Direct cytogenetic studies by needle aspiration of Burkitt's lymphoma in Ghana, West Africa.

With the use of a needle aspiration technique for obtaining tumor material, the direct karyotype of Burkitt's lymphoma cells was examined from 15 Ghanaian patients. The 14q+ chromosome (in addition to other chromosomal abnormalities) was present in 8 (57%) of the 14 patients; 6 of these 8 patients had t(8;14) (q24;q32). One of the remaining 2 patients had a #8 chromosome deleted, whereas the second had 2 normal-appearing #8 chromosomes. Other numerical and structural abnormalities were frequent. No correlation between type or frequency of abnormality and clinical status or survival was found. Within cells of the same tumor aspirate, the karyotype abnormalities were generally similar. In 3 patients, karyotypes from two separate tumor sites (abdomen-bone marrow, 2 cases; right maxilla-left mandible, 1 case) showed identical markers. The same marker was seen in specimens from the initial and second relapse abdominal tumors of 1 patient. The similarity of chromosomal markers from two sites or in serial studies further supports the concept that African Burkitt's lymphoma is a disease of monoclonal origin.

Very late relapses in patients with Burkitt's lymphoma: clinical and serologic studies.

Of 117 patients in remission for at least 12 months after chemotherapy for confirmed Burkitt's lymphoma, 14 subsequently relapsed. Frequency of ever relapsing in this group varied from 12% 2 years after chemotherapy to 3-8% 3-6 years after chemotherapy. Risk of very late relapse (VLR) increased with the occurrence of meningeal disease and/or relapse before a remission of 12 months or more was achieved. The use of combination chemotherapy and especially prophylactic intrathecal methotrexate significantly lowered the risk of VLR (P less than 0.03). Serial testing for antibodies to Epstein-Barr viral capsid antigen to the diffuse and restricted components of the early antigen complex and to the Epstein-Barr virus-specific nuclear antigen revealed minor fluctuations but no consistent increases in antibody titers preceding detection of VLR. The serologic follow-up tests thus were not clinically useful for prediction of the imminence of a recurrence. Patients developing VLR generally maintained moderate-to-high titers of antibodies to restricted or diffuse components throughout the long remission periods, which indicated that they were not beyond the danger of a relapse at an unspecified time in the future.

Cerebrospinal fluid markers in African Burkitt's lymphoma with central nervous system involvement.

Several cerebrospinal fluid markers were found to be elevated in Burkitt's lymphoma patients with central nervous system (CNS) involvement. Antibody levels to the virus capsid antigen of the Epstein-Barr virus and to the brain cell antigens myelin and cerebroside were elevated during active CNS disease. Immune complexes were present in levels above 100 micrograms/ml in most patients with CNS involvement but tended to be low or negative in patients without CNS disease. Oligoclonal IgG bands were present in 12 of 13 patients with CNS disease and in only 3 of 26 patients with no clinical evidence of disease. None of these markers were present in 6 other tumor patients without CNS disease. The presence of these markers in 12 of 13 patients in whom CNS disease was involved suggests that these markers may be useful in determining the status of the tumor with regard to involvement of the CNS.

HLA-DR7 association with African Burkitt's lymphoma.

Association between HLA-DR7 and Burkitt's lymphoma previously reported has been confirmed by a second study. Analysis of additional data from a second study of 33 Ghanaian patients with African Burkitt's lymphoma and 54 Ghanaian controls matched for age and ethnic origin showed that 39.4% of cases, but only 14.8% of controls, had HLA-DR7 (p less than 0.01). The relative risk of 3.7 is similar to that observed in the earlier study (3.3). Combining the earlier and present studies, analysis of clinical data from 94 patients with Burkitt's lymphoma and 116 controls shows the relative risk of Burkitt's lymphoma among individuals with HLA-DR7 was 3.4 (p less than 0.001). There was an increased relative risk of the disease associated with HLA-DR7 in: patients under 10 years of age; and patients with advanced stages of disease (Stage III or IV). However, comparison of relative risks by sequential analysis of 2 X 2 tables showed that these differences by age and stage were not statistically significant.

Study of the HLA system in Burkitt's lymphoma.

Seventy-eight patients with Burkitt's lymphoma and seventy controls from Ghana were typed for HLA-A, B, C and DR antigens, to determine whether there is an association between the HLA system and Burkitt's lymphoma. Increased relative risk was observed in Burkitt's lymphoma patients with DR7, HLA-A1 and B12(BW44).

Sickle cell trait, hemoglobin C trait, and Burkitt's lymphoma.

In a controlled study in Ghana, the hemoglobin electrophoretic pattern in 112 patients with Burkitt's lymphoma was compared to that of their nearest neighbor controls of the same age, sex, and tribe, as well as their sibling controls. Analysis of the data obtained did not show any statistically significant protective advantage for sickle cell trait against Burkitt's lymphoma. Hemoglobin C trait appeared to offer a slight protective advantage (p less than 0.1), but this did not reach statistical significance. These results do not disprove the malaria co-factor hypothesis in the etiology of 0urkitt's lymphoma, but deprive it of an additional indirect evidence in its favor.

Severe anemia in young children after high and low malaria transmission seasons in the Kassena-Nankana district of northern Ghana.

Malaria and anemia accounted for 41% and 18% respectively of hospital deaths in the Kassena-Nankana district of northern Ghana during 1996. We measured hemoglobin (Hb), malaria prevalence, and anthropometric indices of 6--24-month-old infants and young children randomly selected from this community at the end of the high (May-October, n = 347) and low (November-April, n = 286) malaria transmission seasons. High transmission season is characterized by rainfall (the equivalent of 800-900 mm/yr.), while the remaining months receive less than 50 mm/yr. Severe anemia, defined as Hb < 6.0 g/dL, was 22.1% at the end of the high transmission season compared to 1.4% at the end of the low transmission season (Odds Ratio [OR] = 20.1; 95% CI: 7.1-55.3). Parasitemia was 71% and 54.3% at these time points (OR = 2.1; 95% CI: 1.5-2.9). Nutritional anemia appeared to have little impact upon this seasonal difference since anthropometric indices were comparable. Although the relative contributions of other causes of severe anemia were not assessed, repeated malaria infections may be a primary determinant of severe anemia among infants and young children during the high transmission season.

Incidence of symptomatic and asymptomatic Plasmodium falciparum infection following curative therapy in adult residents of northern Ghana.

Adult residents of holoendemic malaria regions in Africa have a naturally acquired immunity (NAI) to malaria that renders them more resistant to new infections, limits parasitemia, and reduces the frequency and severity of illness. Given such attributes, it is not clear how one might evaluate drug or vaccine efficacy in adults without serious confounding. To determine symptomatic and asymptomatic malaria attack rates in adults of northern Ghana, 197 men and women underwent curative therapy for any pre-existing malaria infections at the start of the high transmission (wet) season. They were monitored for first parasitemia and first clinical episode of infection by Plasmodium falciparum over a 20-week period (May-October 1996). The cumulative incidence of primary infection by P. falciparum was 0.98 and incidence density of infection was calculated to be 7.0 cases/person-year. Symptoms were reported by 19.5% of the individuals at the time of first recurrent parasitemia. Incidence of infection, parasite density, and the frequency of symptoms were comparable in males and females. The results suggest that NAI did not provide these adults with significant defense against rapid re-infection and suggest that this population-infection design could serve to demonstrate the efficacy of a drug or vaccine in preventing parasitemia.

A randomized double-blind placebo-controlled field trial of ivermectin and albendazole alone and in combination for the treatment of lymphatic filariasis in Ghana.

The efficacy and safety of single-dose ivermectin (150-200 micrograms/kg) and albendazole (400 mg) treatment administered separately or in combination for Wuchereria bancrofti infections were assessed in 1996-98 in a randomized double-blind placebo-controlled field trial in Ghana: 1425 individuals from 4 lymphatic filariasis-endemic villages, 340 of whom were microfilaria (mf)-positive before treatment, were randomized into 4 groups to receive albendazole alone, ivermectin alone, combination of albendazole and ivermectin, or placebo, respectively. Individuals were followed for 5 days after treatment to record any adverse reactions, and the effect of treatment on microfilaraemia was monitored in night-blood samples after 3, 6 and 12 months. Treatment efficacy was analysed for 236 mf-positive individuals who had > or = 100 mf/mL of blood and who were also present for examination at 12 months after treatment. Compared to the placebo group, the ivermectin and combination groups both showed statistically significant reductions in geometric mean mf intensities at the follow-up examinations (to 6.7% and 0.9%, 9.9% and 6.9%, and 21.7% and 11.4% of pre-treatment levels, respectively, at 3, 6 and 12 months after treatment). Compared to the ivermectin group, however, the reduction in the combination group was significantly greater only at 3 months after treatment, but not after 6 or 12 months. The albendazole group showed a slow but non-significant reduction over the same period. Adverse reactions were few and mostly mild (no severe reactions were recorded), and no significant differences were observed between the treatment groups. Both ivermectin and combination treatment thus appeared effective and safe for treatment of lymphatic filariasis, but the difference in efficacy was minor and the study did not provide clear evidence for the combination drug therapy, as compared to ivermectin therapy alone, to be superior for control of lymphatic filariasis.

Single-dose treatment of Wuchereria bancrofti infections with ivermectin and albendazole alone or in combination: evaluation of the potential for control at 12 months after treatment.

The effect of single-dose ivermectin (150-200 micrograms/kg) and albendazole (400 mg) treatment alone and in combination on Wuchereria bancrofti microfilaraemia, antigenaemia and clinical manifestations was compared 12 months after treatment in a double-blind placebo-controlled field trial carried out in Ghana in 1996-98, to evaluate the potential of these treatments for control. Both ivermectin and combination treatments resulted in pronounced reductions in microfilaraemia among individuals who were microfilaria positive before treatment. Among individuals who were positive for circulating filarial antigen before treatment, antigen levels increased considerably over the 1-year period after treatment in the placebo group, whereas they decreased in the ivermectin and combination groups. However, the post-treatment difference reached statistical significance in neither microfilaraemia nor antigenaemia between the ivermectin and the combination groups. Albendazole treatment alone showed only a minor effect on microfilaraemia and antigenaemia. No effect of the treatments on the incidence of new cases of microfilaraemia or antigenaemia, or on clinical manifestations, was observed. Both ivermectin and combination treatment thus appeared effective for control of W. bancrofti infections, but the difference in efficacy between the 2 treatments after 12 months appeared to be minimal.

Serum immunoglobulin levels and malaria antibodies in Burkitt's lymphoma.

Data are presented to support a relationship between malaria infection and Burkitt's lymphoma in African children. IgG, IgM and IgA levels were measured in sera from Burkitt's lymphoma patients and from sex- and age-matched, nearest-neighbour controls. All three classes of immunoglobulins were present in significantly lower amounts in the sera from Burkitt's lymphoma patients than in the sera from controls. The mechanism of this apparent B-cell suppression is not yet clear. Malaria-specific IgG and IgM antibody titres were determined in the indirect immunofluorescence test. No significant difference in the IgG malaria-specific antibodies was detected between the two groups of sera. Malaria antibody levels measured using IgM specific conjugates were significantly lower in the sera from Burkitt's lymphoma patients in reactions with Plasmodium falciparum antigen. No significant difference was observed when P. malariae was used. Confirmation of this finding would serve as a positive link between Burkitt's lymphoma and P. falciparum infection.

A study on the provocative day test effect of ivermectin and albendazole on nocturnal periodic Wuchereria bancrofti microfilaraemia.

We conducted a randomized double-blind placebo-controlled study, in the Ahanta West District of Ghana, on the provocative day test effect of ivermectin and albendazole alone and in combination on nocturnal periodic Wuchereria bancrofti microfilaraemia. Sixty-three individuals with high night-time microfilaria (mf) intensities were identified in 1997 or 1998 and randomized into 4 groups. Blood samples for mf were then collected from the same individuals in the daytime (between 09:00 and 15:00) immediately before and 30-50 min after treatment. Groups 1-4 were treated with ivermectin alone (150-200 micrograms/kg), albendazole alone (400 mg), the combination of ivermectin and albendazole, and placebo, respectively. Intensities of mf in daytime samples were considerably lower than in night-time samples. Neither ivermectin or albendazole alone nor their combination provoked significant liberation of W. bancrofti mf into the peripheral circulation after the daytime treatment.

A monoclonal antibody-based dipstick assay for diagnosis of urinary schistosomiasis.

A Schistosoma haematobium species-specific mouse immunoglobulin (Ig) G1 monoclonal antibody (mab) Sh2/15.F that bound a 29 kDa peptide was utilized to develop a membrane-based dipstick enzyme-linked immunosorbent assay for specific diagnosis of urinary schistosomiasis. Strips of polyvinylidene difluoride membrane were wetted with methanol and stored in distilled water. The strips were used to capture urinary antigens which were then revealed by incubation in a mixture of specific mab and peroxidase-conjugated goat anti-mouse IgG. The assay correctly identified 26/30 (87%) of egg-negative control individuals and 53/54 (98%) of parasitologically confirmed cases including all of 6 individuals treated with praziquantel (40 mg/kg) but not cured. Also, the assay detected S. haematobium antigens in the urine of 3 individuals from whom 2 specimens had to be examined microscopically to confirm infection, thus suggesting that the mab detection method may have greater sensitivity than microscopy.

Health centre versus home presumptive diagnosis of malaria in southern Ghana: implications for home-based care policy.

A study was conducted in 1997 to compare the accuracy of presumptive diagnosis of malaria in children aged 1-9 years performed by caretakers of the children to that of health centre staff in 2 ecological zones in southern Ghana. Similar symptoms were reported in the children at home and at the health centre. In the home setting, symptoms were reported the same day that they occurred, 77.6% of the children with a report of fever were febrile (axillary temperature > or = 37.5 degrees C) and 64.7% of the reports of malaria were parasitologically confirmed. In the health centre, the median duration of symptoms before a child was seen was 3 days (range 1-14 days), 58.5% of the children with a report of fever were febrile and 62.6% of the clinically diagnosed cases were parasitologically confirmed. In the 2 settings almost all the infections were due to Plasmodium falciparum. Parasite density was 3 times higher in the health centre cases compared to the home-diagnosed cases. Early and appropriate treatment of malaria detected in children by caretakers may prevent complications that arise as a result of persistence of symptoms and attainment of high parasitaemic levels.

Lymphatic filariasis on the coast of Ghana.

Parasitological, clinical and entomological surveys for lymphatic filariasis were carried out in 6 villages and 3 towns on the coast of Ghana. Few or no filarial infections were observed in the towns or in the villages east of Accra. However, Wuchereria bancrofti microfilaraemia was common in the 4 western villages, with overall prevalences of 9.2%-25.4% and overall microfilariae (mf) geometric mean intensities of 321-1172 mf/mL of blood. In the same villages, hydrocele affected 8.5%-27.9% of adult males (aged > or = 20 years), and 5.6%-6.6% of adult individuals had elephantiasis (mainly of the legs). In general, the patterns of filarial infection and disease in the endemic villages resembled those observed in endemic villages in the coastal part of East Africa, with the exception that in the Ghanaian focus more females than males were affected by elephantiasis. Entomological surveys revealed that Anopheles gambiae s.l. and A. funestus were vectors of filariasis in the endemic villages. Only negligible prevalences of microfilaraemia were observed in town communities located close to highly endemic villages. Control of filariasis in this area is difficult with presently available measures, and new control tools, especially development of new drug regimens for mass treatment, are greatly needed.

Anaemia caused by asymptomatic Plasmodium falciparum infection in semi-immune African schoolchildren.

A cohort of 250 Ghanaian schoolchildren aged 5-15 years was followed clinically and parasitologically for 4 months in 1997/98 in order to study the effect of asymptomatic Plasmodium falciparum infections on haematological indices and bone-marrow responses. Of the 250 children 65 met the predefined study criteria. Thus, 14 children were parasite-free throughout (group 1), 44 had P. falciparum in all blood samples collected but no symptoms of malaria (group 2), and 7 had 1 malaria attack during the study period (group 3). At the end of the study the mean haemoglobin (Hb) level in group 1 was 123 g/L, significantly higher than the value of 114 g/L in groups 2 and 3 (P < 0.02, adjusted for age and splenomegaly). The low Hb in group 2 was associated with subnormal plasma iron. Low Hb was associated with elevated erythropoietin (EPO) levels, and there was a positive correlation between EPO and reticulocyte counts. However, the reticulocyte response to EPO was more pronounced in uninfected than in infected children, suggesting a partial interference with erythropoiesis in asymptomatic infections. Children with asymptomatic infections had significantly higher plasma levels of tumour necrosis factor than uninfected children (geometric means 50 ng/L and 27 ng/L, respectively, P < 0.001) and this cytokine may contribute to bone-marrow suppression and disturbed iron metabolism. We suggest that asymptomatic malaria leads to a homeostatic imbalance in which erythrocyte loss due to parasite replication is only partially compensated for by increased erythropoiesis. The consequences of the reduced Hb levels on the development and cognitive abilities of children with asymptomatic infections, and the risk of precipitation of iron deficiency, deserve further study and should be considered in malaria control programmes that aim at reducing morbidity rather than transmission.

Species composition and inversion polymorphism of the Anopheles gambiae complex in some sites of Ghana, west Africa.

Samples of Anopheles gambiae s.1. were collected from eight localities belonging to four of the five main ecological strata of Ghana. Analysis of ovarian polytene chromosomes revealed the presence of A. gambiae s.s. in all the sites studied, while A. arabiensis was detected only in the extreme northern locality of Navrongo and A. melas in some southern sites. Anopheles arabiensis showed a degree of inversion polymorphism comparable to the one observed in other West African countries. The analysis of the chromosomal polymorphism of A. gambiae s.s. showed the presence of the FOREST form in the rain forest localities and the SAVANNA form in the coastal savanna sites. The MOPTI form occurred sympatrically with the SAVANNA form in the northernmost locality. The possible influence of the presence of various taxa of the A. gambiae complex and of their intra-specific variants on malaria vectorial system is discussed.

Predicting the timing of second praziquantel treatment and its effect on reduction of egg counts in southern Ghana.

Schistosoma haematobium infection could be associated with morbidity. Generally, the cost of schistosomiasis control is high and it becomes a burden for governments or non-governmental organisations to repeat control programs so as to reduce morbidity. There is therefore, the need to optimise the available meagre resources for its control. From 1993 to 1997 the Noguchi Memorial Institute for Medical Research of the University of Ghana carried out a schistosomiasis control program in southern Ghana. Using the generated data, an attempt is made to determine the timing of the second praziquantel treatment and the period needed after the second chemotherapy to have egg counts reduced to low levels in southern Ghana. It was revealed that the second praziquantel treatment in areas 1, 2, and 3 should be administered latest at 13.8, 11.8 and 13.2 months, respectively after the first one. Most importantly, it takes 24.4 months to bring egg counts to zero in area 3 while in area 1, it takes about 29 months after the second praziquantel treatment. Egg counts were not reduced to zero in area 2 after the second chemotherapy. At least passive health education and continuous safe water supply should support the chemotherapy in addition to weed removal at the water contact sites.

Lymphatic filariasis related perceptions and practices on the coast of Ghana: implications for prevention and control.

A qualitative study to investigate lymphatic filariasis related perceptions and practices that may be relevant for the design of appropriate health education and control programmes was conducted in four endemic villages in coastal Ghana. The villagers were aware of the common manifestations of filariasis, such as adenolymphangitis (ADL), lymphoedema, elephantiasis and hydrocele, which were specifically described with local terminology. ADL attacks were identified as the most dreaded health problem in the communities, and elephantiasis and hydrocele also ranked high in importance among reported diseases. Generally the respondents did not accept the mosquito theory of transmission, but they believed in other physical, and in spiritual and hereditary causes. Hydrocele was considered to have no link to the other disease manifestations. The manifestations were most often treated with herbal preparations which were used orally, smeared on affected parts or given as enema. In some cases the affected parts were scarified before herbal preparations were applied. The manifestations affected the work output of its victims and subjected them to hardships such as teasing, unsuitability for marriage, sexual dysfunction and divorce. Although the etiology was seen as different, the local perception of the developmental process of elephantiasis closely paralleled that of the biomedical understanding. It is suggested that this coincidence is used as an entry point for health education, to advance a broader biomedical knowledge on etiology, transmission and treatment options, and thereby to ensure co-operation of the target populations in the control of this complex disease.

Distinct patterns of cytokine regulation in discrete clinical forms of Plasmodium falciparum malaria.

The pathogenesis of two of the most severe complications of Plasmodium falciparum malaria, cerebral malaria (CM) and severe malarial anaemia (SA) both appear to involve dysregulation of the immune system. We have measured plasma levels of TNF and its two receptors in Ghanaian children with strictly defined cerebral malaria (CM), severe malarial anaemia (SA), or uncomplicated malaria (UM) in two independent studies in an area of seasonal, hyperendemic transmission of P. falciparum. Levels of TNF, soluble TNF receptor 1 (sTNF-R1) and 2 (sTNF-R2) were found to be significantly higher in CM than in the other clinical categories of P. falciparum malaria patients. Levels of both receptors depended on clinical category, whereas only sTNF-R1 levels were significantly dependent on parasitemia. Detailed analysis of the interrelationship between these variables resolved this pattern further, and identified marked differences between the patient categories. While levels of TNF, sTNF-R1 and sTNF-R2 correlated with parasitemia in UM, this was not the case in CM and SA. Rather, there was a tendency towards high levels of TNF and its receptors in CM and low levels in SA without significant correlation to parasitemia in either category. This, and the fact that malaria-induced increases in plasma levels of IL-10 are much lower in SA compared to CM, suggest that distinct forms of dysregulation of the immune response to infection contribute to the pathogenesis of CM and SA.