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This analysis of the 1986 Liberia Demographic and Health Survey data finds remarkably high fertility levels among women who have never married or lived with a man, reflecting widespread pre-marital sex and a lack of use of contraception. It is found that single Liberian women are more likely to foster out children than married Liberian women of the same age.

The prevalence of hypertension in rural African communities has been reported previously to be relatively low, with prevalence rates ranging between 2.5% and 10.9%. The authors obtained blood pressure recordings in 3,588 adult residents (age > 20 years) of the Liberian Agricultural Company rubber plantation, located in rural Liberia, West Africa. Blood pressures were obtained using automated digital blood pressure machines in a house-to-house survey. Individuals with a systolic blood pressure greater than 139 mm Hg or a diastolic blood pressure greater than 89 mm Hg were referred to a central site, where three subsequent blood pressure determinations were made, the mean of which was used to determine whether people were hypertensive. The overall prevalence of hypertension (blood pressure > 139/89 mm Hg) was 12.5%. Hypertension was most common in the older women (prevalence 5.7% in women age 20-24 years old, 50% in women older than 55). Using more stringent criteria for hypertension, systolic blood pressure greater than 159 mm Hg or diastolic blood pressure greater than 94 mm Hg, 20% of women between 50-54 had hypertension and 26% of the women older than 55 had hypertension. In some ethnic groups, the prevalence of hypertension was as high as 25%. Based on these results, the prevalence of hypertension in some rural African communities may be higher than reported previously, particularly in older women and among certain ethnic groups, possibly suggesting a strong hereditary component.

Human infections with the tissue nematode Onchocerca volvulus result in a variety of clinical conditions that possibly include protective immunity. In a West African area hyperendemic for human onchocerciasis, 120 residents were classified according to clinical and laboratory findings as presenting with generalized onchocerciasis, localized onchocerciasis, or as being putatively immune. The three groups differed in the distribution of HLA-D variants as determined by DNA typing. The most pronounced differences were found among alleles of the DQ loci. The haplotype DQA1*0501-DQB1*0301 was significantly more frequent among putatively immune individuals than among patients with generalized or localized disease. Conversely, DQA1*0101-DQB1*0501 and, independently, the allele DQB1*0201 were more frequent in generalized disease than in localized disease or putative immunity. In these correlations, the frequencies of allelic variants were in localized disease intermediate to those of the two other groups. The only distinct association found with localized disease was that of the DP allele DPB1*0402. The findings indicate that HLA-D variants influence the course of O. volvulus infection and help to define a state that may reflect protective immunity.

To determine the influence of meterological factors on the diurnal biting cycle of Simulium yahense Vajime & Dunbar (a member of the Simulium damnosum Theoblad complex), we captured host-seeking females as they landed on the exposed lower legs of humans in the Harbel area of Liberia. Biting activity was greatest during the morning hours and was characterized by a unimodal harmonic curve. Although meteorological conditions had no decisive influence on the unimodal pattern of diurnal biting activity, hourly variation in the number of S. yahense captured at human bait was affected by meterological factors (i.e., the diurnal pattern of S. yahense biting activity is regulated by an internal clock, but the number of bits during any given hour is in response to meterological conditions). The transmission of Onchocerca volvulus (Leuckart) was highest during the morning hours when high transmission potentials were in phase with peak human activity and served to maintain the hyperendemicity of onchocerciasis in the Harbel area.

As part of an evaluation of child survival programmes in 13 African countries, cluster surveys were carried out in two Liberian counties in 1984 and 1988 to measure use of three primary health care services: immunization of infants, antimalarial treatment of children with fever, and oral rehydration of childhood diarrhoea. Immunization rates increased (30-53% for DPT-1 and 13-33% for measles), treatment of malaria with drugs available in the home increased from 5 to 35%, and home use of sugar-salt solution to prevent dehydration remained essentially unchanged, 5.9% in 1984 and 3.8% in 1988.

A baseline survey of childhood mortality in two counties of Liberia in 1984 found the risk of dying before age 5 to be almost one-third. Three years into the Combatting Childhood Communicable Diseases (CCCD) project, a survey using a pregnancy history questionnaire was conducted in the same clusters to determine if any change in mortality had occurred. Reinterviews were done in a subsample and pregnancies were matched from the two surveys to determine levels of missing events. After adjustment for omission, infant mortality was estimated at 180 per 1000, a 25% decline from the estimated 1984 level. Childhood mortality declined by an estimated 28%. Tabulations of death by reported cause using a verbal autopsy questionnaire showed that the risks of neonatal tetanus and fever associated deaths declined significantly. These reductions might have been a direct result of programme activities which were shown by a marked increase in tetanus toxoid immunization and access to antimalarial drugs in the study area.

To estimate baseline infant and child mortality in Liberia, a survey was carried out in 1984 as part of the Combatting Childhood Communicable Diseases (CCCD) project. The project, a collaborative effort of the Liberian Ministry of Health, the US Agency for International Development, and the US Centers for Disease Control, is aimed at reducing childhood morbidity and mortality through oral rehydration therapy, vaccination and treatment for malaria. As a measure of programme impact, mortality estimates from this survey will be compared with those from a second survey after 4-5 years. A sample of 40 clusters (50-70 households per cluster) was used. The size is sufficient to detect a 25% reduction in mortality of children under 5 years of age. Mortality was estimated from a pregnancy history questionnaire asked of women aged 15-49 residing in cluster households. A reliability survey was conducted and pregnancies were matched to determine the level of omission of births and deaths. Results show a very high level of mortality with a risk of death in infancy above 20% and a risk of dying before the fifth birthday of one-third. Since the extent of omission of deaths in the first survey proved substantial, the reinterview survey was essential.

The Mortality and Use of Health Services studies were designed to measure changes in the coverage of health services and in infant and child mortality rates associated with the implementation of the Combatting Childhood Communicable Diseases programme. The papers in this supplement provide the results of research carried out in areas of Zaire and Liberia. Data from these studies provide credible evidence that these programmes actually reduced mortality. The proportion of children dying by their fifth birthday declined by 17% in Zaire and by 32% in Liberia. These estimates of programme impact are consistent with the increases in the use of health services and with data from similar studies in other countries. Results of these surveys suggest that child survival programmes in Africa can reduce mortality substantially in populations living in different environments at very different initial levels of child mortality.

In sub-Saharan African countries where AIDS is established, HIV transmission is primarily by means of heterosexual intercourse. A major co-factor in such transmission is the presence of other, sexually transmitted diseases (STDs). Efforts to limit the heterosexual transmission of HIV in Africa must therefore address the high prevalence of other, standard STDs. The present study attempts to establish a preliminary information base for interventions to prevent the spread of HIV in Liberia where there is relatively high incidence of standard STDs but low incidence of HIV seropositivity. Employing in-depth, key-informant interviews with traditional healers, prostitutes and others, as well as focus group discussions with groups selected on the basis of several criteria, knowledge, beliefs, attitudes and behavior related to AIDS and STDs were elicited. Although evidence of exposure to scientific concepts was found, traditional, ethnomedical views predominated. Notions of sorcery, taboo violation and contamination were often expressed when describing the etiologies of locally-recognized sexually transmitted diseases. More 'naturalistic' explanations were often based on simplified notions of human anatomy and biochemistry. Three basic messages about AIDS that were broadcast in a recent radio campaign were retained, namely 'AIDS kills;' 'there is no cure for it;' and 'it is transmitted through sex.' There was also evidence of Liberians beginning to view AIDS in frameworks of interpretation compatible with traditional ethnomedical beliefs, such as sorcery. Most traditional healers reported they knew little or nothing about AIDS, including those who had a lot to say about other STDs that are well-established in Liberia. Many cases of STDs seem to be handled by traditional healers. Treatment typically consists of decoctions from the leaves and roots of various medicinal plants, administered as teas--less often as enemas or vaginal implants--to be taken over a 2-4 day period. It is recommended that efforts to lower incidence of standard STDs be given priority comparable to promotion of condom use and 'safer sex' in efforts to slow the transmission of HIV in Liberia. Strategies for combating STDs will have to take into account popular beliefs and attitudes regarding STDs as well as the role and influence of traditional healers. Strategies of this sort are recommended.

A Plasmodium falciparum antigen gene coding for a 220-kD glutamate-rich protein (GLURP) has been cloned, and the 783 C-terminal amino acids of this protein (GLURP489-1271) have been expressed as a beta-galactosidase fusion protein in Escherichia coli. The encoded 783 amino acid residues contain two areas of repeated amino acid sequences. Antibodies against recombinant GLURP489-1271, as well as against a synthetic peptide corresponding to GLURP899-916, and against a synthetic peptide representing the major glutamate rich repeat sequence from the P. falciparum ring erythrocyte surface antigen (Pf155/RESA) (EENV)6 were examined in 423 individuals (age range 30 days-78 years) living in a malaria holoendemic area of Liberia. In the 5-9-year-old age group, subjects with anti-GLURP489-1271 antibody concentrations greater than the mean value of the group had lower parasite densities than those with low antibody concentrations (P = 0.0151). High levels of anti-GLURP899-916 antibodies did not correlate with low parasite densities. However, high levels of anti-(EENV)6 antibodies were associated with significantly lower parasite densities in the 2-4-year-old age group (P = 0.0189). There was no correlation between the anti-GLURP489-1271 and anti-(EENV)6 antibody responses. The data provide indirect evidence for a protective role of antibodies reacting with recombinant GLURP489-1271 as well as with the synthetic peptide (EENV)6 from the Pf155/RESA.

Savanna species of the Simulium damnosum complex, the major vectors of the blinding savanna type of onchocerciasis, were considered to be rare in Liberia, until the dry season of 1988. In 1988 they became a serious nuisance, biting people at the Bong iron ore mine within the rain forest zone. S. damnosum s.str. and S. sirbanum were found breeding, in association with S. adersi a non man-biting savanna species, in a stream emerging from the mine's tailings pond. The local forest species were extremely rare in this stream. The water of the stream was characterized by an increased hardness and higher temperatures in comparison with those of natural watercourses in the area. The mass occurrence of flies was probably related to expansions of the tailings ponds, when rich nutrition was provided for the blackfly larvae by the decaying forests submerged by the rising water levels. The phenomenon did not recur in 1989 when only a few savanna flies were caught, and none were seen in the dry season of 1990. Although it is not known why the artificial environment of the tailings ponds was so attractive for the savanna species the events clearly demonstrated that savanna flies seasonally invading the area, possibly aided by the northeasterly harmattan winds, can become established in the rain forest zone if suitable conditions are met. No infections with Onchocerca volvulus were found in more than 1000 flies caught by vector collectors but, after experimental infection with the local forest strain, a few parasites developed to the infective stage. As yet there is no evidence that the occurrence of savanna flies in the rain forest zone of Liberia was of epidemiological significance.

Purpose: Skin disease is the most common clinically important manifestation of onchocerciasis. Ivermectin, a newly available drug, is well tolerated and effective in Onchocerca volvulus infection. However, little information is available regarding its effect on onchocercal skin disease. The purpose of this study was to examine, in patients with well-characterized onchodermatitis, the effect of a single dose of ivermectin., Subjects and Methods: Twenty-one persons with severe onchodermatitis were followed over a 6-month period. In order to evaluate the effect of ivermectin on their skin lesions, photographic transparencies were made before treatment and at 3 and 6 months after treatment. These were then evaluated in a blinded fashion., Results: Following a single dose of 150 micrograms/kg, there was a significant improvement in dermatitis in the first 3 months after treatment. All 14 persons with the worst skin disease showed improvement. The drug had no demonstrable effect on depigmented lesions over the period of observation. Treatment was well tolerated., Conclusion: Single-dose ivermectin shows promise as the first acceptable treatment for severe onchocercal dermatitis.

The seroreactivities to Pf155/RESA antigen and to three oligopeptides (EENV)2, EENVEHDA and K(DDEHVEEPTVA)2, which constitute repeat subunits of the RESA molecule, were investigated between 1980 and 1986 in two cohorts of children (n = 114) with and without monthly chemosuppression (pulsed reduction of parasite load) against malaria from six months to five years of age during development of protective immunity. Serum samples were collected first at half-yearly and then yearly intervals. Positive immunofluorescence against Pf155/RESA (EMIF) was only found in 24% of the samples. The children with chemosuppression were more often seropositive (30%) than the non prophylactic children (17%). This was in contrast to the seroreactivity against crude parasitic antigens which was highest in the non prophylactic children. In these children, there was a general decrease of EMIF titres around two years of age. Immunosuppression by chronic parasitaemia may be suggested as a reason for this. ELISA seroreactivity was found against one, two or three oligopeptides in all children with high EMIF titres (greater than 250) although (EENV)2 appeared to best correlate (92%) with the EMIF seropositivity. While EMIF seropositivity only showed partial correlation to immunoprotection against patent parasitaemia in the non prophylactic children, the individual profiles of the seroreactivities to the different specific epitopes of the Pf155/RESA molecule and their relevance with regards to protective immunity to malaria need to be investigated further.

The epidemiology and natural history of onchocerciasis and its ocular complications in rain forest areas are poorly understood. The present study was conducted on a rubber plantation in a hyperendemic area in the rain forest of Liberia, West Africa, where 800 persons were examined. The prevalence of infection was 84% overall 29% had intraocular microfilariae, and 2.4% were blind in one or both eyes. Onchocerciasis was the cause of all binocular blindness and one-third of all visual impairment. Over half of the visual impairment caused by onchocerciasis was due to posterior segment diseases. Chorioretinal changes were present in 75% of people, and included intraretinal pigment clumping in 52% and retinal pigment epithelium atrophy in 32%. Atrophy of the retinal pigment epithelium was associated with increasing age and severity of infection. Intraretinal pigment was strongly associated with anterior uveitis. There was a strong correlation between uveitis and the inflammatory chorioretinal sequelae: retinitis, intraretinal pigment, subretinal fibrosis, and optic neuropathy. These findings indicate that considerable visual impairment associated with rain forest onchocerciasis is common and is due largely to chorioretinal disease.

The safety, acceptability, and efficacy of ivermectin during community-based mass treatment of onchocerciasis was assessed. Ivermectin was distributed three times, 1 year apart, to the population of a rubber plantation (14,000 people) in Liberia where greater than 80% of adults have Onchocerca volvulus infection. In a sample of adults, the microfilarial density was reduced by 84% after 2 years of treatment. Acceptance was as high as 98% during the third year. Adverse reactions occurred in 6-13 in 1000 people after first treatment and in only 3-4 in 1000 receiving their second or third annual dose of ivermectin; severe adverse reactions were not seen. These data show that community-based treatment with ivermectin is safe, well accepted, and effective in reducing microfilarial loads and suggest that ivermectin is the first practical drug suitable for mass treatment campaigns to control human onchocerciasis.

A seven-and-half-month study of single observations for congenital malformations on 2228 Liberian neonates at the St. Joseph's Catholic Hospital is presented. An overall incidence of 22.4 per 1000 was recorded in this study.

Burn care in developing countries remains a challenge. This paper reviews the acute burn care of 21 patients admitted during a 1-year period to a hospital in Liberia. Lack of supplies and education, coupled with the local belief system, reflect on patient management. The study population totalled 21 patients, ranging from 1 to 62 years of age. TBSA burns ranged from 2 to 60 per cent (mean 21 per cent), 61 per cent of patients were grafted. The time between burn and graft varied between 5 and 96 days (mean 29.8). Graft take varied between 40 and 100 per cent (mean 81 per cent). Of the grafted patients 66.6 per cent received blood (average 732 ml). At the time of presentation 61.9 per cent of patients had other illness. The average number of hospital days was 37.9 (range 2-76). The mortality rate was 14.2 per cent. When managing burns in a developing country, adoption of a simple, clearly defined method of treatment, together with education of the care-givers, is suggested. As in the developed world, however, prevention is the critical factor.

Sera from 32 adult men residing in a malaria holoendemic area of Liberia were investigated for seroreactivities to different asexual blood-stage malaria antigens on five consecutive occasions from 1984 to 1986. The seroreactivities to crude parasitic antigens and to Pf 155/RESA (EMIF) were determined by immunofluorescence and to repetitive sequences of Pf 155/RESA by enzyme-linked immunosorbent assay (ELISA). All sera were highly reactive against the crude parasitic antigens with reciprocal titres varying from 5000 to 100,000. The EMIF titres showed a wider variation from negative (less than 10) to 25,000, and when the same individuals were re-examined on subsequent surveys similar EMIF titres were found. The ELISA seroreactivities to three different repetitive sequences of Pf 155/RESA also showed different individual profiles which were rather consistent on consecutive surveys. High EMIF titres appeared to be correlated mainly to one of the peptide sequences, namely (EENV)2. The consistent individual profiles of the seroreactivities to Pf 155 and its repetitive sequences suggest genetic restriction of the humoral immune response. Although no significant correlation was found between EMIF titres and parasitic densities in the adult hyperimmune men the specific peptides, however, offer new possibilities of further investigating protective capacities of different immune responses to specific epitopes of the malaria parasite.

During a community-based treatment trial of onchocerciasis with ivermectin, verbal autopsies were employed as one method to assess the safety of the drug. The verbal autopsy questionnaire was designed to determine causes of death and mortality differentials in the treated population. During the 8 months of surveillance here reported, 25 individuals died, yet only 9 of these deaths were certified. Seven of the deaths occurred to individuals who had been treated with ivermectin and the majority of the deaths occurred to children under 5, who were excluded from treatment. The verbal autopsy method was evaluated and validated by comparing the verbal autopsy diagnosis of cause of death to death certificate diagnosis, when available. In addition, verbal autopsies were retrospectively performed for all deaths which had occurred at the hospital during the 6 months preceding the start of the study, if these deaths were traceable to households in the surveillance population. We found that in 80% of the adult deaths, the verbal autopsy and death certificate diagnoses of underlying cause of death agreed. The verbal autopsy was less accurate in diagnosing child deaths which we attribute to the design of the verbal autopsy (being to detect potential drug related deaths in adults) and to the delay between death and interview. We conclude that verbal autopsies are an important addition to surveillance systems in remote areas where the absence or inadequacy of health information systems does not allow a thorough follow-up of all subjects in drug studies.

In seven Liberian villages of different endemicity for onchocerciasis 629 persons were tested for tuberculin reactions using 5 i.u. purified protein derivative or old tuberculin. No correlation between infection with Onchocerca volvulus and reactivity to tuberculin was detected on a community level, but a direct comparison of results of infected and non-infected individuals in two neighboring villages revealed a lower responsiveness in persons with onchocerciasis. The conversion rate three months after BCG vaccination was significantly lower in children with onchocerciasis (48%) than in controls (85%). The possible impact of this finding on the efficacy of BCG vaccinations is discussed. Girls aged 2-16 years were screened for rubella antibodies using a latex agglutination test. Sera from 74 girls, who showed no antibodies, were examined before and four months after rubella vaccination by haemagglutination-inhibition-test and haemolysis-in-gel-test. No difference in the humoral immune response of girls with or without onchocerciasis was found. Seroconversion rates were 98% and 100%. Delayed cutaneous hypersensitivity (DCH) to seven ubiquitous recall antigens was tested in 147 persons infected with O. volvulus and compared to the results of 142 non-infected controls. A reduced responsiveness was seen in persons with onchocerciasis, the difference being greatest in young children 2-7 years of age. In connection with the results of tetanus vaccinations reported earlier, these findings verify the existence of a reduced in vivo responsiveness of cell-mediated immunity to non-specific antigens in onchocerciasis in the rain forest of West Africa. Humoral immune responses however appeared to be unaffected.

In order to assess the possible suppression of immune responses to non-specific antigens in patients with generalized onchocerciasis, a vaccination study was conducted among the population of eight Liberian villages. Hundred and eighty-four persons infected with Onchocerca volvulus and 142 non-infected individuals were tested for delayed cutaneous hypersensitivity to tetanus antigen using the Multitest Mérieux. Prevalence of malaria and infections with intestinal nematodes with larval migration to the lung were much the same in all the villages examined. Other parasitic diseases had no significant influence. Persons aged 2-29 years with onchocerciasis had a significantly lower prevalence of positive tetanus reactions (p less than 0.05). Hundred and eighty persons showing a negative skin test were vaccinated twice with 75 i.u. tetanus toxoid and cell-mediated as well as humoral immune responses were recorded three months later. Analysis of sera collected before vaccinations indicated that 56% of the vaccinees had tetanus antibody levels of 0.01 i.u./ml or more and had, therefore, received a booster vaccination. Rates of seroconversion or booster were the same in persons with or without onchocerciasis (81% and 82% respectively). The conversion rate in the delayed cutaneous hypersensitivity test, however, was significantly lower in those infected with O. volvulus (67%) as compared to the controls (92%, p less than 0.001). These results demonstrate a diminished cell-mediated immune response to tetanus toxoid vaccinations in patients with generalized onchocerciasis. Considering the unimpaired humoral immune response, no changes in vaccination schedules are recommended.

Antibodies to Plasmodium falciparum sporozoites were detected in children aged 6 months to 9 years, and in adults, in a holendemic village near Yekepa, Liberia, by enzyme linked immunosorbent assay (ELISA) using the recombinant circumsporozoite protein R32tet32 or by inhibition of sporozoite invasion (ISI) of hepatoma cells. Both assays were significantly correlated with each other and showed that anti-sporozoite antibodies increase with age. ISI was more sensitive than ELISA and demonstrated significantly increased anti-sporozoite antibodies at age 5-6 years, when young children show partial clinical resistance to malaria. These results suggest that anti-sporozoite antibodies, as measured by ISI, may contribute to protection against malaria.

Pf155 (RESA), a malaria antigen in the membrane of infected red cells, was recently identified as a possible future malaria vaccine candidate. In this study the seroreactivities against this antigen were compared with those against crude parasitic antigens in 195 subjects from a Somali village with mesoendemic malaria. The seroreactivities were determined with immunofluorescence. With age, there was an increased seroreactivity to both Pf155 and the crude parasitic antigens. However, the acquisition of seroreactivity was much slower against Pf155. Hence in the age group 15-24 years, only half of the subjects had detectable antibodies against Pf155.