SARS-COV-2 antibody responses to AZD1222 vaccination in West Africa.

Real-world data on vaccine-elicited neutralising antibody responses for two-dose AZD1222 in African populations are limited. We assessed baseline SARS-CoV-2 seroprevalence and levels of protective neutralizing antibodies prior to vaccination rollout using binding antibodies analysis coupled with pseudotyped virus neutralisation assays in two cohorts from West Africa: Nigerian healthcare workers (n = 140) and a Ghanaian community cohort (n = 527) pre and post vaccination. We found 44 and 28% of pre-vaccination participants showed IgG anti-N positivity, increasing to 59 and 39% respectively with anti-receptor binding domain (RBD) IgG-specific antibodies. Previous IgG anti-N positivity significantly increased post two-dose neutralizing antibody titres in both populations. Serological evidence of breakthrough infection was observed in 8/49 (16%). Neutralising antibodies were observed to wane in both populations, especially in anti-N negative participants with an observed waning rate of 20% highlighting the need for a combination of additional markers to characterise previous infection. We conclude that AZD1222 is immunogenic in two independent West African cohorts with high background seroprevalence and incidence of breakthrough infection in 2021. Waning titres post second dose indicates the need for booster dosing after AZD1222 in the African setting despite hybrid immunity from previous infection.

Common bacteria in sputum or gastric lavage of patients presenting with signs and symptoms of lower respiratory tract infections.

INTRODUCTION: lower respiratory tract infections (LRTIs) are infections involving the trachea, primary bronchi and lungs. People with LRTIs typically experience coughs as the primary symptoms; however, shortness of breath, weakness, fever and fatigue may be coupled with the cough. It is common among the aged, children under five and the immune-suppressed. Persons with symptoms suggestive of pulmonary tuberculosis (TB) may have tuberculosis, other respiratory tract infection or co-infection of tuberculosis and other respiratory pathogens. This study aimed to identify the presence of pathogens in sputum of suspected tuberculosis cases and their antimicrobial resistance patterns. METHODS: this was a retrospective study conducted from September 2018 to November 2019 at Tamale Public Health Laboratory. Sputum or gastric lavage samples were collected from persons with suspected clinical presentations of TB and/or LRTI. These samples were cultured using standard microbiological protocols and antimicrobial susceptibility test performed on the positive cultures by Kirby-Bauer disc diffusion method. Molecular identification of M. tuberculosis was performed on all the suspected TB cases using GeneXpert mycobacterium tuberculosis/rifampin (MTB/RIF) assay. RESULTS: during the study period, there were 264 cases of which 49.2% were males and 50.8% were females. Positive cases for culture were 47.3%. Out of the 264 cases, 186 (70.5%) were suspected TB with 51.6% being positive for culture, 6.5% positive for M. tuberculosis (GeneXpert confirmed) and 3.8% co-infection of TB with other bacteria pathogens. Klebsiella spp. (35/125; 28%) and Pseudomonas spp. (19/125; 15.2%) were the most predominant pathogens isolated. There was no significant difference in detection of bacteria in males and females (p=0.89), however individuals with suspected TB were significantly infected with other bacterial species than the unsuspected individuals (p=0.03). Almost all the isolates showed high susceptibility towards carbapenem (meropenem) and high resistance towards the third generation cephalosporins (cefotaxime and ceftriaxone). CONCLUSION: this study highlights the need to test individuals with classical symptoms of LRTIs for other bacterial infections other than TB only. Sputum culture is recommended for all suspected tuberculosis cases to provide accurate laboratory diagnosis to LRTIs and mitigate unnecessary use of antimicrobials.

Human defensins and Th-1 cytokines in hepatitis C viral infection.

INTRODUCTION: active or chronic exacerbated forms of hepatitis C virus (HCV) infection subsequently progress to liver disease and human defensins has been determined to have some level of anti-viral properties invitro whilst the expression of T helper-1 cytokines is known to promote complete recovery from acute HCV infection. The study sought to determine relationship between these immune responses. METHODS: a cross sectional descriptive study design was employed. Hundred and thirty-two individuals were assessed were assessed for to anti-HCV, HCV RNA, serum levels of human alpha defensins 1 (HAD-1) and human beta defensins 1 (HBD-1). T helper 1 cytokines (IL-2, IFN gamma, TNF alpha) secreted in serum were also analyzed using commercial ELISA assay. The study was conducted in Kumasi, Obuasi and Daboya in Ghana. RESULTS: the serum mean concentrations of HAD-1, HBD-1, IL-2, IFN gamma and TNF alpha showed no significant difference in concentrations among participants with chronic, spontaneously recovered or negative to HCV infection (p>0.05). Persons with hepatitis B co-infection were more likely to develop chronic HCV infection (p=0.039). HAD-1 and HBD-1 showed significant positive association with IL-2 (p=0.000) whilst only HAD-1 positively correlated with IL-2 (p<0.000). CONCLUSION: the immunological markers determined had no association with the status of HCV infection. HAD-1 increased with increasing levels of IL-2. These findings suggest that during HCV infection, inflammatory response through the production of cytokines by IL-2 cells may affect the release of HAD-1 and HBD-1.

Increased levels of circulating IL-10 in persons recovered from hepatitis C virus (HCV) infection compared with persons with active HCV infection.

OBJECTIVE: Approximately 70% of all hepatitis C (HCV) infections develop chronic disease. Active or exacerbated chronic hepatitis C infection subsequently progress to liver disease. The role of T-cells secretions in achieving viral clearance is still not well understood. Thus, the current study was set to determine the relationship between the T cell cytokine profiles, biochemical parameters and persistent HCV infection or spontaneous recovery. RESULTS: Twenty-five percent (41/163) of the anti-HCV positive participants had recovered from HCV and had significantly higher concentration of IL-10 compared to those with active HCV infection (P < 0.012). Other circulating cytokines measured; IL-2, IFN gamma, TNF alpha, IL-5 and IL-17 were similar in both groups. Participants with active HCV infection had significantly higher aspartate transaminase (AST) (35 units) and alanine transaminase (46 units) compared to those in the recovered state (P < 0.001). Thus, serum levels of IL10 could be explored in larger prospective cohort study as a predictive marker of recovering from an active HCV infection.

Asymptomatic Bacteriuria and Anti-Microbial Susceptibility Patterns among Women of Reproductive Age. A Cross-Sectional Study in Primary Care, Ghana.

Background: Asymptomatic bacteriuria (ASB) poses serious future clinical repercussions for reproductive women. The study determined the prevalence of asymptomatic bacteriuria along with anti-microbial susceptibility patterns among women of reproductive age in a primary care facility. Method: The study recruited a total of 300 women of reproductive age attending the Tetteh Quarshie Memorial Hospital at Akuapem-Mampong, Ghana, between January and March 2018. Questionnaires were administered to obtain demographic data and predisposing risk factors of ASB. An early-morning midstream urine sample was collected from participants. Urinalysis, urine culture, and anti-microbial susceptibility testing were performed. Results: The mean age of participants was 25.43 years. The overall prevalence rate of ASB was 40.3%. The prevalence was higher among pregnant women compared to non-pregnant women (33.3% vs 7.0%). The most common bacterial isolate was E. coli (47.0%) followed by Proteus spp. (36.4%), Klebsiella spp. (8.3%), and E. faecalis (8.3%). Leukocyturia (35.0%) followed by nitrate (30.0%) were the most common urine abnormalities identified on dipstick urinalysis. Most bacteria isolates showed increased resistance to ampicillin (95.04%) and tetracycline (95.04%) while most of the bacterial isolates were sensitive to levofloxacin (94.35%). Demographic characteristics including age (p < 0.001), educational level (p < 0.001), residency (p = 0.001), and marital status (p = 0.005) were significantly associated with ASB. Lifestyle characteristics such as sexual status (p = 0.001) and frequency of washing of intimate parts after sexual intercourse (p < 0.001) were also significantly associated with ASB. Conclusion: Asymptomatic bacteriuria, particularly E. coli and Proteus spp. are prevalent in the urine of pregnant women living in Akuapem-Mampong municipality. Hence public education along with early screening of ASB is essential to reducing future risk of reproductive health complications. Future studies are required to assess the impact of public health on the rate of bacterial infections.

Hepatitis C Virus (HCV) RNA screening and sequencing using dry plasma spots.

BACKGROUND: HCV RNA screening of large sample repositories provides data on HCV epidemic patterns that may help guide control policies. In resource-limited settings, shipment of frozen samples to molecular laboratory facilities and testing of individual samples may be prohibitively expensive. OBJECTIVE: Our aim was to detect and sequence HCV RNA in a large HIV-positive cohort from Kumasi, Ghana, using pooled and individual dried plasma spots (DPS) produced from samples stored at -80°C. STUDY DESIGN: In the validation phase, replicate DPS were prepared with six dilutions (500-10,000 IU/ml) of the 4th International Standard for HCV and tested in three independent experiments. In the testing phase, DPS prepared with plasma samples from 875 HIV-positive subjects were pooled for screening, followed by testing of individual DPS of positive pools. Input from individual DPS was two 6mm punches; pools comprised two punches from each of five DPS. Genotypes were determined by Sanger sequencing of HCV core and NS5B. RESULTS: With the dilution series, sensitivity of HCV RNA detection was ≥2500 IU/ml. Replicate DPS gave intra-assay and inter-assay coefficients of variation ≤1.4%. With the stored samples, HCV RNA was detected in 5/175 DPS pools and in one DPS from each positive pool, yielding a HCV RNA prevalence of 5/875 (0.57%; 95% confidence interval 0.07-1.07%). The five samples were sequenced as HCV genotypes 2l and 2r. DISCUSSION: DPS allowed reproducible HCV RNA detection, and pooling effectively contained the cost and labour of screening a previously untested, low-prevalence cohort. DPS were also suitable for HCV sequencing.