS: A cross-sectional study that involved the genetic characterization of V. cholerae isolates from eleven regions in Tanzania was carried out. There were 99 V. cholerae isolates collected between January 2016 and December 2017. The study perfomed a Multi-locus Variable-number tandem-repeat analysis for genetic relatedness and Mismatch Amplification Mutation Analysis polymerase chain reaction for analyzing toxin genes. All the isolates were tested for antimicrobial susceptibility using the Kirby Bauer disk diffusion method. Data were generally analyzed using Microsoft excel, where genetic relatedness was analyzed using eBurst software v3. RESULTS: All isolates were V. cholerae O1. Ogawa was the most predominant 97(98%) serotype. Isolates were genetically related with a small genetic diversity and were positive for ctxA, tcpA El Tor virulence genes. All isolates (100%) were sensitive to doxycycline, trimethoprim-sulphamethoxazole, tetracycline, ceftriaxone, and chloramphenicol, while 87.8% were sensitive to ciprofloxacin. A high resistance rate (100%) was detected towards erythromycin, nalidixic acid, amoxicillin, and ampicillin. CONCLUSION: The V.cholerae O1 serotypes Ogawa, El Tor variant predominantly caused cholera outbreaks in Tanzania with strains clonally related regardless of the place and time of the outbreak. Most of the isolates were susceptible to the antibiotic regimen currently used in Tanzania. The high resistance rate detected for the other common antibiotics calls for continuous antimicrobial susceptibility testing during outbreaks.

Prevalence, recent infection and predictors of HIV infection in fishing community along the shore of Lake Victoria in Tanzania.

BACKGROUND: Fishing communities are a subpopulation burdened by human immunodeficiency virus (HIV), mainly due to their mobility and cash income access. Strategies to mitigate the spread of HIV in fishing communities have varying outcomes. We conducted a study to determine the prevalence of HIV, recent infection and associated factors among fishing communities at Lake Victoria in Tanzania. METHODS: We conducted a cross-sectional study in the first quarter of 2019. The participants' information was collected using a structured questionnaire. Blood samples were screened for HIV infection; the positive samples were tested for avidity and viral load to determine the recent infection. Logistic regression analysis was used to determine the factors associated with HIV infection. RESULTS: A total of 1048 individuals were included with a mean age of 34 years (SD ± 11.5). The overall prevalence of HIV was 9.1%, while 7.4% had a recent infection. Lack of formal education, being separated/divorced/widowed, transactional sex, history of sexually transmitted infections, not tested for HIV in the last 12 months had 1.7 to three times more odds of contracting HIV. CONCLUSION: A proportion of HIV recent infection among the fisherfolks was relatively high, signifying the continuous spread, which is predisposed by some demographic and behavioural characteristics.

Systematic comparison of HIV-1 Envelope-specific IgG responses induced by different vaccination regimens: Can we steer IgG recognition towards regions of viral vulnerability?

Immunogens and vaccination regimens can influence patterns of immune-epitope recognition, steering them towards or away from epitopes of potential viral vulnerability. HIV-1 envelope (Env)-specific antibodies targeting variable region 2 (V2) or 3 (V3) correlated with protection during the RV144 trial, however, it was suggested that the immunodominant V3 region might divert antibody responses away from other relevant sites. We mapped IgG responses against linear Env epitopes in five clinical HIV vaccine trials, revealing a specific pattern of Env targeting for each regimen. Notable V2 responses were only induced in trials administering CRF01_AE based immunogens, but targeting of V3 was seen in all trials, with the soluble, trimeric CN54gp140 protein eliciting robust V3 recognition. Strong V3 targeting was linked to greater overall response, increased number of total recognised antigenic regions, and where present, stronger V2 recognition. Hence, strong induction of V3-specific antibodies did not negatively impact the targeting of other linear epitopes in this study, suggesting that the induction of antibodies against V3 and other regions of potential viral vulnerability need not be necessarily mutually exclusive.

Bacterial vaginosis, the leading cause of genital discharge among women presenting with vaginal infection in Dar es Salaam, Tanzania.

BACKGROUND: Pathological vaginal discharge is a common complaint of women in reproductive age worldwide caused by various agents. The prevalence and etiologic agents vary depending on the population studied. Management of vaginal discharge in low-income countries, typically depend on the syndromic approach, which limits understanding the specific causative agents. We determined the proportion of bacterial vaginosis, candidiasis, and trichomoniasis among women with vaginal discharge at a regional referral hospital in Dar es Salaam, Tanzania. METHODS: We conducted a cross-sectional study between June and August of 2017 among nonpregnant women at Amana Regional Referral Hospital. Experienced staff performed physical examination to establish a clinical diagnosis, and collection of the high vaginal swab for microscopic examination. Descriptive statistics were performed to assess the characteristics of study participants and the proportion of vaginal infections. RESULTS: A total of 196 samples were collected, of all, 128 (65.3%) had either bacterial vaginosis, candidiasis, or trichomoniasis. Bacterial vaginosis was the leading infection at 33.2%, followed by candidiasis (19.4%) and trichomoniasis (13.3%). Laboratory confirmed vaginal infection were generally found more in age below 25, unmarried, and those employed or petty business. CONCLUSION: The proportion of bacterial vaginosis in women with vaginal discharge was relatively higher than others, and the presence of vaginal infection relate to socio-demographic characteristics. Further advanced studies are needed to understand the potential role of aetiologic agents in causing vaginal infections.

Seroprevalence of Human Herpesvirus Infections in Newly Diagnosed HIV-Infected Key Populations in Dar es Salaam, Tanzania.

BACKGROUND: Human herpesvirus (HHV) infections can significantly increase the risk of human immunodeficiency virus (HIV) transmission and accelerate disease progression. In the population at high risk of HIV infection, also termed as key populations (female sex workers (FSW), men who have sex with men (MSM), and people who inject drugs (PWID)), and their sexual partners, HHV infections can potentially compromise the efforts to prevent and control HIV infection. Here, we investigated the seroprevalence of HHV infections among HIV-infected key populations in Dar es Salaam, Tanzania. Methodology. We analyzed 262 archived serum samples of HIV-infected key populations from the integrated biobehavioral surveillance (IBBS) study conducted in Dar es Salaam, Tanzania. The enzyme-linked immunosorbent assay was used to determine IgG and IgM titers for cytomegalovirus (CMV) and herpes simplex virus (HSV) types 1 and 2. RESULTS: The overall seropositivity of HHV IgG was 92% (95% CI: 87.7-95.3%). HHV IgM was not detected in any of the samples. The most seroprevalent coinfection was CMV at 69.1% (181/262), followed by HSV-2 33.2% (87/262) and HSV-1 32.1% (84/262). HSV-2 infection differed by key population groups; it accounted for FSW (46.3%) (p=0.0001) compared to PWID (21.6%) and MSM (22.7%). In contrast, seroprevalence for CMV and HSV-1 was comparable across the key population groups; whereby, CMV was 62%, 75.3%, and 75% and HSV-1 was 26.4%, 39.2%, and 31.8% for FSW, MSM, and PWID, respectively. We also observed that multiple coinfections with CMV-HSV-2 (p=0.042) and CMV-HSV-1-HSV-2 (p=0.006) were significantly associated with key population aged above 40 years. CONCLUSION: The IgG seroprevalence of CMV, HSV-1, and HSV-2 was high among HIV-positive key populations. These findings indicate that these individuals are prone to recurrence of HHV infections and may harbor replicating viruses that subsequently may affect HIV disease progression. Therefore, this warrants concerted efforts for integrated HIV and sexually transmitted infection prevention programs targeting key populations.

High Level of Multidrug-Resistant Gram-Negative Pathogens Causing Burn Wound Infections in Hospitalized Children in Dar es Salaam, Tanzania.

BACKGROUND: Bacterial infection remains the most common cause of morbidity and mortality in pediatric patients with burn wounds. The increase in infection and multidrug-resistant (MDR) pathogens necessitates a periodic review of antimicrobial susceptibility patterns in the burn units. The study aimed to determine the magnitude of multidrug-resistant Gram-negative (MDRGN) bacteria in children with burn wound infections and describe the resistance patterns in the tertiary and regional hospitals in Dar es Salaam, Tanzania. MATERIALS AND METHODS: The study was a hospital-based cross-sectional study design conducted between May 2017 and February 2018. Bacterial isolates from 103 wound swabs of pediatric patients with burn wounds were identified using conventional methods and API 20E. The antimicrobial susceptibility pattern was determined by the Kirby-Bauer disc diffusion method. Data were analyzed using Statistical Package for Social Science (SPSS) version 23.0. RESULTS: A total of 136 pathogenic Gram-negative organisms were isolated from burn wound infections in pediatric patients. The most isolated Gram-negative bacterium was Pseudomonas aeruginosa (39.0%), followed by Acinetobacter spp. (28.7%) and Klebsiella spp. (16.2%). MDRGN strains made up 80.1% of all Gram-negative isolates. All (100%) Klebsiella spp. and E. coli were MDR, while 69.2% and 79.2% of Acinetobacter spp. and P. aeruginosa, respectively, displayed MDR strains. We observed high levels of resistance to commonly prescribed antibiotics. Among P. aeruginosa isolates, highest resistance (81.8%) was seen toward meropenem and piperacillin, 79.5% of Acinetobacter spp. showed resistance to aztreonam, while 93-100% of Klebsiella spp and E. coli displayed resistance to amoxyclavulanic acid, ceftriaxone, and ceftazidime. The proportion of extended-spectrum beta-lactamase producers among Enterobacteriaceae was 78.6%. There was a significant higher rate of infection with MDRGN organisms in pediatric patients with a higher percentage of total burn surface area (TBSA) than patients with lower TBSA (p = 0.016). CONCLUSIONS: P. aeruginosa, Acinetobacter spp., and Klebsiella spp. are the common Gram-negative pathogens causing burn wound infections in hospitalized pediatric patients in our setting. A high proportion of these organisms were multidrug resistant. The findings appeal for regular antimicrobial resistance surveillance in burn wound infection to inform empirical therapy.

High Carriage Rate of Extended-Spectrum ß-Lactamase-Producing Escherichia coli and Klebsiella Species among Poultry Meat Vendors in Dar es Salaam: The Urgent Need for Intervention to Prevent the Spread of Multidrug-Resistant Pathogens.

BACKGROUND: Bacteria possessing extended-spectrum beta-lactamase (ESBL), especially E. coli and Klebsiella species, are problematic, particularly in hospitalized patients. Poultry meat vendors are at risk of carrying ESBL-producing bacteria when processing and handling meat products in an unhygienic environment. There is limited information on the carriage rate of ESBL-producing pathogens among poultry meat vendors that necessitated the conduction of the study. METHOD: A cross-sectional study was conducted among poultry meat vendors in Dar es Salaam, Tanzania. Participants provided rectal swabs in transport media upon instruction. The primary isolation of ESBL-producing bacteria was carried out using MacConkey agar supplemented with ceftazidime. Identification of isolates relied on conventional methods. Double-disk synergy was the method used to confirm ESBL-producing isolates. We performed descriptive statistics using Statistical Package for Social Sciences version 23. A p value < 0.05 was considered statistically significant. RESULTS: A total of 300 participants were recruited from five districts, with a mean age of 27.2 ± 6.7 years. The majority was male (67.3%), and 74.7% worked as poultry meat vendors for more than one year. Out of 300 participants, 107 (35.7%) had confirmed ESBL-producing E. coli and Klebsiella spp. The majority of confirmed ESBL-producing isolates was E. coli (78.5%). Participants from Ubungo District had significantly higher carriage of ESBL-producing Escherichia coli and Klebsiella spp. (48.0%, 95% CI: 34.8-47.7) than Temeke District (21.4%, 95% CI: 13.4-32.4). Only 28.0% of participants had access to latrines at the workplace, and all working areas lacked access to running water. CONCLUSION: The study revealed a relatively high fecal carriage rate of ESBL-producing E. coli and Klebsiella spp. among poultry meat vendors. Poor working environments and hygienic practices are risks for spread of these multidrug-resitant pathogens.

Frequent and Durable Anti-HIV Envelope VIV2 IgG Responses Induced by HIV-1 DNA Priming and HIV-MVA Boosting in Healthy Tanzanian Volunteers.

We evaluated antibody responses to the human immunodeficiency virus (HIV) envelope variable regions 1 and 2 (V1V2) in 29 vaccinees who had received three HIV-1 DNA immunizations and two HIV-modified vaccinia virus Ankara (MVA) boosts in the phase I/II HIVIS03 vaccine trial. Twenty vaccinees received a third HIV-MVA boost after three years in the HIVIS06 trial. IgG and IgG antibody subclasses to gp70V1V2 proteins of HIV-1 A244, CN54, Consensus C, and Case A2 were analysed using an enzyme-linked immunosorbent assay (ELISA). Cyclic V2 peptides of A244, Consensus C, and MN were used in a surface plasmon resonance (SPR) assay. Four weeks after the second HIV-MVA, anti-V1V2 IgG antibodies to A244 were detected in 97% of HIVIS03 vaccinees, in 75% three years later, and in 95% after the third HIV-MVA. Anti-CN54 V1V2 IgG was detectable in 48% four weeks after the second HIV-MVA. The SPR data supported the findings. The IgG response was predominantly IgG1. Four weeks after the second HIV-MVA, 85% of vaccinees had IgG1 antibodies to V1V2 A244, which persisted in 25% for three-years. IgG3 and IgG4 antibodies to V1V2 A244 were rare. In conclusion, the HIV-DNA/MVA vaccine regimen induced durable V1V2 IgG antibody responses in a high proportion of vaccinees.

Frequent Anti-V1V2 Responses Induced by HIV-DNA Followed by HIV-MVA with or without CN54rgp140/GLA-AF in Healthy African Volunteers.

Antibody responses that correlated with reduced risk of HIV acquisition in the RV144 efficacy trial were assessed in healthy African volunteers who had been primed three times with HIV-DNA (subtype A, B, C) and then randomized into two groups; group 1 was boosted twice with HIV-MVA (CRF01_AE) and group 2 with the same HIV-MVA coadministered with subtype C envelope (Env) protein (CN54rgp140/GLA-AF). The fine specificity of plasma Env-specific antibody responses was mapped after the final vaccination using linear peptide microarray technology. Binding IgG antibodies to the V1V2 loop in CRF01_AE and subtype C Env and Env-specific IgA antibodies were determined using enzyme-linked immunosorbent assay. Functional antibody-dependent cellular cytotoxicity (ADCC)-mediating antibody responses were measured using luciferase assay. Mapping of linear epitopes within HIV-1 Env demonstrated strong targeting of the V1V2, V3, and the immunodominant region in gp41 in both groups, with additional recognition of two epitopes located in the C2 and C4 regions in group 2. A high frequency of V1V2-specific binding IgG antibody responses was detected to CRF01_AE (77%) and subtype C antigens (65%). In conclusion, coadministration of CN54rgp140/GLA-AF with HIV-MVA did not increase the frequency, breadth, or magnitude of anti-V1V2 responses or ADCC-mediating antibodies induced by boosting with HIV-MVA alone.

Etiologic Agents of Fever of Unknown Origin Among Patients Attending Mnazi Mmoja Hospital, Zanzibar.

BACKGROUND: Fever of unknown origin (FUO) remains an important public health problem. With malaria transmission declining in some parts of Africa, the evidence suggests other infectious agents now account for most FUO. The purpose of this study was to identify the etiologic agents of FUO in a cross-section of patients at the Mnazi Mmoja hospital in Zanzibar, Tanzania. METHODOLOGY: A multiplex TaqMan gene expression Array Card (TAC) and plates were used for detection and classification of different pathogens in blood samples obtained from patients with FUO. Logistic regression analyses was performed using pathogens detected and sociodemographic characteristics as outcome and exposure variables respectively. Odd ratios and 95% confidence interval were calculated and statistical significance was set at P < .05. RESULT: Thirty-three different pathogens were detected in 27 patient blood samples. The following pathogens were detected in decreasing order of prevalence; Dengue virus, Plasmodium species, Rickettsia, Brucella species, Salmonella typhi, and less than 1% for each of Bartonella, Coxiella burnetii, Salmonella species, and Leptospira. Co-infections of Plasmodium with Dengue and S. typhi were also detected, including one case with three different pathogens-Plasmodium, Rickettsia and Brucella. There was no association between the etiologic agents of FUO and demographic or clinical characteristics. CONCLUSIONS: Zoonotic and arboviral etiological agents of fever of unknown origin are present among patients at the Mnazi Mmoja hospital in Zanzibar, Tanzania. There is a need to develop a baseline of standardized diagnostic approaches particularly within the hospital setting. In areas with low malaria prevalence like Zanzibar, Dengue, Rickettsia, Coxiella burnetii, Brucellosis should be considered by clinicians in the differential diagnoses of FUO.

Induction of Identical IgG HIV-1 Envelope Epitope Recognition Patterns After Initial HIVIS-DNA/MVA-CMDR Immunization and a Late MVA-CMDR Boost.

In the RV144 trial, to date the only HIV-1 vaccine efficacy trial demonstrating a modestly reduced risk of HIV-1 acquisition, antibody responses toward the HIV Envelope protein (Env) variable (V) 2 and V3 regions were shown to be correlated with a reduced risk of infection. These potentially protective antibody responses, in parallel with the vaccine efficacy, however, waned quickly. Dissecting vaccine-induced IgG recognition of antigenic regions and their variants within the HIV-1 Env from different vaccine trials will aid in designing future HIV-1 immunogens and vaccination schedules. We, therefore, analyzed the IgG response toward linear HIV-1 Env epitopes elicited by a multi-clade, multigene HIVIS-DNA priming, and heterologous recombinant modified vaccinia virus Ankara (MVA-CMDR) boosting regimen (HIVIS03) and assessed whether a late MVA-CMDR boost 3 years after completion of the initial vaccination schedule (HIVIS06) restored antibody responses toward these epitopes. Here we report that vaccination schedule in the HIVIS03 trial elicited IgG responses against linear epitopes within the V2 and V3 tip as well as against the gp41 immunodominant region in a high proportion of vaccinees. Antibodies against the V2 and gp41 Env regions were restricted to variants with close homology to the MVA-CMDR immunogen sequence, while V3 responses were more cross-reactive. Boosting with a late third MVA-CMDR after 3 years effectively restored waned IgG responses to linear Env epitopes and induced targeting of identical antigenic regions and variants comparable to the previous combined HIVIS-DNA/MVA-CMDR regimen. Our findings support the notion that anti-HIV-1 Env responses, associated with a reduced risk of infection in RV144, could be maintained by regular boosting with a single dose of MVA-CMDR.

Seroprevalence of Brucella infection and associated factors among pregnant women receiving antenatal care around human, wildlife and livestock interface in Ngorongoro ecosystem, Northern Tanzania. A cross-sectional study.

BACKGROUND: Brucellosis is a zoonotic disease transmitted to humans through contact with infected animals, animal products or consumption of infected dairy products. Brucella infection during pregnancy is of special interest due to association with adverse pregnancy outcomes. This study determined the seroprevalence and factors associated with Brucella infection among pregnant women around the human-wildlife-livestock interface area in Ngorongoro ecosystem, Northern Tanzania. METHODS: A facility-based cross-sectional study was conducted between May and June 2018 at six health facilities that provide antenatal services. Pregnant women receiving antenatal care were invited to participate. A structured questionnaire was used to collect socio-demographic and obstetric characteristics in addition to behavior and practices related to the occurrence of human brucellosis. The presence of serum immunoglobulin against Brucella was determined using Rose Bengal Plate Test (RBPT). The positive samples were further assayed for the presence of IgG and IgM using The enzyme-linkedimmunosorbent assay. Bivariate analysis was conducted to determine the variables associated with Brucella seropositivity. Multivariable logistic regression analysis was performed to examine the factors independently associations with Brucella seropositivity after adjustment for other explanatory variables. RESULTS: A total of 313 participants were enrolled in the study. The overall seroprevalence of Brucella infection was 10.9% (34/313) determined by Rose Bengal plate test. Of 34 positive individuals, 27(79.4%) and 8(23.5%) were positive in the ELISA specific for IgG and IgM Brucella antibodies respectively. Regular contact with manure (AOR 3.16, 95%CI 1.27-7.83) and preference for animal fresh milk (AOR 3.80, 95% CI 1.23-11.69), raw meat (AOR 2.58, 95% CI 1.14-5.81) and raw animal blood (AOR 2.71, 95% CI 1.15-6.35) increased the odds of being Brucella seropositive. Contact with the animal placenta were not associated with Brucella seropositivity after adjustment. CONCLUSION: This study has found that brucellosis is an important public health problem among pregnant women in areas with interactions of humans; livestock and wildlife. The risk of infection increased with the regular contact with manure and preference of raw foodstuffs like animal blood, meat, and milk. We emphasize the need for interventional strategies to reduce the risk of exposure.

Factors associated with Salmonella infection in patients with gastrointestinal complaints seeking health care at Regional Hospital in Southern Highland of Tanzania.

BACKGROUND: Salmonellosis remains an important public health problem globally. The disease is among the leading causes of morbidity and mortality in developing countries that experience poor hygiene and lack of access to clean and safe water. There was an increase in reported cases of Salmonellosis in Njombe Region, Southern Highland of Tanzania between 2015 and 2016 based on clinical diagnosis. Nevertheless, little is known about the factors contributing to the transmission of this disease in the region. This study was conducted to determine the prevalence, antimicrobial susceptibility, and factors associated with Salmonella infection among patients who report gastrointestinal complaints. METHODS: A cross-sectional study was conducted from December 2017 to February 2018 among patients with gastrointestinal complaints at Kibena Regional Hospital. Stool samples were submitted for isolation of Salmonella spp. Identification was based on conventional biochemical tests and serotyping to differentiate typhoid and non-typhoid Salmonella (NTS). Antimicrobial susceptibility was performed using the Kirby-Bauer disc diffusion method. Multivariable logistic regression analysis was performed to examine the factors independently associated with Salmonella infection. RESULTS: The prevalence of Salmonella infection among participants with gastrointestinal complaints was 16.5% (95% CI: 12.7-21.1) of them, 83.7, 95% CI: 70.9-91.5 were NTS while 16.3, 95% CI: 8.5-29.0 were Typhoid Salmonella species. All isolates were sensitive to ceftriaxone and ciprofloxacin, whereas 27.8 and 100% were resistant to co-trimoxazole and ampicillin respectively. The odd of Salmonella infection was fourfold higher among participants with formal employment (AOR 3.8, 95% CI, 1.53-9.40). Use of water from wells/rivers (AOR 2.2, 95% CI, 1.07-4.45), drinking untreated water (AOR 2.6, 95% CI, 1.21-5.48) and often eating at a restaurant (AOR 3.4, 95% CI, 1.28-8.93) had increased odds of Salmonella infection. Likewise, having abdominal pain (AOR 8.5, 95% CI, 1.81-39.78) and diarrhea (AOR 2.3, 95% CI, 1.12-4.68) were independent symptoms that predict Salmonella infection. CONCLUSION: There is a high prevalence of Salmonella infection among people who report gastrointestinal complaints and it is clinically predicated by diarhoea and abdominal pain. Employed participants and those eating at restaurant and drinking unsafe water had higher risk of infection. Salmonella spp. causing gastroenteritis has developed resistance to commonly used antibiotics.

Prospective exploration of the effect of adiposity and associated microbial factors on healing and progression of diabetic foot ulcers in Tanzania: study protocol of a longitudinal cohort study.

BACKGROUND: Diabetic foot ulcers (DFUs) are associated with high morbidity and mortality in low-income countries. This coexists with an increasing prevalence of obesity which has been reported to alter antimicrobial susceptibility and potentially affect the outcome of infected foot ulcers. This study aims to determine whether adiposity and local microbial factors affect the progression and healing of foot ulcers in people with type 2 diabetes in hospital settings in Tanzania. METHODS AND ANALYSIS: A prospective cohort of 300 individuals with type 2 diabetes presenting with DFUs at an outpatient clinic will be enrolled into the study. At baseline, participants will be stratified into normal and high adiposity groups (150 per group) as measured by bioelectrical impedance analysis (BIA). Both groups will receive DFU management according to locally appropriate standards of care and will be followed up for 24 weeks or until complete wound healing, whichever occurs first. The primary end point is complete wound healing at 24 weeks while secondary end points are ulcer progression (worsening or improving), amputation and death. Enrolling 150 participants per group will have a minimum power of 80% to detect a 20% difference in cumulative incidence of complete ulcer healing (at the 5% level of statistical significance) between the normal and high adiposity groups. ETHICAL CONSIDERATIONS AND DISSEMINATION OF RESULTS: This study will be conducted in compliance with the independent institutional review boards (IRBs), informed consent guidelines, the declaration of Helsinki and International Conference on Harmonisation, Good Clinical Practice Guidelines. Ethical clearance has been granted by the Muhimbili University of Health and Allied Sciences ethical review board (MUHAS Ref. No. DA.282/298/01 .C/). Permissions to conduct the study have been granted by the Abbas Medical Centre and the Muhimbili Academic Medical Centre (MAMC).Progress and results emanating from this work will be communicated to the scientific community through conference presentations, short communications (using journal letters and interesting case reports) and peer-reviewed publications. When necessary, through proper channels, popular means of communication (newspapers, magazines and online communications) will be used to inform policy and the public. TRIAL REGISTRATION NUMBER: NCT03960255; Pre-results.