Posted on

Review Article: Epidemiology of Malaria in Africa

TM Akande, IO Musa

 

Abstract

Malaria is a life threatening parasitic disease transmitted by female anopheles mosquitoes. There are four types of human parasites; Plasmodium vivax, P. malariae, P ovale and P. falciparum. P. falciparum and P. vivax are the most common and P. falciparum, the most deadly type of infection, is most common in sub-Saharan Africa. A large number of environmental factors affect the distribution, seasonality and transmission intensity of malaria. Rainfall provides breeding sites for mosquitoes and increases the humidity, which enhances their survival. While malaria is largely endemic in Africa, varying proportion of countries in the continent are at risk of endemic malaria. Today, approximately 40% of the world population, mostly those living in the world’s poorest countries, is at risk of malaria. This is mostly in the tropical and sub-tropical regions of the world. There are at least 300 million acute cases of malaria each year globally resulting in more than a million deaths, around 90% of these occur in Africa, mostly young children. In areas of stable malaria transmission, very young children and pregnant women are the population at highest risk for malaria morbidity and mortality. The populations most at risk of epidemics are those living in highlands, arid and desert-fringe zones and those living in areas where successful control measures have not been consolidated or maintained.
Key words: Epidemiology, Malaria, Africa

Afr. J. Clin. Exper. Microbiol. 2005; 6(2): 107 – 111

Posted on

Review Article: Recent Advances in Childhood Antimalaria Chemotherapy

SK Ernest, OA Mokuolu

 

Abstract

As malaria continues to kill many people in our world and spreading into areas that were never known to have it before, it becomes necessary to make occasional reviews of what therapeutic measures are effective in areas of malaria endemicity. There is a global concern as to reducing malaria morbidity and mortality worldwide. Malaria eradication had been viewed as impossible with the mechanisms used against it and the world has settled for just a control. One of the critical areas of this control is effective case management. As it was the case with tuberculosis, leprosy and bacterial infections, there is a paradigm shift from the monotherapy that have been used for nearly three centuries (Quinine) and nearly 60 years after other drugs were discovered (Chloroquine, since early 1940s and subsequently others) with no remarkable drop in the global morbidity and mortality. The World Health Organization (WHO) now advocates combination therapy, which are mainly Artemisinin–based. We in this article made an extensive review of the combination chemotherapeutic possibilities and advocacy for it to achieve increase survival, reduced disease burden through effective parasitaemic clearance with reduced chance of early recrudescence. A necessary overview has been made of the life cycle and clinical presentation of malaria which has not changed significantly over the years. Also, the combination chemotherapy including Artemisinin-based, Sulphadoxine/Pyrimethamine–based and the non-Artemisinin non-Sulphadoxine/Pyrimethamine-based chemotherapy have all been reviewed and concluded that their use will lead to effective case management and reduced mortality. We therefore advocate for a therapeutic paradigm shift to these combination therapy.
Key words: Combination chemotherapy, antimalaria, childhood, review

Afr. J. Clin. Exper. Microbiol. 2005; 6(2): 129-137

Posted on

Review Article: Vaccine for Malaria – How Far?

GO Oyeyinka

 

Abstract

This is a review of the progress made so far in the effort to produce a malaria vaccine. The problems that have made it impossible to get an effective vaccine for malaria are discussed. Also examined are the current efforts to produce the vaccine and the prospects for an effective vaccine in the future.
Key words: Vaccine, malaria, review.

Afr. J. Clin. Exper. Microbiol. 2005; 6(2): 139-143

Posted on

Review Article: Prospect and Progress of Malaria Vaccine Development

OA Adeyeba, AF Fagbenro-Beyioku, O Ojurongbe

 

Abstract

Malaria kills one child every 30 seconds in Africa. The development of a safe vaccine remains an urgent unmet need which could greatly control and even lead to the eradication of the disease. The success recorded in the recent vaccine trials have given some ray of hope that a safe and effective vaccine against malaria will soon be produced. In this article, we bring together important published information on the status of malaria vaccine development and reviewed some field trials and the obstacles as well as prospect for effective malaria vaccination.
Key words: Malaria vaccine, prospect, review

Afr. J. Clin. Exper. Microbiol. 2005; 6(2): 145-152

Posted on

Review Article: ‘Miasma’ Theory and the Possibility of Malaria Eradication

Ademola O Awoyemi

 

Abstract

Malaria as a disease entity caused by plasmodium species only became recognized towards the end of the 19th Century. Prior to that time, Mal’aria or ‘bad air’ was believed to be the cause of fevers or paludal. This article traces the history of ‘Miasma’ theory which had been accepted for Centuries before the ‘Germ’ theory became established. Comparing the ‘Miasma’ theory with current understanding of Africans about disease causation, it was concluded that there are great similarities. It is therefore recommended that concurrent application of both the ‘Germ’ theory and the ‘Miasma’ theory could lead to a more effective control or even global eradication of malaria.
Key words: Miamsa, malaria, eradication

Afr. J. Clin. Exper. Microbiol. 2005; 6(2): 153-158

Posted on

Epidemiological Study Of Asymptomatic Bacteriuria Among Nursery School Children In Ahvaz, Iran

M Jalali, T Asteraki, E Emami-Moghadam, E Kalantar

 

Abstract

This study was undertaken to determine the prevalence of asymptomatic bateriuria in preschool children of different age and sex groups and to isolate the organisms responsible for asymptomatic bacteriuria and determine their antimicrobial susceptibility pattern. A total of 475 children from 17 nurseries in Ahvaz city, Iran were screened by collecting mid-stream urine samples for the presence of causative organisms. Asymptomatic bacteriuria was observed in 16 cases (3.36%). The isolated pathogens included Escherichia coli (50 %), Proteus mirabilis (25 %) and coagulase negative staphylococcus (25 %). The antibiograms indicated that Gentamicin (100 %), Nalidixic acid (100 %), Amikacin (75%), Kanamycin (75 %), Nitrofurantoin ( 62.5 %), Tobramycin ( 62.5 %), Tetracycline ( 50 %) and Chloramphenicol (37.5%), were in that order the most effective of the antibiotics tested against E. coli isolates. Proteus mirabilis showed 100% sensitivity to Amikacin, Gentamicin, Kanamycin, Nalidixic acid and Tobramycin followed by Nitrofurantoin (75%), Cephalotin (50%) and Chloramphenicol (50%). Similarly, antibiogram of coagulase negative staphylococcus showed 75% sensitivity to both Nalidixic acid and Kanamycin. This result indicated a significant rise in the frequency of Escherichia coli in asymptomatic bacteriuria.
Key words: Asymptomatic bacteriuria, children, urinary tract infections

Afr. J. Clin. Exper. Microbiol. 2005; 6(2): 159-161

Posted on

Characteristics of Nosocomial MRSA in Assir Central Hospital, Abha, Kingdom of Saudi Arabia

T Al-Azraqi, CSS Bello

 

Abstract

The objective of this study is to determine the characteristics of nosocomial methicillin-resistant and sensitive Staphylococcus aureus (MRSA & MSSA) and their minimum inhibitory concentration (MIC) to vancomycin and oxacillin. Over a six-month period a study of Staphylococcus aureusisolates from clinical specimens of patients with nosocomial infections in Assir Central Hospital (ACH), Abha, Saudi Arabia, between September 2003 and February 2004, was carried out. Isolation and identification of Staphylococcus aureus was performed using standard microbiological methods. MIC to vancomycin and oxacillin was carried out using the E-test strips. Eighty-five Staphylococcus aureus isolates were identified. These were made up of 39 (45.9%) MRSA and 46 (54.1%) MSSA. The MIC to oxacillin showed that 37/39 (94.9%) MRSA had MIC >256 µg/ml and only 2/39 (5.1%) had MIC of 4 and 32 µg/ml. Thirty of forty six (65.2%) of the MSSA had MIC < 0.50 µg/ml and 16/46 (34.8%) had MIC of between 0.50 -2 µg/ml. All the 85 isolates were fully sensitive to vancomycin (MIC breakpoint < 4 µg/ml). There is even distribution of sensitivity pattern to vancomycin among MRSA and MSSA isolates. 31/39 (79.5%) of MRSA had MIC of 2 µg/ml while 34/46(74.0%) of MSSA had MIC of 2 µg/ml. The prevalence of MRSA in nosocomial infections in ACH is 45.9%. Thirty-seven out of thirty-nine (94.9%) of the MRSA strains show high resistance to oxacillin (MIC > 256 µg/ml). The use of oxacillin-related drugs to treat nosocomial Staphylococcal infections in ACH should be reviewed and infection control practices should be intensified so as to stem any future increase in MRSA prevalence in the hospital.
Key words: MRSA, Characteristics, MICs, Vancomycin, Oxacillin.Afr. J. Clin. Exper. Microbiol. 2005; 6(2): 163-166

Download full journal in PDF below

Posted on

Mycobacterium africanum – A Review

AO Onipede, B de Jong, RA Adegbola

 

Abstract

Tuberculosis, a curable infectious disease, remains the leading cause of adult death. The HIV/AIDS epidemic has greatly exacerbated the already grave situation in the developing world by creating a deadly synergy each worsening the course of the other. Mycobacterium africanumis a subspecies of Mycobacterium tuberculosis complex (MBC) and is isolated from tuberculous patients in certain parts of Africa. Genotypically, members of the MBC are closely related, exhibiting 99.9% similarity at the nucleotide level and identical 16s RNA gene (rDNA) and 16s-23s rDNA spacer sequences. However, identification and discrimination between members of the MBC are important for epidemiological purposes. This paper reviewed current knowledge about this subspecies.

Afr. J. Clin. Exper. Microbiol. 2005; 6(2): 167-175

Posted on

Invasive behaviour and depolarization effect of Pseudomonas fluorescens on rat cerebellar granule neurons

S Mezghani-Abdelmoula, A Khemiri, O Lesouhaitier, S Chevalier, L Cazin

 

Abstract

Previous studies have shown that Pseudomonas fluorescens exerts cytotoxic effects on neurons and glial cells. In the present work, we investigated the time course effect of Pseudomonas fluorescens MF37 and of its lipopolysaccharide (LPS) on cultured rat cerebellar granule neurons. The kinetics of binding of P. fluorescens to cerebellar granule neurons is identical to that of cortical neurons but the binding index is lower, suggesting the presence of a reduced number of binding sites. As demonstrated by measurement of the concentration of nitrites in the culture medium, P. fluorescens induces a rapid stimulation (3 h) of the nitric oxide synthase (NOS) activity of the cells. In contrast, LPS extracted from P. fluorescens requires a long lag phase (24 h) before observation of an activation of NOS. Measurement of the resting membrane potential of granule neurons showed that within 3 h of incubation, there was no difference of effect between the action of P. fluorescens and that of its LPS endotoxin. Two complementary approaches allowed us to demonstrate that P. fluorescens MF37 presents a rapid invasive behaviour, suggesting a mobilisation of calcium in its early steps of action. The present study reveals that P. fluorescens induces the sequential activation of a constitutive calcium dependent NOS and that of an inducible NOS activated by LPS. Ours results also suggest that P. fluorescens cytotoxicity and invasion are not mutually exclusive events.

Key Words: Cytotoxicity, Lipopolysaccharide, Patch-clamp, Invasion, Pseudomonas fluorescens

Afr. J. Clin. Exper. Microbiol. Vol.6(1) 2005: 1-13

Posted on

Quinolones resistance and R-plasmids of some gram negative enteric bacilli

OA Daini, OD Ogbolu, A Ogunledun

 

Abstract

Out of the two hundred and sixty bacteria isolates from clinical specimens obtained from different body sites at the University College Hospital Ibadan, 166 belonged to the family of Enterobacteriaceae and Pseudomonaceae. The isolated gram-negative enteric bacilli consist of Escherichia coli (22), Klebsiella species (65), Proteus species (20), Salmonella typhi (2), Pseudomonas aeruginosa (39) and Pseudomonas species (18). Among the antimicrobial agents tested, high resistance was found with ofloxacin 44.0%, followed by pefloxacin 30.1% and ciprofloxacin 21.7%. Ciprofloxacin has the lowest MIC of 2 – 32 μg/ml while ofloxacin has the highest 64 μg/ml. Of the 166 strains, 44 were resistant to most of the antimicrobial agents tested. All the strains that were resistant to any antimicrobial agents were also resistant to ofloxacin. A total of 27 plasmids ranging in molecular sizes from 6.6.kb to 17.4kb were extracted from the resistant strains and grouped into 5 plasmid profiles. Transformation experiment revealed that 59.2% of the resistant strains carried a common R-plasmid of size 10.7kb. Plasmid-mediated resistance to ciprofloxacin and pefloxacin was found. Klebsiella species harboured the highest number of R-plasmids with 8, followed by Pseudomonas aeruginosa with 4.

Afr. J. Clin. Exper. Microbiol. Vol.6(1) 2005: 14-20