Viral etiology and epidemiology of acute respiratory infections in children in Nairobi, Kenya.

Acute respiratory infection (ARI) is the most common cause of illness and death in young children worldwide. Because of inadequate laboratory facilities and financial resources the etiological agents responsible for most cases in developing countries remain unknown, thus obviating appropriate management. Therefore, an ARI program was commenced at the Kenyatta National Hospital, Nairobi, Kenya in 1981 with the objectives of establishing the microbial causes, clinical presentations, and diagnoses of ARI in children under 5 years of age and of developing simple, rapid, and inexpensive diagnostic techniques. Viruses were demonstrated in 54% of the 822 children studied, but over half of the viruses identified were types not commonly associated elsewhere with the causation of severe ARI. Respiratory syncytial, parainfluenza, and adenoviruses occurred in the same age groups and during similar weather conditions as elsewhere. Measles virus occurred most frequently in those 7 to 9 months old. Herpes simplex, rhino-, and enteroviruses play causative roles in some cases of severe ARI in Kenyan children. A combination of immunofluorescent and cell culture techniques were shown to be essential for the detection of viruses.

Investigation of the effectiveness of measles vaccination in children in Kenya.

Laboratory studies were performed on 128 children clinically diagnosed as measles when seen at the Infectious Diseases Hospital, Kenyatta National Hospital (IDH), Nairobi (86 cases) and the Rural Health Training Centre, Maragua, Central Province (42 cases) between 9 July and 31 August 1984. A concurrent measles infection was confirmed in 95% of the children seen at IDH and in 85% of those seen at Maragua, with similar proportions of confirmations in children who had, and who had not, received measles vaccine. No differences in the number of sero-conversions nor in the absolute levels of acute or convalescent HI antibody titres could be detected between vaccinated and unvaccinated children. Analysis of the cases seen at Maragua indicates that about two thirds of the children who had received vaccine were protected. A pilot study of vaccinating children at 8 months and again at 12-13 months is suggested in an attempt to eradicate measles.

Herpes simplex virus in clinically suspected chancroid in Nairobi, Kenya.

PIP: Of 110 males selected for review with possible chancroid, 96 were clinically diagnosed as having chancroid, 7 as having herpetic lesions, and 7 as having syphilis. Of the 96 patients diagnosed clinically as chancroid, 76 (79.2%) were culture positive for H. ducreyi. 9 (9.4%) of these 96 patients yielded Herpes Simplex Virus (HSV). Both HSV and H. ducreyi were isolated from 5 of the patients, and from 4 of the patients HSV alone was isolated. 7 patients (6.4%) were clinically diagnosed as having herpetic ulcers. 5 of these grew HSV. Overall, 14 of the 110 patients (12.7%) yielded HSV. 1 patient, who presented with small vesicular lesions characteristic of HSV, yielded the virus on culture. The vesicles were initially negative for H. ducreyi, but 6 days later he had developed deep purulent ulcers in the same sites as the vesicular lesions and became culture positive for H. ducreyi snd HSV-negative. The possible association between HSV and chancroid is discussed in the light of these findings and comparisons made between the results of the present study and earlier findings made in Kenya and elsewhere, with suggestions being given as to the reasons for the apparent differences. The HSV isolation techniques used in this study may be less sensitive than those used in other studies, but it is highly unlikely that this possibility alone accounts for all of the observed differences. Patients with hepetic ulcers may be less likely to present early in the course of the disease, if at all, believing the infection to be minor and one that will heal on its own. It is also possible that HSV infection is less common in Kenya, either alone or as an initiator of chancroid, than in the US or Europe, becuase of a higher rate of childhood HSV infections in Kenya, which may confer a degree of immunity against genital HSV infection in this population. The lower prevalence of HSV in association with H. ducreyi reported may be at least partly the result of a much higher incidence in Kenya of chancroid which is not initiated by HSV. A higher incidence of HSV genital infection in Europe and America would also make it more likely that HSV would fortuitously be isolated more frequently from H. ducreyi positive lesions.^ieng