Mastomys natalensis and Tatera gambiana as probable reservoirs of human cutaneous leishmaniasis in Nigeria.

Leishmania sp. was isolated from the livers and spleens of 4 of 56 Mastomys natalensis and one of 21 Tatera gambiana in Keana District, Nigeria; none of the rodents had cutaneous lesions. Parasites were not found in 42 Rattus rattus. Experimentally infected mice developed cutaneous lesions characteristic of L. major infection. The organisms could not be cultivated in vitro.

Transplacental passage of Plasmodium falciparum and seroevaluation of newborns in northern Nigeria.

The findings of a prospective study of 656 near-term pregnant; women, and of the cord and peripheral blood of newborns of positive mothers are reported. 292 (44.51%) of the pregnant women were infected with Plasmodium falciparum. Further microscopic screening of the cord blood of newborns of the 292 positive cases at delivery showed a parasite rate of 10.95%. Transplacental passage of P. falciparum was confirmed by detection of parasitemia in the peripheral blood of 2.82% of newborns within 7 days of birth. Serological investigation of sera of 284 newborns by indirect fluorescent technic (IFA) with P. falciparum IgM specific conjugate indicated that 72 (24.66%) had IgM antibodies of P. falciparum in their blood. The average birthweight of seropositive newborns was 400 g less than seronegative ones. There was no significant difference in the rate of neonatal infection regardless of whether or not the mothers had taken chloroquine prophylaxis.

Malaria infection of the cord and birthweights in Nigerians.

OBJECTIVES: To establish the prevalence of cord malaria parasitaemia in Nigerians and to elucidate its effect on birthweight. DESIGN: Case series. SUBJECTS: 1,905 women resident in three parts of Nigeria. SETTING: University of Jos Teaching Hospital, Jos, Plateau State, Bauchi Specialist Hospital and Eku Baptist Hospital, Eku Delta State. RESULTS: 21.6 pc (405) were infected with Plasmodium falciparum. The prevalences by residence were 21.8 pc in Bauchi, 23.2 pc in Jos and 17.5 pc in Eku. The cord malaria prevalence was significantly higher among newborns of first pregnancies than those of two or more pregnancies. Although no significant seasonal fluctuation in mean birthweights was found, the mean for the August to October quarter were the lowest in the three study sites. The mean birthweights of newborns with parasitized cords were generally lower than those that were not parasitized. Birthweights of infected cords also decreased with increasing parasite densities. Of the newborns 215 (11.2 pc) weighed < or = 500 g, of which 202 (10.5 pc) had cord malaria. CONCLUSION: There is a need for more efficient malaria chemoprophylaxis regime during antenatal care in public hospitals to effectively manage malaria in pregnancy and reduce the incidence of low birthweight.

Development and survival of Haemonchus contortus larvae on pasture at Vom, Plateau State, Nigeria.

The development and survival of the eggs of Haemonchus contortus on pasture at Vom were studied by depositing faecal pellets on grass plots over a period of 12 months. Development and survival to the infective larvae occurred throughout the study except during the dry season months of December to April. More infective larvae were recovered from the herbage in June, July and August than in other months. The survival time of the infective larvae ranged from 2 weeks in October to 10 weeks in June, July and August. Rainfall was the most important epizootiological factor influencing the development and survival of the infective larvae. Temperature was not a limiting factor.

Transplacental passage of Plasmodium falciparum and seroevaluation of newborns in northern Nigeria.

The findings of a prospective study of 656 near-term pregnant women, and of the cord and peripheral blood of newborns of positive mothers are reported. 292 (44.51%) of the pregnant women were infected with P. falciparum. Further microscopic screening of the cord blood of newborns of the 292 positive cases at delivery showed a parasite rate of 10.95%. Transplacental passage of P. falciparum was confirmed by detection of parasitemia in the peripheral blood of 2.82% of newborns within 7 days of birth. Serological investigation of sera of 284 newborns by Indirect Fluorescent Technique (IFA) with P. falciparum IgM specific conjugate indicated that 72 (25.35%) had IgM antibodies of P. falciparum in their blood. The average birth weight of seropositive newborns was 400 gm less than seronegative ones. There was no significant difference in the rate of neonatal infection regardless of whether or not the mothers had taken chloroquine prophylaxis.

Seasonal variation of malaria parasite density in paediatric population of Northeastern Nigeria.

Malaria is a major cause of morbidity and mortality in children and adults in the Sudano Sahel of Northeastern Nigeria with the highest prevalence of malaria in pregnancy of 64.5 in Nigeria recorded in this region. This study was carried out in 2003 and 2004 to provide parasitological baseline data for the development of Malaria Early Warning System (MEWS) for the surveillance of type I epidemic caused by meteorological conditions and to provide data for timing malaria key vector control measures such as Indoor Residual Spraying (IRS) for maximum effect. Clinical information about malaria cases were used in this study. In all 692 children aged 6 to 96 months were screened for Plasmodium infection and used for the analysis. The results showed that the majority of infected children (68.06%) were aged 12-60 months and their asexual parasite density (ap/ u1) was between 100-500 ap/u1 of the whole blood. The month of September recorded the highest Geometric Mean Asexual-Densities (GMPD) of 13,655 while the lowest parasite densities were observed at the peak of the dry season, especially during the months of March and April. Significance difference (p<0.05) was observed between the sexes in infection rate. It is obvious that male children have higher infection rate (about 67.5%), than while female children (32.5%) regardless of climate seasonality. Designing a malaria early warning system and providing baseline parasitological data for timing of spraying cycles for key malaria vector control measures such as Indoor Residual Spraying (IRS) should be encouraged to complement other effective malaria control strategies .Hence the need for this investigation.

Effects of Aureo-S-700R on sporulation, viability and infectivity of ovine coccidial oocysts.

Sporulation rates of normal oocysts and oocysts isolated from lambs infected with coccidia and fed Aureo-S-700R for 25 days were studied at different temperatures. The viability and infectivity of the latter were also investigated. Temperatures of 5 and 10 degrees C inhibited sporulation of oocysts, but when the same oocysts were subsequently incubated at 25 degrees C, they sporulated. At 35 and 40 degrees C, sporulation was initially fast, but death and degeneration of oocysts occurred at these temperatures after 3 days. Normal oocysts sporulated faster and in greater numbers than oocysts isolated from medicated lambs; both kinds of oocysts sporulated best between 20 and 25 degrees C. Lambs inoculated with oocysts from medicated lambs passed fewer oocysts for a shorter period of time than lambs inoculated with normal oocysts. The former lambs gained more weight, passed better formed faeces, ate better and had higher PCV and haemoglobin values than the latter.

Malaria morbidity among children attending maternal and child welfare clinics in northern Nigeria.

Blood samples from 522 children within the ages of 0-9 years attending maternal and child welfare clinics in northern Nigeria who were clinically diagnosed as being malarious were obtained for parasitological examination. Results revealed a parasite rate of 41%, density index of 7.72 and 19.5% of the population with parasite densities higher than the critical value of 10,000 parasites/mm3. There was no direct relationship between body temperature and rate of infection and between febrile illness and parasite density. Sex unlike age had no effect on the infection in the population. The study confirms that accurate diagnosis of malaria rests upon parasitological examination and not clinical acumen.

Strongyloides papillosus infestations of lambs in Plateau State of Nigeria.

The frequent appearance of patent infestations of Strongyloides papillosus in lambs under one week is observed, and it is suggested that either the short generation interval or pre-natal infection is the cause. Pathogenic effects associated with heavy infestations in young lambs consisted of anorexia, loss of weight, diarrhoea and a moderate anaemia. The lambs were usually very weak, unable to stand and laying prostrate. Death usually followed at this stage and three such lambs examined showed severe enteritis. There was also severe dermatitis noticed around the flanks and abdomen. The epidemiology studies which were based on worm egg counts taken at monthly intervals for a twelve-month period showed high counts in October and November, intermediate counts in May to August and low counts from February to April. The egg counts per g of faeces ranged from 100 to 18,000.

Plasmodium/intestinal helminth co-infections among pregnant Nigerian women.

Hospital based studies were conducted to investigate the occurrence of Plasmodium/intestinal helminth co-infections among pregnant Nigerian women, and their effects on birthweights, anaemia and spleen size. From 2,104 near-term pregnant women examined, 816 (38.8%) were found to be infected with malaria parasites. Among the 816 parasitaemic subjects, 394 (48.3%) were also infected with intestinal helminths, 102 (12.5%) having mixed helminth infections. The prevalence of the helminth species found in stool samples of parasitaemic subjects examined was, Ascaris lumbricoides (19.1%), hookworm (14.2%), Trichuris trichiura (7%) Schistosoma mansoni (3.4%), Enterobius vermicularis (2%), Hymenolepis sp. (1.6%) and Taenia sp. (1%). Mothers with Plasmodium infection but without intestinal helminth infection had neonates of higher mean birthweights than those presenting both Plasmodium and intestinal helminth infections and this effect was more pronounced in primigravids. The mean haemoglobin values of malarial mothers with intestinal helminth infections were lower than those with Plasmodium infection but without intestinal helminth infections but these were not statistically significant. Severe splenomegaly was predominant among parasitaemic gravidae who also harboured S. mansoni infection in two of the hospitals studied.

Malaria in pregnancy in Nigerians: seasonality and relationship to splenomegaly and anaemia.

The effect of malaria parasitaemia on spleen size and anaemia in 1,905 pregnant women in Jos Plateau highlands, Bauchi Savannah plains and Ethiope river basin of Nigeria was evaluated. The overall spleen rates in Jos Plateau, Bauchi and Ethiope were 15, 23, 16.33 and 10.71% respectively. Higher cases of palpable spleen were detected in pregnant women than non-pregnant controls. Spleen rates also showed seasonal variation, but not very significant. Malaria prevalence rates were higher than spleen rates. In all three study sites, parasitaemic pregnant women had significantly lower haemoglobin values than malaria negative mothers, especially among primigravids. However, there was no constant association between higher parasite density and splenomegaly, since few cases of enlarged spleens were also recorded among subjects with low parasitaemia. Severe anaemia was predominant among parasitaemic pregnant women with high spleen classes.