Dynamics of IgG antibody response against Plasmodium antigens among Nigerian infants and young children

Background

Plasmodium falciparum malaria is a leading cause of child mortality in Nigeria. Neonates are born with maternal antibodies from placental transfer which may protect against malaria infection in the first months of life. The IgG dynamics of the transition from passively transferred antimalarial antibodies to actively acquired IgG from natural exposure have not been well elucidated.

Methods

Blood samples collected during a 2018 Nigeria nationwide HIV/AIDS household survey were available for 9,443 children under 5 years of age, with a subset of infants under 2 months of age having maternal samples available (n=41). Samples were assayed for the P. falciparum HRP2 antigen and anti-malarial IgG antibodies. LOESS regression examined the dynamics in IgG response in the first 5 years of life. Correlation with maternal IgG levels was assessed for mother/child pairs.

Results

Consistent decreases were observed in median IgG levels against all Plasmodium spp. antigen targets for the first months of life. At a population level, P. falciparum apical membrane antigen-1 (AMA1) and merozoite surface protein-1 19kD (PfMSP1) IgG decreased during the first 12 months of life before reaching a nadir, whereas IgGs to other targets only declined for the first 4 months of life. Seropositivity showed a similar decline with the lowest seropositivity against AMA1 and PfMSP1 at 10-12 months, though remaining above 50% during the first 2 years of life in higher transmission areas. No protective association was observed between IgG positivity and P. falciparum infection in infants. Maternal antibody levels showed a strong positive correlation with infant antibody levels for all P. falciparum antigens from birth to 2 months of age, but this correlation was lost by 6 months of age.

Discussion

Maternally transferred anti-malarial IgG antibodies rapidly decline during the first 6 months of life, with variations among specific antigens and malaria transmission intensity. From 3-23 months of age, there was a wide range in IgG levels for the blood-stage antigens indicating high individual variation in antibody production as children are infected with malaria. Non-falciparum species-specific antigens showed similar patterns in waning immunity and correlation with paired mother's IgG levels compared to P. falciparum antigens.

Treponemal Antibody Seroprevalence Using a Multiplex Bead Assay from Samples Collected during the 2018 Nigeria HIV/AIDS Indicator and Impact Survey: Searching for Yaws in Nigeria

Yaws is a chronic, relapsing disease of skin, bone, and cartilage caused by Treponema pallidum subsp. pertenue. Yaws was last reported in Nigeria in 1996, although neighboring countries have recently reported cases. We investigated serological evidence for yaws among children aged 0-14 years in Nigeria by measuring antibodies to the treponemal antigens rp17 and TmpA in blood specimens from a 2018 nationally representative HIV survey using a multiplex bead assay. The presence of antibodies to both antigens ("double positive") likely reflects current or recent treponemal infection. Overall, 1.9% (610/31,549) of children had anti-TmpA antibodies, 1.5% (476/31,549) had anti-rp17 antibodies, and 0.1% (39/31,549) were double positive. Among households, 0.5% (84/18,021) had a double-positive child, with a clustering of double-positive children. Although numbers are low, identification of antibodies to both TmpA and rp17 may warrant investigation, including more granular epidemiologic and clinical data, to assess the potential for continuing yaws transmission in Nigerian children.

Non-falciparum malaria infection and IgG seroprevalence among children under 15 years in Nigeria, 2018

Plasmodium falciparum (Pf) is the dominant malaria parasite in Nigeria though P. vivax (Pv), P. ovale (Po), and P. malariae (Pm) are also endemic. Blood samples (n = 31,234) were collected from children aged 0-14 years during a 2018 nationwide HIV survey and assayed for Plasmodium antigenemia, Plasmodium DNA, and IgG against Plasmodium MSP1-19 antigens. Of all children, 6.6% were estimated to have Pm infection and 1.4% Po infection with no Pv infections detected. The highest household wealth quintile was strongly protective against infection with Pm (aOR: 0.11, 95% CI: 0.05-0.22) or Po (aOR= 0.01, 0.00-0.10). Overall Pm seroprevalence was 34.2% (95% CI: 33.3-35.2) with lower estimates for Po (12.1%, 11.6-12.5) and Pv (6.3%, 6.0-6.7). Pm seropositivity was detected throughout the country with several local government areas showing >50% seroprevalence. Serological and DNA indicators show widespread exposure of Nigerian children to Pm with lower rates to Po and Pv.

Plasmodium falciparum infection prevalence among children aged 6-59 months from independent DHS and HIV surveys: Nigeria, 2018

Prevalence estimates are critical for malaria programming efforts but generating these from non-malaria surveys is not standard practice. Malaria prevalence estimates for 6-59-month-old Nigerian children were compared between two national household surveys performed simultaneously in 2018: a Demographic and Health Survey (DHS) and the Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). DHS tested via microscopy (n = 8298) and HRP2-based rapid diagnostic test (RDT, n = 11,351), and NAIIS collected dried blood spots (DBS) which were later tested for histidine-rich protein 2 (HRP2) antigen (n = 8029). National Plasmodium falciparum prevalence was 22.6% (95% CI 21.2- 24.1%) via microscopy and 36.2% (34.6- 37.8%) via RDT according to DHS, and HRP2 antigenemia was 38.3% (36.7-39.9%) by NAIIS DBS. Between the two surveys, significant rank-order correlation occurred for state-level malaria prevalence for RDT (Rho = 0.80, p < 0.001) and microscopy (Rho = 0.75, p < 0.001) versus HRP2. RDT versus HRP2 positivity showed 24 states (64.9%) with overlapping 95% confidence intervals from the two independent surveys. P. falciparum prevalence estimates among 6-59-month-olds in Nigeria were highly concordant from two simultaneous, independently conducted household surveys, regardless of malaria test utilized. This provides evidence for the value of post-hoc laboratory HRP2 detection to leverage non-malaria surveys with similar sampling designs to obtain accurate P. falciparum estimates.

Assessing the Suitability of Oil Palm (Elaeis guineensis) Production in Peninsular Malaysia based on Soil, Climate and Land Use

In recent years, palm oil production has grown rapidly as a result of rising demand. Oil palm plantations have been established on thousands of acres to meet this demand. The objective of this study is to assess the suitability of oil palm production as driven by soil, climate, and land use. The land suitability assessment (LSA) method was adopted in this study. We use geospatial techniques of overlay mapping as a suitable land suitability assessment method, in which the evaluation criteria are recorded as superimposed layers. A land suitability map is produced by integrating these layers into a single layer. The method is also applied to delineate available areas for growing oil palm in Peninsular Malaysia. The findings revealed that suitable soil areas for oil palm production are extensively found in the selected regions of Peninsular Malaysia, in states like Selangor and some parts of Kedah, Kelantan, and Terengganu with clay loam and sandy loam soil properties, while in the southern region like Melaka, moderate suitability for oil palm production was found due to the domination of clay soil in the area. Highly suitable areas were estimated (mean annual water deficit <150 mm) to be 3688254.00 ha (29.54%) of the total land area; suitable areas (mean annual water deficit <250 mm) were 6540669.00 ha (52.38%); moderately suitable areas were (mean annual water deficit <400 mm) 2227500.00 ha (17.84%), and unsuitable areas (mean annual water deficit >400mm) for oil palm production as a result of poor water availability was 31104.00ha (0.25%). The Land Use Land Cover Map of Peninsular Malaysia revealed the suitable areas to cover an average of 10885001.46 ha (82.45%), water bodies 1239505.58 ha (9.39%), built-up areas (unsuitable areas) 1051544.34 ha (7.96%), and bare surface areas are also not suitable areas for oil palm production at 26509.73 ha (0.20%). This study recommends that oil palm plantations be expanded into areas with highly suitable soils and climates.

Performance of SARS-CoV-2 Antigens in a Multiplex Bead Assay for Integrated Serological Surveillance of Neglected Tropical and Other Diseases

Serosurveillance can provide estimates of population-level exposure to infectious pathogens and has been used extensively during the COVID-19 pandemic. Simultaneous, serological testing for multiple pathogens can be done using bead-based immunoassays to add value to disease-specific serosurveys. We conducted a validation of four SARS-CoV-2 antigens-full-length spike protein, two receptor binding domain proteins, and the nucleocapsid protein-on our existing multiplex bead assay (MBA) for enteric diseases, malaria, and vaccine preventable diseases. After determining the optimal conditions for coupling the antigens to microsphere beads, the sensitivity and specificity of the assay were determined on two instruments (Luminex-200 and MAGPIX) when testing singly (monoplex) versus combined (multiplex). Sensitivity was assessed using plasma from 87 real-time reverse transcription polymerase chain reaction (rRT-PCR) positive persons collected in March-May of 2020 and ranged from 94.3% to 96.6% for the different testing conditions. Specificity was assessed using 98 plasma specimens collected prior to December 2019 and plasma from 19 rRT-PCR negative persons and ranged from 97.4% to 100%. The positive percent agreement was 93.8% to 97.9% using 48 specimens collected > 21 days post-symptom onset, while the negative percent agreement was ≥ 99% for all antigens. Test performance was similar using monoplex or multiplex testing. Integrating SARS-CoV-2 serology with other diseases of public health interest could add significant value to public health programs that have suffered severe programmatic setbacks during the COVID-19 pandemic.

Appraisal of trimester-specific fetal heart rate and its role in gestational age prediction

INTRODUCTION

The aim of this study was to evaluate and report normal sonographic FHR values among low-risk singleton women across the three trimesters of pregnancy and determine FHR role in gestational age prediction.

METHOD

A prospective cross-sectional study of 2727 low-risk singleton pregnant women was undertaken. FHR measurements were obtained by a consultant radiologist and three experienced sonographers using transabdominal approach from January 2019 to December 2020. Two FHR measurements were taken for each participant. The fetal lie and presentation were also documented in the first trimester. Data were analysed using SPSS version 24 (IBM, Armonk, NY, USA).

RESULT

The maternal mean ± SD age was 25.8 ± 6.5 years and mean FHR for first, second and third trimesters were 151 ± 16, 145 ± 6 and 125±6 bpm respectively. The mean ± SD gestational age were 10 ± 2, 19 ± 3 and 34 ± 2 weeks for the first, second and third trimester respectively. Using ANOVA, there were statistically significant differences in FHR across the three trimesters (p ≤ 0.05). A positive correlation existed between maternal age and FHR (r = 0.57, p ≤ 0.05).

CONCLUSION

This study has established normal values for FHR in first, second and third trimester respectively. Referring physicians, radiologists, sonographers, obstetricians and gynaecologists may consider FHR of (135-167) bpm (139-151) bpm and (119-131) bpm as normal FHR ranges for the first, second and third trimester respectively. This study has also revealed the possibility of gestational age prediction using FHR with the equation [Gestational Age = 87.8 - (0.47) FHR].

IMPLICATIONS FOR PRACTICE

This paper provides the most up-to-date sonographic FHR recommendations for fetal management. More importantly, findings from this study also suggests that ultrasound practitioners can use FHR measurements as a reliable alternative for fetal dating.

FIRST CARDIAC COMPUTED TOMOGRAPHY TYPICAL RADIATION DOSE VALUES FROM A SINGLE CENTRE IN NIGERIA: A PILOT STUDY

Concern regarding radiation dose associated with cardiac computed tomography (CT) still exists and requires the use of diagnostic reference levels for dose optimisation. Typical median doses were established for 58 consented adult patients from a single centre for coronary artery calcium score (CACS) as volume computed tomography dose index (CTDIvol): 5.9 mGy; dose length product (DLP): 86.6 mGy*cm and cardiac CT angiography (CCTA) as CTDIvol: 11.1 mGy; DLP: 190.8 mGy*cm. Wide radiation dose variability in terms of CTDIvol was noted for CACS: 2.7-15.9 mGy, a 6-fold, whereas for CCTA it ranges from 3.8 to 52.8 mGy, a 14-fold. The DLP values for CACS range from 33.2 to 344.2 mGy*cm, which is 10-fold, whereas for CCTA it ranges from 32.8 to 834.9 mGy*cm, a 25-fold. The typical values compared lower than the radiation dose from other countries; however, the wide variability in dose remains a call for concern.

Knowledge of heat waves and practice of protective measures against it in a rural West African

Background

Heat wave has a direct linkage to global climate change and is associated with increased morbidity and mortality. Between March and May 2019, Nigeria experienced severe heat waves. Understanding heat waves provides an opportunity for individuals to proactively take measures to prevent its negative health impacts. However, illiteracy levels in rural Sub-Saharan Africa are higher than in urban areas.This study was therefore conducted to assess knowledge of heat waves and practice of protective measures against it in an affected rural community of Nigeria.

Methods

A cross-sectional, community based descriptive study conducted among household heads in Nasarawan Buhari, a rural agrarian community in Nigeria. An interviewer-administered questionnaire was used to collect data from 104 household heads, selected using systematic random sampling technique. Data was analyzed using SPSS (version 20).

Results

A majority of the respondents were males (79.8%) and most of them (89.4%) had poor knowledge of heat waves. Farming occupation was significantly associated with knowledge of heat waves (P = 0.025). Awareness of measures needed to protect against the negative health impacts of heat waves was also poor. Hence fluid intake and cold showers were the only protective measures used by majority of respondents to reduce effect of the extreme heat.

Conclusions

Both knowledge of heat waves and practice of protective measures against it were poor among respondents. A health education intervention on heat waves and how to prevent its negative health impacts was conducted in the community.

Key messages

Due to poor knowledge of heat waves and its negative health effects, practice of protective measures against it was poor among respondents. There is need for more public health response to address this rural public health challenge.

High Reticulocyte Count with Abnormal Red Blood Cell Morphology in Normal Wistar Rats after Garlic Administration

Despite the high acceptability of Allium sativa (Garlic) as a remedy for many diseases as earlier stated by manyresearchers, previous studies have shown that chronic and unregulated consumption of garlic may result to intra vascularhaemolytic anaemia in rats. The present study was conducted to examine the effect of crude extract of garlic on microscopicstatus of red blood cells and some other haematological indices of normal albino rats. The animals were grouped into two;group 1 were normal animals treated with water while group 2 were normal animals administered 150mg/kg body weight ofcrude extract of garlic on alternate days for three weeks. At the end of three weeks treatment, blood samples obtained fromthe tail vein of the rats were used for haematological indices and erythrocyte morphology. The values obtained wereexpressed as Mean± SEM and compared using student t test. The results showed that there was no significant difference inthe PCV which was 43.20 ± 0.80% and 45.00 ± 0.36% in both control and experimental groups respectively. However, theRBCs were significantly decreased (P< 0.05) from 166.80 ± 3.44 x106 µL-1 in the control group to 87.80 ± 9.34 x106 µL-1 inthe treatment group. The percentage reticulocyte counts on the other hand significantly increased from 2.60±4.25% in controlgroup to 11.20± 16.4% in treated group. Fragmented RBCs with a lot of schistocytes with adequate platelets were seen onperipheral blood film of crude garlic treated rats as compared to control. Our results suggested intravascular haemolysis andnumerous reticulocytes on blood film confirmed our view on bone marrow response. The presence of schistocytes andacanthocytes may be an indication that the liver is involved in the observed effect.

Time interval to initiation of contraceptive methods following childbirth in a low-resource setting

OBJECTIVES

The objectives of the study were to determine factors affecting the interval between a woman's last childbirth and the initiation of contraception.

MATERIALS AND METHODS

This was a retrospective study. Family planning clinic records of the Barau Dikko Teaching Hospital Kaduna from January 2000 to March 2014 were retrieved. Information was collected on demographics, reproductive, and contraceptive history. Data were analyzed using the SPSS version 15 software, and missing responses were excluded. Chi-square was used as a test of association with significance level established at P = 0.05.

RESULTS

A total of 5992 client's cards were retrieved. All were female and married. Majority were aged 25-34 years (53.1%), had completed secondary education (56%) and were Muslims (52.3%). Only 4979 cards (83.1%) had correct data on intervals and 22.1% of these clients initiated contraception within 6 months of their last childbirth. Education, religion, source of information, number of living children, desire to have more children, previous use of contraception, and type of contraception chosen were significantly associated with intervals for initiating contraception after last childbirth (P < 0.05) while the presence of complications in the last delivery was not (P > 0.05).

CONCLUSIONS

Majority of women initiate contraception late after childbirth in this setting. Increased awareness on immediate/early postpartum contraception is required. Further qualitative studies will help to explore findings of this study.

Assessment of biochemical liver function tests in relation to age among steady state sickle cell anemia patients

BACKGROUND AND OBJECTIVE

Multiorgan failure including liver dysfunction is a common finding in sickle cell anemia (SCA) patients, the cause of which is multifactorial with advancing age said to be a major determinant. There is a paucity of data on liver function among SCA patients in relation to age in northern Nigerian hospitals, including Ahmadu Bello University Teaching Hospital (ABUTH), Zaria. This study was to assess the biochemical liver function tests (LFTs) as they relate to age among SCA patients in steady state, with a view to improving the overall monitoring of these patients.

SUBJECTS AND METHODS

This study was carried out in ABUTH, Zaria, Northern Nigeria. LFTs were carried out in 100 SCA and 100 apparently healthy participants (controls). The SCA group was made up of fifty adults and fifty children diagnosed of SCA, whereas the control group was made up of fifty adults and fifty children who were apparently healthy and had hemoglobin AA. Paired two-tailed Student's t-test for matched samples and Pearson's linear correlation statistical methods were employed for the data analysis using Microsoft Office Excel 2007. A P ≤ 0.05 was considered as statistically significant.

RESULTS

The serum concentrations of total bilirubin (TB), alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and AST/ALT ratio were significantly higher in SCA patients compared to the controls (P = 0.001, P = 0.001, P = 0.05, P = 0.05 and P = 0.001, respectively). Serum total protein (TP) and ALB were significantly lower (P = 0.01 and P < 0.05, respectively) in SCA patients compared with the controls. The levels of TB, ALT, AST, ALP, and AST/ALT were significantly lower in SCA adults compared to SCA children, whereas TP and ALB were higher in SCA adults compared to the SCA children. There were significant negative correlations between age and each of TB, ALT, AST, ALP, and AST/ALT, and significant positive correlations between age and each of TP and ALB in SCA patients.

CONCLUSION

There are mild LFTs derangements in SCA patients even in steady state with the extent of the abnormalities decreasing with advancing age of the patients.

Burden of acute respiratory disease of epidemic and pandemic potential in the WHO Eastern Mediterranean Region: A literature review

There are gaps in the knowledge about the burden of severe respiratory disease in the Eastern Mediterranean Region (EMR). This literature review was therefore conducted to describe the burden of epidemicand pandemic-prone acute respiratory infections (ARI) in the Region which may help in the development of evidence-based disease prevention and control policies. Relevant published and unpublished reports were identified from searches of various databases; 83 documents fulfilled the search criteria. The infections identified included: ARI, avian influenza A(H5N1), influenza A(H1N1)pdm09 and Middle East respiratory syndrome coronavirus (MERS-CoV) infection. Pneumonia and ARIs were leading causes of disease and death in the Region. Influenza A(H1N1) was an important cause of morbidity during the 2009 pandemic. This review provides a descriptive summary of the burden of acute respiratory diseases in the Region, but there still remains a lack of necessary data.

Middle East respiratory syndrome coronavirus: current knowledge and future considerations

A literature review of publically available information was undertaken to summarize current understanding and gaps in knowledge about Middle East respiratory syndrome coronavirus (MERS-CoV), including its origin, transmission, effective control measures and management. Major databases were searched and relevant published papers and reports during 2012-2015 were reviewed. Of the 2520 publications initially retrieved, 164 were deemed relevant. The collected results suggest that much remains to be discovered about MERS-CoV. Improved surveillance, epidemiological research and development of new therapies and vaccines are important, and the momentum of recent gains in terms of better understanding of disease patterns should be maintained to enable the global community to answer the remaining questions about this disease.

Zika virus: no cases in the Eastern Mediterranean Region but concerns remain

Following the WHO declaration on 1 February 2016 of a Public Health Emergency of International Concern (PHEIC) with regard to clusters of microcephaly and neurological disorders potentially associated with Zika virus, the WHO Regional Office for the Eastern Mediterranean conducted three rounds of emergency meetings to address enhancing preparedness actions in the Region. The meetings provided up-to-date information on the current situation and agreed on a set of actions for the countries to undertake to enhance their preparedness and response capacities to Zika virus infection and its complications. The most urgent action is to enhance both epidemiological and entomological surveillance between now and the coming rainy seasons in countries with known presence of Aedes mosquitoes. Zika virus like other vector-borne diseases poses a particular challenge to the countries because of their complex nature which requires multidisciplinary competencies and strong rapid interaction among committed sectors. WHO is working closely with partners and countries to ensure the optimum support is provided to the countries to reduce the risk of this newly emerged health threat.

Improved Performance of COBAS AmpliPrep/COBAS TaqMan Version 2.0 Assay Over Amplicor Monitor Version 1.5 in the Quantification of HIV-1 RNA Viral Load in Abuja, Nigeria

BACKGROUND

Improved viral detections by the real time PCR over the manual assays have been reported by various manufacturers. However, discrepancies and discordance between different platforms targeting the same pathogen have also been observed at different settings.

METHODS

We used an analytical study design to compare the performance of the Cobas Taqman /Cobas Ampliprep version 2.0 against the standard Amplicor Monitor 1.5 using 200 routine clinical samples, in Abuja- Nigeria.

RESULTS

Taqman and Amplicor detected 118/200 (59%) and 83/200 (41.5%) samples respectively. Two of 83 samples (2.4%) undetectable by Cobas Taqman, were detectable by Roche Amplicor, while 5 of 37 samples (13.5%) which were undetectable by Amplicor using Taqman. Among the 81 detectable samples by both assays 4 samples (4.9%) had a log10 difference > 0.5 log copies, while 9 samples (11.1%) showed a wider discrepancy of >1 log10. Bland and Altman's comparison shows no significant difference between the two methods (p=0.2825) and CI-0.06171 to 0.2087.

CONCLUSION

We observed a remarkable improvement in the performance of COBAS AmpliPrep/COBAS TaqMan version 2.0 Assay over Amplicor Monitor version 1.5 in the quantification of HIV1 RNA viral load. Discrepancies of clinical significance, in the viral load between the two platforms were also recorded. The implications of the inability of the automated Taqman 2.0 to detect 2.4% of samples detectable by the Amplicor need to be considered by programs, clinicians and the manufacturers. Periodic evaluation of platforms to detect new circulating HIV subtypes within each locality is also recommended.

Developmental inventories using illiterate parents as informants: Communicative Development Inventory (CDI) adaptation for two Kenyan languages

Communicative Development Inventories (CDIs, parent-completed language development checklists) are a helpful tool to assess language in children who are unused to interaction with unfamiliar adults. Generally, CDIs are completed in written form, but in developing country settings parents may have insufficient literacy to complete them alone. We designed CDIs to assess language development in children aged 0;8 to 2;4 in two languages used in Coastal communities in Kenya. Measures of vocabulary, gestures, and grammatical constructions were developed using both interviews with parents from varying backgrounds, and vocabulary as well as grammatical constructions from recordings of children's spontaneous speech. The CDIs were then administered in interview format to over 300 families. Reliability and validity ranged from acceptable to excellent, supporting the use of CDIs when direct language testing is impractical, even when children have multiple caregivers and where respondents have low literacy levels.

Diabetes mellitus and comorbid depression in Zambia

AIMS

To replicate, in Zambia, a recent global study by the WHO, which reported that the odds of depression were not increased in African people with diabetes, and to explore the sociodemographic and clinical factors associated with depression.

METHODS

A total of 773 control subjects and 157 Zambian patients with diabetes completed the Major Depression Inventory and a list of demographic indicators.

RESULTS

Compared with control subjects (mean ± sd Major Depression Inventory score 15.10 ± 9.19), depressive symptoms were significantly more common in patients with diabetes (mean ± sd Major Depression Inventory score 19.12 ± 8.95; P < 0.001). ancova showed that having diabetes [F(1,698) = 16.50, P < 0.001], being female [F(1,698) = 7.35, P < 0.01] and having low socio-economic status (F(1,698) = 13.35, P < 0.001) were positive predictors of depression.

CONCLUSIONS

Contrary to the WHO study, we found that depression was a common comorbid health problem among Zambian people with diabetes. Clinicians should consider patients' health status, sex and socio-economic status as potential factors predicting depression.

Evaluation of nine HIV rapid test kits to develop a national HIV testing algorithm in Nigeria

Background: Non-cold chain-dependent HIV rapid testing has been adopted in many resource-constrained nations as a strategy for reaching out to populations. HIV rapid test kits (RTKs) have the advantage of ease of use, low operational cost and short turnaround times. Before 2005, different RTKs had been used in Nigeria without formal evaluation. Between 2005 and 2007, a study was conducted to formally evaluate a number of RTKs and construct HIV testing algorithms. Objectives: The objectives of this study were to assess and select HIV RTKs and develop national testing algorithms. Method: Nine RTKs were evaluated using 528 well-characterised plasma samples. These comprised 198 HIV-positive specimens (37.5%) and 330 HIV-negative specimens (62.5%), collected nationally. Sensitivity and specificity were calculated with 95% confidence intervals for all nine RTKs singly and for serial and parallel combinations of six RTKs; and relative costs were estimated. Results: Six of the nine RTKs met the selection criteria, including minimum sensitivity and specificity (both ≥ 99.0%) requirements. There were no significant differences in sensitivities or specificities of RTKs in the serial and parallel algorithms, but the cost of RTKs in parallel algorithms was twice that in serial algorithms. Consequently, three serial algorithms, comprising four test kits (BundiTM, DetermineTM, Stat-Pak® and Uni-GoldTM) with 100.0% sensitivity and 99.1% - 100.0% specificity, were recommended and adopted as national interim testing algorithms in 2007. Conclusion: This evaluation provides the first evidence for reliable combinations of RTKs for HIV testing in Nigeria. However, these RTKs need further evaluation in the field (Phase II) to re-validate their performance.

Anticonvulsant activity of aqueous fraction of Carissa edulis root bark

CONTEXT

Carissa edulis Vahl (Apocynaceae) is used in Nigerian folk medicine to manage a plethora of diseases including epilepsy, cancer, and inflammation; its efficacy is widely acclaimed among communities of northern Nigeria.

OBJECTIVE

This study establishes anticonvulsant activities of aqueous fraction of ethanol root bark extract of Carissa edulis (RAF) and sub-fractions (S1 and S2) in animal models.

MATERIALS AND METHODS

We evaluated the acute toxicity of the RAF, S1 and S2, and the anticonvulsant activity using pentylenetetrazole (PTZ), picrotoxin, strychnine, N-methyl-d-aspartate (NMDA), isoniazid (INH), and aminophylline-induced seizures in mice. Their effects on maximal electroshock (MES) and kindling-induced seizures were studied in chicks and in rats, respectively, and in the electrophysiological study. The doses used for RAF were 150, 300, and 600 mg/kg while S1 and S2 were 250, 500, and 1000 mg/kg. Both RAF and sub-fractions were administered once during the experiment.

RESULTS

The intraperitoneal LD50 of the RAF was estimated to be 2222.61 mg/kg and that of the S1 and S2 were above 5000 mg/kg. RAF protected the mice by 50% while sub-fractions by 16.67% against PTZ-induced seizures. RAF offered 33.33 and 16.67% protection against strychnine and NMDA models, respectively. However, RAF offered 66.67-33.33% protections against aminophylline-induced seizures at doses of 150 and 600 mg/kg, but RAF, S1, and S2 had no effect on MES-induced seizures.

DISCUSSION AND CONCLUSION

Our results validate the use of the plant traditionally in the management of epilepsy, thus supporting the appraisal of biologically active components of this plant as antiepileptic agents.

Effects of centrifugal stress on cell disruption and glycerol leakage from Dunaliella salina

Dunaliella salina accumulates large amounts of intracellular glycerol in response to the increases in salt concentration, thus is a potential source for producing fuel grade glycerol as an alternative to biodiesel-derived crude glycerol. D. salina lacks a cell wall; therefore the mode of harvesting Dunaliella cells is critical to avoid cell disruption caused by extreme engineering conditions. This study explored cell disruption and glycerol leakage of D. salina under various centrifugal stresses during cell harvesting. Results show a centrifugal g-force lower than 5000 g caused little cell disruption, while a g-force higher than 9000 g led to ~40% loss of the intact cells and glycerol yields from the recovered algal pellets. Theoretical calculations of the centrifugal stresses that could rupture Dunaliella cells were in agreement with the experimental results, indicating optimisation of centrifugation conditions is important for recovering intact cells of D. salina enriched in glycerol.

Blood pressure and heart rate adjustment following acute Frenkel's ambulatory exercise in chronic hemiparetics stroke survivors: a comparative study

BACKGROUND

Frenkel's ambulatory activity has been routinely employed by physiotherapists for rehabilitation of gait coordination, however, its immediate influence on blood pressure and heart rate has not been investigated.

OBJECTIVE

To investigate the acute effect of Frenkel's ambulatory activity on blood pressure and heart rate of chronic hemiparetic stroke survivors.

METHOD

Using a comparative study design, 60 chronic hemiparetic stroke survivors of varying onset of stroke, ≤6, >6-11 and ≥12 months were subjected to a 2-minute Frenkel's ambulatory activity on marked footsteps (from standard adult described footsteps). Participants were assessed for both blood pressure and heart rate before and after the Frenkel's ambulatory activity.

RESULTS

Blood pressure and heart rate significantly increased (p<0.05) following Frenkel's ambulatory activity in all the 3 categories of stroke onset above baseline. However, there was no significant difference (p>0.05) across the onsets in both blood pressure and heart rate responses.

CONCLUSION

The outcome of this study indicated that Frenkel's ambulatory activity has the propensity to increase blood pressure and heart rate of hemiparetic stroke survivors irrespective of the onset of stroke. We recommend a pre, within and post-activity monitoring of stroke survivors while subjecting them to Frenkel's ambulatory activity.

Nutritional status and pattern of infant feeding practices among children under five in a rural community of northwestern Nigeria

The study assessed the factors influencing nutritional status of children less than five years in Biye village in rural Nigeria. The study was a cross sectional descriptive study: 119 caregivers and mothers were interviewed. A structured questionnaire was used to collect data using multi-stage sampling. Anthropometric measurements of children were also taken. Data analysis was done using SPSS version 17.0. Respondents age ranged from 11-50 years, mean age of 26 (± 11.7); 79.8% had Quranic education; and 50.4% were not gainfully employed. Two-thirds (68.9%) were polygamous, and 64.7% had 1-3 children. Less than 1% of children were exclusively breast fed. From anthropometric data obtained, 62.2% were stunted, 12.6% wasted, and 48.7% underweight. A statistically significant relationship exists between family size and children's nutritional status. The prevalence of malnutrition was high with poor child feeding practices. Thus, healthcare providers should carry out community-wide health education on the need to promote appropriate infant feeding practices and nutritional status.

Rapid and complete decompression of chronic urinary retention: a safe and effective practice

We carried out a prospective study of consecutive patients who presented with chronic urinary retention over a period of 2 years in order to determine the safety and effectiveness of rapid and complete decompression of chronic urinary retention. A total of 22 patients met the inclusion criteria. Although slow decompression is thought to reduce complications, it harbours the disadvantages of impracticability, time and labour demands and an increased risk of infection. Post-obstructive diuresis, haematuria and hypotension are relatively frequent in rapid and complete decompression of chronic urinary retention. However, they are mild, transient and clinically insignificant. Rapid and complete decompression of the chronically obstructed urinary bladder not only saves time, it is safe and effective and should be adopted as the standard practice.

The factor structure of the 12-item General Health Questionnaire in a literate Kenyan population

The study evaluated the factorial structure of the 12-item General Health Questionnaire (GHQ-12) in a population of Kenyan adults and adolescents. A sample of 1216 people aged 12-60 years completed the English version of the GHQ-12. To evaluate the factor structure of the GHQ-12, a confirmatory analysis using MPLUS was carried out. A unidimensional model of GHQ-12 as originally conceptualized did not provide a good fit for the data (Comparative Fit Index = 0.843, Tuckler Lewis Index = 0.841, Root Mean Square of Error Approximation = 0.078, Standardized Root Mean Square Residual = 0.063). Unidimensional models, which partial out the effects of negative wording showed an adequate fit to the data. Additionally, multidimensional models showed an excellent fit to the data. Based on the principles of parsimony, pattern of item loading and the correlation between identified factors in the multidimensional models, it was concluded that the GHQ-12 is a unidimensional measure whose structure is significantly influenced by wording effects. The GHQ-12, when applied to a literate population in Africa, showed similar factor structure as in other regions of the world; hence, it can be recommended for use as a screening tool for general symptoms of psychological distress.