Prenatal immune priming in onchocerciasis-onchocerca volvulus-specific cellular responsiveness and cytokine production in newborns from infected mothers.
(1/70)
This study investigated the effect of maternal Onchocerca volvulus infection on humoral and cellular responsiveness in newborn children and their mothers. Onchocerca volvulus-specific IgG isotypes and IgE were significantly elevated in infected mothers and their infants. One year post partum, O. volvulus-specific IgG4 was strongly reduced in children of infected mothers, while IgG1 responses weakened only slightly. Umbilical cord mononuclear blood cells (UCBC) and peripheral blood cells (PBMC) from mothers proliferated in response to phytohaemagglutinin (PHA), concanavalin A (Con A), and the bacterial antigens streptolysin-O (SL-O) or purified protein derivative (PPD). UCBC from neonates born to O. volvulus-infected mothers responded lower (P < 0.01) to Con A (at 5 micrograms/ml), PPD (at 10 and 50 micrograms/ml) and O. volvulus-derived antigens (OvAg) (at 35 micrograms/ml), and in parallel, a diminished cellular reactivity (P < 0.01) by PBMC was observed to OvAg in mothers positive for O. volvulus. Several Th1-type (IL-2, IL-12, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha)) and Th2-type (IL-4, IL-5, IL-10, IL-13) cytokines were secreted by UCBC and PBMC in response to OvAg, bacterial SL-O and PHA. OvAg did not stimulate IL-2 and none of the mitogens or antigens induced production of IL-4 in neonates. In response to OvAg, substantially elevated (P < 0.01) amounts of IFN-gamma were produced by UCBC from newborns of O. volvulus-infected mothers. UCBC secreted low levels of IL-5 and IL-13, while higher amounts of IL-10 were found (P < 0. 01) in newborns from onchocerciasis-free mothers. In conclusion, maternal O. volvulus-infection will sensitize in utero parasite-specific cellular immune responsiveness in neonates and activate OvAg-specific production of several Th1- and Th2-type cytokines. (+info)
Musculoskeletal conditions in children attending two Togolese hospitals.
(2/70)
OBJECTIVE: A retrospective study was conducted in order to point out the different kinds of musculoskeletal conditions observed in children attending two Togolese hospitals. RESULTS: A total of 434 (242 females, 192 males) of the 29 620 children examined (1.5%) were suffering from these conditions. Probable joint and bone infections (187 patients, 43%), limb deformities (106 patients, 24%), osteochondrosis (60 patients, 14%) and vaso-occlusive crisis due to haemoglobinopathies (29 patients, 7%) were the main conditions observed. Osteomyelitis observed in 128 patients affected the humerus (25 patients), radius (10 patients), femur (68 patients), tibia (15 patients), fibula (five patients), and both tibia and fibula (five patients). Probably, infectious arthritis seen in 30 patients affected mainly the hip (11 patients) and the knee (13 patients). In the spine, infection affected the midthoracic and upper lumbar areas. Underdevelopment, sickle cell anaemia and sickle cell haemoglobin C disease were the main risk factors in determining susceptibility to infections. Vaso-occlusive crises were due to sickle cell anaemia (11 patients) and sickle cell haemoglobin C disease (18 patients). Osteochondrosis seen in 60 patients free from haemoglobinopathy involved the spine (Scheuermann's disease, 38 patients) and the hip (Legg-Calve-Perthes disease, 22 patients). Limb deformities were observed in the knee (varus and valgus deformities in 64 patients) and the foot (talipes varus equin in 40 patients). CONCLUSION: This study's findings, which require further confirmation, suggest some conclusions. Scheuermann's disease can explain in part the degenerative disc conditions observed in African adults. Valgus and varus deformities play an important role in the development of knee osteoarthritis in Black Africa. An African child with joint or bone pain should be investigated for sickle cell anaemia. In the future, improved lifestyle and better health care will be essential to reduce bone and joint infections, and allow refined diagnosis of connective tissue diseases now probably underestimated in African children. (+info)
Geographic distribution and epidemiology of Oesophagostomum bifurcum and hookworm infections in humans in Togo.
(3/70)
In contrast to the rest of the world, infections with Oesophagostomum bifurcum are commonly found in humans in northern Togo and Ghana. In addition, infections with hookworm are endemic in this region. In the present study, a detailed map of the geographic distribution of O. bifurcum and hookworm infections in northern Togo was made. There were a number of foci with high prevalence of infection with O. bifurcum. All the villages examined were infected with hookworm, and the distribution was quite patchy. Women were infected with O. bifurcum more often than men, while infections with hookworm were more prevalent in men than in women. The prevalence and intensity of infection with both parasites were clearly age-dependent. We estimate that more than a 100,000 people in Togo are infected with O. bifurcum and more than 230,000 are infected with hookworm. (+info)
Concentrations of riboflavin and related organic acids in children with protein-energy malnutrition.
(4/70)
BACKGROUND: Riboflavin, flavin mononucleotide (FMN), and flavin adenine dinucleotide (FAD) concentrations have been little studied in cases of malnutrition. OBJECTIVE: Our objective was to investigate the effects of malnutrition on riboflavin status and riboflavin's relation with thyroid hormones and concentrations of urinary organic acids. DESIGN: Malnourished children from the savannah in Benin (group S, n = 30) and the coast in Togo (group C, n = 30), as well as 24 control subjects from both regions, were studied. Blood riboflavin, FMN, and FAD were analyzed by HPLC; urinary organic acids were analyzed by gas chromatography-mass spectrometry. RESULTS: Children in group S were more severely malnourished than children in group C. Triiodothyronine concentrations were lower in group S than in group C or the control group (1.12 +/- 0.24 compared with 1.74 +/- 0.18 and 2.92 +/- 0.19 nmol/L, respectively; P < 0.0001). Plasma riboflavin concentrations in group S were higher than those in group C or the control group (66.90 +/- 12.75 compared with 28.09 +/- 9.12 and 20.08 +/- 3.03 nmol/L, respectively; P < 0.001). Plasma FAD concentrations in group S were lower than those in group C or the control group (31.57 +/- 10.19 compared with 59.02 +/- 5.60 and 65.35 +/- 5.23 nmol/L, respectively; P < 0.0001). Dicarboxylic aciduria was higher in group C than in group S or the control subjects. CONCLUSIONS: Children in group S had low triiodothyronine concentrations and low conversion of plasma riboflavin into its cofactors, leading to a plasma FAD deficiency. Plasma FAD was not correlated with urinary dicarboxylic acid concentrations. (+info)
A new technique for the determination of microfilarial densities in onchocerciasis.
(5/70)
Precise measurement of the parasite load in helminthic infections makes it possible to correlate morbidity, the individual response to treatment, and the best control methods. A membrane filtration technique was recently developed for quantifying Wuchereria bancrofti microfilaraemia. The present paper describes its application to onchocerciasis in a study on 107 patients in northern Togo. The technique is cheap and simple to apply under field conditions, and is extremely efficient at recovering microfilariae from skin snips. (+info)
Epidemiological studies on onchocerciasis by means of a new field technique.
(6/70)
A new membrane filter concentration technique for the detection and quantification of Onchocerca volvulus microfilariae in skin snips was compared for sensitivity and efficiency with a widely used "standard" technique. A field study was carried out in five villages in an onchocerciasis focus north-east of the town of Sokode, Mo river valley, Togo. Use of the new technique resulted in a substantial rise in the observed prevalence and density of microfilariae. (+info)
Value of phage typing of Vibrio cholerae biotype eltor in West Africa.
(7/70)
The epidemiological value of phage typing of El Tor vibrios in West Africa was assessed by testing 211 representative strains from all outbreaks of the cholera epidemic in Togo (1970-73) with the prophage typing method of Nicolle et al. and the lytic El Tor phages of Basu & Mukerjee. Prophage typing proved to be of limited epidemiological value in Togo since 203 of the 211 strains tested belonged to the same phage type-namely, type 2 of Nicolle et al., which corresponds to the Celebes type of Takeya. Six strains belonged to type 1, 1 strain to type 4, and 1 strain was untypable.Tested by the lytic El Tor phages, 175 strains were found to belong to type 4 of Basu & Mukerjee, 35 strains to type 1, and 1 strain was untypable. All but two strains of type 1 were isolated from 3 outbreaks in which this phage type was found almost exclusively. The results are in good agreement with epidemiological data collected during the epidemic. El Tor phage V reacted with a specificity of over 99% when tested against 601 strains of El Tor and NCV vibrios from Togo and may be recommended for the rapid identification of El Tor vibrios. (+info)
Effectiveness of incidence thresholds for detection and control of meningococcal meningitis epidemics in northern Togo.
(8/70)
BACKGROUND: Early outbreak detection is necessary for control of meningococcal meningitis epidemics. A weekly incidence of 15 cases per 100 000 inhabitants averaged over 2 consecutive weeks is recommended by the World Health Organization (WHO) for detection of meningitis epidemics in Africa. This and other thresholds are tested for ability to predict outbreaks and timeliness for control measures. METHODS: Meningitis cases recorded for 1990-1997 in health centres of northern Togo were reviewed. Weekly and annual incidences were determined for each district. Ability of different weekly incidence thresholds to detect outbreaks was assessed according to sensitivity, specificity, and positive and negative predictive values. The number of cases potentially prevented by reactive vaccination in 1997 was calculated for each threshold. RESULTS: Outbreaks occurred in 1995-1996 and in 1996-1997. The WHO-recommended threshold had good specificity but low sensitivity. Thresholds of 10 and 7 cases per 100,000 inhabitants in one week had sensitivity and specificity of 100% and increased the time available for intervention by more than one or two weeks, respectively. A maximum of 65% of cases could have been prevented during the 1997 epidemic, with up to 8% fewer cases prevented for each week of delay in achieving vaccine coverage. CONCLUSIONS: In northern Togo, thresholds of 7 or 10 cases per 100,000 inhabitants per week were excellent predictors of meningitis epidemics and allowed more time for a reactive vaccination strategy than current recommendations. (+info)