Poliovirus antibody in children from a paediatric hospital in Ibadan, Nigeria.

The immune status of 100 Nigerian children (ages 0-14) from a paediatric hospital in Ibadan, against poliovirus, after the administration of polyvalent oral poliovirus vaccine (types 1, 2 and 3) was determined using serum neutralisation test. High antibody titres were demonstrated in 78% of all the age groups tested. 57% of children under two years of age, 75% of those three to five years, and 100% of those above six years, had high poliovirus antibodies. 77% of male (47 out of 61) and 79% of female (31 out of 39) were positive. The difference between the sexes is not statistically significant (P greater than 0.05).

Rotavirus infection in children presenting with acute gastroenteritis Ibadan, Nigeria.

Faecal samples from 84 children presenting with acute gastroenteritis at the University College Hospital, Ibadan, Nigeria and 28 from a non-diarrhoeal control group were tested for rotavirus by an ELISA. 18 cases (21%) and none of the controls were positive. Hospital in-patients had a higher percentage of positives (25%) than did out-patients (10%). The age distribution of infections showed that the highest infection rate (67%) occurred in children four to six months old. Percentages of positive samples from other age groups was as follows: 0 to 3 months, 13%; 7 to 12 months, 33%; and 13 to 24 months, 16%. None of the faecal extracts from children older than two years was positive for rotavirus.

Arthropod-borne viral infections of man in Nigeria, 1964-1970.

During the years 1964 to 1970, 171 arboviruses of 15 different types were isolated from humans in Nigeria. Isolation rates were highest in 1969, and lowest in 1965 and 1967. Monthly arbovirus activity was highest in the rainy season months of June, July and August and lowest in the dry months of January and February. Viruses were isolated from all age groups, with the majority from children one to four years old. The viruses isolated in largest numbers were chikungunya and yellow fever, which caused epidemics in 1969, and dengue types 1 and 2 and Tataguine, which are endemic in Ibadan. Bwamba virus was isolated in 1964 and 1969, and Bunyamwera group viruses were encountered for the first time in 1969. Other viruses recovered less frequently were Zika, Igbo-Ora (an agent related to o'nyong-nyong), two viruses related to the Uganda mosquito virus Ug MP 359, Dugbe, Thogoto, Lebombo and Shuni. Several of these are new agents and have not previously been isolated from man. Clinical details are presented where available.

Concurrent and consecutive infection and immunisation with yellow fever and UGMP-359 viruses.

Concurrent and consecutive infection and immunisation with yellow fever virus and UGMP-359 virus was investigated in mice, using identical doses of both viruses. In double infection it was shown that both viruses could multiply independently of one another, when both were inoculated simultaneously by the intracerebral route. On the other hand, there was mutual exclusion between them when the inoculation of one antedated the other, by the same intracerebral route. Both viruses multiplied to similar titres, in single infection, in the target organ (brain). By the intraperitoneal route, the outcome was influenced byhe relative sensitivity of this route of inoculation to support and sustain the replication of either virus. Thus, because yellow fever virus replicated more than UGMP-359 after intraperitoneal inoculation, the latter is always excluded, even when the inoculation ofUGMP-359 preceded that of yellow fever. In the double immunization studies it was shown that comparative specific antibody titres to both viruses were obtained either when both viruses, as immunogens, were given simultaneously, or when the inoculation of one was alternated, at weekly intervals, with the other.

Cytological, cytochemical and immuno-fluorescence studies with Dugbe virus - a new Nigerian tick-borne virus.

Dugbe virus, a new tick-borne arbovirus from Nigeria, was propagated in continuous porcine kidney (PS) cells, and the cytopathology studied by various staining techniques such as May-Grunwald-Giemsa, methyl-green pyronine, Feulgen, and immuno-fluorescence. The gross cytopathology was slight and infected cells continued to undergo normal mitotic divisions. The outstanding cytopathologic feature was the presence of large basophilic intracytoplasmic inclusion bodies, which were pyroninophilic and Feulgen negative. By immunofluorescence these inclusions were shown to be depots of viral antigen; specific fluorescence was confined to the cytoplasm throughout the replication of the virus.

Biophysical and immunological studies on the differential effect of guanidine hydrochloride on type A and type B influenza viruses.

Guanidine hydrochloride selectively inactivated both the biological activity and the immunogenicity of the haemagglutinin of influenza A/X-7 (HON2). The residual neuraminidase was fully active biologically and immunologically. The reverse was observed with influenza B/ROB; with this virus the haemagglutinin was resistant, and was immunogenic; while the neuraminidase was selectively inactivated, and was not immunogenic.

Laboratory and clinical investigation of the 1974 influenza epidemic in Nigeria.

Altogether 13 strains of virus were isolated during the 1974 influenza epidemic in Nigeria. These A/Nigeria/1/74 strains were shown by haemagglutination-inhibition tests to be closely related to the A/Port Chalmers/1/73 virus. Antibody to the epidemic strains developed rapidly in the population and 80-95% of all age groups tested possessed high antibody levels; of 145 paired sera tested, 133 (92%) showed sero-conversion to A/Nigeria/1/74 virus.

Seroepidemiology of Congo virus (related to the virus of Crimean haemorrhagic fever) in Nigeria.

A survey for neutralizing antibodies to Congo virus was carried out in Nigeria. Of a total sample population of 250, comprising 141 males and 109 females, 9 males and 15 females had antibody levels >/= 1.5 log neutralization index. In the age group 0-10 years 4 of 84 males and 14 of 79 females had antibody levels >/= 1.5 log neutralization index. There was no evidence of nonspecific antiviral activity in the sera tested.