Evaluation of the sensitivity and specificity of rapid human immunodeficiency virus (HIV)1 and 2 test kits commonly used in Nigeria

The sensitivity and specificity of five rapid HIV antibody test kits commonly used in Nigeria were evaluated. The kits were selected based on their high percentage frequency of use as compared to others. A total of 100 EIA HIV-1and RNA HIV-1 positive sera were used as positive gold standard; while 100 EIA HIV-1 and RNA HIV-1 negative sera were used as negative gold standard. The positive gold standard sera were pooled; serially diluted and analysed to determine the sensitivities of the kits. The methods used were strictly as provided by the manufacturers. Of the 100 positive gold standard serum samples used; Immunocomb-II gave false negative results with 10 (Sensitivity = 90); while HIV-SAV; Hexagon; Determine and SD-Bioline were false negative with 12 specimens; representing 88 sensitivity for each. On the other hand; of the 100 negative gold standard sera; Immunocomb-II gave 6 false positive results (Specificity = 94); HIV-SAV 12 (Specificity = 88); Hexagon 2 (Specificity = 98); Determine 12 (Specificity = 88); while SD-Bioline had no false positive result (specificity = 100). In analytical sensitivity; Immunocomb-II detected the highest serum titre of 30 000; making it the most sensitive. Two of the five test kits (Immunocomb and SD-Bioline) demonstrated excellent analytical sensitivity and specificity respectively. The two could be recommended for use as combination test algorithms instead of EIA/Western Blot algorithm; which is time-consuming; expensive and often not technically feasible in a developing country like ours. This study shows that not all the analytical performance indices cited in the literature from the manufacturers of diagnostic kits are necessarily reproducible in end-user laboratories

Apport du scanner thoracique dans le dépistage des cas suspects de COVID-19 au Service d'imagerie médicale du Centre Hospitalier et Universitaire (CHU) de Libreville - Gabon / Contribution of chest ct-scan in the screening of suspected cases of COVID-19 at the Medical Imaging Department

Objectifs.Evaluer l'apport de la TDM thoracique dans le diagnostic de la COVID-19 chez les patients suspects en prenant comme référence le Test RT ­PCR et secondairement déterminer les anomalies scanographiques caractéristiques associés au Test RT ­PCR.Matériels etméthodes.Il s'est agi d'une étude rétrospective, descriptive à visée analytique, menée au service d'imagerie du CHU de Libreville. Aux vues de la disponibilité des dossiers nous avons exploité ceux de la période d'activité de mars à juin 2020, soit une période quatre mois. Cette étude a inclus tous les patients ayant une infection à COVID-19 confirmée par la réaction de polymérase en chaine en temps réel (RT ­PCR), après écouvillonnages nasal et/ou pharyngé et / ou les signes typiques de la pneumonie à COVID-19. Pour déterminer les anomalies scanographiques caractéristiques de la COVID-19 associées au test RT ­PCR nous avons comparé 25 patients avec un test RT ­PCR négatifs et 119 patients avec un test RT ­PCR positifs. Une valeur de p < 0,05 était considérée comme significative. La sensibilité de la TDM thoracique a été calculée à l'aide de la relation, Sensibilité=VP/ (VP+FN), (VP : vrai positif de la TDM : TDM positive et test RT PCR positif ; et le FN : Faux négatif de la TDM : TDM négative et test RT PCR positif). L'analyse statistique a été rendu possible grâce au logiciel SPSS 25. Résultats. En régression logistique multivariée, les anomalies scanographiques caractéristiques de la COVID-19 positivement associés à un test RT ­PCR positif étaient :verre dépoliOR = 33,236, IC95% [6,939 ­59,192], p=0,0001), la condensation alvéolaire (OR = 8,093 [1,488 ­44,013]; p=0,016). La sensibilité du scanner thoracique pour le diagnostic de la COVID-19, chez les patients suspects était de 93,2%, la spécificité de 64,2% avec une valeur prédictive positive de 90,2% et une valeur prédictive négative de 73,0%.Conclusion.Le diagnostic scanographique de la COVID-19 chez les patients suspects est aisé avec une bonne sensibilité et spécificité. La présence des anomalies scanographiques caractéristiques à type de verre dépoli et de condensation alvéolaire est associéeà un test RT ­PCR positif

Objective. Evaluate the contribution of Thoracic CT in the diagnosis of COVID-19 in suspected patients by taking the RT ­PCR Test as a reference and secondarily determine the impact of the RT ­PCR Test on characteristic scan abnormalities, in the service of thoracic imaging at Libreville University Hospital.Materials and methods. This was a retrospective, descriptive study with an analytical aim. In view of the availability of files, we used those from the period of activity from March to June 2020, i.e. a four-month period. To determine the impact of the RT ­PCR test on characteristic scan abnormalities, we compared 25 patients with negative RT ­PCR and 119 patients with negative RT ­PCR. A value of p < 0.05 was considered significant. The sensitivity of chestCT was calculated using the relationship, Sensitivity=VP/(VP+FN), (VP: true positive of CT: positive CT and positive RT PCR test; and FN: False negative CT: negative CT and positive RT PCR test). Statistical analysis was made possible using SPSS 25 software.Results. In multivariate logistic regression, CT abnormalities characteristic of COVID-19 were positively associated with a positive RT ­PCR: ground glass, (OR = 33.236, 95% CI [6.939 ­59.192], p = 0.0001), condensation alveolar (OR = 8.093 [1.488 ­44.013]; p = 0.016). The sensitivity of chest CT for the diagnosis of COVID-19 in suspected patients was 93.2%, the specificity of 64.2% with a positive predictive value of 90.2% and a negative predictive value of 73. 0%.Conclusion. CT diagnosis of COVID-19 in suspected patients is easy with good sensitivity and specificity. The presence of characteristic scan abnormalities such as ground glass and alveolar condensation is associated with a positive RT ­PCR tes

Value of baseline radiograph for COVID-19 infected patients

Introduction: A cluster of pneumonia cases of unknown origin was first reported in Wuhan China then the causative pathogen was identified and named severe acute respiratory syndrome coronavirus 2 (SARS-Cov2) and the associated disease was named coronavirus disease 2019 (COVID-19). Chest radiograph has lower sensitivity for the detection of lung abnormalities but it has a role in disease progression and also in the late stages of COVID19. This study aims to evaluate the value of baseline radiographs in COVID-19-infected patients. Method: This is a retrospective study of COVID-19 patients with RT-PCR confirmation who were admitted to Eka Kotebe General Hospital and had baseline chest x-ray between April and May 2020. Baseline chest x-ray of all patients who have confirmed COVID-19 infection was reviewed and analyzed. Result: The study included 355 patients, 224 (63.1%) were male and 131 (36.9%) were female. Patient age ranged from 4 - 82 years with a mean age of 35. Two hundred twelve patients were symptomatic; the rest 143 were asymptomatic. Of the 355 baseline CXR, only 60 (16.9%) had abnormal radiographs and the rest 295 (83.1%) had normal radiographs. A combination of interstitial changes and GGO were the predominant descriptive finding accounting for 33.3% . Conclusion: Even if chest radiographs are important in the workup of patients with COVID-19 infection, the use of baseline radiographs in COVID-19 infection should not be a routine practice. Disease severity and timing of imaging appear to impact the rates of normal baseline imaging.

Value of dynamic subtraction MRI in assessing HCC response to image-guided loco-regional therapy

Background: Hepatocellular carcinoma (HCC) is considered one of the foremost cancers worldwide. Although the hepatic resection of HCC has a high existence in the clinical scenarios, locoregional management is preferred owing to the preservation of hepatic parenchyma with lower morbidity and mortality. Dynamic contrast-enhanced MR with subtraction imaging improves the evaluation of managed HCC with easy detection of residual or recurrent viable lesions. Patients and methods: This study was designed in a retrospective pattern from December 2020 to December 2022. Forty patients were referred to our radiology department with solitary HCC, underwent therapeutic intervention, then underwent follow-up by dynamic MRI study. Results: Forty patients with solitary HCC were conducted during our study; all underwent locoregional therapy with follow-up by dynamic MRI with subtraction technique one month later. The subtraction image has a sensitivity of 100%, specificity of 100%, PPV of 100%, NPV of 100%, and 100% accuracy, compared to 90.91%, 77.78%, 83.33%, 87.5%, and 85% for conventional dynamic images, 45.45%, 100%, 100%, 60% and 70% for diffusion-weighted images. Analysis of those results exhibited a considerable additive value of the subtraction technique to the dynamic MRI to detect the response of HCC after management. Conclusions: Subtraction MRI is a pivotal tool to assess the interventional treatment of HCC, particularly in lesions having pre-contrast high signal intensity with distinguished radiologists' confidence

SD bioline malaria rapid diagnostic test performance and time to become negative after treatment of malaria infection in southwest Nigerian children

Context and Aim: Given the challenges of microscopy, we compared its performance with SD Bioline malaria rapid diagnostic test (MRDT) and polymerase chain reaction (PCR) and evaluated the time it took for positive results to become negative after treatment of children with acute uncomplicated malaria. Subjects and Methods: We present the report of 485 participants with complete MRDT, microscopy, and PCR data out of 511 febrile children aged 3­59 months who participated in a cohort study over a 12 month period in rural and urban areas of Ibadan, Nigeria. MRDT positive children received antimalaria and tested at every visit over 28 days. Speciation was also carried out by PCR. Results: With microscopy as the gold standard, SD-Bioline™ had 95.2% sensitivity, 66.4% specificity, 67.5% positive predictive value (PPV), and 94.9 negative predictive value (NPV), while with PCR the findings were 84.3% sensitivity, 66.5% specificity, 72.7% PPV, and 80.1% NPV. PCR speciation of malaria parasites revealed 91.6% Plasmodium falciparum, 18.9% Plasmodium malariae, and 4.4% Plasmodium ovale. Among the 47 children with P. malariae infections, 66.0% were coinfected with P. falciparum, while 54.6% cases of P. ovale occurred as coinfections with P. falciparum. The median time to a negative MRDT was 23.2 days, while the median time to a negative malaria microscopy was 3.8 days. The two survival curves were significantly different. Conclusions: The SD BiolineTM MRDT performed well, with remarkable persistence of rapid test-positive for an average of 23 days post treatment. The prevalence of P. malaria is somewhat greater than expected.

Validation of the COVID-19 IgG/IgM Rapid Test Cassette (BNCP ­ 402 and BNCP402) in a South African setting

Background: Different diagnostic tools could improve early detection of coronavirus disease 2019 (COVID-19). A number of antibody-based serological point-of-care tests have been developed to supplement real-time reverse transcriptase polymerase chain reaction (RT-PCR)-based diagnosis. This study describes the validity of an antibody test, namely the immunoglobulin G (IgG)/immunoglobulin M (IgM) Rapid Test Cassette® (BNCP ­ 402 and BNCP402), manufactured by Spring Healthcare Services. Methods: A prospective cohort validation study was undertaken at Chris Hani Baragwanath Academic Hospital between 16 July 2020 and 12 August 2020. A total of 101 patients admitte as COVID-19 cases under investigation were included in the study. They were divided into two categories depending on time since symptom onset: testing performed within seven days (early cohort) and after seven days (late cohort). The rapid antibody test was compared to the RT-PCR. Results: Overall, the test has a sensitivity and specificity of 85.2% and 80.0%, respectively, for a combination of IgG and IgM. Sensitivity and specificity of IgG testing alone were 81.5% and 85%. Sensitivity improved for testing with increasing time from symptom onset; however, specifity was not significantly different. Conclusion: The study data adds to the body of evidence that because of relatively low sensitivity and specificity, there is a limited role for antibody-based point-of-care testing in the acute phase of COVID-19 infection, as was the case with this IgG/IgM Rapid Test Cassette (BNCP ­ 402 and BNCP402). There may exist a role for such testing in patients recovered from prior COVID-19 infection or in seroprevalence studies; however, additional evaluations at later timepoints from symptom onset are required.

Pre-evaluation assessment of serological-based COVID-19 point-of-care lateral flow assays in Kenya

Background: Timely testing is a key determinant of management outcomes of coronavirus disease 2019 (COVID-19). Real-time reverse transcription polymerase chain reaction tests are currently the mainstay for COVID-19 testing. However, serological point-of-care tests (PoCTs) can be useful in identifying asymptomatic and recovered cases, as well as herd immunity. Objective: The aim of this study was to assess COVID-19 PoCTs in Kenya to support the emergency use authorisation of these tests. Methods: Between March 2020 and May 2020, 18 firms, of which 13 were from China, submitted their PoCTs to the national regulatory authority, the Pharmacy and Poison Board, who in turn forwarded them to the Kenya Medical Research Institute for pre-evaluation assessment. The tests were run with real-time reverse transcription polymerase chain reaction COVID-19-positive samples. Pre-COVID-19 plasma samples that were collected in June 2019were used as negative samples. The shelf lives of the PoCTs ranged from 6 to 24 months. Results: Only nine (50%) tests had sensitivities ≥ 40% (range: 40% ­ 60%) and the ability of these tests to detect IgM ranged from 0% to 50%. Many (7/18; 38.9%) of the kits had very weak IgM and IgG band intensities (range: 2­3). Conclusion: Serological-based PoCTs available in Kenya can only detect COVID-19 in up to 60% of the infected population.

Sensitivity and specificity of malaria rapid diagnostic test (mRDT CareStatTM) compared with microscopy amongst under five children attending a primary care clinic in southern Nigeria

Background: Malaria diagnosis using microscopy is currently the gold standard. However, malaria rapid diagnostic tests (mRDTs) were developed to simplify the diagnosis in regions without access to functional microscopy. Aim: The objective of this study was to compare the diagnostic accuracy of mRDT CareStatTM with microscopy. Setting: This study was conducted in the paediatric primary care clinic of the Federal Medical Centre, Asaba, Nigeria. Methods: A cross-sectional study for diagnostic accuracy was conducted from May 2016 to October 2016. Ninety-eight participants were involved to obtain a precision of 5%, sensitivity of mRDT CareStatTM of 95% from published work and 95% level of confidence after adjusting for 20% non-response rate or missing data. Consecutive participants were tested using both microscopy and mRDT. The results were analysed using EPI Info Version 7. Results: A total of 98 children aged 3­59 months were enrolled. Malaria prevalence was found to be 53% (95% confidence interval [CI] = 46% ­ 60%), whilst sensitivity and specificity were 29% (95% CI = 20% ­ 38%) and 89% (95% CI = 83% ­ 95%), respectively. The positive and negative predictive values were 75% (95% CI = 66.4% ­ 83.6%) and 53% (95% CI = 46% ­ 60%), respectively. Conclusion: Agreement between malaria parasitaemia using microscopy and mRDT positivity increased with increase in the parasite density. The mRDT might be negative when malaria parasite density using microscopy is low

The Susceptibility Pattern of Salmonella Species to Commonly Used Antibiotics in the Bamenda District Health Area; Cameroon

The susceptibility of Salmonella bacteria to commonly used antibiotics such as ampicillin; chloramphenicol and trimethoprim/sulphamethoxazole is threatened by the emergence of resistance strains of Salmonella. A cross-sectional study was carried out from September 2014 to November 2014 in the Regional Hospital Bamenda on individuals presenting with symptoms of salmonellosis. The Salmonellae were isolated from stool by culturing in Salmonella-Shigella Agar and Kliger Iron Agar; the later in which the isolates produced specific biochemical characteristics which were conclusive. They were assessed for antimicrobial susceptibility by the disc diffusion method using Mueller-Hinton Agar following both CLSI and EUCAST manual instructions. A total of 253 samples were collected and 22 cases were positive for Salmonella species with a prevalence of 8.70%. The susceptibility of the isolated Salmonellae to seven antibiotics was noted with ciprofloxacin having an overall sensitivity of 52.38%; ofloxacin; 47.62%; ceftriaxone; 47.62%; and gentamicin; 38.10%. Chloramphenicol had a low sensitivity percentage of 28.57%; while co-trimoxazole and amoxicilin had a high resistance level of 100.00% (0% sensitivity). The fluoroquinolones were found to be the best drugs for the treatment of typhoid; but there was also a noticeable re-emergence of chloramphenicol susceptible Salmonella

Improved sensitivity, safety and laboratory turn around time in the diagnosis of pulmonary tuberculosis by use of bleach sedimentation

Background: Inadequate diagnostic processes and human resources in laboratories contribute to a high burden of tuberculosis (TB) in low- and middle-income countries. Direct smear microscopy is relied on for TB diagnosis; however; sensitivity rates vary. To improve sensitivity of direct microscopy; the researchers employed several approaches; including sputum digestion and concentration of acid-fast bacilli (AFB); a technique which uses commercial bleach. Objectives: This study compared methods used to diagnose active Mycobacterium tuberculosis infections. Methods: Three sputum specimens were collected from each of 340 participants in Abuja; Nigeria; over two consecutive days. Direct microscopy was performed on all specimens; following microscopy; one specimen from each patient was selected randomly for bleach sedimentation and one for Lowenstein-Jensen culture.Results: Direct microscopy produced 28.8% AFB-positive results; whilst bleach sedimentation resulted in 30.3%. When compared with the cultures; 26.5% were AFB true positive using direct microscopy and 27.1% using bleach sedimentation. Whilst the specificity rate between these two methods was not statistically significant (P = 0.548); the sensitivity rate was significant (P = 0.004).Conclusion: Based on these results; bleach increases the sensitivity of microscopy compared with direct smear and has similar specificity. When diagnosing new cases of pulmonary TB; one bleach-digested smear is as sensitive as three direct smears; reducing waiting times for patients and ensuring the safety of laboratory technicians

Normal Conjunctival Flora as Seen in Adult Patients at Kigali University Teaching Hospital

The aim of this study was to assess the pattern of normal ocular bacterial flora isolated from patients attending the Department of ophthalmology at the Kigali University Teaching Hospital and to evaluate their in vitro susceptibility to common antimicrobial agents. From June to October 2011; collection of specimen was performed by rotating a sterile cotton swab on the lower conjunctival sac from the temporal to the medial fornix. Gram stain and culture was performed and antibiotic sensitivity determined in case of bacterial growth. Of the 120 collected samples; 74 (61.6) showed bacterial growth and all were gram positive. 48.6 were Staphylococcus aureus ; while 51.4 were Staphylococcus epidermidis. There was high sensitivity of Staphylococcus aureus to chloramphenicol (100); clindamycine (92); oxacilline (86.7); ciprofloxacine (76.7) and norfloxacine (71.9). However; there was a high resistance of Staphylococcus aureus to penicilline G (11.1) and tetracycline (52.8). Staphylococcus epidermidis was highly sensitive to chloramphenicol (71.9) and oxacilline (71.1) while it was resistant to erythromycine (28.6); norfloxacine (35.3) and penicilline G (40.6 In this study; all of the isolated pathogens were revealed to be gram-positive bacteria. Chloramphenicol; clindamycine and oxacilline showed good activity against normal flora of the ocular surface and should be used in prevention of post-operative end ophtalmitis

Childhood Urinary Tract Infection in Abakaliki: Etiological Organisms and Antibiotic Sensitivity Pattern

Urinary tract infection (UTI) is a common childhood infection in the Tropics which causes significant illness and is frequently missed; probably because of its non-specific presentation and similarity with other common illnesses. Objectives: To determine the prevalence; common etiological agents; and the susceptibility of these pathogens to the commonly available antimicrobial agents in this center. Materials and Methods: This was a retrospective study carried out at the Children's Outpatient Clinic and Children's Emergency Ward of Ebonyi State University Teaching Hospital Abakaliki (EBSUTH). The study was carried out between January 1; 2007 and December 31; 2009. Results: One hundred ten subjects of the 3625 children seen in the center during the period of study had UTI giving a case prevalence rate of 3.0. Majority of the patients (59; 53.6) were less than 2 years of age with a male:female ratio of 1:1.3. Fever was the commonest presenting symptom and the commonest organisms isolated in urine were Klebsiella (27; 24.5); and Staphylococcus aureus (24; 21.8). The drugs that were most sensitive to these organisms were Gentamicin (50; 45.5); Ceftriaxone (49; 44.5); and Ciprofloxacin (36; 32.7). Conclusion: The study revealed a high prevalence of UTI among children. Klebsiella was the commonest causative organism isolated in the urine. Gentamicin; Ceftriaxone; and Ciprofloxacin were the antimicrobials with the highest sensitivity to all the isolated microorganisms

Antimicrobial Susceptibility Patterns of Escherichia Coli Strains Isolated From Urine Samples in South Africa from 2007-2011

Escherichia coli is the most common cause of urinary tract infections. Knowledge of its local antimicrobial susceptibility patterns can be used to inform choice of empiric antimicrobial therapy. In this article; we review data on antimicrobial susceptibility patterns of E. coli isolated from unselected urine specimens; in both the private and public sectors of South Africa from 2007-2011. Between 65 000-84 000 E. coli urinary isolates were reported annually from 19 laboratories located across South Africa. Susceptibility to fluoroquinolone and beta-lactam antibiotics decreased significantly and steadily in both private and public sectors over the five-year period; although laboratory-based surveillance data may underestimate susceptibility rates due to selection bias and lack of differentiation between community- and hospital-acquired infections. Our data suggest that fluoroquinolones; co-amoxiclav and first- and second-generation cephalosporins can still be used for empiric treatment in many local settings; but clinicians should be alert to the risk of treatment failure. With the withdrawal of nitrofurantoin from the local market; other oral antibiotic options are limited; and fosfomcyin may become increasingly important. Given their sustained high susceptibility rates; aminoglycosides should be considered to treat pyelonephritis more often. Judicious use of laboratory testing is advised and further research and surveillance is warranted

The Sensitivity and Specificity of Lassa Virus IgM by ELISA as Screening Tool at Early Phase of Lassa Fever Infection

"Background: Early diagnosis; prompt treatment; and disease containment are vital measures in the management of Lassa fever (LF); a lethal and contagious arenaviral hemorrhagic disease prevalent in West Africa. Lassa Virus (LAV)-specific Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) test; the gold standard for diagnosis; is unavailable in most centers. Serologic detection of LAV IgM is a more accessible tool and this work was to investigate its adequacy as an early marker for LF. Patients and Methods: A prospective case-control study conducted July 2007-March 2011 in a tertiary referral health center in Nigeria. Blood samples for test and control were evaluated for Lassa specific antigens and IgM using RT-PCR (primers S36+ and LVS 339) and indirect ELISA (Lassa Nucleo-protein (NP)-Antigen) respectively. RT-PCR outcome was used as standard to test for the sensitivity and specificity of IgM. Results: Of the 37 confirmed cases of LF infection by RT-PCR; 21 (57) were IgM positive. Amongst the 35 confirmed negative cases (control group); eight were IgM positive. The diagnostic sensitivity and specificity of the IgM assay were 57 and 77 respectively. The negative and positive predictive values of the IgM serological assay were 63 and 72 ; respectively; while the efficiency of the test was 67. Conclusion: The specificity and sensitivity of IgM as a screening tool for early detection of LF appear weak and; hence; the need for a reliable LF ""rapid screening kit"" since RT-PCR is unavailable in most centers. In the interim; ""high clinical index of suspicion;"" irrespective of IgM status; requires urgent referral to confirmatory centers."

Sensitivity and specificity of typhoid fever rapid antibody tests for laboratory diagnosis at two sub-Saharan African sites

Objective:To evaluate three commercial typhoid rapid antibody tests for Salmonella Typhi antibodies in patients suspected of having typhoid fever in Mpumalanga; South Africa; and Moshi; United Republic of Tanzania. Methods The diagnostic accuracy of Cromotest (semiquantitative slide agglutination and single tube Widal test); TUBEX and Typhidot was assessed against that of blood culture. Performance was modelled for scenarios with pretest probabilities of 5and 50. Findings In total 92 patients enrolled: 53 (57.6) from South Africa and 39 (42.4) from the United Republic of Tanzania. Salmonella Typhi was isolated from the blood of 28 (30.4) patients. The semiquantitative slide agglutination and single-tube Widal tests had positive predictive values (PPVs) of 25.0(95confidence interval; CI: 0.6-80.6) and 20.0(95CI: 2.5-55.6); respectively. The newer typhoid rapid antibody tests had comparable PPVs: TUBEX; 54.1(95CI: 36.9-70.5); Typhidot IgM; 56.7(95CI: 37.4-74.5); and Typhidot IgG; 54.3(95CI: 36.6-71.2). For a pretest probability of 5; PPVs were: TUBEX; 11.0(95CI: 6.6-17.9); Typhidot IgM; 9.1(95CI: 5.8-14.0); and Typhidot IgG; 11.0(6.3-18.4). For a pretest probability of 50; PPVs were: TUBEX; 70.2(95CI: 57.3-80.5); Typhidot IgM; 65.6(95CI: 54.0-75.6); and Typhidot IgG; 70.0(95CI: 56.0-81.1). Conclusion Semiquantitative slide agglutination and single-tube Widal tests performed poorly. TUBEX and Typhidot may be suitable when pretest probability is high and blood cultures are unavailable; but their performance does not justify deployment in routine care settings in sub-Saharan Africa

Susceptibility of Culex Quinquefasciatus say (Diptera: Culicidae) in Khartoum Locality (Sudan) to Malathion; Temephos; Lambdacyhalothrin and Permethrin Insecticides

Abstract:background et objectives:Mosquito control is becoming increasingly difficult because of the developmentof resistance in vectors to conventional insecticides. The resistance in vectors warrants development of newer insecticides for mosquito control besides use of other counter-measures. This study aimed to determine the susceptibility of adult and larvae of Cx.quinquefasciatus mosquitoes (Diptera: Culicidae) to malathion; temephos; lambdacyhalothrin and permethrin insecticides in Khartoum locality.Material et methods:Susceptibility of Culex quinquefasciatus mosquitoes to malathion; lambdacyhalothrin and permethrin; and of the larvae to temephos in Khartoum locality was carried out; following WHO standard susceptibility tests. One to three days old female mosquitoes; which were reared from field collected immature stages; were exposed to discriminating dosages of the insecticides; for respective exposure periods. Then knockdown time and 24-hours mortality were recorded. For larvae which were exposed to a series of temephos concentrations; and LC 50 and LC 90 values were calculated.results:The study revealed that;Culex quinquefasciatus is predominant in Khartoum locality. Evidence of resistance was revealed to malathion and the two pyrethroids against Culex quinquefasciatus. The average KDT 50 values consider high and indicated resistance. But larvae stages were found to be susceptible to temephos.Interpretation et conclusion:Resistance of the field population of Cx. quinquefasciatus in Khartoum was revealed to malathion; lambdacyhalothrin and permethrin. On the other hand; the same population of Cx. quinquefasciatus is still sensitive to temephos. Therefore; the vector control unit should consider introducing rotation of insecticidesas a management strategy to increase the duration of the usage of the current insecticides. Furthermore; a rationalized use of insecticides coupled with regular monitoring of insecticide resistance is recommended to mitigate the rapid emergence of insecticide resistance

Genital Mycoplasmas in Women Attending the Yaounde University Teaching Hospital in Cameroon

Genital mycoplasmas are implicated in pelvic inflammatory diseases; puerperal infection; septic abortions; low birth weight; nongonococcal urethritis and prostatitis as well as spontaneous abortion and infertility in women. There is paucity of data on colonisation of genital mycoplasma in women and their drug sensitivity patterns. The aim of our study was to determine the prevalence of genital mycoplasmas (Ureaplasma urealiticum and Mycoplasma hominis) infection and their drug sensitivity patterns in women. A mycofast kit was used for biochemical determination of mycoplasma infection in 100 randomly selected female patients aged 19-57 years; attending the University of Yaounde Teaching Hospital (UYTH) from March to June 2010. Informed consent was sought and gained before samples were collected. Genital mycoplasmas were found in 65 patients (65) [95CI=55.7-74.3] and distributed as 41 (41) [95CI=31.4-50.6] for U. urealiticum and 4 (4) [95CI=0.20-7.8] for M. hominis while there was co-infection in 20 women (20) [95CI=12.16-27.84]. In our study; 57 (57) [95CI=47.3- 67] had other organisms; which included C. albicans (19 [19]); G. vaginalis (35 [35]) and T. vaginalis (3 [3]). Among the 65 women with genital mycoplasma; the highest co-infection was with G. vaginalis (33.8). Pristinamycine was the most effective antibiotic (92) and sulfamethoxazole the most resistant (8) antibiotic to genital mycoplasmas. We concluded that genital mycoplasma is a problem in Cameroon and infected women should be treated together with their partners

The Sensitivity and Specificity of the Conventional Symptoms and Signs in Making a Diagnosis of Acute Appendicitis

Introduction: Simple appendicitis can progress to perforation; which is associated with a much higher morbidity and mortality. So; surgeons have therefore been inclined to operate when the diagnosis is probable rather than wait until it is certain. Objective: This study is designed to evaluate the sensitivity and specificity of clinical examination in the diagnosis of acute appendicitis.Methods: The study included 866 patients of acute appendicitis who had undergone appendicectomy with preoperative diagnosis of acute appendicitis. They were analyzed retrospectively. The parameters evaluated were age/gender; clinical presentation (signs and symptoms) and total white blood cell counts. The operative findings were recorded and the inflammation of the appendix was graded into normal; acutely inflamed and gangrenous. Results: Clinical diagnosis was made correctly in 807 (93.2) of the patients. White blood cells count ranged from 3.70 to 45.30 /mm3 (mean 17.5353 /mm3). It was 10;000/mm3 in 133 (15.4) patients.Conclusions: Clinical assessment is the best criterion to reach a confident diagnosis. Investigations may supplement the diagnosis but are never a substitute for it