The Potentials of Fas Receptors and Ligands in Monitoring HIV-1 Disease in Children in Yaoundé, Cameroon.

OBJECTIVE: Difficulties in systematically monitoring HIV viral load in resource-limited settings prompt the search for alternate approaches. The authors aimed at assessing the correlation between the plasma levels of soluble forms of Fas receptors (Fas) and Fas ligands (FasL) with standard indicators of HIV disease progression in children. METHODS: Twenty-two HIV-1-positive children were enrolled in Yaounde. CD4 counts, CD4% counts, plasma levels of Fas, FasL, and HIV-1 RNA levels were assayed. RESULTS: The correlation coefficients (P values) between FasL levels and each of HIV-1 viral load, CD4 counts, and CD4% were, respectively, .56 (.01), -.29 (.18), and .30 (.18). On the other hand, the respective correlation coefficients (P values) with Fas levels were .12 (.60), -.30 (.18), and -.29 (.19). CONCLUSION: The significant correlation between levels of HIV-1 viral load and FasL suggests that the latter needs to be further studied as a potential biomarker to monitor HIV-1 disease progression in children in resource-limited setting.

Afriflu--international conference on influenza disease burden in Africa, 1-2 June 2010, Marrakech, Morocco.

The burden of influenza disease is to a large extent unknown for the African continent. Moreover, the interaction of influenza with common infectious diseases in Africa remains poorly described. Solid scientific evidence on the influenza disease burden in Africa is critical for the development of effective influenza vaccine policies. On 1st and 2nd June 2010 in Marrakech, Morocco, over eighty surveillance and influenza experts from 22 African countries as well as Europe and America met at the 'Afriflu' conference to discuss influenza challenges and solutions for the continent. During the meeting, participants exchanged their experiences and discussed a wide variety of topics related to influenza in Africa, including diagnosis, surveillance, epidemiology, and interventions. The meeting concluded with a pledge to improve influenza knowledge and awareness in Africa, with an emphasis on accurate determination of disease burden to help orient public health policies.

Dried blood spots versus plasma for the quantification of HIV-1 RNA using the manual (PCR-ELISA) amplicor monitor HIV-1 version 1.5 assay in Yaounde, Cameroon.

OBJECTIVES: Considering the recent accrued need for viral load quantification in resource-limited settings, this study evaluated the use of dried blood spots (DBS) compared to plasma as a means of sample collection and storage for HIV-1 RNA quantification using a non-automated assay. METHODS: Venous blood was collected from 60 consenting HIV-1-positive patients, plasma separated within 4 hours, and stored at -20 degrees C. Venous blood, 50 microL, was blotted on 4 designated areas of Whatman filter paper and air-dried at room temperature for 2 hours. RESULTS: There was a strong statistically significant correlation between HIV-1 RNA viral load using plasma and DBS (r = .955, P < .001). On average plasma viral loads were only slightly higher than DBS viral loads (mean difference: 0.06 log(10) copies/mL). CONCLUSION: Even when using an entirely manual HIV-quantification assay, DBS may provide a reliable, cost-effective method for sample collection and storage for HIV-1 RNA quantification in resource-limited settings.

Interactions between human immunodeficiency virus and herpes viruses within the oral mucosa.

There is evidence from clinical case reports and epidemiological studies that human immunodeficiency virus (HIV) can be transmitted through oral sex. Herpes viruses that appear in the oral mucosa might influence the oral replication of HIV. A review of data suggesting that interactions occur between HIV and herpes viruses indicates that such interactions might operate in the oral mucosa. Defining the mechanisms by which herpes viruses interact with HIV in the oral mucosa should permit intervention measures to be targeted more precisely.

[Cysticercosis and epilepsy: a case-control study in Mbam Valley, Cameroon]. / Cysticercose et épilepsie: étude cas-témoins dans la Vallée du Mbam, Cameroun.

The impact of neurocysticercosis in Africa is not well known, and its role in the occurrence of epilepsy is not well defined. The concomitant high prevalence of both diseases in this region suggests a causal association of cysticercosis and epilepsy. The few attempts to find such a link in Africa have yielded discordant data. In order to answer this question, we conducted a case-control study between June and August 1998 in the Bilomo village in Central Cameroon, where a recent study had demonstrated very high epilepsy prevalence of 58/1000. Ninety-three epilepsy patients and eighty-one age matched controls were included. All subjects were examined by a neurologist and serology for cysticercosis was performed using an ELISA method. Serologies for cysticercosis were positive in twenty-nine out of one hundred and seventy four patients (16.7%; 95% CI: 11.6-23.2). Seventeen cases (18.3%) and twelve controls (14.8%) had a positive serology The odd ratio was 1.3 (95% CI: 0.6-3.0). This study was not in favour of an epidemiological relationship between cysticercosis infection and epileptic disorders.

Hematuria and Dysuria in the Self-Diagnosis of Urinary Schistosomiasis among School-Children in Northern Cameroon

The present study was designed to assess the value of self reported hematuria and dysuria in the diagnosis of urinary schistosomiasis at the individual level. A sample of 964 school children of grade 5 and 6 from 15 schools of the French speaking educational system in the Sudano-sahelian zone of northern Cameroon were submitted to a questionnaire related to hematuria and dysuria; and provided a urine sample each. The urine samples were processed using the dip stick and sedimentation methods; and the degree of microhematuria and oviuria determined. In all 964 questionnaires were collected; 843 urine samples examined for microhematuria and 871 for oviuria. The percentage of children reporting hematuria increased with the degree of microhematuria and the intensity of infection. Among the various indicators of urinary schistosome infection; microhematuria had the highest sensitivity (76); followed by self reported hematuria or dysuria (65); and dysuria (52). The specificity was highest for self reported hematuria; and lowest for self reported hematuria or dysuria. The efficiency of self reported hematuria or dysuria increased with the intensity of infection and was highest (100) for heavy infections ( 400 eggs/ml g urine). We advocate the use of self reported hematuria or dysuria for the assessment of S. haematobium at the individual level

Serological findings amongst first-time blood donors in Yaoundé, Cameroon: is safe donation a reality or a myth?

Blood safety remains an issue of major concern in transfusion medicine in developing countries where national blood transfusion services and policies, appropriate infrastructure, trained personnel and financial resources are lacking. This is aggravated by the predominance of family and replacement, rather than regular benevolent, nonremunerated donors. Thus, in order to identify and encourage healthy, regular and benevolent nonremunerated donors, consenting first-time blood donors in the Yaoundé University Teaching Hospital were screened for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBSAg), hepatitis C virus (HCV), human T-cell lymphotropic virus-I (HTLV-I) and syphilis using standard methods. Of 252 first-time donors recruited, 66 (26.2%) were positive for at least one of the infections screened. There were 7.9% positive for HIV, 10.7% for HBSAg, 4.8% for HCV and 9.1 and 1.6%, respectively, for syphilis and HTLV-I. About 30% of the 66 infected persons had co-infections. HIV-positive donors had a significantly increased risk of being positive for antibodies to syphilis (OR = 7.27; 95% CI = 2.23-23.51; P = 0.0007), not observed for HBV, HCV and HTLV-I. These results suggest that blood transfusion is still very unsafe in this community and that it is imperative that emphasis be laid on donor education. Furthermore, donors with a history of sexually transmitted infections should be totally excluded from all donations.

Biological phenotypes of HIV-1 subtypes A and B strains of diverse origins.

The identification of specific biologic phenotypic traits that can be correlated with different HIV-1 genetic subtypes was sought. The genetic subtypes were determined by either sequencing (Cameroonian strains, n = 18) or by the heteroduplex mobility assay (HMA) (Belgian strains, n = 21 and Ivorian strains, n = 25). Seventeen (81%) of the 21 Belgian isolates belonged to subtype B and 4 (17%) were subtype A strains. Subtype A variants were predominant in the two African countries studied; 11 (61%) of 18 strains from Cameroon and 23 (92%) of 25 strains from the Ivory Coast. Of the 64 isolates, 38 (58%) and 19 (29%) belonged to subtypes A and B, respectively. No significant difference was observed for biological phenotypes (slow/low and rapid/high) of both genetic subtypes. In symptomatic individuals, however, a significantly higher number of subtype B isolates were of rapid/high phenotype, compared with subtype A (5 of 10; 50%) vs. 2 of 22; 9%), respectively; X2 = 6.7, P = 0.02). The findings suggest that overall HIV-1 isolates belonging to genetic subtype B are not distinguishable from subtype A variants on the basis of their biological phenotypes. Syncytium-inducing variants were less prevalent regardless of the geographic origin of the isolates.

Comparison of Edmonston-Zagreb, Connaught and Schwarz measles vaccines in Cameroonian infants aged 3-8 months.

Eighty-five Cameroonian infants aged between 3 and 8 months were vaccinated with a high-dose Edmonston-Zagreb (EZ) strain (10(5.6) TDIC50), 81 with a low-dose Connaught strain (10(3) TCID50) and 74 with a medium-dose Schwarz strain (10(4) TCID50). Side-effects were mild (less than 32% of infants) and were not significantly different among the groups, nor were postvaccination anti-measles antibody levels. Postvaccination seropositivity and seroconversion rates were respectively 91.6% and 69% for EZ, 85.3% and 67.7% for Connaught and 75.6% and 62.2% for Schwarz. In the light of concerns regarding high-titre measles vaccines, the overall performance of the Connaught strain warrants its wider evaluation in young infants.

Genotypic subtypes of HIV-1 in Cameroon.

OBJECTIVE: The only two HIV-1 strains (ANT70 and MVP5180) reported to date from Cameroon are members of the outlier clade (group O). In this study, we assessed the prevalence of group O viruses and other HIV-1 subtypes in Cameroon. DESIGN: A phylogenetic analysis of 18 HIV-1 strains isolated from seropositive individuals from Yaoundé and Douala, Cameroon. METHODS: A 900 base-pair fragment of the env gene coding for V3, V4, V5, and the beginning of gp41 of 17 out of 18 HIV-1 isolates from Cameroon was amplified, cloned and sequenced using polymerase chain reaction. A phylogenetic tree was constructed. RESULTS: The overall env nucleotide sequence divergence among the Cameroon isolates ranged from 6.1 to 27.5%. In a phylogenetic tree, six subtypes were identified when compared with 23 reference strains of different geographic origin. Of these 17 Cameroonian strains, 11 (61%) were of subtype A of which the interpatient distances at the sequence level varied from 6.1% to 18.3% (average, 11.9%). Three (17%) strains were of subtype F, and the other three strains (6% each) belonged to subtypes B, E and H, respectively. The remaining isolate was classified as belonging to group O, on the basis of the sequence of part of the pol gene. A very broad spectrum of different tetrameric amino-acid sequences was observed at the apex of the V3 loop. Eleven strains contained the tetrameric globally predominant GPGQ sequence at the tip of the V3 motif. Two strains had the GPGR sequence typical of the American and European HIV-1 strains. The remaining tetrameric sequences included GPGS, GSGQ, GRGQ, and GLGR. CONCLUSION: These findings on a limited number of viruses suggest extensive env gene diversity of HIV-1 strains from Cameroon, and could have implications for vaccine development in Africa.

Seroprevalence of hepatitis and HIV infection among rural pregnant women in Cameroon.

Since some hepatitis viruses and the human immunodeficiency viruses share common modes of transmission, such as the sexual route, we undertook to investigate the prevalence of antibodies to these and other pathogens among 384 rural pregnant women. Our study was intended to form the basis of infection management policies in pregnancy. Antibodies and other markers of the hepatitis A, B, C, and D viruses (HAV, HBV, HCV, HDV), the human immunodeficiency virus type 1 (HIV-1) and Treponema pallidum were sought. We tested for antibodies to the viruses using the appropriate enzyme-linked immunosorbent assays. HCV and HIV-1 infection were confirmed using standard immunoblotting techniques. Regarding HBV, we tested for the surface antigen (HBsAg), antibody to the surface antigen (anti-HBs) and antibody to the core antigen (anti-HBc). A non-specific test, the rapid plasma reagin test (RPR), was used for estimating Treponema pallidum (syphilis) infection. We found an overall prevalence of antibodies to HAV of 91.4%, to HCV of 6.8%, to HDV of 0%, and to HIV-1 of 3.5%. We found no IgM antibodies to HAV. The incidence of HBV markers was as follows: 5.4% for HBsAg, 61.3% for anti-HBs, and 84.6% for anti-HBc. RPR reactivity was found in 15.8% of the women. These results will be used to establish appropriate management and preventative policies for women attending the antenatal clinic. Prevention and appropriate early treatment of infections in these women will be considered.

Infections among pygmies in the Eastern Province of Cameroon.

The health requirements of pygmies is poorly understood because of their continued isolation from the other tribes in Central Africa. This study was undertaken among the Baka pygmies of the Eastern Province of Cameroon to generate basic health data among them. A total of 141 adults (18-45 years) were tested for the hepatitis B surface antigen (HBsAg), antibody to the surface antigen (anti-HBs), antibody to the core antigen (anti-HBc) and antibody to the hepatitis C virus (anti-HCV). All HBsAg-positive sera were tested for the hepatitis B e antigen (HBeAg) and antibody (anti-HBe). The presence of antibodies to the hepatitis D virus was determined in most of the anti-Hbs-positive sera, and some of the HBsAg-positive sera. In addition to these, previous infection with syphilis, measles, HIV 1/2 and HTLV were determined by looking for the specific antibodies. We found HBsAg in 14.2% (20/141), anti-HBs in 93.6% (132/141), anti-HBs in 52.2% (73/140), anti-HCV in 7.9% (11/139, measles antibody in 99.3% (139/140), antibody to Treponema pallidum in 13.4% (18/134), antibody to HTLV-1 in 10.9% (15/138) and antibody to HIV-1 in 0.7% (1/140) of the sera tested.

PIP: Pygmies remain isolated from other tribes and urban communities in central Africa. This study was undertaken among the Baka pygmies of the Eastern Province of Cameroon in an effort to redress the lack of published information on the health needs of that population. 141 adults aged 18-45 years were tested for the hepatitis B surface antigen (HBsAg), antibody to the surface antigen (anti-HBs), antibody to the core antigen (anti-HBc), and antibody to the hepatitis C virus (anti-HCV). HBsAg-positive sera were tested for the hepatitis B e antigen and antibody, while the presence of antibodies to the hepatitis D virus was determined in most of the anti-HBs-positive sera and some of the HBsAg-positive sera. Furthermore, previous infection with syphilis, measles, HIV-1 and HIV-2, and HTLV were determined by looking for the specific antibodies. Test results identified HBsAg in 14.2%, anti-HBc in 93.6%, anti-HBs in 52.2%, anti-HCV in 7.9%, hepatitis D in 46%, measles antibody in 99.3%, antibody to Treponema pallidum in 13.4%, antibody to HTLV-1 in 10.9%, and antibody to HIV-1 in 0.7% of sera tested. This prevalence of HIV-1 infection is lower than the estimated 1-1.5% projected for the sexually active general population.

Characteristics of HIV/AIDS patients attending a rural hospital in Cameroon. Manyemen HIV/AIDS Team.

Manyemen, a rural community in Cameroon, has now been hit by the HIV epidemic. This paper describes the experiences gained at the Presbyterian General Hospital in Manyemen between 1990 and 1992 regarding HIV infection in pregnant women, AIDS case management, counseling and home visits. A total of 383 pregnant women attending antenatal clinics were tested. We found a 2.9% HIV-1 seroprevalence and a 17% reactivity to a non-specific syphilis test, rapid plasma reagin, RPR. In 1990, 1991 and 1992, we diagnosed 55, 89 and 94 cases of clinical AIDS respectively. New TB cases seen in the same period showed the following HIV positive rates 3.5%, 2.4% and 5.8%. A detailed study of 78 AIDS patients revealed that the five most common presenting signs in our patients were wasting (80%), prolonged fever (28%), chronic diarrhoea (17%), oropharyngeal candidiasis (14%) and pulmonary TB (10%). Pretest and post test counseling is routinely done by the AIDS team. About 79% of the patients were post counselled as were 27% of their relatives. Home visits have been started. These results show that AIDS is no longer an issue confined to cities in Cameroon and that rural hospitals should institute a programme, similar to ours, to help them cope with the AIDS epidemic.

Hepatitis C virus infection in different populations in Cameroon.

We tested serum samples collected in an urban setting (Yaounde) and in a rural area (Manyemen) for the presence of antibody to hepatitis C virus (HCV) (anti-HCV). Screening was done by second-generation ELISA and confirmation with second-generation RIBA. In Yaounde, anti-HCV was found in 12.5% of patients with febrile jaundice (95% CL 3.8-21.2), 5.5% of pregnant women (95% CL 3.3-7.3), 0% of children below 4 years of age, 31% of sickle cell patients (95% CL 20.2-41.8%), 1.6% of medical students (95% CL 0-4.7%) and 15.4% of prostitutes (95% CL 8.5-22.3). Only HBsAg-negative sera were tested for anti-HCV, except sera originating from subjects with febrile jaundice. In Manyemen, anti-HCV was detected in 6.4% of blood donors, 6.0% of pregnant women, 5.3% of HIV-positive subjects, 7.3% of RPR-positive and 3.9% of RPR-negative subjects. There was an increase in antibody prevalence with age. We conclude that HCV infection is common in Cameroon and that it is transmitted mainly by blood transfusion and probably by sexual activity.

Update on the HIV epidemic in Cameroon

The study aimed at estimating the extent of AIDS epidemic in Cameroon upon which a guideline for activities of the National AIDS programme could be based. It comprises a total of 2377 individuals who attended the antenatal clinic (n=1091); subjects attending sexually transmitted diseases (STD) clinics (n=382) and blood donors (n=212). In Kumba a random recruited individuals attending the hospital casual consultation (n=160) was done; and compared their HIV seroprevalence results with those of frozen samples (n=391) collected from a malaria community survey in 1989; and 141 randomly selected pygmies aged between 18-45 years in the eastern province of Cameroon was screened. HIV-1/2 infection was detected with one or the other of a combined screening assay. The results obtained were as follows: in Kumba; one of the 391 was positive (0.3 percent; CL; 0-0.8) compared with one of the 160 casual consultants sera in 1992 (0.6 percent; CL; 0-1.4). In the rural areas; 13 individuals (3.5 percent; 95 percent CL; 1.7-5.3) were HIV-1 positive; one was HIV-2 positives and one of the 141 pygmies (0.7 percent; 95 percent CL; 0-2) was HIV-1 positive. The seroprevalence results in Bamenda and Bafoussam ranged from 4.2 percent and 1.2 percent. Thus rate varied from 4.3 percent in Kumba to 8.8 percent in Ngaoundere and those reported in Yaounde between 189-90 were 3.3. High HIV seroprevalence was found in blood donors in Bamenda and Limbe (3.1 to 5.7 percent). The authors concluded that since HIV will inevitably reach the remote areas in Africa; HIV control activities must be inititated in all populations in Cameroon irrespective of their location