Influence of α2-Macroglobulin, Anti-Parasite IgM and ABO Blood Group on Rosetting in Plasmodium falciparum Clinical Isolates and Their Associations with Disease Severity in a Ghanaian Population.

Purpose: The severity of Plasmodium falciparum infections is associated with the ability of the infected red blood cells to cytoadhere to host vascular endothelial surfaces and to uninfected RBCs. Host blood group antigens and two serum proteins α2-macroglobulin (α2M) and IgM have been implicated in rosette formation in laboratory-adapted P. falciparum. However, there is only limited information about these phenotypes in clinical isolates. Methods: This was a hospital-based study involving children under 12 years-of-age reporting to the Hohoe Municipal Hospital with different clinical presentations of malaria. Parasite isolates were grown and rosette capabilities and characteristics were investigated by fluorescence microscopy. α2M and IgM were detected by ELISA. Results: Rosette formation was observed in 46.8% (75/160) of the parasite isolates from all the blood groups tested. Rosettes were more prevalent (55%) among isolates from patients with severe malaria compared to isolates from patients with uncomplicated malaria (45%). Rosette prevalence was highest (30%) among patients with blood group O (30%) and B (29%), while the mean rosette frequency was higher in isolates from patients with blood group A (28.7). Rosette formation correlated negatively with age (r = -0.09, P= 0.008). Participants with severe malaria had a lower IgM concentration (3.683±3.553) than those with uncomplicated malaria (5.256±4.294) and the difference was significant (P= 0.0228). The mean concentrations of anti-parasite IgM measured among the clinical isolates which formed rosettes was lower (4.2 ±3.930 mg/mL), than that in the non rosetting clinical isolates (4.604 ±4.159 mg/mL) but the difference was not significant (P=0.2733). There was no significant difference in plasma α2M concentration between rosetting and non rosetting isolates (P=0.442). Conclusion: P. falciparum parasite rosette formation was affected by blood group type and plasma concentration of IgM. A lower IgM concentration was associated with severe malaria whilst a higher α2M concentration was associated with uncomplicated malaria.

Levels of serum eosinophil cationic protein are associated with hookworm infection and intensity in endemic communities in Ghana.

BACKGROUND: The eosinophil cationic protein (ECP) is a cytotoxic protein mainly secreted by eosinophils granulocytes and plays a role in host defense against parasitic infections. Infection with Necator americanus (hookworm) is traditionally diagnosed by the Kato-Katz method which is inherently tedious, subjective and known to underestimate infection intensity. This study aimed to assess levels of serum ECP in relation to hookworm infection intensity. METHODS: Stool samples from 984 (aged 4 to 80 years) participants in a cross-sectional study conducted in the Kintampo North Municipality of Ghana were examined using the Kato-Katz and formol-ether concentration methods. Serum ECP levels were measured by ECP assay kit and compared between 40 individuals infected with hookworm only, 63 with hookworm- Plasmodium falciparum co-infection, 59 with P. falciparum infection and 36 with no infection. RESULTS: Hookworm infection prevalence was 18.1% (178/984). ECP levels were significantly higher in individuals infected with hookworm only (ß = 2.96, 95%CI = 2.69, 3.23, p<0.001) or co-infected with P. falciparum (ß = 3.15, 95%CI = 2.91, 3.39, p<0.001) compared to the negative control. Levels of ECP were similar between those with only P. falciparum infection and the uninfected control (p>0.05). Increased hookworm intensity was associated with a significant increase in ECP level (ß = 4.45, 95%CI = 2.25, 9.11, rs = 0.193, n = 103, p<0.01). ECP threshold of 84.98ng/ml was associated with a positive predictive value (PPV) of 98% (95% CI = 92, 100), and negative predictive value (NPV) of 76% (95% CI = 62, 87) in classifying hookworm infection status with an AUROC of 96.3%. CONCLUSION: Serum ECP level may be a good biomarker of hookworm infection and intensity and warrant further investigations to help improve current hookworm diagnosis.

Hepatitis B and C infections in HIV-1 and non-HIV infected pregnant women in the Brong-Ahafo Region, Ghana.

BACKGROUND: Hepatitis B (HBV) or hepatitis C (HCV) virus co-infections in HIV are alarming during pregnancy due to the risk of vertical transmission and the eventual adverse effects on neonates. This study was conducted to ascertain the sero-prevalence of HIV/HBV and HIV/HCV co-infections, evaluate the effect of the co-infections on the immunological and virological characteristics and assess the association between some demographic and lifestyle characteristics and risk of HBV, HCV, HIV/HBV and HIV/HCV co-infections among pregnant women living in the Brong-Ahafo Region of Ghana. METHODS: This comparative cross-sectional study was conducted at the anti-retroviral therapy (ART) clinics of the St. Elizabeth Hospital and the Holy Family Hospital, Brong-Ahafo Region, Ghana. A total of 248 consecutive consenting pregnant Ghanaian women, 148 diagnosed with HIV [HIV (+)] and 100 who were HIV negative [HIV (-)], were recruited. Validated questionnaire was used to obtain demographic and lifestyle data. Venous blood samples were obtained and HCV status, HBV profile, CD4+ T cell count, and HIV-1 RNA load were determined. RESULTS: The sero-prevalence of HIV (+) /HBV, HIV (+) /HCV, HIV (-)/HBV, and HIV (-)/HCV infections were 22 (14.9%), 6 (4.1%), 10 (10.0%), and 12 (12.0%) respectively. HIV-1 viral load was not significantly different between HIV/HBV, HIV/HCV co-infection and HIV mono-infection. However, CD4+ T lymphocyte count (364 vs 512 vs 514 cells/µl; p = 0.0009) was significantly lower in HIV/HBV co-infection compared to HIV/HCV and HIV mono-infection respectively. There was no significant association between demographic and lifestyle characteristics and risk of HBV and HCV infections in HIV positive and negative subjects except for late diagnosis of HIV and history of sharing razors blades and pins, where increased odds of HIV (+) /HBV and HIV (-)/HBV infection were observed. CONCLUSIONS: The prevalence of HIV (+)/HBV (14.9%), HIV (+)/HCV (4.1%), HIV (-)/HBV (10.0%), and HIV (-)/HCV (12.0%) are high among pregnant women in the Brong Ahafo Region of Ghana. HIV/HBV is associated with reduced CD4+ T lymphocyte count but not HIV-1 viral load. Early diagnosis of HIV and intensification of routine antenatal HBV and HCV are essential to abate the risk of maternal to child transmission.

Cytokine profiles of Necator americanus and Plasmodium falciparum co-infected patients in rural Ghana.

BACKGROUND: Necator americanus (hookworm) and Plasmodium falciparum co-infections are common in endemic communities in rural Ghana. Human immune responses to P. falciparum and hookworm are complex, and the dynamics of cytokine levels and effector mediators are poorly understood. This study aimed to determine the effect of hookworm and P. falciparum co-infection on parasite intensities and cytokine profiles in individuals before and after deworming drug treatment. METHODS: In this cross-sectional study conducted in the Kintampo North Municipality of Ghana blood and stool samples were analyzed from 984 participants (aged 4-88 years). Stool samples were collected at baseline from all participants and examined for the presence of hookworm using the Kato-Katz method. Blood and stool samples were analysed again two weeks after albendazole treatment of hookworm infected individuals. Malaria parasitaemia was estimated by light microscopy and P. falciparum-specific 18S rRNA gene PCR method used for species identification. Serum levels of circulating cytokines interleukins -5, -10 (IL-5, IL-10), tumor necrosis factor [TNF]-α, and eotaxin [CCL11] were determined using ELISA based methods. RESULTS: Malaria parasitaemia was significantly reduced in hookworm and P. falciparum co-infected individuals (p = 0.0018) while hookworm intensity was similar between groups. IL-10 level was significantly higher in the co-infected individuals (39.9 ±â€¯12.2 pg/ml) compared to the single infected or the uninfected group (10.7 ±â€¯7.6 mg/ml). IL-5 level was higher in the hookworm only infected individual. TNF-α levels were higher in all infected groups compared to the uninfected controls. CCL11 levels were significantly higher in subjects infected with hookworm only or co-infected with hookworm and P. falciparum. There was a significantly negative correlation (rs = -0.39, p = 0.021) between hookworm eggs per gram of stool and CCL11 levels in the group mono-infected with hookworm which was not affected by treatment. Treatment with albendazole led to a significant reduction of TNF-α (p = 0.041), IL-5 (p = 0.01) and IL-10 (p = 0.001) levels. CONCLUSION: This study shows that in the absence of other helminths, co-infection of hookworm with P. falciparum may modulate blood parasitemia levels and cytokine responses. Data also show that deworming drug treatment alters these cytokine profiles in hookworm infected subjects. Future studies to elucidate the potential mechanisms underlying these observations should include an assessment of parasite specific cellular responses.

Epidemiology of soil transmitted Helminth infections in the middle-belt of Ghana, Africa.

BACKGROUND: Helminths are among the most widespread infectious agents prevalent in tropical and sub-tropical regions of the developing world defined by inadequate sanitation, poverty and unsafe water sources. This study was carried out to describe the distribution of helminth and malaria parasite infections in the middle-belt of Ghana in sub-Saharan Africa where disease burden, including anaemia is rife and helminths are perceived to be significant contributors of the burden. METHODS: A cross-sectional survey involving 1826 residents located in the middle belt of Ghana where no or very little previous community-based helminth work had been carried out. The participants randomly recruited at household level provided biological samples collected over a 12-month period following a rigorous consenting process and these were analysed to describe the different types and seasonal distribution of helminths. FINDINGS: Overall, 19.3% intestinal helminth infection prevalence was documented. Also based on parasites targeted for elimination, 12.1% Hookworm, 4.0% Hymenolepis nana/Hymenolepis dimunita, 1.5% Ascaris lumbricoides, 1.5% Taenia species, 0.9% Strongyloides stercoralis and 0.8% Trichuris trichiura, with about 1.0% polyphelminthiasis were recorded in the survey. About 55.4% and 44.4% of the participants had heavy hookworm and Trichuris infections respectively. Most of the Ascariasis (83.3%) infections were light in intensity. Hookworm infection was identified with significant odds considering decreasing age (OR = 2.09, p = 0.03), inappropriate footwear use (OR = 1.88, p = 0.021), malaria parasite co-infection (OR = 1.62, p = 0.018), not scrubbing nails during hand washing (OR = 0.68, p = 0.048), source of drinking water (OR = 2.51, p = 0.027) and religion (OR = 4.36, p = 0.002). CONCLUSIONS: Hookworm infection was significantly higher in younger age groups and among those who did not have safe drinking water. Proper sanitation, protective footwear, religion and good personal hygiene practices were found to influence helminth and hookworm prevalence in the area. Malaria parasite coinfection with helminths, especially hookworm infections increased 2-fold.

Seroconversion of Hepatitis B Vaccine in Young Children in the Kassena Nankana District of Ghana: A Cross-Sectional Study.

BACKGROUND: Hepatitis B Virus (HBV) infection is an important public health problem that requires high priority efforts towards prevention and control. Active immunization is the single most important and effective preventive measure against HBV infection. As a protective measure, Ghana introduced the mass immunization program against hepatitis B infection in children in 2002 in her Expanded Programme on Immunization (EPI). This study evaluated seroconversion (the point in time when the amount of antibody in the blood becomes detectable) and seroprotection (the point in time when the amount of antibody in the blood is enough to confer protection from the antigen that induced it production) status of children under this mass immunization program and measured their antibody levels five years after immunization. MATERIALS AND METHOD: 200 archived plasma samples of children between the ages of 1-10 years were retrieved from a previous cross-sectional study by researchers from NHRC between 2009 and 2010. Of these, 104 have completed the EPI and were screened for HBsAg. Those found to be HBsAg-seronegative were stratified into three groups according to their age at which the last vaccine was administered. Their anti-HBsAg titer levels were estimated by enzyme linked immunosorbant assay (ELISA). RESULTS: Two (1.9%) samples were HBsAg seropositive and were excluded from further analyses. 10 more samples were excluded from analyses because they were insufficient. The anti-HBs titers recorded ranged from 1.021 IU/L to 751.64 IU/L indicating a 100% seroconversion rate. In group one (0-6 months), 87.9% were seroprotected. Group two (2-3yrs) had 78.3% seroprotection and group three (3-5yrs) had 41.7% seroprotection. There was no significant difference between group 1 and 2. However, there was a significant difference between group 1 and 3 (p = 0.0137) and between group 2 and 3 (p = 0.0390) respectively. There was no significant difference between male and female children. CONCLUSION: All the children who received doses of hepatitis B vaccine at 6, 10 and 14 weeks in the immunization program seroconverted, but their levels of protection waned with increasing years. Booster doses are therefore recommended after 5 years.