Pilot studies on the occurrence of some infectious diseases in two different areas in south Yemen (Aden) (part II. Microbiology).

This paper is the second part of the article dealing with intestinal bacteria. The findings are relatively poor in comparing with the frequency of intestinal protozoa. Among 83 stool specimens taken for bacteriological examination 14 isolations of different bacteria were proved. One S. muenchen was isolated from a 3 year old boy with fever, diarrhoea. Five cases of Alkalescens dispar 05 manit negative and 05 manit positive were identified. Two of these cases were without clinical symptoms. All were males aged 10-17 years. One isolation of E. coli EPEC 086 K6 H11 was in a 10 year-old boy with diarrhoea, four watery stools daily and cramps. Six cases of other E. coli were of different types, all with clinical symptoms. Of them three were males and three females at the age from 3-46 years. One case had a mixed infection of Citrobacter, E. coli and Klebsiella with diarrhoea, about 5 watery stools daily and abdominal pain. The frequency of intestinal bacteria in males was nearly three times higher than in females. The occurrence in age groups 10-20 was almost equal 20.0-22.2%, in 0-4 it was 42.9% and surprisingly low in 5-9 years old--3.4% only.

Pilot studies on the occurrence of some infectious diseases in two different areas in south Yemen (Aden). Part I. Parasitology.

Two pilot studies on malaria, leishmaniasis, schistosomiasis and intestinal parasites were carried out in 104 children 6-15 years old from villages in the lowland and highland areas of South Yemen in November 1988. Some of the results presented are in the order lowland and highland. The occurrence of malaria parasites in blood smears was 6.7% and 3.8%. P. falciparum was detected only. The antimalarial IFAT antibodies were proved in 66.7% and 11.5% respectively. IFAT antibodies against leishmania were in 43.8% and 39.3% respectively of sera examined. Ova of S. haematobium diagnosed with the frequency 29.0% and 13.3% respectively. S. mansoni infection was found in 19.2% of examined children in highland only. From parasites found in stool specimens should be mentioned E. histolytica (42.3% and 36.8%), G. lamblia (34.6% and 35.1%). The other intestinal protozoa were less frequent. Further details of sex and age groups distribution are mentioned.

Complement-fixing antibodies against rotaviruses in healthy children in the Czech Socialist Republic and People's Democratic Republic of Yemen.

Levels of complement-fixing antibodies against rotaviruses were evaluated in the sera of 900 healthy children aged 1-9 years 300 sera were collected in the People's Democratic Republic of Yemen in September-October 1985, 300 sera were obtained in the Czech Socialist Republic in the same period and another 300 also in the Czech Socialist Republic in September-October 1986. The latter two groups were investigated in the framework of immunological surveys. A complement-fixation antigen was prepared from a simian strain of the rotavirus type SA-11 in a tissue cell line MA-104. The sera from Yemen featured lower mean titres in the age groups and thus the lowest overall titre. As the antibody titre increased, the portion of seropositive sera from Yemen declined by far more rapidly than in the Czech children, where it remained virtually the same. The sera from Yemen showed the lowest negative rate and lowest ratio of high titres. The antibody titre of 1:64 and higher was not detected in children from Yemen, while they occurred in the two groups of Czech children. There was no correlation between antibody titres and probands' sex, nor was there linear dependence of titre magnitude on age. The mean positivity rate in each group as assessed by the antibody titres was the lowest in the sera from Yemen. The percentage of positive sera in all age groups was higher in the Czech children with the exception of children from Yemen aged 6 and 9 years. The aim of the present study was to evaluate the antibody status in infant populations and thus expand knowledge of rotavirus epidemiology.

Screening of serum antibodies against Mycobacterium tuberculosis by enzyme-linked immunosorbent assay (ELISA) in healthy population.

Serum samples of venous blood of healthy individuals, chosen at random from two areas of the People's Democratic republic of Yemen, were examined for the presence of IgG antibodies against mycobacterial antigen by ELISA. From the district of Aden, the capital (A), there were 214 samples (72% vaccinated by BCG, 108 men and 106 women), other 235 ones originated from mountain area Laudar Muhairas (H) (66% vaccinated, 115 men and 120 women). The overall average of acquired titres was 1:81.4 in area A, and an average of 1:102.2 was recorded in area H. There was no substantial difference in the titres level in men of the two areas (1:86.9 and 1:90 resp.), however, a significant difference was observed in women: 1:75.7 in area A and 1:114.7 in area H. In area A the titres were ranging in all age groups from 1:61 to 1:83 and the differences between age groups and between vaccinated and unvaccinated individuals were not significant. In area H the titres were generally higher (1:72 to 1:164) in the unvaccinated and 1:79 to 1:204 in the vaccinated. The differences in the unvaccinated were not of a statistical importance: in the vaccinated, the titres of the 20-29 years old (1:204.5) substantially differed from the titres obtained in other groups. The differences in titres level between the two studied areas are explained by a different epidemiological situation, namely by a higher tuberculosis infestation of some age groups in area H.

Serological survey of measles in Yemen in 1985.

The HI assay for measles was used to evaluate the sera of 191 children of preschool age (1-6 ys) from five regions of South Yemen: highland, coastal, Vadi Hadramot, the agricultural area Abijan and the capital city Aden. The serum positivity rate was 47.5% in 1-2-year-old children, 75.5% in 3 year-old and 88.5% in 4-6 year-old children. The geometric mean of HI titres was 4.8 log2 in preschool children. An optimal strategy of vaccination against measles in Yemen is discussed.

Serological survey of rubella in Yemen in 1985.

476 sera from subjects of 6 age groups were investigated using the HI test for rubella, the sera originating from 5 distinct regions of Yemen, namely highland, coastal the agricultural area Abijan, Vadi Hadramot and the capital Aden. The positivity rate among children aged 1-6 ys was 46.2%, the values obtained for girls aged 15-18, women in the 19-24 and 25-29 ys age group being 81%, 86.3% and 89.9%, respectively. When the findings of the immunological survey were evaluated with respect to the five different regions studied, the positivity rate in the highlands was found to be significantly higher among girls under 18 ys of age. The geometric means of HI titres for rubella antibodies proved to be the lowest in 1-3-year-old children (1: 59) and the highest in girls aged 15-18 ys (1: 163). The authors discuss the comparatively high risks of contracting rubella during pregnancy in four regions of Yemen.