The presence of pathogens and the state of diseases, particularly skin diseases, may alter the co... more The presence of pathogens and the state of diseases, particularly skin diseases, may alter the composition of human skin microbiome. HIV infection has been reported to impair gut microbiome that leads to severe consequences. However, with cutaneous manifestations, that can be life-threatening, due to the opportunistic pathogens, little is known whether HIV infection might influence the skin microbiome and affect the skin homeostasis. This study catalogued the profile of skin microbiome of healthy Cameroonians, at three different skin sites, and compared them to the HIV-infected individuals. Taking advantage on the use of molecular assay coupled with next-generation sequencing, this study revealed that alpha-diversity of the skin microbiome was higher and beta-diversity was altered significantly in the HIV-infected Cameroonians than in the healthy ones. The relative abundance of skin microbes such as Micrococcus and Kocuria species was higher and Cutibacterium species was significant...
In pregnancy-associated malaria, chemokines such as CXCL-4, CXCL-13, CXCL-16, and CCL-24 play cri... more In pregnancy-associated malaria, chemokines such as CXCL-4, CXCL-13, CXCL-16, and CCL-24 play critical roles in leucocyte trafficking to tissue sites in the infected placenta where inflammatory reactions are active. However, how plasma levels of these chemokines associate with Plasmodium falciparum placental malaria and pregnancy outcomes remains not well understood. The present study analyzed the plasma levels of CXCL-4, CXCL-13, CXCL-16, and CCL-24 chemokines in matched peripheral, placental and cord blood in relation with placental malaria (PM), and with submicroscopic parasitaemia. This was a retrospective case-control study (1:3 ratio) involving samples from 134 women (34 PM+ and 100 PM-) enrolled at delivery at the Marie Reine Health Center in Yaoundé, Cameroon between June 2013 and October 2018. Samples were collected just after delivery and used to diagnose microscopic and submicroscopic Plasmodium falciparum infections. Submicroscopic infections were detected by reverse tra...
Background Co-infection with malaria and intestinal parasites is common in children in Africa and... more Background Co-infection with malaria and intestinal parasites is common in children in Africa and may affect their immune response to a malaria parasite infection. Prior studies suggest that co-infections may lead to increased susceptibility to malaria infection and disease severity; however, other studies have shown the reverse. Knowledge on how co-morbidities specifically affect the immune response to malaria antigens is limited. Therefore, this study sought to determine the prevalence of co-infection of malaria and intestinal parasites and its association with antibody levels to malaria merozoite antigens. Methods A cross sectional study was carried out in two villages with high transmission of malaria in Cameroon (Ngali II and Mfou) where mass drug administration (MDA) had been administered at ~6-month intervals (generally with albendazole or mebendazole). Children aged 1–15 years were enrolled after obtaining parental consent. A malaria rapid diagnostic test was used on site. F...
Drug-resistant tuberculosis, especially multidrug-resistant tuberculosis (MDR-TB), is a major pub... more Drug-resistant tuberculosis, especially multidrug-resistant tuberculosis (MDR-TB), is a major public health problem. Effective management of MDR-TB relies on accurate and rapid diagnosis. In this study, we assessed the diagnostic accuracy of the Genotype MTBDRplus assay in diagnosing MDR-TB in Cameroon, and then discuss on its utility within the diagnostic algorithm for MDR-TB. In this cross-sectional study, 225 isolates of Mycobacterium tuberculosis cultured from sputum samples collected from new and previously treated pulmonary tuberculosis patients in Cameroon were used to determine the accuracy of the Genotype MTBDRplus assay. We compared the results of the Genotype MTBDRplus assay with those from the automated liquid culture BACTEC MGIT 960 SIRE system for sensitivity, specificity, and degree of agreement. The pattern of mutations associated with resistance to RIF and INH were also analyzed. The Genotype MTBDRplus assay correctly identified Rifampicin (RIF) resistance in 48/49 ...
Background. Human immunodeficiency virus (HIV) infection reduces placental transfer of antibodie... more Background. Human immunodeficiency virus (HIV) infection reduces placental transfer of antibodies from mother to the fetus for many antigens; however, conflicting data exist for transfer of immunoglobulin G (IgG) to malarial antigens. The mechanism(s) underlying reduced placental transfer is unknown. Methods. Levels of maternal and cord total IgG, IgG subclasses, and cord-to-mother ratios (CMRs) were measured in 107 mother-cord pairs to 3 malarial antigens: circumsporozoite protein (CSP), apical membrane antigen 1 (AMA-1), merozoite surface protein 1 (MSP-1), and tetanus toxoid C-fragment (TTc). Results. Immunoglobulin G levels to CSP and TTc were lower in HIV+ mothers, and cord IgG to CSP, MSP-1, and TTc were significantly lower in neonates born to HIV+ mothers (all P values <.05). The prevalence of mothers with hypergammaglobulinemia was significantly higher among HIV+ women (68%) compared with HIV− mothers (8%) (P < .0001). Maternal hypergammaglobulinemia was associated ...
Background. During pregnancy, the placenta is inaccessible for diagnosis of placental malaria (P... more Background. During pregnancy, the placenta is inaccessible for diagnosis of placental malaria (PM), but soluble tumor necrosis factor-α receptors (sTNFR) are elevated in the plasma of women with PM. Methods. In this study, sTNFR-1 and sTNFR-2 were quantified in urine of pregnant and nonpregnant Cameroonian women who were positive or negative for malaria by blood-smear microscopy. Results. We found that levels of both sTNFR in urine were higher in pregnant compared with nonpregnant women, but malaria-positive pregnant women excreted substantially more sTNFR-1 (P = .005) and sTNFR-2 (P < .001) than malaria-negative pregnant women. The amount of sTNFR-1(rs = 0.784, P < .001) and sTNFR-2 (rs = 0.816, P < .001) in urine correlated with parasitemia, even in afebrile pregnant women. Urine sTNFR-2 predicted maternal malaria with an area under curve of 0.892 (95% confidence interval, .787–.898). At cutoff concentrations of 9.8 ng and 13.6 ng of sTNFR-2 per mL urine, the sensitivi...
Bulletin de la Société de pathologie exotique et de ses filiales, 1988
In the first phase of our study, a group of 58 patients were investigated: electromyographic abno... more In the first phase of our study, a group of 58 patients were investigated: electromyographic abnormalities were recorded in 52%, electrocardiographic abnormalities in 48%, electroencephalographic abnormalities in 47%, spirographic abnormalities in 31%. Impairments of central nervous system occur classically in Trypanosoma gambiense infection, while cardiac damage is more frequent in T. rhodesiense infection. Noted lesions are due to an immunological mechanism. In the second phase, 25 patients and controls from the same area were investigated. We tried to confirm existence and pathogeny of cardiac impairments in T. gambiense infection: incidence, symptoms, clinical and electrocardiographic signs, disturbances of cardiac rythm. There were ST segment, T wave and PR interval changes. Chest X ray showed cardiomegaly. Echocardiography revealed right ventricular dilatation. There were pericardial effusion and thickening. The immunological tests showed significantly higher IgM and immunocon...
The commensal microbes of the skin have a significant impact on dermal physiology and pathophysio... more The commensal microbes of the skin have a significant impact on dermal physiology and pathophysiology. Racial and geographical differences in the skin microbiome are suggested and may play a role in the sensitivity to dermatological disorders, including infectious diseases. However, little is known about the skin microbiome profiles of people living in Central Africa, where severe tropical infectious diseases impose a burden on the inhabitants. This study provided the skin profiles of healthy Cameroonians in different body sites and compared them to healthy Japanese participants. The skin microbiome of Cameroonians was distinguishable from that of Japanese in all skin sites examined in this study. For example, Micrococcus was predominantly found in skin samples of Cameroonians but mostly absent in Japanese skin samples. Instead, the relative abundance of Cutibacterium species was significantly higher in healthy Japanese. Principal coordinate analysis of beta diversity showed that th...
This study was carried out in two parts. Part 1 consisted of an epidemiological survey of 1011 su... more This study was carried out in two parts. Part 1 consisted of an epidemiological survey of 1011 subjects aged 3-65 yrs from 2 adjoining villages hyper-endemic for Onchocerciasis and 890 subjects in a control area, relatively free from this infection but otherwise with a similar parasitological profile. There was a significantly higher prevalence of proteinuria in subjects from the onchocercal zone than in controls (observed difference greater than 5 1/2 times its standard error). Part 2 comprised detailed investigations, including renal biopsy, of 63 consecutive patients admitted into hospital with severe proteinuria and/or renal failure from a caption area extending into the onchocercal zone. There were a variety of causative factors, but in 9 cases filarial antigen was demonstrable in the immune-complex deposits in the kidney. A plenum of renal histopathological changes were seen in patients with onchocerciasis. The significance of these findings is discussed.
Fourty onchocercal nodules were taken from patients living in forest areas where onchocerciasis i... more Fourty onchocercal nodules were taken from patients living in forest areas where onchocerciasis is highly endemic, in order to identify the various types of lymphocytes present in these nodules. For this purpose, each nodule was submitted to two histological procedures: one after fixation in formalin of part of the nodule and hematoxylin-eosin stain; the other after freezing part of the nodule in liquid nitrogen, cryostat cutting and staining by immuno-peroxidase method using avidin-biotin and the following monoclonal antibodies: Pan B, OK T3, OK T4 and OK T8. Fifty-five of the 40 nodules show lymphocytes. All the 25 nodules with lymphocytes present T-lymphocytes. Only 20 of these 25 nodules have B lymphocytes and therefore only 20 nodules with lymphocytes have both T and B lymphocytes. Of the 25 nodules with T lymphocytes: 19 present T4 lymphocytes, 25 show T8 lymphocytes and therefore 19 have both T4 and T8 lymphocytes. These results are analysed and discussed in this study which ...
The presence of pathogens and the state of diseases, particularly skin diseases, may alter the co... more The presence of pathogens and the state of diseases, particularly skin diseases, may alter the composition of human skin microbiome. HIV infection has been reported to impair gut microbiome that leads to severe consequences. However, with cutaneous manifestations, that can be life-threatening, due to the opportunistic pathogens, little is known whether HIV infection might influence the skin microbiome and affect the skin homeostasis. This study catalogued the profile of skin microbiome of healthy Cameroonians, at three different skin sites, and compared them to the HIV-infected individuals. Taking advantage on the use of molecular assay coupled with next-generation sequencing, this study revealed that alpha-diversity of the skin microbiome was higher and beta-diversity was altered significantly in the HIV-infected Cameroonians than in the healthy ones. The relative abundance of skin microbes such as Micrococcus and Kocuria species was higher and Cutibacterium species was significant...
In pregnancy-associated malaria, chemokines such as CXCL-4, CXCL-13, CXCL-16, and CCL-24 play cri... more In pregnancy-associated malaria, chemokines such as CXCL-4, CXCL-13, CXCL-16, and CCL-24 play critical roles in leucocyte trafficking to tissue sites in the infected placenta where inflammatory reactions are active. However, how plasma levels of these chemokines associate with Plasmodium falciparum placental malaria and pregnancy outcomes remains not well understood. The present study analyzed the plasma levels of CXCL-4, CXCL-13, CXCL-16, and CCL-24 chemokines in matched peripheral, placental and cord blood in relation with placental malaria (PM), and with submicroscopic parasitaemia. This was a retrospective case-control study (1:3 ratio) involving samples from 134 women (34 PM+ and 100 PM-) enrolled at delivery at the Marie Reine Health Center in Yaoundé, Cameroon between June 2013 and October 2018. Samples were collected just after delivery and used to diagnose microscopic and submicroscopic Plasmodium falciparum infections. Submicroscopic infections were detected by reverse tra...
Background Co-infection with malaria and intestinal parasites is common in children in Africa and... more Background Co-infection with malaria and intestinal parasites is common in children in Africa and may affect their immune response to a malaria parasite infection. Prior studies suggest that co-infections may lead to increased susceptibility to malaria infection and disease severity; however, other studies have shown the reverse. Knowledge on how co-morbidities specifically affect the immune response to malaria antigens is limited. Therefore, this study sought to determine the prevalence of co-infection of malaria and intestinal parasites and its association with antibody levels to malaria merozoite antigens. Methods A cross sectional study was carried out in two villages with high transmission of malaria in Cameroon (Ngali II and Mfou) where mass drug administration (MDA) had been administered at ~6-month intervals (generally with albendazole or mebendazole). Children aged 1–15 years were enrolled after obtaining parental consent. A malaria rapid diagnostic test was used on site. F...
Drug-resistant tuberculosis, especially multidrug-resistant tuberculosis (MDR-TB), is a major pub... more Drug-resistant tuberculosis, especially multidrug-resistant tuberculosis (MDR-TB), is a major public health problem. Effective management of MDR-TB relies on accurate and rapid diagnosis. In this study, we assessed the diagnostic accuracy of the Genotype MTBDRplus assay in diagnosing MDR-TB in Cameroon, and then discuss on its utility within the diagnostic algorithm for MDR-TB. In this cross-sectional study, 225 isolates of Mycobacterium tuberculosis cultured from sputum samples collected from new and previously treated pulmonary tuberculosis patients in Cameroon were used to determine the accuracy of the Genotype MTBDRplus assay. We compared the results of the Genotype MTBDRplus assay with those from the automated liquid culture BACTEC MGIT 960 SIRE system for sensitivity, specificity, and degree of agreement. The pattern of mutations associated with resistance to RIF and INH were also analyzed. The Genotype MTBDRplus assay correctly identified Rifampicin (RIF) resistance in 48/49 ...
Background. Human immunodeficiency virus (HIV) infection reduces placental transfer of antibodie... more Background. Human immunodeficiency virus (HIV) infection reduces placental transfer of antibodies from mother to the fetus for many antigens; however, conflicting data exist for transfer of immunoglobulin G (IgG) to malarial antigens. The mechanism(s) underlying reduced placental transfer is unknown. Methods. Levels of maternal and cord total IgG, IgG subclasses, and cord-to-mother ratios (CMRs) were measured in 107 mother-cord pairs to 3 malarial antigens: circumsporozoite protein (CSP), apical membrane antigen 1 (AMA-1), merozoite surface protein 1 (MSP-1), and tetanus toxoid C-fragment (TTc). Results. Immunoglobulin G levels to CSP and TTc were lower in HIV+ mothers, and cord IgG to CSP, MSP-1, and TTc were significantly lower in neonates born to HIV+ mothers (all P values <.05). The prevalence of mothers with hypergammaglobulinemia was significantly higher among HIV+ women (68%) compared with HIV− mothers (8%) (P < .0001). Maternal hypergammaglobulinemia was associated ...
Background. During pregnancy, the placenta is inaccessible for diagnosis of placental malaria (P... more Background. During pregnancy, the placenta is inaccessible for diagnosis of placental malaria (PM), but soluble tumor necrosis factor-α receptors (sTNFR) are elevated in the plasma of women with PM. Methods. In this study, sTNFR-1 and sTNFR-2 were quantified in urine of pregnant and nonpregnant Cameroonian women who were positive or negative for malaria by blood-smear microscopy. Results. We found that levels of both sTNFR in urine were higher in pregnant compared with nonpregnant women, but malaria-positive pregnant women excreted substantially more sTNFR-1 (P = .005) and sTNFR-2 (P < .001) than malaria-negative pregnant women. The amount of sTNFR-1(rs = 0.784, P < .001) and sTNFR-2 (rs = 0.816, P < .001) in urine correlated with parasitemia, even in afebrile pregnant women. Urine sTNFR-2 predicted maternal malaria with an area under curve of 0.892 (95% confidence interval, .787–.898). At cutoff concentrations of 9.8 ng and 13.6 ng of sTNFR-2 per mL urine, the sensitivi...
Bulletin de la Société de pathologie exotique et de ses filiales, 1988
In the first phase of our study, a group of 58 patients were investigated: electromyographic abno... more In the first phase of our study, a group of 58 patients were investigated: electromyographic abnormalities were recorded in 52%, electrocardiographic abnormalities in 48%, electroencephalographic abnormalities in 47%, spirographic abnormalities in 31%. Impairments of central nervous system occur classically in Trypanosoma gambiense infection, while cardiac damage is more frequent in T. rhodesiense infection. Noted lesions are due to an immunological mechanism. In the second phase, 25 patients and controls from the same area were investigated. We tried to confirm existence and pathogeny of cardiac impairments in T. gambiense infection: incidence, symptoms, clinical and electrocardiographic signs, disturbances of cardiac rythm. There were ST segment, T wave and PR interval changes. Chest X ray showed cardiomegaly. Echocardiography revealed right ventricular dilatation. There were pericardial effusion and thickening. The immunological tests showed significantly higher IgM and immunocon...
The commensal microbes of the skin have a significant impact on dermal physiology and pathophysio... more The commensal microbes of the skin have a significant impact on dermal physiology and pathophysiology. Racial and geographical differences in the skin microbiome are suggested and may play a role in the sensitivity to dermatological disorders, including infectious diseases. However, little is known about the skin microbiome profiles of people living in Central Africa, where severe tropical infectious diseases impose a burden on the inhabitants. This study provided the skin profiles of healthy Cameroonians in different body sites and compared them to healthy Japanese participants. The skin microbiome of Cameroonians was distinguishable from that of Japanese in all skin sites examined in this study. For example, Micrococcus was predominantly found in skin samples of Cameroonians but mostly absent in Japanese skin samples. Instead, the relative abundance of Cutibacterium species was significantly higher in healthy Japanese. Principal coordinate analysis of beta diversity showed that th...
This study was carried out in two parts. Part 1 consisted of an epidemiological survey of 1011 su... more This study was carried out in two parts. Part 1 consisted of an epidemiological survey of 1011 subjects aged 3-65 yrs from 2 adjoining villages hyper-endemic for Onchocerciasis and 890 subjects in a control area, relatively free from this infection but otherwise with a similar parasitological profile. There was a significantly higher prevalence of proteinuria in subjects from the onchocercal zone than in controls (observed difference greater than 5 1/2 times its standard error). Part 2 comprised detailed investigations, including renal biopsy, of 63 consecutive patients admitted into hospital with severe proteinuria and/or renal failure from a caption area extending into the onchocercal zone. There were a variety of causative factors, but in 9 cases filarial antigen was demonstrable in the immune-complex deposits in the kidney. A plenum of renal histopathological changes were seen in patients with onchocerciasis. The significance of these findings is discussed.
Fourty onchocercal nodules were taken from patients living in forest areas where onchocerciasis i... more Fourty onchocercal nodules were taken from patients living in forest areas where onchocerciasis is highly endemic, in order to identify the various types of lymphocytes present in these nodules. For this purpose, each nodule was submitted to two histological procedures: one after fixation in formalin of part of the nodule and hematoxylin-eosin stain; the other after freezing part of the nodule in liquid nitrogen, cryostat cutting and staining by immuno-peroxidase method using avidin-biotin and the following monoclonal antibodies: Pan B, OK T3, OK T4 and OK T8. Fifty-five of the 40 nodules show lymphocytes. All the 25 nodules with lymphocytes present T-lymphocytes. Only 20 of these 25 nodules have B lymphocytes and therefore only 20 nodules with lymphocytes have both T and B lymphocytes. Of the 25 nodules with T lymphocytes: 19 present T4 lymphocytes, 25 show T8 lymphocytes and therefore 19 have both T4 and T8 lymphocytes. These results are analysed and discussed in this study which ...
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