Histoplasmosis in Africa: Current perspectives,knowledge gaps,and research priorities

BackgroundHistoplasmosis is a chronic granulomatous disease caused by the thermally dimorphic fungus Histoplasma capsulatum. The 2 variants Histoplasma capsulatum var. capsulatum (Hcc) and Histoplasma capsulatum var. duboisii (Hcd) causes infection in humans and commonly termed classical or American histoplasmosis and African histoplasmosis, respectively. Histoplasma capsulatum var. farciminosum (Hcf) affects equines. In recent times, there have been heightened sensitization on fungal infections such as histoplasmosis in Africa, aimed at improving awareness among relevant stakeholders, particularly healthcare workers. This effort is expected to be paralleled with increased detection of both classical and African histoplasmosis, which has remained underdiagnosed over the years. In this narrative review, we describe the current perspectives of histoplasmosis in Africa, identify knowledge gaps, and suggest research priorities.MethodsA PubMed, Google Scholar, and Africa Journal Online (AJOL) literature search was conducted for studies on histoplasmosis in Africa between 2000 and 2020. Histoplasmosis essays in medical mycology textbooks were also consulted. This narrative review was prepared from the data gathered.FindingsIn the past 2 decades, histoplasmosis in general has seen a relative increase in case detection in some Africa countries, probably attributable to the gradually increasing medical mycology advocacy efforts in Africa. Histoplasmosis cases are dominated by African histoplasmosis mostly in Western and Central Africa, while classical histoplasmosis is more common in Southern and Northern Africa. Although both classical and African histoplasmosis are common in Africa, the latter is more restricted to Africa, and cases outside the continent usually have a travel history to the continent. Despite the clinical and laboratory difference between African histoplasmosis and classical histoplasmosis, it is not straightforward to distinguish them. The typical manifestation of African histoplasmosis is the appearance of lesions affecting the skin, bones, and lymph nodes and unusually linked to human immunodeficiency virus (HIV)/AIDS. By contrast, classical histoplasmosis mostly affects the lungs and is often associated with immunosuppression, mainly HIV/AIDS. The present perspectives of histoplasmosis in Africa highlight unclear details on the true burden, strain diversity, infection route and genetic basis of African histoplasmosis, availability of specie-specific diagnostic tools, and compliance with recommended antifungal therapy. These knowledge gaps represent research questions that require scientific exploration.ConclusionsDespite a subtle increase in identifying histoplasmosis cases in Africa, it remains underdiagnosed and neglected in some parts of the continent. Increasing awareness and training among healthcare workers, bridging diagnostic and therapeutic gaps, and encouraging more research in Africa are crucial to improve the current perspectives of histoplasmosis in Africa.     

A ten-year review of neonatal tetanus cases managed at a tertiary health facility in a resource poor setting: The trend,management challenges and outcome

BackgroundNeonatal Tetanus (NNT) is a vaccine preventable disease of public health importance. It is still being encountered in clinical practice largely in developing countries including Nigeria.NNT results from unhygienic delivery practices and some harmful traditional cord care practices.The easiest, quickest and most cost-effective preventive measure against NNT is vaccination of the pregnant women with the tetanus toxoid (TT) vaccine. The case-fatality rate from tetanus in resource-constrained settings can be close to 100% but can be reduced to 50% if access to basic medical care with adequate number of experienced staff is available.Materials and methodsThis retrospective study reviewed the admissions into the Special Care Baby Unit (SCBU) of the Ekiti State University Teaching Hospital, Ado-Ekiti from January 2011 to December 2020. The folders were retrieved from the records department of the hospital; Information obtained from folders were entered into a designed proforma for the study.ResultsDuring the study period, NNT constituted 0.34% of all neonatal admissions with case fatality rate of 52.6%. Seven [36.8%] of the babies were delivered at Mission home/Traditional Birth Attendant’s place while 5 [26.3%] were delivered in private hospitals. Cord care was with hot water compress in most of these babies16 [48.5%] while only 9% of the mothers cleaned the cord with methylated spirit. Age at presentation of less than one week was significantly associated with mortality, same with presence of autonomic dysfunction. Low family socio-economic class 5 was significantly associated with poor outcome, so also maternal age above 24 years.ConclusionThis study revealed that neonatal tetanus is still being seen in our clinical practice with poor outcome and the risk factors are the same as of old.Increased public health campaign, promotion of clean deliveries, safe cord care practices, affordable and accessible health care provision are recommended to combat NNT scourge.     

Regulatory mutations affecting the synthesis of cellulase in Bacillus pumilus

A wild strain of Bacillus pumilus was investigated for cellulase production, and putative mutants of this strain were screened for catabolite repression insensitivity after chemical mutagenesis using ethyl methanesulphonate (EMS) as a mutagenic agent. Out of four classes of mutants studied and classified according to their cellulase induction rate and level of cellulase production in the presence of high concentrations of glucose (2.6%[w/v]), classes III and IV exhibited cellulase production up to 6.2 mg cellulase and 11.4 mg cellulase per gram of dry cell mass respectively. These mutants were referred to as catabolite repression-insensitive when compared to the wild strain which exhibited a total repression of cellulase synthesis under the same conditions. How EMS triggered the catabolite repression insensitivity in these mutants was not established. However this mutation brought out new strains of cellulase hyperproducers (mutants 6 and 11) in the presence of glucose when compared to other cellulase producers such as Aspergillus terreus, A. nidulans and Trichoderma reesei, which exhibited catabolite repression of cellulase synthesis. These mutants were selected as the most promising candidates for cellulase synthesis even at high glucose concentration.     

Lectin Complement Protein Collectin 11 (CL-K1) and Susceptibility to Urinary Schistosomiasis

BackgroundUrinary Schistosomiasis is a neglected tropical disease endemic in many sub Saharan -African countries. Collectin Kidney 1 (CL-K1, encoded by COLEC11 on chromosome 2p25.3), a member of the vertebrate C-type lectin super family, has recently been identified as pattern-recognition molecule (PRR) of the lectin complement pathway. CL-K1 is preferentially expressed in the kidneys, but also in other organs and it is considered to play a role in host defense to some infectious agents. Schistosome teguments are fucosylated and CL-K1 has, through its collagen-like domain, a high binding affinity to fucose.ConclusionsIn agreement with findings from our earlier published study, our findings support the observation that CL-K1 and their functional variants may be host factors associated with protection in schistosomiasis and may be a useful marker for further investigations.     

Co-endemicity of Plasmodium falciparum and Intestinal Helminths Infection in School Age Children in Rural Communities of Kwara State Nigeria

Background

Malaria and intestinal helminths co-infection are major public health problems particularly among school age children in Nigeria. However the magnitude and possible interactions of these infections remain poorly understood. This study determined the prevalence, impact and possible interaction of Plasmodium falciparum and intestinal helminths co-infection among school children in rural communities of Kwara State, Nigeria.

Methods

Blood, urine and stool samples were collected from 1017 primary school pupils of ages 4–15 years. Stool samples were processed using both Kato-Katz and formol-ether concentration techniques and microscopically examined for intestinal helminths infection. Urine samples were analyzed using sedimentation method for Schistosoma haematobium. Plasmodium falciparum was confirmed by microscopy using thick and thin blood films methods and packed cell volume (PCV) was determined using hematocrit reader. Univariate analysis and chi-square statistical tests were used to analyze the data.

Results

Overall, 61.2% of all school children had at least an infection of either P. falciparum, S. haematobium, or intestinal helminth. S. haematobium accounted for the largest proportion (44.4%) of a single infection followed by P. falciparum (20.6%). The prevalence of malaria and helminth co-infection in the study was 14.4%. Four species of intestinal helminths were recovered from the stool samples and these were hookworm (22.5%), Hymenolepis species (9.8%), Schistosoma mansoni (2.9%) and Enterobius vermicularis (0.6%). The mean densities of P. falciparum in children co-infected with S. haematobium and hookworm were higher compared to those infected with P. falciparum only though not statistically significant (p = 0.062). The age distribution of both S. haematobium (p = 0.049) and hookworm (p = 0.034) infected children were statistically significant with the older age group (10–15 years) recording the highest prevalence of 47.2% and 25% respectively. Children who were infected with S. haematobium (RR = 1.3) and hookworm (RR = 1.4) have equal chances of being infected with P. falciparum as children with no worm infection. On the other hand children infected with Hymenolepis spp. (p<0.0001) are more likely to be infected with P. falciparum than Hymenolepis spp. uninfected children (RR = 2.0)

Conclusions

These findings suggest that multiple parasitic infections are common in school age children in rural communities of Kwara State Nigeria. The Hymenolepis spp. induced increase susceptibility to P. falciparum could have important consequences on how concurrent infections affect the expression or pathogenesis of these infections.     

Tracking the Quality of Care for Sick Children Using Lot Quality Assurance Sampling: Targeting Improvements of Health Services in Jigawa,Nigeria

Background

In Nigeria, 30% of child deaths are due to malaria. The National Malaria Control Program of Nigeria (NMCP) during 2009 initiated a program to improve the quality of paediatric malaria services delivered in health facilities (HF). This study reports a rapid approach used to assess the existing quality of services in Jigawa state at decentralised levels of the health system.

Methods

NMCP selected Lot Quality Assurance Sampling (LQAS) to identify the variation in HF service quality among Senatorial Districts (SD). LQAS was selected because it was affordable and could be used by local health workers (HW) in a population-based survey. NMCP applied a 2-stage LQAS using a structured Rapid Health Facility Assessment (R-HFA) tool to identify high and low performing SD for specified indicators.

Findings

LQAS identified variations in HF performance (n = 21) and enabled resources to be targeted to address priorities. All SD exhibited deficient essential services, supplies and equipment. Only 9.7% of HF had Artemisinin-based Combination Therapies and other first-line treatments for childhood illnesses. No SD and few HF exhibited adequate HW performance for the assessment, treatment or counselling of sick children. Using the IMCI algorithm, 17.5% of HW assessed the child’s vaccination status, 46.8% assessed nutritional status, and 65.1% assessed children for dehydration. Only 5.1% of HW treatments were appropriate for the assessment. Exit interviews revealed that 5.1% of caregivers knew their children’s illness, and only 19.9% could accurately describe how to administer the prescribed drug.

Conclusion

This R-HFA, using LQAS principles, is a rapid, simple tool for assessing malaria services and can be used at scale. It identified technical deficiencies that could be corrected by improved continuing medical education, targeted supervision, and recurrent R-HFA assessments of the quality of services.     

Strategies for Rapid Muscle Fatigue Reduction during FES Exercise in Individuals with Spinal Cord Injury: A Systematic Review

Background

Rapid muscle fatigue during functional electrical stimulation (FES)-evoked muscle contractions in individuals with spinal cord injury (SCI) is a significant limitation to attaining health benefits of FES-exercise. Delaying the onset of muscle fatigue is often cited as an important goal linked to FES clinical efficacy. Although the basic concept of fatigue-resistance has a long history, recent advances in biomedical engineering, physiotherapy and clinical exercise science have achieved improved clinical benefits, especially for reducing muscle fatigue during FES-exercise. This review evaluated the methodological quality of strategies underlying muscle fatigue-resistance that have been used to optimize FES therapeutic approaches. The review also sought to synthesize the effectiveness of these strategies for persons with SCI in order to establish their functional impacts and clinical relevance.

Methods

Published scientific literature pertaining to the reduction of FES-induced muscle fatigue was identified through searches of the following databases: Science Direct, Medline, IEEE Xplore, SpringerLink, PubMed and Nature, from the earliest returned record until June 2015. Titles and abstracts were screened to obtain 35 studies that met the inclusion criteria for this systematic review.

Results

Following the evaluation of methodological quality (mean (SD), 50 (6) %) of the reviewed studies using the Downs and Black scale, the largest treatment effects reported to reduce muscle fatigue mainly investigated isometric contractions of limited functional and clinical relevance (n = 28). Some investigations (n = 13) lacked randomisation, while others were characterised by small sample sizes with low statistical power. Nevertheless, the clinical significance of emerging trends to improve fatigue-resistance during FES included (i) optimizing electrode positioning, (ii) fine-tuning of stimulation patterns and other FES parameters, (iii) adjustments to the mode and frequency of exercise training, and (iv) biofeedback-assisted FES-exercise to promote selective recruitment of fatigue-resistant motor units.

Conclusion

Although the need for further in-depth clinical trials (especially RCTs) was clearly warranted to establish external validity of outcomes, current evidence was sufficient to support the validity of certain techniques for rapid fatigue-reduction in order to promote FES therapy as an integral part of SCI rehabilitation. It is anticipated that this information will be valuable to clinicians and other allied health professionals administering FES as a treatment option in rehabilitation and aid the development of effective rehabilitation interventions.     

Specific Detection of Xylella fastidiosa Pierce's Disease Strains

Pierce's disease (PD, Xylella fastidiosa) of grapevine is the primary pathogen limiting vinifera grape production in Florida and other regions of the southeastern United States. Quick and accurate detection of PD strains is essential for PD studies and control. A unique random amplified polymorphic DNA (PD1-1-2) was isolated from a PD strain from Florida. Fragment PD1-1-2 was cloned, sequenced, and found to be 1005 bp in length. PCR primers were designed to utilize these sequence data for PD strain detection. One primer set (XF176f–XF954r) amplified a 779-bp DNA fragment from 34 PD strains including seven pathotypes of X. fastidiosa, but not from strains of Xanthomonas campestris pv. campestris, Xan. vesicatoria or Escherichia coli. A second primer set (XF176f and XF686r) amplified a 511-bp fragment specific to 98 PD strains, but not from strains of citrus variegated chlorosis, mulberry leaf scorch, oak leaf scorch, periwinkle wilt, phony peach, or plum leaf scald. Sequence analysis indicated that RAPD fragment PD1-1-2 contains a Ser-tRNA gene. The PD-specific region includes a TaqI restriction site (TCGA) and is 150 bp downstream of the Ser-tRNA gene. Received: 1 March 1999 / Accepted: 5 April 1999     

Occurrence of keratinophilic fungi anddermatophytes on domestic birds in Nigeria

Feathers, nails and beaks of one hundred and twenty common birds in Nigeria, Chicken [50], Ducks [20], Turkeys [15] and Pigeons[35], were examined using the soil plate technique for their mycoflora.15 species of fungi were recovered and they belong to the genera Chrysosporium, Trichophyton, Microsporum, Aspergillus, Fusarium, Mucor, Rhizopus, Penicillium and Trichoderma. Microsporum gypseum was the species most frequently isolated (35% of the samples). The most common genus was Chrysosporium and C. keratinophilum was the species with the highest frequency in the genus (28.3%). The species isolated included potential pathogens and mycotoxin producing fungi (Aspergillus flavus, A. niger, Fusarium oxysporum). This revised version was published online in June 2006 with corrections to the Cover Date.