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Seroepidemiology of human immunodeficiency virus in Africa
40 Infectious Diseases Newsletter 6(5) May 1987 COMMENTS ON CURRENT PUBLICATIONS Holmberg SD, Wachsmuth IK, Hickman-Brenner FW, et al: Piesiomonas enteric infections in the United States. Ann Int Med 105:690-694, 1986. A prospective nationwide study of 31 persons whose stools contained Plesiomonas shigelloides (Gramnegative, facultatively anaerobic bacteria of the family Vibrionaceae) was conducted in 1985. Three patients had concomitant gastrointestinal illnesses and were not analyzed further for clinical symptoms. The most common manifestations were diarrhea (28/28), abdominal cramping (21/28), visible blood in the feces (10/28), and vomiting (9/28). The most common epidemologic association was consumption of raw shellfish within 48 hours of the onset of gastrointestinal illness (16/29 patients, and only 2/58 ageand sex-matched controls). Foreign travel was frequent--9/31 patients but 0/62 controls. P. shigelloides appeared to cause diarrhea by enteroinvasion rather than enterotoxin production. All isolates were susceptible to gentamicin, chloramphenicol, cephalothin, trimethoprim, and trimethoprim-sulfamethoxazole.
Comment
P. shigelloids may be indistinguishable from normal flora unless colonies grown on nonselective blood agar are tested for oxidase production. A history of travel (especially to Mexico) and/or consumption of raw shellfish should alert the clinician to consider P. shigelloides. RML []
Holmberg SD, Schell WL, Fanning GR, et al: Aeromonas intestinal infections in the United States. Ann Int Med 105:686-689, 1986.
Wendler I, Schneider J, Gros B, et al: Seroepidemiology of human immunodefieiency virus in Africa. Brit Med J 293:782-285, 1985.
Thirty-four persons nationwide from whom Aeromonas hydrophila had been isolated from feces were studied. Six had other concurrent gastrointestinal problems and were excluded from further analysis. Of the remaining 28 patients, 20 had diarrhea (3 or more loose stools in a 24-hour period). Vomiting, abdominal cramps, fever, and blood in the feces were also reported in some patients. Four persons were asymptomatic. There was a high association of infection with A. hydrophila and drinking untreated water. Eighteen isolates belonged to a single DNA-relatedness group but there was no correlation between type of illness and any genotypic or phenotypic characteristic of A. hydrophila. The broad range of illness suggests that A. hydrophila, as other enteric Gram-negative rods, may cause disease by more than one mechanism. The isolates were almost all resistant to ampicillin, carbenicillin, and cephalothin. Most isolates were susceptible to trimethoprim-sulfamethoxazote, tetracycline, kanamycin, and chloramphenicol. All were susceptible to gentamicin.
Serum specimens were collected between 1976 and 1984 from 6,015 asymptomatic African citizens of Senegal, Liberia, Ivory Coast, Burkina Faso, Nigeria, Gabon, Zaire, Uganda, and Kenya. All were tested for antibodies to human immunodeficiency virus (HIV) by a combination of ELISA and radioimmunoprecipitation or immunofluorescence. Specific antibodies to HIV were found in only 4 specimens (0.07%). Specimens collected in 1985 from 2/6 persons suspected of having AIDS, and 13 patients with AIDS were seropositive. The lack of specific HIV antibody in African sera prior to 1985 does not support the hypothesis that HIV originated in subSaharan Africa.
Comment Unless the clinical laboratory tests colonies that grow on nonselective blood agar plates for oxidase production, the presence of Aeromonas spp. may not be suspected. The true incidence of disease caused by Aeromonas spp. is unknown, but persons who drink untreated water from private wells seem to be at greater risk. RML []
© 1987ElsevierSciencePublishingCo., Inc.
Comment The high prevalence of antibodies to HIV reported in other African series may have been caused by nonspecific reactions from high titers of antibodies to malarial antigens or other agents. It is not yet known whether some of the reactivity was caused by other retroviruses such as HTLV-IV or primate retroviruses. The recent development of a group of cooperating national AIDS committees in African countries should help to answer these questions. RML []
McDonald GA, Anacker RL, Garjian A: Clont~l gene of R/e/u~ts/a rickettsii surface antigen: Candidate
Comment
P. shigelloids may be indistinguishable from normal flora unless colonies grown on nonselective blood agar are tested for oxidase production. A history of travel (especially to Mexico) and/or consumption of raw shellfish should alert the clinician to consider P. shigelloides. RML []
Holmberg SD, Schell WL, Fanning GR, et al: Aeromonas intestinal infections in the United States. Ann Int Med 105:686-689, 1986.
Wendler I, Schneider J, Gros B, et al: Seroepidemiology of human immunodefieiency virus in Africa. Brit Med J 293:782-285, 1985.
Thirty-four persons nationwide from whom Aeromonas hydrophila had been isolated from feces were studied. Six had other concurrent gastrointestinal problems and were excluded from further analysis. Of the remaining 28 patients, 20 had diarrhea (3 or more loose stools in a 24-hour period). Vomiting, abdominal cramps, fever, and blood in the feces were also reported in some patients. Four persons were asymptomatic. There was a high association of infection with A. hydrophila and drinking untreated water. Eighteen isolates belonged to a single DNA-relatedness group but there was no correlation between type of illness and any genotypic or phenotypic characteristic of A. hydrophila. The broad range of illness suggests that A. hydrophila, as other enteric Gram-negative rods, may cause disease by more than one mechanism. The isolates were almost all resistant to ampicillin, carbenicillin, and cephalothin. Most isolates were susceptible to trimethoprim-sulfamethoxazote, tetracycline, kanamycin, and chloramphenicol. All were susceptible to gentamicin.
Serum specimens were collected between 1976 and 1984 from 6,015 asymptomatic African citizens of Senegal, Liberia, Ivory Coast, Burkina Faso, Nigeria, Gabon, Zaire, Uganda, and Kenya. All were tested for antibodies to human immunodeficiency virus (HIV) by a combination of ELISA and radioimmunoprecipitation or immunofluorescence. Specific antibodies to HIV were found in only 4 specimens (0.07%). Specimens collected in 1985 from 2/6 persons suspected of having AIDS, and 13 patients with AIDS were seropositive. The lack of specific HIV antibody in African sera prior to 1985 does not support the hypothesis that HIV originated in subSaharan Africa.
Comment Unless the clinical laboratory tests colonies that grow on nonselective blood agar plates for oxidase production, the presence of Aeromonas spp. may not be suspected. The true incidence of disease caused by Aeromonas spp. is unknown, but persons who drink untreated water from private wells seem to be at greater risk. RML []
© 1987ElsevierSciencePublishingCo., Inc.
Comment The high prevalence of antibodies to HIV reported in other African series may have been caused by nonspecific reactions from high titers of antibodies to malarial antigens or other agents. It is not yet known whether some of the reactivity was caused by other retroviruses such as HTLV-IV or primate retroviruses. The recent development of a group of cooperating national AIDS committees in African countries should help to answer these questions. RML []
McDonald GA, Anacker RL, Garjian A: Clont~l gene of R/e/u~ts/a rickettsii surface antigen: Candidate