Effect of acute uncomplicated malaria on platelet counts.

OBJECTIVE: To determine the effect of uncomplicated malaria on platelet count. PATIENTS AND METHODS: Adult Nigerians (residing in the Lagos metropolis) who were diagnosed as having uncomplicated malaria were treated with a standard regime of chloroquine. Platelet counts were obtained before treatment, Day 0, and again on day 14 when parasitaemia had been cleared in the patients. There were 40 (21 males, 19 females) patients enrolled for the study. Their ages ranged from 15 years to 56 years with a mean +/- SEM of 27. 4 +/- 1.8 years. 28 (14 males, 14 females) patients had both day 0 and 14 platelet counts. RESULTS: The malaria parasite counts ranged from 1020 /mm(3) to 72,000 /mm(3) at day 0 with a mean +/-SEM of 15,638.0 +/- 3,727.0/mm(3) and zero on day 14. The mean platelet count on day 0 was 137.0 +/- 58.4x 10(9)/L while the day 14 mean platelet count was 234.0 +/- 96.9 x 10(9)/L. Comparison of mean platelet counts on day 0 with those on day 14 showed a highly statistically significant difference (p < 0.001). The degree of malaria parasitaemia was not significantly related to the level of platelet count. Transient thrombocytopenia is very common in uncomplicated malaria in semi -immune adults. The mechanism, aetiology, and clinical relevance of the phenomenon deserve further studies.

Efficacy and tolerability of a low-dose mefloquine-sulfadoxine-pyrimethamine combination compared with chloroquine in the treatment of acute malaria infection in a population with multiple drug-resistant Plasmodium falciparum.

The efficacy and tolerability of single, low-dose mefloquine, sulfadoxine-pyrimethamine (MSP) combination was compared with chloroquine (CQ) for malaria treatment in a malaria-endemic area of Nigeria with multiple drug-resistant Plasmodium falciparum. The two drug regimens (MSP and CQ) were tested in a 12-month prospective population study. The patients were divided into two groups. Group 1 patients were treated presumptively, based on malaria symptoms. Group 2 patients were treated based on a parasitologic diagnosis using the World Health Organization seven-day in vivo test and extended to a 28-day follow-up period. Tolerability was assessed by the incidence and intensity of adverse events. One thousand nine hundred thirty-five patients visiting 10 health facilities, including the University of Calabar Teaching Hospital, were enrolled. The study showed that the low-dose MSP was efficacious, with day 7 response rates of 95% and 91% for (presumptive) Group 1 and (in vivo) Group 2, respectively, while CQ had day 7 response rates of 82% and 66% in Groups 1 and 2, respectively. The low-dose MSP was significantly (P < 0.0001) more efficacious, with faster fever and parasite clearance times than CQ in this area of CQ-resistant P. falciparum malaria. Eight patients treated with CQ, including seven severe cases (RII-RIII) were successfully re-treated with MSP. Adverse events were generally more common among those treated with MSP (29%) than those treated with CQ (17%). However, the adverse events caused by both drugs were mild to moderate and self-limited. The MSP combination appears to be a good substitute for CQ, in view of multiple drug resistance, especially in areas with severe (RII-RIII) malaria.

Treatment of malaria in north-eastern and south-eastern Nigeria: a population study of mefloquine, sulphadoxine, pyrimethamine combination (MSP) vs chloroquine (CQ).

In a population-based study involving 4019 patients in 20 peripheral health facilities in Nigeria, the outcome of presumptive malaria treatment with MSP was compared to that of CQ. The study was conducted between January 1995 and January 1996. Patients aged 6 months or more with a clinical diagnosis of malaria based on history of fever and axillary temperature > 37.5 degrees C were either treated with MSP (250 mg mefloquine, 500 mg sulphadoxine, and 25 mg pyrimethamine per tablet) or CQ (150 mg chloroquine base per tablet). The clinical cure rate was assessed by the disappearance of clinical signs and symptoms over a 7-day period. Tolerability was assessed by the incidence of adverse events (adverse drug reaction and intercurrent illness). The result shows that the clinical care rate of suspected malaria was 97.6% with MSP and 85.6% with CQ. The incidence of adverse event was 9.5% with MSP and 9.2% with CQ. The withdrawal rate was 2.0% with MSP and 5.0% with CQ; 3.5% of the patients in the CQ group withdrew due to adverse events compared to 0.47% with MSP. In conclusion it was observed that in addition to superior efficacy of MSP over CQ, fever clearance rate with MSP was comparable to that of CQ. The study also demonstrated that two tablets maximum dose of MSP is safe and effective in a large population of Nigeria malaria patients.

Preliminary assessment of the efficacy of mefloquine/-sulphadoxine/ pyrimethamine combination in the treatment of uncomplicated malaria in children in North Eastern Nigeria.

Preliminary assessment of efficacy of mefloquine/-sulphadoxine/pyrimethamine (MSP) combination in the treatment of uncomplicated Plasmodium infections was conducted in-vivo in non-immune and semi-immune children in Damboa, in the North east of Nigeria using a 7-day protocol. Six hundred and forty-six (76.4%) subjects out of 846 screened had positive Plasmodium infections. Seventy-two patients aged 6 months to 11 years were enrolled, of whom 69 (95.8%) completed the study. MSP demonstrated high clinical efficacy, producing 100% cure rate against pure P. falciparum (77.8%), pure P. malariae (18.1%) and mixed P. falciparum and P. malariae (4.2%) infections. GMPDs for P. falciparum, P. malariae and mixed infections were 4,826, 3,680 and 12,573 a sexual stages per microl of whole blood. The mean parasite clearance time (MPCT) was 4.42 days for pure P. falciparum parasitaemia and 4.82 days for P. malariae alone. No parasitologic failure occurred in the patients. Clinical response occurred rapidly; all fever cases cleared within 24 hours. Moreover, significant (P<0.05) PCV improvement occurred in 7 days from an average of 33.8 +/- 4.5% on D0 to 35.5 +/- 3.5% on D7. Besides, this drug was well tolerated by majority of patients. Details of these findings are presented and discussed against the background of increased efforts towards effective malaria treatment and control in Nigeria.

Monitoring community response to malaria control using insecticide-impregnated bed nets, curtains and residual spray at Nsukka, Nigeria.

A project testing the efficacy of insecticide (permethrin)-impregnated bed nets, compared with impregnated door and window curtains, residual house spraying, and a control group was implemented in 12 village clusters in the Nsukka Local Government Area of Enugu State, Nigeria, using epidemiologic and entomologic indicators. The appropriate materials and services were given free to all families. During the first year of study, three monitoring exercises were carried out in a random selection of homes where children under 5 years of age resided. Information was collected on perceived effectiveness of the interventions, condition of nets and curtains, reasons for not sleeping under nets, and recall of steps required in caring for nets and curtains. Bed nets were perceived as more effective in reducing mosquito bites compared with the two other interventions. At the last monitoring period, which occurred a few weeks before a re-impregnation exercise, respondents also perceived bed nets to be most effective in preventing malaria. These findings coincided with epidemiologic evidence. Curtains, especially those at doors, were more likely to be torn and dirty than bed nets. Although holes would not reduce the effectiveness of the insecticide, they could reduce the 'beauty' of the curtains, a perceived benefit that initially attracted villagers to both curtains and nets. Bed net owners reported significantly less frequent use of other mosquito control measures in their homes than did members of the other groups. Finally, bed net users demonstrated increased knowledge of use and care steps than did those with curtains. These findings suggested a high level of social acceptability of bed nets, and point to the need to test their acceptability further under conditions where people would pay for nets and communities would manage distribution and re-impregnation systems.

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.

Social and behavioural baseline for guiding implementation of an efficacy trial of insecticide impregnated bed nets for malaria control at nsukka, Nigeria.

Insecticide impregnated bed nets are being tested in many tropical areas as a major tool to control malaria. In a few African countries, there is a history of local bed net production and use, while in most others, ownership of commercially-produced nets is rare due to high costs relative to local income. Such variations in pre-existing bed net use behavior must be studied prior to designing new intervention trials. A "baseline" diagnostic study in Nsukka Local Government of Enugu State, Nigeria, found that local beliefs about malaria causation, which include heat from the sun and hard work, may reduce the perceived efficacy of bed nets as an appropriate malaria control action. While the belief that mosquitos can cause malaria increased with level of formal education, the study also documented that educated people simultaneously hold both indigenous and scientific perceptions about malaria. Although the project provided bed nets, curtains and residual house spray for free, long-term sustainability may be influenced by the main constraint to current ownership of a bed net, i.e., cost. Issues, such as concern about feeling hot under the nets, a tendency to sleep outside during the hot dry season, and variations in people's ideas about what constitutes a malaria episode, point to the need to monitor the bed net intervention. This is recommended as a means of learning how people perceive the efficacy of the nets, whether they use them correctly and whether the intervention can be sustained and integrated into local primary health care programs.

Amodiaquine treatment of uncomplicated malaria in children, in an area of chloroquine-resistant Plasmodium falciparum in north-central Nigeria.

The efficacy of amodiaquine against Plasmodium falciparum malaria was assessed in an area of confirmed chloroquine resistance in the cool, north-central plateau of Nigeria, using a 14-day protocol. The patients were all children aged <5 years of age. The drug proved highly efficacious, giving a cure 'rate' of 100% on day 14 and mean fever- and parasite-clearance times of 1.11 and 3.11 days, respectively. It was also well tolerated. Following treatment, packed-cell volumes (PCV) generally increased (65% of patients) but remained constant (12%) or even decreased (23%) in some patients; the overall improvement in PCV was not statistically significant (P >0.05). The results justify the use of amodiaquine to treat P. falciparum malaria in those who have failed treatment with chloroquine and the second-line drugs (e.g. sulfadoxine-pyrimethamine) currently used in Nigeria. As the amodiaquine would be better employed as one part of a combination than on its own, there is a need to identify suitable partner compounds.

Sensitivity of Plasmodium falciparum to chloroquine and sulfadoxine/pyrimethamine in Negerian 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 per cent of 36 children and sulfadoxine/pyrimethamine in 91.7 per cent 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 per cent of 44 children were parasitological failures on day 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 per cent of the children treated with chloroquine. The in vitro sensitivity to chloroquine, quinine, and mefloquine at Igbo Ora ...(AU)