Sodium Bicarbonate (NaHCO3) Increases Growth, Protein and Photosynthetic Pigments Production and Alters Carbohydrate Production of Spirulina platensis.

Improving the biochemical status of Spirulina platensis will enhance the functional properties of this microalgae. The present study investigated the effects of adding NaHCO3 to the culture medium on the growth rate and biochemical composition, particularly the coproduction of proteins, carbohydrates, and photosynthetic pigments of S. platensis. Spirulina platensis was grown in different NaHCO3 concentrations (0-16 g L-1). NaHCO3 positively affected the biomass production. The growth of S. platensis and biochemical compound content increased with an increase in the NaHCO3 concentration. The microalgae biomass grown on NaHCO3 also contained higher amounts of protein (64.20 ± 4.18% w w-1) and photosynthetic pigments (phycocyanin and chlorophyll a, b, and total). Protein productivity was especially enhanced by approximately 6-25% (from 0.006 ± 0.0030 to 0.025 ± 0.0031 mg L-1 day-1) with the addition of NaHCO3 compared to the control. In contrast, the content of carbohydrates and antioxidant compounds (phenolic, polyphenol oxidase, and peroxidase activities) decreased with culture age and an increase in the NaHCO3 concentration. These results suggest that S. platensis uses NaHCO3 as a carbon source for photosynthesis, biomass production, and acts as a metabolic energy carrier toward the synthesis of proteins and photosynthetic pigments, which are more energy-consuming metabolites than carbohydrates. The addition of NaHCO3 to the culture media is a potentially useful strategy toward improving the protein and photosynthetic pigment productivity of S. platensis.

Prevalence, Patterns, and Determinants of Malaria and Malnutrition in Douala, Cameroon: A Cross-Sectional Community-Based Study.

BACKGROUND: Malaria and malnutrition are major public health problems in developing countries. This studywas mainly focused on the prevalence, patterns, and predictors of these conditions and their associations. METHODS: A cross-sectional community study was conducted from February to March 2018 among 281 participants living in two districts in Douala. A questionnaire was used to collect sociodemographic information and parasitological and anthropometric data of participants. Nutritional status was determined using age, weight, and height. Body mass index for age (BMIAZ), height-for-age (HAZ), weight-for-age (WAZ), and weight-for-height (WHZ) Z scores were computed based on the World Health Organization growth reference curves. Malaria infection was diagnosed using light-emitting diode fluorescence microscopy. RESULTS: The overall prevalence of malaria was 18.9%, mostly asymptomatic cases. Malaria infection was associated with study site (p = 0.04), age (p = 0.01), WAZ (p = 0.0049), HAZ (p = 0.03), and BMI (p = 0.02). The overall prevalence of malnutrition was 43.1%, and stunting was the main form of malnutrition recorded in children under five years of age (23.6%). The risk of being stunted in this group was about quintupled in malaria-infected participants (ARR = 4.70; p = 0.02). In those aged 5-19 years, the prevalence of underweight was significantly higher in malaria-positive individuals as compared to their negative counterparts (p = 0.02). The overall prevalence of malaria and malnutrition cooccurrence was 8.5% and varied with age (p < 0.0001) and study site (p = 0.04). Conclusion and Recommendation. Malaria was associated with malnutrition among the study participants. Early detection and treatment of these ailments would reduce morbidity and mortality.

Knowledge, Attitude, and Practices towards Malaria among Employees from Enterprises in the Town of Douala, Cameroon.

BACKGROUND: Malaria remains a public health issue in the world especially in resource-limited countries, where it has a negative impact on their economy. There is a body of recent reports outlining the crucial role of enterprises in control of malaria. The present study aimed at determining the knowledge, attitudes, and practices (KAP) towards malaria among employees from enterprises in the town of Douala, Cameroon. METHODS: A cross-sectional descriptive study took place between February 2015 and June 2017 in 14 enterprises of Douala. A pretested structured questionnaire was used to document sociodemographic parameters and KAP of employees. RESULTS: A total of 2705 employees, mainly consisted of males (83.1%), were included in the study. The mean age of respondents was 37.33 ± 9.78 years (range 19-87). Over 90% of respondents knew at least one sign/symptom (94.1%) and associated malaria transmission with mosquito bites (91%). Artemether-Lumefantrine (36.2%), under commercial name "Coartem," was the most cited antimalarial drug. Nearly 98.2% considered malaria as a dangerous disease. Misconceptions on malaria transmission, causative agent, prevention, and treatment were recorded. More than 77% of employees declared to use mosquito bed nets to prevent malaria. About 63% employees declared going to the hospital when they were feel having malaria while 12.9% were seeking care through street drugs. Educational level, socioprofessional category, area of residence, and enterprise were significantly associated with the level of knowledge on malaria transmission, causative agent, and preventive and treatment practices. CONCLUSION: This study showed a good level of knowledge, attitudes, and practices of employees even though some misconceptions and bad behaviors are still present especially in people with a low level of education. Hence, there is a need to develop strategies for sensitization especially in this fraction of employees. In addition, enterprises could be an interesting approach in order to control malaria in Cameroon.

Evaluation of Urine Reagent Strip as a Tool for Routine Diagnosis of Maternal Urogenital Schistosomiasis at Antenatal Clinic Visit in Munyenge, South West Region, Cameroon.

Urine reagent strip used in detecting microhaematuria has been recommended in pregnancy for diagnosis of urogenital schistosomiasis (UGS) during routine antenatal care (ANC). This study evaluated its sensitivity, specificity, and predictive values in the diagnosis of maternal UGS using filtration method as a reference test. We also assessed the variation in its performance in the diagnosis of UGS using multiple-sample collection. A total of 93 pregnant women reporting for first ANC clinic visit at any of the three functional health care centres (Munyenge Integrated Health Centre, Banga Annex Health Centre, and Trans African Health Centre) were enrolled and followed up for three consecutive monthly visits. Urine samples were observed microscopically for S. haematobium egg using urine filtration and screened for microhaematuria and proteinuria using urine reagent strips. Twenty-two (23.7%) out of the 93 women were diagnosed for UGS, all of whom showed S. haematobium egg excretion during all three visits. There was a significant difference (p < 0.001) between the prevalence of S. haematobium infection and the prevalence of microhaematuria. The intensity of infection was significantly higher in microhaematuria-positive women compared with microhaematuria-negative cases. Sensitivity of reagent strip ranged from 54.5 to 59.1%, while specificity was above 98.0% (range: 98.6-100%). The measure of agreement between urine filtration and reagent strip method was substantial (0.61-0.8) irrespective of different sampling periods. Urine reagent strip is a moderately sensitive method in the detection of UGS and will most likely identify women with high egg load burden. Proper diagnosis of schistosomiasis during pregnancy is recommended.

Malaria screening at the workplace in Cameroon.

Malaria remains a major health problem in Cameroon; It accounts for 38% of consultations, 24% of deaths and 36.8% of absenteeism in the country. The negative economic impact of malaria has encouraged a new control approach targeting companies. In this regard, a cross sectional study was conducted from February 2015 to June 2017 in 14 companies in the town of Douala. This study aimed at determining the prevalence, control practices of employees and identifying associated factors with malaria. A total of 2705 workers were interviewed and systematically screened for malaria using LED fluorescence microscopy (CyScope®). All positive cases were given a malaria treatment. The prevalence of malaria and asymptomatic malaria was 30.1% and 28.9% respectively; asymptomatic malaria accounted for 95.7% of all positive diagnostic test. Malaria infection was significantly higher in employees aged 36-60 years (30.5%) and having completed primary studies (36%). ITNs ownership and utilization were 86.36% and 77.23% respectively. The risk for malaria infection has significantly decreased with age and educational level while the employees' level of education and size of households were significantly associated with the regular utilization of ITNs. This is the first study assessing malaria prevalence and risk factors in workplace in Cameroon and using a novel diagnostic tool. This study outlines a high prevalence of malaria infection, especially asymptomatic carriage, high rates of ITNs ownership and utilization, as well as the influence of level of education, age and household size as associated factors. Active case detection of asymptomatic carriers through systematic screening of employees at workplace and their treatment is feasible with the Cyscope microscope and could be a good complement to ongoing control strategies.

Schistosoma haematobium infection status and its associated risk factors among pregnant women in Munyenge, South West Region, Cameroon following scale-up of communal piped water sources from 2014 to 2017: a cross-sectional study.

BACKGROUND: In 2014, a study in Munyenge revealed a high prevalence of urogenital schistosomiasis (UGS) among pregnant women. This study investigated he prevalence and risk factors of UGS in pregnancy following scale-up of piped water sources from 2014 to 2017. Secondly, we compared stream usage, stream contact behaviour, infection rate and intensity with the findings of 2014. METHODS: Consenting pregnant women reporting for antenatal care (ANC) in the different health facilities were enrolled consecutively between November 2016 and January 2018. Information on age, gravidity status, residence, marital status, educational level, occupation, household water source, frequency of contact with water and stream activities were obtained using a semi-structured questionnaire. Urine samples were examined for the presence of microhaematuria and S. haematobium ova using test strip and filtration/microscopy methods respectively. Data were analysed using univariate and multivariate regression analyses and relative risk reductions calculated. RESULTS: Of the 368 women enrolled, 22.3% (82) were diagnosed with UGS. Marital status (single) (aOR = 2.24, 95% CI: 1.04-4.79), primary - level of education (aOR = 2.0; 95% CI: 1.04-3.85) and domestic activity and bathing in the stream (aOR = 3.3; 95% CI: 1.83-6.01) increased risk of S. haematobium infection. Meanwhile, fewer visits (< 3 visits/week) to stream (aOR = 0.35, 95% CI = 0.17-0.74) reduced exposure to infection. Piped water usage was associated with reduced stream usage and eliminated the risk of infection among women who used safe water only. Compared with the findings of 2014, stream usage (RRR = 23 95% CI: 19-28), frequency (≥ 3 visits) (RRR = 69 95% CI: 59-77) and intensity of contact with water (RRR = 37 95% CI = 22-49) has reduced. Similarly, we observed a decrease in infection rate (RRR = 52, 95% CI = 40-62) and prevalence of heavy egg intensity (RRR = 71, 95% CI = 53-81). CONCLUSION: Following increased piped water sources in Munyenge, S. haematobium infection has declined due to reduced stream contact. This has important implication in the control of UGS in pregnancy.

Schistosomiasis among pregnant women in Njombe-Penja health district, Cameroon.

INTRODUCTION: Schistosomiasis is a neglected tropical disease with endemic foci in Cameroon. Epidemiological data on schistosomiasis in pregnancy are scarce in the country. This study describes the prevalence, diversity and factors associated with schistosomiasis in pregnant women in Njombe-Penja where schistosomiasis was first reported in 1968. METHODOLOGY: Two hundred and eighty-two (282) pregnant women were enrolled at first antenatal consultation between April and December 2016. A questionnaire was used to document socio-economic and obstetric information. Stool and terminal urine samples were collected and analysed using Kato-Katz/Formol-Ether concentration techniques and centrifugation methods respectively. Haemoglobin concentration was measured from finger prick blood, using an URIT®-12 electronic haemoglobinometer. Bivariate and logistic regression were used for statistical analyses with Epi-Info version 7.2.1.0. Statistical significance level was set at 0.05. RESULTS: The overall prevalence of schistosomiasis was 31.91%. Schistosoma guineensis, S. haematobium and S. mansoni infections were found in 0.35% (n = 1), 4.96% (n = 14) and 28.01% (n = 79) of participants, respectively. Co-infection with two species of Schistosoma was found in 4.44% of these women. The prevalence of this disease was significantly higher in younger women (≤ 20 years old) and among residents of Njombe. All S. haematobium infected women were anemic and infection was associated with significantly lower haemoglobin levels (p = 0.02). CONCLUSION: The prevalence of schistosomiasis is high among pregnant women in Njombe-Penja, with some adverse effects on blood levels. Three Schistosoma species were found. Female of childbearing age should be considered for mass drug administration.

Efficacy and safety of praziquantel against Schistosoma haematobium in the Ikata-Likoko area of southwest Cameroon.

BACKGROUND: Schistosomiasis remains a parasitic infection of public health importance especially in Africa south of the Sahara including Cameroon. Chemotherapy using praziquantel has been the most effective and widespread control measure used. However, there are reports of reduced efficacy of the drug. The aim of this study was to assess the efficacy and safety of praziquantel against Schistosoma haematobium among infected individuals in the Ikata-Likoko area of southwest Cameroon. Following a baseline study, S. haematobium egg load was determined using the urine filtration technique and microscopy. Participants were treated with a unique dose of praziquantel of 40 mg/Kg body weight. A control test was carried out on the 42nd day post-treatment to determine the proportion of positive participants with viable eggs (cure rate) and the egg loads. The egg loads obtained during the control and at baseline were used to calculate the egg reduction rate (ERR) used as the main indicator of praziquantel efficacy according to the WHO, 2013 protocol. RESULTS: At baseline, the prevalence of S. haematobium was 34.3% (177/516). Out of these a total of 174 participants aged between 4 and 76 years were recruited into the study. A total of 130 participants came for follow up on day 42. Among them, 22.3% (29) were positive for eggs of S. haematobium but none of the eggs were viable giving a cure rate of 100%. The overall mean egg load per 10 mL (MEL/10 mL) of urine reduced from 31 (1-400) at baseline to 6.0 (1-35) on day 42. The overall ERR was reduced (80.3%). However, the efficacy was satisfactory (ERR ≥ 90%) in females, children ˂ 5 years, and some localities and for individuals with heavy infection intensity. Fifteen (8.6%) of the participants presented minor adverse events including abdominal disorders, headache and vomiting but did not last for more than 24 h. CONCLUSIONS: Treatment with praziquantel was efficacious and safe showing reduction in prevalence as well as mean egg load in some individuals with few adverse events recorded. The distribution of praziquantel in the area should be extended to other age groups and not just school-age children. A study with multiple drug doses and longer period of evaluation could reveal more information on praziquantel efficacy in the area.

Anopheles coluzzii larval habitat and insecticide resistance in the island area of Manoka, Cameroon.

BACKGROUND: The effectiveness of Long-Lasting Insecticidal Nets and Indoor Residual Spraying in malaria vector control is threatened by vector resistance to insecticides. Knowledge of mosquito habitats and patterns of insecticide resistance would facilitate the development of appropriate vector control strategies. Therefore, we investigated An. coluzzii larval habitats and resistance to insecticides in the Manoka rural island area compared with the Youpwe suburban inland area, in Douala VI and II districts respectively. METHODS: Anopheline larvae and pupae were collected from open water bodies in December 2013 and April 2014 and reared until adult emergence. Two to four day old emerging females were morphologically identified as belonging to the An. gambiae complex and used for WHO susceptibility tests with 4 % DDT, 0.75 % permethrin, and 0.05 % deltamethrin, with or without piperonyl butoxide (PBO) synergist. Control and surviving specimens were identified down to the species using a PCR-RFLP method. Survivors were genotyped for kdr L1014 mutations using Hot Oligonucleotide Ligation Assay. RESULTS: In both study sites, ponds, residual puddles, boats, and drains were identified as the major An. gambiae s.l. larval habitats. A total of 1397 females, including 784 specimens from Manoka and 613 from Youpwe, were used for resistance testing. The two mosquito populations displayed resistance to DDT, permethrin and deltamethrin, with variable mortality rates from 1 % to 90 %. The knock-down times were also significantly increased (at least 2.8 fold). Pre-exposure of mosquitoes to PBO did not impact on their mortality to DDT, conversely the mortality rates to permethrin and deltamethrin were significantly increased (7.56 ≤ X(2) ≤ 48.63, df = 1, p < 0.01), suggesting involvement of P450 oxidases in pyrethroid resistance. A subsample of 400 An. gambiae s.l. specimens including 280 control and 120 survivors from bioassays were all found to be An. coluzzii species. Only the kdr 1014 F mutation was found in survivors, with 88.5 % (N = 76) and 75 % (N = 44) frequencies in Youpwe and Manoka respectively. CONCLUSION: This is the first report of An. coluzzii resistance to insecticides in an insular area in Cameroon. Since permanent larval habitats have been identified, larval source management strategies may be trialed in this area as complementary vector control interventions.

Impact of vegetable crop agriculture on anopheline agressivity and malaria transmission in urban and less urbanized settings of the South region of Cameroon.

BACKGROUND: The use of inland valley swamps for vegetable crop agriculture contributes to food security in urban and less urbanized settings in Africa. The impact of this agriculture on aggressive mosquitoes' diversity and malaria transmission in central Africa is poorly documented. This study is aimed at assessing the impact of vegetable crop agriculture on these entomological parameters in urban and less urbanized settings of the forest area, south of Cameroon. METHODS: The human bait technique was used for the capture of aggressive mosquitoes from January to December 2012. For three consecutive days each month, captures were performed on volunteers in hydro-agricultural and river bank sites of Akonolinga and Yaoundé. Physico-chemical characteristics of mosquito breeding sites were recorded. Molecular alongside morpho-taxonomic techniques were used for the identification of mosquito species; ELISA test was used to reveal Plasmodium falciparum infected mosquitoes through the detection of CSP. Mosquito diversity, aggressivity and malaria transmission in sites and settings were determined and compared. RESULTS: Biting rates were higher in hydro-agricultural sites of less urbanized and urban settings (31.8 b/p/n and 28.6 b/p/n respectively) than in river banks sites (6.83 b/p/n and 3.64 b/p/n respectively; p < 0.0001). Physico-chemical parameters of breeding sites were not fundamentally different. Five anopheline species were identified; An. gambiae, An. funestus s.s., An. moucheti s.s., An. hancocki and An. nili s.s. In hydro-agricultural sites 2 species were captured in the urban setting versus 4 in the less urbanized setting, meanwhile in river bank sites, 3 species were captured in the urban setting versus 4 species in the less urbanized setting. An. nili s.s. was found in river banks only. An. hancocki was not found to insure Plasmodium falciparum Welch transmission. EIR in hydro-agricultural sites varied from 1.86 ib/p/n (urban area) to 2.13 ib/p/n (less urbanized area) with higher rates in April/May and August. Overall, EIR was higher in less urbanized areas (p < 0.0001) but the difference was nullified with the practice of vegetable crop agriculture (p = 0.2). CONCLUSION: These results highlight the need for specific preventive measures that take into account the ecological peculiarities related to vegetable crop agriculture on hydro-agricultural lands, in order to protect inhabitants from malaria.

HIV, HBV, HCV and T. pallidum infections among blood donors and Transfusion-related complications among recipients at the Laquintinie hospital in Douala, Cameroon.

BACKGROUND: Transfusion-transmissible infections (TTIs) pose a major health risk in Cameroon given the high prevalence of such pathogens and increased demands for blood donations in the local communities. This study aims at establishing the prevalence of commonly encountered TTIs among blood donors and transfusion-related complications among recipients in an urban center of Cameroon. METHODS: A total of 477 blood donors and 83 blood recipients were recruited by consecutive sampling at the Laquintinie Hospital in Douala (LHD), Cameroon. Serum samples from blood donors were tested by quantitative enzyme-linked immunosorbent assays (ELISA) and/or using various Rapid diagnostic test (RDT) for presence of Hepatits B (HBV) viral antigens, and antibodies to human immunodeficiency (HIV-1/2), Hepatits B (HCV) and Treponema pallidum. Recipient's medical records were also analyzed for possible transfusion-associated complications. RESULTS: The male/female sex ratio of the blood donors was 4/1 with a mean age of 30.2 (Sd = 8.3) years. Of all blood donors, 64/467 (13.7%) were infected by at least one of the four TTIs. Infected volunteer donors represented 8.3% while infected family donors comprised 14.3% of the donor population. The prevalence of HCV, HIV, HBV and T. pallidum were 1.3%, 1.8%, 3.5%, and 8.1%, respectively. More than half of the blood recipients were female (78.3%) and the mean age was 20.6 (SD = 16.1) years. The causes of severe anemia indicative of transfusion in recipients varied with wards (postpartum hemorrhage, caesarean section, uterine or cervical lacerations, abortions, urinary tract infections, severe malaria, vaso-occlusive attacks, wounds and gastrointestinal bleeding). The most frequent complications were chills and hematuria, which represented 46.1% of all observed complications. Other complications such as nausea, vomiting, jaundice, sudden diarrhea, anxiety, tachycardia, or hyperthermia were also found in recipients. Three cases of deaths occurred during the study, including a girl of less than one year. CONCLUSION: This study confirms the presence of blood-borne infectious diseases in blood donors at the LHD, identifying T. pallidum as the greatest threat to blood safety in the region, and hematuria as the most common immunological complications in blood recipients.

Intestinal parasitic and candida infection associated with HIV infection in Cameroon.

INTRODUCTION: HIV causes progressive impairment of the cellular immune system leading to increased susceptibility to infectious agents. Parasitic infestations are common in HIV-infected patients and usually lead to diarrhoea. Few studies have addressed the issue of intestinal parasites among HIV-infected persons in Cameroon.  This investigation was conducted in Douala, Cameroon, to assess the prevalence of gastrointestinal parasites in HIV-infected patients, taking into account their immune status and treatment course. METHODOLOGY: Stool and blood samples were collected from 201 HIV-positive patients for the investigation of intestinal pathogens and CD4+ counts. RESULTS: Fifty-six (27.9%) patients harbored pathogens. The most frequent pathogens were Candida spp. (14.9%), Cryptosporidium spp. (7.5%), Entamoeba histolytica, and Entamoeba dispar (3%). The presence of pathogens was significantly associated with diarrhoea, as they were found in 48.6% of diarrhoeic stools and 23.2% of non-diarrhoeic stools (OR = 3.14, p= 0.0018). Prevalence of pathogens and diarrhoea were significantly higher in patients with CD4+ counts ≤ 200 cells/µL (OR = 2.17, p = 0.0349 and OR = 8.46, p = 0.000019 respectively). CONCLUSIONS: This study highlights the need for investigating intestinal pathogens in HIV-infected patients presenting with diarrhoea, especially when their CD4+ counts are low.

High mosquito burden and malaria transmission in a district of the city of Douala, Cameroon.

BACKGROUND: Rapid demographic growth in Douala city, Cameroon, has resulted in profound ecological and environmental changes. Although demographic changes can affect anopheline mosquito breeding sites, there is a lack of understanding about the epidemiological impact that such changes might have on vector ecology and malaria transmission. METHODS: A 12-month entomological study was conducted in a highly populated district of Douala called Ndogpassi. Adult mosquitoes were collected using two methods: 1) human landing catches (HLC); and 2) Centers for Disease Control and Prevention (CDC) light traps; these methods were used twice monthly from January to December 2011. Mosquito genus and species were identified with morphological and molecular diagnostic tools. The sampling efficiency of the CDC light trap and HLC were compared. Anopheles gambiae infection with Plasmodium falciparum was detected using ELISA. Susceptibility to DDT, permethrin, and deltamethrin insecticides were also determined. RESULTS: A total of 6923 mosquitoes were collected by HLC (5198) and CDC light traps (1725). There was no equivalence in the sampling efficiency between light traps and human landing catches (P > 0.01). With 51% of the total, Culex was the most common, followed by Anopheles (26.14%), Mansonia (22.7%) and Aedes (0.1%). An. gambiae ss (M form) comprised ~98% of the total anophelines collected. An. gambiae had a biting rate of 0.25 to 49.25 bites per human per night, and was the only species found to be infected with P. falciparum. A P. falciparum infection rate of 0.5% was calculated (based on enzyme-linked immunosorbent assays using the circumsporozoite surface protein). The entomological inoculation rate was estimated at 31 infective bites per annum. Insecticide susceptibility tests on An. gambiae females revealed a mortality rate of 33%, 76% and 98% for DDT, permethrin and deltamethrin, respectively. The West African kdr allele (L1014F) was detected in 38 of the 61 An. gambiae analyzed (62.3%). CONCLUSIONS: The present study revealed seasonal malaria transmission in Douala. High levels of An. gambiae were detected along with a high prevalence of insecticide resistance in this vector population. These findings highlight the need to promote use of insecticide-impregnated bed nets in Douala.

Simplified volumetric flow cytometry allows feasible and accurate determination of CD4 T lymphocytes in immunodeficient patients worldwide.

The determination of CD4 cells is of crucial clinical importance for patients with AIDS. However, the high costs involved represent limitations for CD4 cell counting in developing countries. In order to provide an affordable technique, we introduced a simplified volumetric counting (SVC) technique without sample manipulations and investigated it in a multicentre study. Blood samples from 434 healthy donors and immunodeficient patients were tested in eight hospital laboratories in Europe, Africa and Asia. CD4 cell counts were compared using in-house flow cytometric methods and the SVC technique. The SVC method was performed on a low-cost flow cytometer (CyFlow SL, Partec, Münster, Germany) after 15 min antibody incubation without pre-analytic manipulations, such as washing or erythrocyte lysing procedures. Linear regression analysis demonstrated a correlation of r=0.942 (Europe), r=0.952 (Africa) and r=0.989 (Asia) between the SVC technique and the in-house methods. Bland Altman plot analysis of all patient data showed a mean bias between the two methods of +26 CD4 cells in favour of the SVC technique (measured range: 6-1905 cells/microl; median CD4 cell count: 388/microl). Three centres used the FACS-count technique (Becton-Dickinson, San José, Calif., USA) as an in-house method dispensing with pre-analytic manipulations. The comparison of SVC and FACS-count method revealed a mean bias of +32 CD4 cells/microl (median CD4 cell count: 349/microl). The accuracy of the SVC was tested on standards with known CD4 cell counts (n=6) and was shown to be 95.2%. The low-cost device and the simplified no-lyse, no-wash test procedure reduces the costs per determination and facilitates the use of flow cytometry in developing countries.