Perceptions on the use of insecticide treated nets in parts of the Imo River Basin, Nigeria: implications for preventing malaria in pregnancy.

This study aimed at assessing perceptions on use of ITNs in parts of the Imo River Basin, Nigeria and its implications in preventing malaria in pregnancy. Data was collected using focus group discussions, key informant interviews and structured questionnaires. Results showed high awareness on the benefits of ITNs. Factors affecting use of ITNs included its high cost, perceptions of chemicals used to treat them as having dangerous effects on pregnancy, low utilization of antenatal care, husband's lack of interest in malaria prevention and perceptions that adolescent girls are at low risk of getting malaria. The implications of these findings include demystifying the negative perceptions on the chemicals used for net treatment and subsidizing the cost of ITNs to increase access. These findings provide important lessons for malaria programmes that aim at increasing access to ITNs by pregnant women in developing countries.

Malaria infection in HIV/AIDS patients and its correlation with packed cell volume (PCV).

BACKGROUND & OBJECTIVES: The study was designed: (i) to determine the prevalence of malaria parasites; (ii) to determine the relationship between parasitaemia and age/sex; (iii) to correlate the PCV levels with parasitaemia; and (iv) to determine the influence of protection against natural transmission on the prevalence of malaria. METHODS: Participants were recruited at the Plateau State Human Virology Research Laboratory (PLASVIREC), Robert Gallo House at the Plateau State Specialist Hospital, Jos and grouped into: (i) Malaria and HIV co-infection group (n = 64); and (ii) HIV infected group without concurrent malaria infection (n = 136). Standard laboratory procedures were used for the HIV and Plasmodium parasites screening, malaria parasite density, and packed cell volume. RESULTS: The results showed a significant difference (p >0.05) among the sexes and age groups. About 64 (32%) of the individuals had Plasmodium infection (30% Plasmodium falciparum, 0.5% P. malariae, and 1.5% mixed infections of P. falciparum and P. malariae). Malaria parasites were more common among the rural dwellers and in the age group of 21-30 yr. Regression analysis showed a negative association of malaria parasitaemia and PCV among the malaria-HIV positive and malaria-HIV negative (r2 = 0.529; p <0.001). INTERPRETATION & CONCLUSION: In the present study, PCV might be of useful indicator and if not monitored could lead to AIDS establishment especially where high malaria parasitaemia is noted. The findings further suggest that the defined stage of HIV infection in the study, malaria coinfection may moderate the impact of HIV infection on PCV.

A survey of predilection sites and degree of disability associated with guineaworm (Dracunculus medinensis).

Of the 1,200 people surveyed for dracontiasis in Ribi and Kanje villages in Awe Local Government Area of Plateau State, Nigeria, 982 (82%) were infected. Most infections (98%) involved the lower limb. Worms emerging from the umbilicus, groin, palm, wrist, and upper arm were also encountered. Of the 982 infected persons 206 (21%) were totally incapacitated, 193 (20%) were seriously disabled, and 431 (44%) suffered mild incapacity, while 152 (16%) were unaffected. Of the 5 species of cyclopoid copepods found in their main water source, only Thermocyclops nigerianus and Mesocyclops aequatorialis harboured guineaworm larvae.

Prevalence of schistosomiasis and other intestinal helminth infections among senior primary school children in Makenene Sub-Division, Cameroon.

A study was carried out in four villages of Makenene Sub-Division some 85 km north-west of Yaounde, between November 1993 and March 1994 to assess the prevalence and intensity of schistosomes and other helminth infections among senior primary school pupils aged 9-16. An extensive questionnaire was used to collect sociodemographic information and information on water-related activities. The overall prevalence of S. mansoni infection was 228 (23.6%) while S. haematobium infection was practically non-existent 03 (< 1%). Infection rates with intestinal nematodes were very high, up to 98% in some villages. Prevalence rates of schistosomiasis varied significantly (P < 0.05) between villages with the highest (36.2%) recorded in Makenene. Infections with other parasite species encountered were significantly different (P < 0.01) while a marked association was observed between water contact activities and the distribution of S. mansoni infections. However, S. mansoni infection intensities were not significantly different (P > 0.05) between those with a history of previous infection and treatment and those without.

Studies on filariasis in Bauchi State, Nigeria. 1. Endemicity of human onchocerciasis in Ningi Local Government Area.

The endemicity of human onchocerciasis was assessed in eight rural, at-risk communities in Ningi Local Government Area, Bauchi State, Nigeria, between July 1990 and March 1991. Of the 1536 subjects skin-snipped, 334 (21.7%) were positive for Onchocerca volvulus microfilariae. Surprisingly, there was a significant inverse relationship between prevalence and mean microfilarial load (r = -0.608; P < 0.05). Males were more likely to be infected than females (P < 0.01) and cattle rearers (71.0% infected), farmers (49.8%) and fishermen (40.0%) had significantly higher prevalences than students/schoolchildren, housewives or traders (P < 0.001). Pruritus and itchy eyes were recorded in all age groups and appeared in much younger subjects than any other manifestations of the infection. Prevalence and onchocercal blindness were linearly related to intensity of infection. The epidemiological significance of these findings, in terms of a future community-wide programme of long-term chemoprophylaxis with Mectizan, is highlighted.

Studies on filariasis in Bauchi State, Nigeria. II. The prevalence of human filariasis in Darazo Local Government area.

In an eleven months study of eleven communities of Darazo Local Government Area of Bauchi state, northern Nigeria, 293 (21.7) of 1,349 persons examined harboured various filarial parasites. Of the sampled population, 18%, 1.9%, 1.6%, 0.5% and 0.2% had microfilariae of Onchocerca volvulus, Wuchereria bancrofti, Mansonella perstans, M. streptocerca and Loa loa respectively. Of the 637 females examined, 90 (14.1%) were infected, while 203 (23.5%) of 712 males sampled had filarial infections. The high rate in males was significant (P < 0.001). O. volvulus mf-rate increased gradually from the first decade to the seventh decade of life but declined thereafter. Prevalence of bancroftian filariasis was consistently lower in females of reproductive age, while the distribution of various filarial parasites varied significantly among age groups and communities (P < 0.05). Fishermen (42.9%), farmers (42.4%) and cattle rearers (40.9%) were the most affected occupational categories. Control strategies are highlighted.

A case of probable transplacental transmission of Wuchereria bancrofti microfilariae.

A case of transplacental transmission of Wuchereria bancrofti microfilariae is reported in endemic are of Bauchi State, Nigeria. The diagnosis was based on the history of illness, clinical symptoms, age of the child and presence of sheathed microfilariae of nocturnal periodic form of W. bancrofti in the peripheral blood films. Also the night blood sample collected from the child's mother revealed mf of W. bancrofti in addition to the unilateral elephantiasis of the hindlimb. The implication of this observation is stressed.

The ecology of animal parasitic nematodes in endemic areas of Jos, Nigeria.

A survey involving 3418 faecal samples collected from three areas of heavy human and animal activities in Jos, Nigeria showed that 2354 (68.9%) of the samples harboured various parasitic nematodes of man and animals. Altogether, twelve species of parasitic nematodes were encountered. Five of these, namely: Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, Trichuris trichiura and Strongyloides stercoralis infect man while five others: Trichostrongylus probolurus, T. colubriformis, Haemonchus contortus, Cooperia pectinata and Strongyloides papillosus are parasites of ruminants. Ancylostoma caninum and Trichuris suis parasitic in dogs and pigs, respectively, were also recorded. Generally these nematodes fluctuated with changes in ecological factors, especially rainfall and temperature. Whereas most of the human parasitic nematodes were encountered in the shaded areas, the open areas harboured more animal parasites, an indication that most human parasitic nematodes are more susceptible to deleterious environmental conditions. Aspects of zoonotic and public health significance are stressed.

A probable case of vertical transmission of Onchocerca volvulus microfilariae.

A probable case of vertical transmission of Onchocerca volvulus microfilariae in Dass Bauchi State, Nigeria is presented. A 28-week-old male child delivered by a 39-year-old Fulani woman suffering from onchocerciasis was positive for O. volvulus microfilariae based on skin snip examinations. The child had general body pruritic rash and intermittent fever. Although the child's skin snip on re-examination five weeks later was also positive, the fever had gradually subsided.

Trichomoniasis amongst students of a higher institution in Nigeria.

A total of 2048 urine specimens were examined to assess the infection prevalence and epidemiological factors of T. vaginalis amongst students in a Nigerian higher institution. Five hundred and five students were infected (24.7%). This included 131 (15.6%) males and 374 (31.0%) females. More male than female students were found to be asymptomatic. Infection was significantly higher in females than males and in the second and third than the fourth and fifth decades of life (P < 0.05). Infection increases progressively with increase in the number of sexual partners. The use and neglect of condoms were also assessed. The pH range of the vagina of most infected females was between 5.8-8.2. Clinical symptoms noted among females were local tenderness, vulval pruritus and intermittent burning sensations in addition to profuse vaginal discharges. The public health implication of the findings and some epidemiological factors enhancing the disease transmission are presented.

Human helminthosis in a rural community of Plateau State, Nigeria.

Urine and faecal samples were obtained from 1,517 people in Fier, a typical rural village in Plateau State, Nigeria, for a parasitological survey among the population. 643 (42.39%) persons were found to be infected with altogether 9 helminths, namely: Ascaris lumbricoides, hookworm, Taenia sp., Trichuris trichiura, Enterobius vermicularis, Schistosoma mansoni, S. haematobium, Hymenolepis nana and Strongyloides stercoralis. Age and religion as opposed to sex, type of sewage system, and type of housing had a significant effect (P < 0.05) on the prevalence rates of the helminths in the population. Snail vector survey for schistosomatosis revealed the presence of Bulinus (Bulinus) truncatus, Bulinus (Physopsis) globosus and Biomphalaria pfeifferi with the latter being the most common with brevifurcate cercariae, and xiphidiocercariae being the most common cercariae harboured by the snails.

Observations on mansonellosis among the Ibos of Abia and Imo States, Nigeria.

Between November, 1988 and April, 1991, parasitological and symptomatological methods of diagnosis were used to survey the prevalence of mansonellosis among the Ibo population in Abia and Imo States of Nigeria. 1,197 or 28.6% of the 4,183 persons examined were positive for microfilariae of Mansonella perstans. The prevalence of mansonellosis was significantly higher (P < 0.05) among rural dwellers (34.6%) than among urban dwellers (22.5%), in males (30.8%) than in females (26.3%), in farmers (59.8%) and palm wine tappers (46.1%) than in civil servants (7.6%), and in persons 21 years of age and above (36.2%) than in those in the first two decades of life (9.4%). Clinical signs observed in most infected persons include body itching, joint and back pains, occasional giddiness and elephantoid scrotum. Body itching was the most commonly observed clinical sign (14.7%), followed by joint pains (12.41%) with elephantoid scrotum (3.5%) as the least. The public health implication of the findings is discussed.

Experimental Wuchereria bancrofti infection of Culex quinquefasciatus and Aedes aegypti.

Laboratory-derived females of Culex quinquefasciatus and Aedes aegypti were experimentally infected with Wuchereria bancrofti by allowing the insects to feed on infected volunteers of known microfilariae density between 24.00 and 2.00 hours. Of the 240 mosquitoes used for the experiments only 67 (55.8%) of C. quinquefasciatus and 83 (69.2%) of the Ae.aegypti actually fed on the volunteers' blood. After 16 days post-infection period, 50 (74.62%) of the engorged C. quinquefasciatus harboured infective L3 larval stages of W. bancrofti, while 16 (23.9%) and 1 (1.49%) harboured L2 and L1 pre-infective larval stages, respectively. On the other hand, no development to the L3 infective stage was observed in the engorged Ae.aegypti though 34 (40.96%) harboured L1 pre-infective stages of the parasite. Our results suggest that C.quinquefasciatus could be actively involved in the transmission of urban bancroftian filariasis in Nigeria.

Glycogen, protein and lipid content of adult Fasciola gigantica (Trematoda).

The concentration of carbohydrates, proteins, and lipids in the whole worm, gut, and body musculature of Fasciola gigantica was investigated from worms collected from cattle slaughtered in the Jos abattoir. Protein accounted for the highest concentration of the constituents constituting 62.59 +/- 0.86% of the dry weight of the fluke. This was followed by lipid with 28.15 +/- 0.86% of the dry weight while carbohydrate (glycogen) was 6.29 +/- 0.11% of the dry weight. Thin-layer chromatography revealed the presence of six distinct bands of neutral lipids, namely: monoglycerides, 1,2-diglycerides, 1,3-diglycerides, free fatty acids, triglycerides and sterol esters from both whole worm homogenate and fractions of the gut and muscle tissues. In the case of phospholipids, lysophosphatidyl choline, sphingomyeline, phosphatidyl choline and phosphatidyl-ethanol amine were recovered. When the free fatty acids were subjected to further fractionation, palmitic, stearic, as well as oleic acids were recovered in appreciable quantities indicating that lipids are being catabolized in these trematodes.

Onchocerciasis in Plateau State; Nigeria: ecological background, local disease perception & treatment; and vector/parasite dynamics.

The physico-biological ecological complex in Plateau State has by definition increased the potential of most rivers to support the breeding and dispersal of vector species as well as human acquisition and dissemination of the disease for several months in a year. Though villagers in endemic areas are of the know of the nuisance of blackfly bites, but the majority of them lacked the aetiological knowledge of onchocercal lesion. Hence disease management is misdirected towards consulting the oracle and appeasing the gods. The vectors of onchocerciasis in Plateau State, S. damnosum, and S. sirbanum are wet season breeders with their peak biting density occurring at the height of rainy season. However, biting flies carry more infective parasites at the beginning and end of rain. These vectors exhibit bimodal biting activity: a small one in the morning hours and a pronounced evening peak. Biting activity is at least influenced by two major climatic factors; illumination and temperature. However, the fastest changing climatic factor relative to an increase in the biting activity of flies was illumination. Microfilarial load in the skin of patients does not significantly change throughout the year or when biopsies are taken under shade throughout the day. Extreme temperatures, however, have significant reducing effect on the skin microfilarial. The epidemiological relevance of these in the ongoing MECTIZAN delivery in the State are discussed.

Hyperendemic onchocerciasis in the Taraba river valley of Gongola state (Old Adamawa province), Nigeria.

A survey of the prevalence of onchocerciasis was carried out in the Taraba river valley, Nigeria where Simulium damnosum s. l. is known to breed but about which no epidemiological data exists. Skin biopsies taken from 2,876 persons in 14 communities were examined for the microfilariae of Onchocerca volvulus. 100% infection rate was recorded in one of the communities, five other communities had prevalence rates between 81.0% and 94.7%. Three communities had infection rates between 44.8% and 69.1%. The mean microfilarial density in all the communities was 64.7 with a range between 3.2 and 167.6. The present findings indicate that the Taraba river valley may be one of the worst onchocerciasis zones in Nigeria.

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.