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Biomedical subjects

J G Breman

Publications and source records attributed to J G Breman.

At least 19 recordsLinked to original sources

Treatment of chloroquine-resistant malaria in African children: a cost-effectiveness analysis.

Because chloroquine (Cq)-resistant Plasmodium falciparum (CRPF) has now spread throughout most of Africa, the efficacy and practicability of other drugs such as amodiaquine (Aq), and pyrimethamine-sulfadoxine (PS), for the treatment of fever needs to be assessed. We used a decision-analysis model to compare the cost and effectiveness of Cq, Aq, and PS. The variables considered were the probability of P. falciparum infection, drug compliance, minor and lethal side effects of the drug, the level of drug resistance in the community, and case-fatality rates associated with treatment. The measures of effectiveness were the number of malaria-related fever episodes cured parasitologically with each treatment and the number of malaria deaths prevented in children 6-59 months old. Cost-effectiveness comparisons were made for cases cured and deaths prevented. For treating 100,000 febrile episodes, Cq, PS, and Aq cost US$1812, US$2622, and US$3044, respectively. Cost of the drug, compliance, and the level of CRPF had the greatest effect on the cost-effectiveness ratio. The prevalence of high-level drug resistance (RIII) was the most important determinant of the cost-effectiveness. In a scenario with high-level CRPF, treatment with Cq costs US$0.47 to cure one patient and US$2.29 to prevent one death compared with US$0.05 and US$1.52 for treatment with PS. When the prevalence of RIII-level CRPF is greater than 14-31% (depending on the level of compliance), the most cost-effective treatment is PS, despite its 45% greater cost. Decision analysis models will be useful for malaria control planners as strategies are reconsidered in the 1990s.

Africa

Tumor necrosis factor and severe malaria.

To investigate the relation of tumor necrosis factor-alpha (TNF alpha) to Plasmodium falciparum infection, plasma TNF alpha concentrations were measured in Zairian children with severe malaria, mild malaria, or other illnesses. The initial geometric mean plasma concentration of TNF alpha among 61 children with P. falciparum infection, (71 pg/ml) was higher than the level in 26 severely ill, aparasitemic children (10 pg/ml; P less than .001). Among 29 parasitemic children, initial geometric mean TNF alpha levels decreased from 77 to 5 pg/ml (P less than .001) at day 7. TNF alpha levels increased with parasite density and were associated with hyperparasitemia, severe anemia, hypoglycemia, and young age but not with cerebral malaria or fatal outcome. However, TNF alpha levels were elevated equally in children with cerebral malaria and with other signs of severe malaria. With multiple linear regression, TNF alpha levels were elevated independently in children with hyperparasitemia (P = .001) and severe anemia (P = .04). In this study, high TNF alpha levels were associated with several manifestations of severe malaria and were not specific to cerebral malaria.

Animals

Trends and risk factors for HIV-1 seropositivity among outpatient children, Kinshasa, Zaire.

To investigate recent trends in pediatric HIV-1 infection and the early impact of a blood screening program begun in one hospital in 1987 in Kinshasa, Zaire, we evaluated 1110 consecutive children seen in the pediatric emergency ward of the city's largest hospital in November 1988. The HIV-1 seroprevalence was 5.0%, not significantly higher than the rate of 3.8% found in 1986 (P = 0.2). The seropositivity rate was bimodally distributed; children less than 6 months of age had a higher rate (12.6%) than children 6-11 months old (1.9%; OR = 7.6; P less than 0.0001) and children 1-13 years old (4.1%; OR = 3.4; P less than 0.0001). Seropositive children greater than or equal to 1 year of age were more likely than seronegative children to be anemic and to have signs of malnutrition. A previous blood transfusion was associated with HIV-1 seropositivity among children greater than or equal to 1 year of age (OR = 5.4, P less than 0.0005), but not among younger children. Fifty-two per cent of seropositive children greater than or equal to 1 year of age received a transfusion (etiological fraction = 42%). The association with seropositivity was higher for those who had received a transfusion before 1987 than for those who had received a transfusion since 1987 (OR = 4.8, P = 0.01). These findings suggest a relatively stable, high pediatric HIV-1 seroprevalence in Kinshasa and a decreased but continued risk of transfusions. Expansion of currently limited blood transfusion screening programs, and the development of new strategies for limiting transfusions and preventing severe anemia, are needed.

Adolescent

Permethrin-impregnated curtains and bed-nets prevent malaria in western Kenya.

The effectiveness of permethrin-impregnated (0.5 g/m2) bed-nets and curtains as malaria control measures was evaluated in Uriri, Kenya in 1988. One hundred five families were randomly assigned to 1 of 3 study groups (control, bed-net, or curtain). All participants were cured of parasitemia with pyrimethamine/sulfadoxine. Selective epidemiologic and entomologic parameters were measured weekly, while knowledge, attitude, and practices surveys were conducted at the beginning and end of the 15 week study. Plasmodium falciparum infections per person week at risk were significantly higher in the control group than in either the curtain group (5.42 vs. 2.35 cases/100 person weeks risk) or the bed-net group (5.42 vs. 3.77 cases/100 person weeks risk). The curtain group had fewer infections per person week at risk than the bed-net group (2.35 vs. 3.77 cases/100 person weeks risk). A difference was found in clinical malaria among the groups: 45% of persons in the bed-net and curtain groups vs. 30% of those in the control group reported no episodes of fever and chills (chi 2, P less than 0.05). Indoor resting Anopheles gambiae or An. funestus were found on 94 occasions in the control houses, but only twice in the treated houses during weekly visits to each house over the study period (chi 2 P less than 0.001). The pyrethrum knockdown method produced similar results with a total of 195, 23, and 3 An. gambiae and An. funestus collected in the control, bed-net, and curtain houses during the same period, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

[Estimation of vital statistics in rural areas of northern Haiti using a simplified sampling method].

In September 1983, we selected 30 villages in four rural counties of northern Haiti for a partial census and malaria prevalence survey. A cohort of 1,577 persons was enumerated in this census. Survey teams revisited the same houses in these villages in September 1984 and updated the previous census, inquiring about all listed family members. We administered an additional questionnaire to each household concerning the occurrence over the past year of deaths, births, pregnancies, and migration. Among the 1,218 persons who had been followed for one year, there were 21 deaths (crude mortality rate: 17 per 1,000 population; 95% confidence interval [95% CI]: 12 per 1,000, 25 per 1,000) and 35 births (birth rate: 29 per 1,000 population year; 95% CI: 19 per 1,000, 38 per 1,000). The infant mortality rate was 171 per 1,000 live births (95% CI: 81 per 1,000, 315 per 1,000), and the mortality rate for children less than 5 years old was 36 per 1,000 (95% CI: 24 per 1,000, 56 per 1,000). Although small sample surveys are subject to limitations of precision dependent on sample size, they can be a simple method by which researchers may estimate vital statistics for rural areas of less-developed countries.

Epidemiologic Methods

Sensitivity of Plasmodium falciparum to chloroquine and sulfadoxine/pyrimethamine in Nigerian children.

The in vivo sensitivity of Plasmodium falciparum to chloroquine and sulfadoxine/pyrimethamine was evaluated in children under 5 years of age in two areas of southern Nigeria in 1987. A modification of the WHO Standard Field and Extended Tests (in vivo) was used, with follow-up on days, 2, 3, 7, and 14 after treatment with 25 mg chloroquine per kg body weight given over 3 days, or with standard doses of sulfadoxine/pyrimethamine. Clinical and parasitological evaluations were performed. At Igbo Ora, in Oyo State, where by day 7 chloroquine was clinically successful in 94.4% of 36 children and sulfadoxine/pyrimethamine in 91.7% of 36 children, there were no parasitological failures in either treatment group. Fever regressed significantly more rapidly with chloroquine than with sulfadoxine/pyrimethamine. At Oban, in Cross River State, initial parasite densities decreased markedly with the chloroquine regimen but 63.6% of 44 children were parasitological failures on days 3, 7, or 14; and all of the 26 children who failed parasitologically and completed follow-up were successfully treated with sulfadoxine/pyrimethamine. By day 7, clinical success was demonstrated for 77.3% of the children treated with chloroquine. The in vitro sensitivity to chloroquine, quinine, and mefloquine at Igbo Ora indicated that isolates of P. falciparum were sensitive to chloroquine and quinine, but had reduced sensitivity to mefloquine. Because of its continued clinical efficacy, chloroquine remains the recommended treatment for children with uncomplicated malaria in Nigeria. Health providers are, however, encouraged to maintain supplies of sulfadoxine/pyrimethamine as an alternative and to refer patients promptly if necessary.

Animals

Ocular findings in botulism type B.

In April 1977, fifty-nine persons became ill with type B botulism in a large, common-source outbreak. A combination of signs and symptoms that should make the clinician strongly suspect botulism was derived from the histories and ocular findings of these persons. Certain signs of third cranial nerve dysfunction reliably predicted in which patients ventilatory insufficiency would develop.

Botulism

Evaluation of smallpox vaccination policy.

During 1978 and 1979 the Global Commission for the Certification of Smallpox Eradication will proceed with verification of smallpox eradication in 31 countries. If current surveillance activities do not discover any further cases before the end of 1979, the world will be declared smallpox free. However, the recent occurrence of two laboratory associated smallpox cases in Birmingham, England, revealed that the stocks of variola virus held in at least 12 laboratories in the world pose a real danger to the achievement of smallpox eradication and efforts are being made to reduce the number of laboratories retaining the virus to not more than 4-all WHO collaborating centres-by 1980. Scientific data indicate the unlikelihood of smallpox recurring once it has been eradicated from the human population, although further confirmatory studies are continuing. If the Global Commission verifies the eradication of smallpox, continuation of smallpox vaccination will be unjustifiable in view of its severe complications, however infrequent, and the expected global savings that would result from the termination of vaccination programmes.

Animals

Botulism type B: epidemiologic aspects of an extensive outbreak.

Between March 31 and April 6, 1977, 59 individuals developed type B botulism. All ill persons had eaten at the same Mexican restaurant and all had consumed a hot sauce made with improperly home-canned jalapeno peppers, either by adding it to their food, or by eating a nacho that had had hot sauce used in its preparation. There was a highly significant association between illness and consumption of hot sauce when a comparison was made between ill persons and well controls: 4% of all restaurant patrons eating at the restaurant during the outbreak period became ill with botulism; however, approximately two-thirds of those actually exposed to the toxic hot sauce became ill. Disease severity was statistically correlated with incubation periods. No differences in disease severity were found between persons of different age groups. The full clinical spectrum (mild symptomatology with neurologic findings through life-threatening ventilatory paralysis) of type B botulism was documented.

Adolescent

Smallpox eradication: progress and problems.

In 1958, the Eleventh World Health Assembly, on the proposal of the USSR, approved a resolution for world-wide smallpox eradication. In that year alone the disease occurred in 59 countries, and in addition many other areas experienced imported cases. When the intensified eradication programme began in 1967, there were 33 countries with endemic smallpox and two more countries subsequently became endemic. These 33 countries had a population of over 1,200,000,000 and were located in four of the six WHO regions. The most important endemic area was in Asia, but the disease was also endemic in South America and in Africa, south of the Sahara. The intensified campaign quickly narrowed the endemic area. In April 1971, the last case was reported from Brazil, the stronghold of the disease in the Western Hemisphere. By 1973, with the exception of those in the Horn of Africa, smallpox transmission was interrupted in all African countries. The last case in Asia occurred in Bangladesh where variola major made its last stand. The last known case of smallpox in the world was reported from Somalia on 27 October 1977. If no more cases are discovered it will be possible, in two years from that date, to certify that smallpox has been eradicated from all areas of the world, and Member States of the World Health Organization will be able to celebrate an unprecedented victory for preventive medicine. The complete eradication of smallpox is not only the liberation of the world from one of its most dangerous diseases, but also provides an example of what can be achieved when countries throughout the world join together with a common aim.

Africa

Human poxvirus disease after smallpox eradication.

A 5-year-old boy living in a small camp in the rural Ivory Coast had a disease resembling smallpox. This occurred 4 years after smallpox had been eradicated from the Ivory Coast and 1.5 years after the last case of smallpox was detected in West and Central Africa. Clinical, serological, and epidemiological evidence indicated this disease was probably monkeypox, a poxvirus of the variola/vaccina subgroup. A serologic survey of poxvirus antibodies in the wild animal population detected neutralizing antibodies in rodents, larger mammals, primates, and birds. The laboratory and ecological characteristics of poxviruses require further elucidation, especially those which have been found in animals near human monkeypox cases.

Adolescent

Smallpox in the Republic of Guinea, West Africa. II. Eradication using mobile teams.

Smallpox transmission was interrupted in the Republic of Guinea in January 1969, 13 months after the beginning of the National Smallpox Eradication Program, and after approximately 60% of the population had been mass vaccinated. The eradication strategy was founded on the recent epidemiology of smallpox in Guinea and surrounding countries. Tactics were based on use of mobile teams specifically trained for mass vaccination, assessment, surveillance, and epidemic investigation. Guinea was one of 15 West African countries officially certified by the World Health Organization in 1976 as having eradicated smallpox. Continued vigilance to detect any possible importation is needed and would best be part of a program to improve quarantinable disease surveillance. An acceptable immunity level to smallpox should be maintained in priority groups until worldwide smallpox eradication is achieved.

Adolescent

Poxvirus in West African nonhuman primates: serological survey results.

Ten species of nonhuman primates in West African habitat were analysed for variolavaccinia subgroup haemagglutination-inhibition (HI) and neutralization antibodies. The animals were taken in 27 different sampling zones in parts of the Ivory Coast, Mali, and Upper Volta. Of the 195 tested, 15 (8%) had elevated HI antibodies after nonspecific reactions were reduced with potassium periodate pretreatment. Positive neutralization antibodies were found in 21% (44 of 206). Antibodies were detected in serum from monkeys living near two areas where monkeypox cases in humans had occurred. Four samples were tested for monkeypox specific antibodies using an indirect immunofluorescent test; 3 were positive. Despite the prevalence of poxvirus antibodies in monkeys (and other animals) in West Africa, smallpox eradication has been maintained in the area since 1970; thus, animal reservoirs of poxvirus appear to pose no threat to the worldwide smallpox eradication programme.

Africa, Western

Malarial antibodies measured by the indirect hemagglutination test in West African children.

The indirect hemagglutination test with Plasmodium falciparum antigen was used to measure malarial antibodies in filter paper blood specimens from 527 West African children. A slight decline in antibodies was noted in 6- to 8-month-old children wh o had no malaria parasites in their blood smears. Children older than 10 months had similar antibody levels regardless of the presence or absence of demonstrated parasites in blood smears.

Africa, Western

Evaluation of a measles-smallpox vaccination campaign by a sero-epidemiologic method.

An assessment technique has been devised whereby children from 30 randomly chosen sampling sites are visited within three days of measles-smallpox vaccination and one month later. Vaccination coverage is measured at house visits and immunologic status is determined by collection of early and late blood samples on filter papers from substratified children in priority age-groups, and by looking at vaccination scars. The methodology was employed in a rural area of the Ivory Coast during the maintenance phase of a measles-smallpox vaccination program; 1762 children from 0--72 months old were inspected. Children in the target age groups, 6--24 months, had a vaccination coverage of 53.6% whereas children outside of the target group had a 10.5% coverage. Of 571 target age children, 94.6% had a measles hemagglutination-inhibition antibody titer of less than 1:10 dilution at the first visit, and were presumed susceptible to measles or vaccine. Of 247 substratified children 6--8 months, 98.3% were susceptible to measles before vaccination; 84.3% of 127 vaccinated children in this age-group sero-converted when re-tested. Of 324 children 9--24 months, 91.7% were susceptible before the campaign; 94.7% of 170 vaccinated children in this age-group converted. A positive history of prior measles or prior measles-vaccination was not a good indicator of measles serologic status. The smallpox vaccination major reaction rate was 93.2%; 91.4% of children with a recent vaccination scar sero-converted to measles vaccine. Thus, the smallpox scar read at the second visit proved the best clinical marker for determining both coverage and immunologic effectiveness of the campaign.

Age Factors