Are flaviviruses again active in Mali?

Using a hemagglutinating yellow fever antigen, a serologic investigation was done on 1237 blood samples collected between 1979 and 1983 in five regions of Mali. The results showed that the percentage of positive reactions (greater than 1:10) was higher in the sera of mothers than in their new borns (24.8 versus 12.4). In young children (6 months to 3 years old) the percentages of positive sera varied between 4.4 and 9.6. The values were much higher for persons between 15 to 70 years (28.3% to 43.7%). The presence of high antibody titers in sera of adults, the occurrence of seroconversion in young children (less than 1:10 to 1:40) are arguments for supposing that yellow fever virus or other flaviviruses were active in Mali in the period of our investigation.

Prevalence of antibodies against respiratory viruses in children of Koulikoro (Mali).

The prevalence of antibodies to viruses associated with respiratory illnesses (influenza, corona, R.S., adeno, parainfluenza Mycoplasma pneumoniae) has been investigated in 119 children under 3 years of age (Koulikoro region Mali) and 50 persons 15-19 years of age (Bamako/Mali). In the surveillance period (March 1982-September 1982) an outbreak of respiratory disease in association with RS virus took place. A rise of CF titer has been found in 90.8% of the children; 59.1% of them presented a fourfold or greater increase of titer. The GMT values rose from 1:7 to 1:48. Concerning influenza viruses a higher incidence of positive reactions has been observed only for H3N2 viruses. A fourfold CF rise of titer has been observed for adenovirus and mycoplasma pneumoniae in 3 cases each, for parainfluenza type I and III in 2 cases each, and for parainfluenza II in 1 case. In persons 15-19 years of age the incidence of positive CF reactions was relatively high (68%-98%), but the GMT values were moderate (1:12-1:25). These data confirm that the frequency of viral respiratory diseases is the same in tropical countries as in countries with a temperate climate.

[Naturally acquired tetanus antitoxin in the serum of children and adults in Mali]. / Uber natürlich erworbene Tetanusantitoxine im Serum von Kindern und Erwachsenen in Mali.

Among 48 adults without a history of tetanus immunization, we found with the aid of indirect hemagglutination test 20 individuals with protective tetanus antibody titers, 23 with low levels of antitoxin (under 0,1 I.U./ml) and 5 devoid of tetanus antitoxin. In two blood samples of 99 unvaccinated children under 3 years of age (taken at 7 months intervall) 12,1% showed tetanus antitoxin in the first serum sample and 16,2% in the second sample. Protective antibody titers could be found only in 4 children in each of the first and second serum sample. The data suggest a silent oral immunization by tetanus bacilli thus boosting under unhygienic conditions the tetanus immunity with advancing age.

[Cytomegalovirus antibody titer (indirect hemagglutination) of mothers and their newborn infants from Hamburg and Bamako]. / Cytomegalieantikörpertiter (indirekte Hämagglutination) von Müttern und ihren Neugeborenen aus Hamburg und Bamako.

Antibodies to cytomegalovirus (CMV) have been detected by the indirect haemagglutination test in 107 paired sera (newborn and mother) from Hamburg and 39 paired sera from Bamako (Mali). In addition, 53 unpaired sera from neonates and different mothers from Mali were evaluated for our study. In Hamburg 63,5% of both newborns and their mothers possessed CMV antibodies. The GMT values of the neonatal CMV-antibody-titres was higher than in the maternal blood (1:780 versus 1:510). In Bamako the frequency of positive reactions was evidently higher: 94,9% (maternal blood) and 82,2% (newborn cord blood). The GMT value of CMV neonates antibodies was under the level registered in their mothers sera: 1:290 and 1:450 respectively. The different socioeconomic conditions of the two groups of population studied may explain the results obtained.

Antibody formation after vaccination with adsorbed and non-adsorbed A/New Jersey/8/76 influenza vaccines.

A study was carried out to determine the titres of haemagglutination inhibiting and neuraminidase antibodies after vaccination of 90 subjects, aged 19 to 35 years, with three aluminium oxide adsorbate and three fluid monovalent influenza A/New Jersey/8/76 vaccines with 54, 108 and 216 IU/dose. Blood samples were taken 1, 3 and 6 months after vaccination. The serological findings showed that adsorbate vaccines induced higher antibody titres than did fluid vaccines with double the antigen content. 'Unprimed persons' reacted to the adsorbate vaccine vaccination with a much higher antibody formation response.

The incidence of Chlamydia psittaci antibodies in patients with respiratory tract diseases.

The incidence of Chlamydia psittaci infections in Hamburg has been studied using the complement fixation test on 655 human sera collected from patients with respiratory tract diseases. Of the 653 sera investigated, 78 (11.9%) showed antibody titers between 1:8 and 1:128. Of the positive sera, 21 (16.9%) presented values of greater than or equal to 1:32. This infection is encountered more often in individuals over 21 years of age (15.9% to 23.4%) than in persons under 20 (0.8% to 6.0%). General practitioners' attention must be drawn to Chlamydia psittaci infections, since they seem to be of greater importance in human pathology than is generally assumed.

Influenza and corona-virus antibodies in the newborns and their mothers in Mali (1980).

In February 1980 blood samples from 91 women and their newborn babies (cord blood) from Mali have been analysed for influenza and corona OC 43 HI antibodies. The titers of influenza HI antibodies were higher in blood samples collected from the mothers at delivery than in their newborns. Considering the GMT values and percentage of persons with protective titers (greater than or equal to 1:40) we may assume that influenza A (H3N2) viruses had been highly active in Mali. Influenza A (H1N1) and B activity may be considered as minor. The prevalence of OC 43 coronaviruses HI antibodies was higher in the cord blood of the newborn babies (95%) than in the blood samples of their mothers (75%).

A two year serological surveillance of coronavirus infections in Hamburg.

The occurrence of OC-43 coronarvirus-like infections in the population of Hamburg was determined by a monthly serological survey (hemagglutintion inhibition test [HI]) undertaken between October 1974 and October 1976. Studies of 3,016 sera revealed a high incidence of HI antibodies (58,2%). The frequency of seropositive reactions (= 1:8) and the geometric mean titer were higher in individuals 15 to 24 years old. Treatment of 50 postive sera (titer 1:16 -1:64) with receptor destroying enzyme, kaolin and ethacridin for elimination of nonspecific inhbitiros did not modify the HI-titer of the investigated sera. The serological seasonal pattern suggests that coronaviruses are circulating the whole year in the urban population with a prevlence in the fall-winter period. Of the 331 paired sera examined, 6.6% presented a four- to eightfold rise intiter within eight weeks.

Influenza A antibodies in Cervine animals.

In the haemagglutination inhibition (HI) test, 20 cervine sera, most of which came from Northern Germany, were treated with receptor destroying enzyme (RDE) and 11 sera were found to contain antibodies against the H1N1 (A/USSR 90/77) and H3N2 (A/Victoria 13/75, A/Texas 1/77) influenza viruses. Only two sera contained antibodies against H3N2 viruses, and seven sera were negative. Evidence of the specificity of influenza antibodies was provided by the following findings: 1) the IgG serum extracts showed the same inhibitory activity of haemagglutinin as the RDE treated sera; 2) addition of protein A led to an increase in the HI titers; 3) in the haemolysis in gel test, some of the HI positive sera formed haemolysis in gel test, some of the HI positive sera formed haemolysis rings of the same diameter as hyperimmune antiinfluenza A (H1N1) serum; and 4) the cervine sera reacted positively in the neuraminidase inhibition (NI) test. It is remarkable that influenza H1N1 antibodies were found in the serum of one cervine before this virus strain appeared in humans.

[Antibody formation following immunization with mono- and bivalent mumps-(measles-)vaccine (author's transl)]. / Die Antikörperbildung nach Gabe von mono- und bivalenter Mumps-(Masern-)Vakzine.

The authors studied the seroconversion of 307 children, 1-11 years old, induced by Mumpsvax (136 children) and a bivalent mumps-measles vaccine (strain Jeryl Lynn/strain Moraten; 171 vaccines) by the HI-test. The seroconversion induced by the measles component of the bivalent vaccine covered 96.3% of the seronegatives prior to immunization. The comparable values for mumps antibodies were lower (Mumpsvax:80.6%; bivlant vaccine: 82.2%). An increase in titer in seropositive children was obtained in 57.1% after immunization with Mumpsvax and in 50.8% with the bivalent vaccine. Comparative studies to investigate the sensitivity of the HI-test versus the neutralisation test (NT) showed the greater accuracy of the latter. Before the vaccination with Mumpsvax, only 26.6% of 60 sera studied were found to be seronegative, whilst the NT gave a more reliable figure (55%). Similar data were found in 62 sera before immunization with the bivalent vaccine (HI-test: 33.8%; NT:66.1% seronegative). The seroconversion rates were slightly higher when the NT had been used: 75.6% (bivalent) and 81.8% (monovalent vaccine) versus 75.6% and 75%, respectively, by the HI-test.

Serological surveillance of influenza in Hamburg and Munich (1976/1977).

A monthly serological survey (HI-test) of influenza infections was done in Hamburg (1083 sera) and Munich (955 sera) between June 1976-February 1977 in order to find out if environment influences the host's response to infection. A higher frequency of seropositive reactions and percentage of protective antibodies (titer 1:40 and over) was found in the population of Hamburg versus Munich. The frequency was greater in individuals over 60 years (group IV) followed by persons 25-29 years (group III) than group II (15-24 years) and group I (0-14 years). There was no difference in the percentage of seropositive reactions within the 4 age groups from Munich. The GMT values of influenza antibodies in both populations studied followed the same pattern. Antibody titers against influenza antigens were found in decreasing order: A/Victoria 3/75, A/England 23/76, A/Port Chalmers 1/73, A/New Jersey 8/76, B/Hong Kong 8/73. The possible influence of climate on the host's response is discussed.