Mosquito bites and stage-specific antibody responses against Plasmodium falciparum in southern Ghana.

BACKGROUND: The human host elicits specific immune responses after exposure to various life stages of the malaria parasite as well as components of mosquito saliva injected into the host during a mosquito bite. This study describes differences in IgG responses against antigens derived from the sporozoite (PfCSP), asexual stage parasite (PfEBA175) and the gametocyte (Pfs230), in addition to an Anopheles gambiae salivary gland antigen (gSG6-P1), in two communities in Ghana with similar blood stage malaria parasite prevalence. METHODS: This study used archived plasma samples collected from an earlier cross-sectional study that enrolled volunteers aged from 6 months to 70 years from Simiw, peri-urban community (N = 347) and Obom, rural community (N = 291). An archived thick and thin blood smear for microscopy was used for the estimation of Plasmodium parasite density and species and DNA extraction from blood spots and P. falciparum confirmation was performed using PCR. This study used the stored plasma samples to determine IgG antibody levels to P. falciparum and Anopheles salivary antigens using indirect ELISA. RESULTS: Individuals from Simiw had significantly higher levels of IgG against mosquito gSG6-P1 [median (95%CI)] [2.590 (2.452-2.783) ng/mL] compared to those from Obom [2.119 (1.957-2.345) ng/mL], p < 0.0001. Both IgG responses against Pfs230proC (p = 0.0006), and PfCSP (p = 0.002) were significantly lower in volunteers from Simiw compared to the participants from Obom. The seroprevalence of PfEBA-175.5R (p = 0.8613), gSG6-P1 (p = 0.0704), PfCSP (p = 0.7798) IgG were all similar in Obom and Simiw. However, Pfs230 seroprevalence was significantly higher at Obom compared to Simiw (p = 0.0006). Spearman correlation analysis showed no significant association between IgG responses against gSG6-P1, PfCSP, Pfs230proC and PfEBA-175.5R and parasite density at both Obom and Simiw (p > 0.05). CONCLUSION: In conclusion, the study showed that participants from Simiw had higher concentrations of circulating gSG6-P1 IgG antibodies but lower concentrations of P. falciparum antibodies, PfCSP IgG and Pfs230proC IgG compared to participants from Obom.

Sero-prevalence of hepatitis B and C viral infections in Ghanaian HIV positive cohort: a consideration for their health care.

BACKGROUND: Antiretroviral therapy (ART) has significantly decreased HIV/AIDS-related morbidity and mortality. However, globally, many people living with HIV die from non-AIDS related illnesses including liver diseases which occur partly due to co-infection with HBV and or HCV. The aim of this study was to determine the seroprevalence of HBV and HCV among HIV infected individuals receiving care from three different hospitals in the Central Region of Ghana. METHODS: This research was a case-case study. The population consisted of ART naive persons (newly confirmed HIV cases) and those who had been on ART for more than 3 months (old cases). Each individual's sociodemographic characteristics and clinical data including their HBV and HCV status were collected. Those who knew their HBV and HCV status and those who did not know their status were tested for circulating HBsAg and anti-HCV using rapid diagnostic test cassettes. Descriptive analysis was done, and the data presented as median with interquartile range, frequency and percentage. Fisher's exact test and Pearson Chi-square (χ2) test were used to determine associations between categorical variables. RESULTS: Overall, 394 HIV individuals aged, 3 to 76 years old with a median age of 41 (IQR:34-49) participated in this study. Circulating HBsAg and anti-HCV were detected in 6.1% (24/394) and 0.5% (2/393) participants respectively with an overall seroprevalence of 6.6% (26/394). None of the participants was positive for both HBV and HCV infections. 92.1% (363/394) had no information on their HBV status while all the 394 participants did not know their HCV status during data collection. No significant association of HBV infection rate was found in all the socio-demographic data of the participants. But HBV infection rates were significantly higher in those at WHO clinical stages 2 and 3 (P = 0.004). CONCLUSION: HBV and HCV were detected among the HIV-infected participants. Majority of the participants had no information on their HBV status and none of the participants had information on his or her HCV status. This study recommends the need for policy makers to provide free HBV and HCV screening for all HIV infected individuals for their effective management.

Immunologic and virological response to ART among HIV infected individuals at a tertiary hospital in Ghana.

BACKGROUND: The need to study the outcome of Antiretroviral Therapy (ART) among Human Immunodeficiency Virus (HIV) infected individuals in Ghana, a sub-Saharan African country crucial in the era of the "Treat All" policy. The aim of this study was to analyze selected determinants of immunological and virological response to ART among HIV infected individuals in a tertiary facility in Cape Coast, Ghana. METHODS: An analytical cross sectional study with a retrospective component was conducted in the Cape Coast Teaching Hospital (CCTH), Central Region. Clients aged 18 years and above attending the HIV Clinics for ART and who were on ART for 6 months or more were recruited. The viral loads, CD4 count and other socio-demographic data were analyzed using STATA version 13 (STATA Corp, Texas USA). Descriptive analysis was done and presented with appropriate measures of central tendencies. In addition, bivariate and multivariate analysis was carried out with p value of 0.05 interpreted as evidence of association between variables. RESULTS: A total of 440 participants were included in this study with a mean age of 45.5 (±11.6) years. The mean CD4 count at baseline, 6 months on ART and currently at study recruitment were 215.1 cells/mm3 (±152.6), 386.6 cells/mm3 (±178.5), and 579.6 cells/mm3 (±203.0) respectively. After 6 months and 12 months on ART, the number who had achieved viral copies < 1000/ml were 149 (47.0%) and 368 (89.6%) respectively. There was strong evidence of an association between having CD4 count < 350 cells/mm3 after 6 months on ART and having a diagnosis of tuberculosis since HIV diagnosis (aOR 8.5, 95% CI 1.1-73.0, p = 0.05) and clients having plasma viral load > 1000 copies/ml after 6 months on ART (aOR 2.0, 95% CI 1.2-3.2, p = 0.01). CONCLUSION: There was good response to ART among clients, high virological suppression and immunological recovery hence low rates of change to second line ART regimen in this cohort studied. With strict adherence to the national policy on HIV testing, management of positive clients and full implementation of the "Treat All" policy, Ghana could achieve, if nothing at all, the third "90, 90, 90" target by 2020.

Prevalence of Toxoplasma gondii infection in HIV-infected patients and food animals and direct genotyping of T. gondii isolates, Southern Ghana.

Toxoplasma gondii is of public health and veterinary importance causing severe diseases in immunocompromised individuals including HIV/AIDS patients and in congenital cases and animals. There is limited information on the epidemiology of T. gondii infection in humans, particularly HIV patients and food animals and the parasite genotypes in Ghana. A total of 394 HIV-infected patients from three hospitals were screened for T. gondii anti-IgG and IgM using ELISA. DNAs from blood samples of seropositve participants and 95 brain tissues of food animals were PCR assayed to detect Toxoplasma gra6. DNA positive samples were genotyped using multilocus nested polymerase chain reaction restriction fragment length polymorphism at 10 loci: sag1, alt.sag2, sag3, btub, gra6, l358, c22-8, c29-2, pk1, and apico. The overall seroprevalence was 74.37% (293/394). Toxoplasma DNAs were detected in 3.07% of the seropositive participants and 9.47% of the animals. Six of the human DNA positive samples were partly typed at sag3: 33.33, 50, and 16.67% isolates had type I, II, and III alleles, respectively. All nine isolates from food animals typed at nine loci except apico were atypical: six isolates were identical to ToxoDB #41 and #145, and one was identical to TgCkBrRj2 all identified in Brazil. The genotype of two isolates has not been reported previously and was named as TgCtGh1. T. gondii seroprevalence is high among the HIV-infected individuals with T. gondii circulating in Ghana being genetically diverse.

Pharmacokinetic and pharmacodynamic interactions of aspirin with warfarin in beagle dogs.

1. Warfarin and aspirin are widely used in a wide spectrum of thromboembolic and atherothrombotic diseases. Despite the potential efficacy of warfarin-aspirin therapy, the safety and side effect of combined therapy remains unclear. 2. The aim of this study was to investigate the pharmacokinetic and pharmacodynamic interactions between warfarin and aspirin in beagles after single and multiple doses. 3. Coadministration of aspirin had no significant effects on the area under the plasma concentration time curve (AUC(0-t)) and maximum plasma concentration (Cmax) of R- and S-warfarin after a single dose of warfarin, but significantly increase the AUC(0-t) and Cmax and dramatically decrease the clearance (CL) of R- and S-warfarin after multiple dose of warfarin. Accordingly, there was a slight increase in the AUEC(0-t) and Emax of activated partial thromboplastin time (aPTT), prothrombin time (PT) and international normalized ratio (INR) after multiple dose of warfarin. 4. Coadministration of warfarin had no markedly effects on the AUC(0-t) and Cmax of aspirin and its metabolite salicylic acid after single or multiple dose of aspirin. Meanwhile, the AUEC(0-t) and Emax of inhibition of platelet aggregation (IPA) were not significantly affected by warfarin. 5. Our animal study indicated that coadministration of aspirin with warfarin can cause significant pharmacokinetic and pharmacodynamic drug-drug interactions in beagles. However, more studies are urgently needed to assess related information of warfarin-aspirin drug interactions in healthy volunteers or patients.

Schistosoma japonicum cystatin attenuates murine collagen-induced arthritis.

Recombinant SjCystatin (rSjCystatin), a recombinant protein of Schistosoma japonicum cystatin, has been reported to have an effect on immunoregulation mediated by IL-10 induction. Rheumatoid arthritis (RA) is a common autoimmune inflammatory arthropathy, and recombinant immune-modulating drugs for RA treatment are under development. We aimed to study the putative immune regulation of rSjCystatin and its prophylactic/therapeutic effects on murine collagen-induced arthritis (CIA). CIA was induced in DBA/1 mice by inoculation with bovine collagen II (CII). rSjCystatin was administered prior or post development of CIA. The severity of CIA was assessed using established clinical and histopathological scoring systems. The incidence was also determined. The CII-specific antibodies in sera and cytokines in splenocyte culture supernatants were measured by ELISA. Th1/Th2/Th17 cells and Tregs development in splenocytes were monitored by flow cytometry. The inflammatory mediators in the diseased joint were semiquantitated by qPCR. Prophylactic injection of rSjCystatin attenuated paw clinical scores, incidence, and histopathology scores of joints in CIA mice. The arthritis-alleviative effects were closely associated with the augmentation of IL-4, IL-10, and collagen-specific IgG1, and with the distinct reduction of IFN-γ, collagen-specific IgG2a, and the marked decrease of proinflammatory cytokines IL-6, IL-17, and TNF-α and RANKL. The data indicate that rSjCystatin may prevent cartilage destruction and inflammation of joints in CIA mice. The effects are related to the inhibitory modulation of Th1 and Th17 and upregulation of Tregs and Th2 via a shift of cytokines profiling from Th1 to Th2 response.

Variation detection based on next-generation sequencing of type Chinese 1 strains of Toxoplasma gondii with different virulence from China.

BACKGROUND: Toxoplasma gondii is an intracellular protozoan that affects most species of endothermic animals including humans with a great infection rate. The vertical transmission of T. gondii causes abortion, constituting a serious threat to humans and leading to great losses in livestock production. Distinct from population structure of T. gondii in North America and Europe, Chinese 1 (ToxoDB #9) is a dominant genotype prevalent in China. Among the isolates of Chinese 1, the Wh3 and Wh6 have different virulence and pathogenicity in mice. However, little has been known about their difference at the genomic level. Thus the next-generation sequencing (NGS) approach was used to discover the association of the phenotypical variations with the genome sequencing data and the expression and polymorphisms of the key effectors. RESULTS: We successfully sequenced the genome of Chinese 1 strains of Wh3 and Wh6. The average sequencing depths were 63.91 and 63.61 for Wh3 and Wh6, respectively. The variations of both isolates were identified in comparison with reference genome of type I GT1 strain. There were 505,645 and 505,856 SNPs, 30,658 and 30,004 indels, 4661 and 2320 SVs, and 1942 and 3080 CNVs for Wh3 and Wh6, respectively. In target search variations of particular factors of T. gondii, the dense granule protein 3 (GRA3) and rhoptry neck protein 3 (RON3) were found to have 35 SNPs, 2 indels and 89 SNPs, 6 indels, respectively. GRA3 and RON3 were both found to have higher expression levels in less virulent Wh6 than in virulent Wh3. Both strains of type Chinese 1 share polymorphic GRA15II and ROPI/III with type I, II, and III strains. CONCLUSIONS: Sequencing of the two strains revealed that genome structure of Chinese 1 and type I strains has considerable genomic variations. Sequencing and qRT-PCR analyses of 26 effectors displayed a remarkable variation that may be associated with phenotype and pathogenic differences.

Prevalence of occult hepatitis B infection among treatment-naive persons living with HIV in Ghana.

Hepatitis B virus (HBV) constitutes a significant global health challenge, with more than 2 billion people infected globally and almost 291 million chronic cases. In Africa, coinfection of HBV with Human Immunodeficiency Virus (HIV) is high, yet the condition remains overlooked in many countries. While antiretroviral therapy (ART) has improved HIV survival, viral hepatitis continues to contribute to morbidity and mortality. Occult Hepatitis B infection (OBI), characterized by a low-level of HBV DNA in individuals with negative hepatitis B surface antigen (HBsAg), is an emerging concern among HIV seropositive individuals due to the risk of HBV reactivation and associated complications, especially hepatocellular carcinoma (HCC). Ghana has an estimated HBV/HIV coinfection prevalence of 13.6% making it important to also determine potential cases of OBI. This study aims to assess OBI prevalence in persons living with HIV (PLHIV). A cross-sectional study was conducted in five health facilities in the Cape Coast Metropolis. HBV-related serological markers were determined among 116 PLHIV using the Enzyme-Linked Immunosorbent Assay (ELISA) method. HBV DNA was extracted from 30 participants found to be HBsAg negative but positive for hepatitis B core antibody (HBcAb+). Nested PCR was employed in detecting HBV DNA and HBV viral load was performed using qPCR. The median age of the participants was 37 years (IQR 22-65). Serologically, 7.8% (n = 9, 95% CI: 3.5-22.7), 12.1% (n = 14), and 25.9% (n = 30) tested positive for solely HBsAg, HBsAb, and HBcAb respectively. OBI prevalence among HBsAg-/HBcAb+ participants was 16.7% (n = 5, 95% CI: 6.5-23.7) with a median HBV DNA level of 139.2 IU/ml (IQR, 96.7-142.0). The prevalence of OBI among HIV-positive participants in the Cape Coast Metropolis highlights the need to consider screening for HBV among HIV patients using nucleic acid amplification tests. This can inform medical management and reduce the risk of liver complications, including HCC.

Strategies Developed by Toxoplasma gondii to Survive in the Host.

One of the most successful intracellular parasites, Toxoplasma gondii has developed several strategies to avoid destruction by the host. These include approaches such as rapid and efficient cell invasion to avoid phagocytic engulfment, negative regulation of the canonical CD40-CD40L-mediated autophagy pathway, impairment of the noncanonical IFN-γ-dependent autophagy pathway, and modulation of host cell survival and death to obtain lifelong parasite survival. Different virulent strains have even evolved different ways to cope with and evade destruction by the host. This review aims to illustrate every aspect of the game between the host and Toxoplasma during the process of infection. A better understanding of all aspects of the battle between Toxoplasma and its hosts will be useful for the development of better strategies and drugs to control the parasite.

Genotyping and sero-virological characterization of hepatitis B virus (HBV) in blood donors, Southern Ethiopia.

Hepatitis B virus (HBV) prevalence is highest in Sub-Saharan Africa including Ethiopia. HBV genotypes have distinct geographic distributions and play a role in course of infection and treatment management. However, in Ethiopia there is paucity of information about distribution of HBV genotypes. This study was done to determine genotype, mutation and sero-virological profiles of HBV isolates in Southern Ethiopia. Cross-sectional, laboratory based study was conducted on 103HBsAg sero-positive samples from a total of 2,237 screened blood donors. HBV serological markers and biochemical assays were done. Serum viral load was measured using quantitative real-time PCR. Partial HBV S-gene was amplified with nested PCR and sequenced. Bioinformatics tools were utilized to determine genotypes, serotypes and mutations. Of 103 HBsAg reactive serum samples, 14.6% and 70.9% were sero-positive for HBeAg and HBeAb, respectively. Ninety-eight samples gave detectable viral load with a median of 3.46(2.62-4.82) log IU/ml. HBeAg sero-positive donors carried elevated levels of viral load. Eighty five isolates were successfully amplified, sequenced and genotyped into 58 (68.2%) genotype A (HBV/A) and 27 (31.8%) genotype D (HBV/D). HBV serotypes found were adw2 (74.1%), ayw2 (24.7%), and ayw3 (1.2%). In twenty-four (28.2%) samples mutations in the major hydrophilic region (MHR) were observed. Donors infected with HBV/A had higher viral load and more frequent MHR mutation than HBV/D infected donors. This study illustrated distribution of HBV genotype A and D among blood donors in southern Ethiopia. It also demonstrated occurrence HBV variants that may influence clinical aspects of HBV infection. The study contributes in narrowing the existing gap of HBV molecular study in Ethiopia.

Sero-prevalence and risk factors for hepatitis E virus infection among pregnant women in the Cape Coast Metropolis, Ghana.

BACKGROUND: Hepatitis E virus is an emerging infection in Africa with poor maternal and foetal outcomes. There is scanty data on the sero-prevalence of HEV infection among pregnant women in Ghana. This study highlighted the prevalence and risk factors associated with HEV infection among pregnant women in Cape Coast Metropolis, Central Region of Ghana. METHODS: A multicenter (3 selected sites) analytical cross sectional study involving 398 pregnant women in the Cape Coast metropolis was conducted. HEV (Anti-HEV IgG and Anti-HEV IgM) ELISA was performed. Sero-positive women had liver chemistries done and data collected on maternal and neonatal outcomes. Data analyses were performed using Stata version 13 software (STATA Corp, Texas USA). RESULTS: Mean age was 28.01 (± 5.93) years. HEV sero-prevalence was 12.2% (n = 48) for IgG and 0.2% (n = 1) for IgM with overall of 12.3%. The odds of being HEV sero-positive for women aged 26-35 years was 3.1 (95% CI: 1.1-8.1), p = 0.02 and ≥36 years it was 10.7 (95% CI; 3.4-33.5), p = 0.0001. Living in urban settlement was associated with lowest odds of HEV infection {OR 0.4 (95% CI; 0.2-0.8), p = 0.01}. Factors with no statistical evidence of association include main source of drinking water and history of blood transfusion. The sero-prevalence of HEV IgG increased progressively across trimesters with the highest among women in their third trimester (55.3%). None of the 49 HEV sero-positive women had elevated ALT level. Ten (N = 41) of the neonates born to sero-positive women developed jaundice in the neonatal period. The mean birth weight was 3.1kg (SD 0.4). CONCLUSION: HEV sero-prevalence among pregnant women in the Cape Coast Metropolis is high enough to deserve more attention than it has received so far. It is therefore important to conduct further research on the potential impact on maternal and neonatal mortality and morbidity in Ghana.

Genotyping of polymorphic effectors of Toxoplasma gondii isolates from China.

BACKGROUND: Toxoplasma gondii is an opportunistic protozoan apicomplexan and obligate intracellular parasite that infects a wide range of animals and humans. Rhoptry proteins 5 (ROP5), ROP16, ROP18 and dense granules 15 (GRA15) are the important effectors secreted by T. gondii which link to the strain virulence for mice and modulate the host's response to the parasite. Little has been known about these molecules as well as GRA3 in type Chinese 1 strains that show polymorphism among strains of archetypical genotypes. This study examined the genetic diversity of these effectors and its correlated virulence in mice among T. gondii isolates from China. RESULTS: Twenty-one isolates from stray cats were detected, of which 15 belong to Chinese 1, and 6 to ToxoDB #205. Wh6 isolate, a Chinese 1 strain, has an avirulent phenotype. PCR-RFLP results of ROP5 and ROP18 presented few variations among the strains. Genotyping of GRA15 and ROP16 revealed that all the strains belong to type II allele except Xz7 which carries type I allele. ROP16 amino acid alignment at 503 locus demonstrated that 17 isolates are featured as type I or type III (ROP16I/III), and the other 4 as type II (ROP16II). The strains investigated may be divided into four groups based on GRA3 amino acid alignment, and all isolates of type Chinese 1 belong to the µ-1 allele except Wh6 which is identical to type II strain. CONCLUSIONS: PCR-RFLP and sequence alignment analyses of ROP5, ROP16, ROP18, GRA3, and GRA15 in T. gondii revealed that strains with the same genotype may have variations in some of their key genes. GRA3 variation exhibited by Wh6 strain may be associated with the difference in phenotype and pathogenesis.

Polarization of macrophages induced by Toxoplasma gondii and its impact on abnormal pregnancy in rats.

Toxoplasma gondii infection is the leading cause of fetal intrauterine growth retardation among the five kinds of pathogens termed as TORCH, including Toxoplasma, Rubella virus, Cytomegalo virus, herpes virus and others during pregnancy. Pathogens infect the fetus through the placenta. T. gondii infection may result in congenital toxoplasmosis, miscarriage, stillbirth, and preemie, and increase pregnancy complications. Adaptive immune response induced by T. gondii infection stimulates T cells and macrophages to produce high levels of cytokines. Physiologically, the microenvironment of pregnancy was Th2-dominant. Here we set up a pregnant Sprague-Dawley rat model, and reported the polarization of macrophages induced by genotype Chinese 1 strain (Wh6) of Toxoplasma, and its adverse impact on pregnancy. The results showed that Wh6 infection pre- or in-gestation both led to abnormal pregnancy outcomes. Peritoneal macrophages in pre-gestation infection were polarized toward classically activated macrophages (M1), while in-gestation infection drove macrophages to polarize toward M2 activation. The Th2-dominant immune response in pregnant rat somewhat inhibits the excessive bias of the macrophages toward M1, and partially, toward M2. Infection of pre- and in-gestation may alter the physiological immune microenvironment in pregnant rats, giving rise to abnormal pregnancy outcomes.