Hot spots in a wired world: WHO surveillance of emerging and re-emerging infectious diseases.

The resurgence of the microbial threat, rooted in several recent trends, has increased the vulnerability of all nations to the risk of infectious diseases, whether newly emerging, well-established, or deliberately caused. Infectious disease intelligence, gleaned through sensitive surveillance, is the best defence. The epidemiological and laboratory techniques needed to detect, investigate, and contain a deliberate outbreak are the same as those used for natural outbreaks. In April 2000, WHO formalised an infrastructure (the Global Outbreak Alert and Response Network) for responding to the heightened need for early awareness of outbreaks and preparedness to respond. The Network, which unites 110 existing networks, is supported by several new mechanisms and a computer-driven tool for real time gathering of disease intelligence. The procedure for outbreak alert and response has four phases: systematic detection, outbreak verification, real time alerts, and rapid response. For response, the framework uses different strategies for combating known risks and unexpected events, and for improving both global and national preparedness. New forces at work in an electronically interconnected world are beginning to break down the traditional reluctance of countries to report outbreaks due to fear of the negative impact on trade and tourism. About 65% of the world's first news about infectious disease events now comes from informal sources, including press reports and the internet.

Remote village survey for agents causing hepatosplenic disease in the Republic of Yemen.

The objective of this study was to epidemiologically describe potential infectious agents among rural people in the Republic of Yemen. This would aid clinicians in designing empirical therapy and public health officials in planning disease prevention. We sought to examine evidence for the geographical distribution of pathogens causing human hepatic and splenic disease among villagers and domestic animals living in three remote areas with differing altitudes. In June 1992, a cross-sectional survey was conducted at three survey sites of differing altitudes: 3080, 1440 and 250 m above sea level. Questionnaires, parasitic and serological tests were administered to 627 human volunteers. Additionally 317 domestic animals were studied. Malaria, schistosomiasis, and hepatitis B and C infections were found to be likely causes of human hepatic or splenic disease. Additionally, evidence of human and animal infections with the agents of brucellosis and Q fever was found: IgG antibodies against hepatitis E virus were discovered in two (2.0%) of the 100 volunteers. The prevalence of markers for human and animal disease was often lowest at the village of highest elevation, suggesting that increasing altitude, as a surrogate or a true independent risk factor, was protective against infection with the agents studied.

The reemergence of Ebola hemorrhagic fever, Democratic Republic of the Congo, 1995. Commission de Lutte contre les Epidémies à Kikwit.

In May 1995, an international team characterized and contained an outbreak of Ebola hemorrhagic fever (EHF) in Kikwit, Democratic Republic of the Congo. Active surveillance was instituted using several methods, including house-to-house search, review of hospital and dispensary logs, interview of health care personnel, retrospective contact tracing, and direct follow-up of suspect cases. In the field, a clinical case was defined as fever and hemorrhagic signs, fever plus contact with a case-patient, or fever plus at least 3 of 10 symptoms. A total of 315 cases of EHF, with an 81% case fatality, were identified, excluding 10 clinical cases with negative laboratory results. The earliest documented case-patient had onset on 6 January, and the last case-patient died on 16 July. Eighty cases (25%) occurred among health care workers. Two individuals may have been the source of infection for >50 cases. The outbreak was terminated by the initiation of barrier-nursing techniques, health education efforts, and rapid identification of cases.

Comparative field evaluation of HIV rapid diagnostic assays using serum, urine, and oral mucosal transudate specimens.

BACKGROUND: Comparative field utility of selected HIV-1 assays using homologous collections of serum, urine and oral mucosal transudate (OMT) was determined in adult populations from a tuberculosis hospital and STD clinic in Djibouti, East Africa. STUDY DESIGN: Enzyme immunoassay with confirmatory Western blot was performed on all serum specimens for comparison with rapid, instrument-free assays (SUDS HIV-1, Murex: TestPack HIV-1/2. Abbott; and COMBAIDS HIV 1 + 2, SPAN Diagnostics) using various specimen sources. Delayed (48 h post-collection) testing was also performed on urine. Sensitivity and specificity for the rapid assays, in descending order, were as follows: serum SUDS HIV-1 assay (100%, 98.3%), serum COMBAIDS HIV-1/2 assay (98.4%, 99.6%), and OMT SUDS HIV-1 assay (98.4%, 94.5%). RESULTS: The OMT EIA optical density cutoff value was modified resulting in an improved specificity from 89.1 to 99.6%, however, sensitivity decreased from 100 to 98.5%. Urine EIA and rapid assays demonstrated unacceptable test performance for use as a screening test.

Seroprevalence survey of Egyptian tourism workers for hepatitis B virus, hepatitis C virus, human immunodeficiency virus, and Treponema pallidum infections: association of hepatitis C virus infections with specific regions of Egypt.

Blood samples from 740 Egyptian Nationals working in the tourism industry at two sites in the South Sinai governorate were screened for markers of infection with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and Treponema pallidum. Study subjects included 467 individuals from a rural seashore tourist village and 273 persons at two hotels in a well-established resort town. Subjects' ages ranged from 15 to 70 years; 99.3% were male. The prevalence of serologic markers for currently asymptomatic or past HBV infection alone was 20.7% (n = 153), of markers for past or chronic HCV infection alone was 7.4% (n = 55), and of markers for both HBV and HCV was 6.9% (n = 51). Of the 204 individuals positive for anti-HBV core antibody, 12 (5.9%) were also positive for hepatitis B surface antigen. Two individuals (0.3%) had a serologic market suggestive of an active syphilitic infection. No subject was found to be HIV-seropositive. History of prior injections and number of injections were associated with infection with HCV. Primary residence in the Nile delta and valley areas where schistosomiasis is highly endemic, was also a statistically significant risk factor for HCV, but not HBV infection.

PIP: In June 1994, in Egypt, a physician, a laboratory technician, and a recorder surveyed 740 nationals aged 15-70 years, 99.3% of whom were male, who worked in the local tourist industry of the South Sinai governorate (a rural seashore tourist village and a well-established tourist town). Researchers aimed to determine the prevalence of past or chronic infections with hepatitis B virus (HBV), hepatitis C virus (HCV), HIV, and Treponema pallidum (syphilis) in tourist workers and to identify risk factors for infection with these pathogens. Condoms were used and safer sex was practiced in about 90% of casual sexual encounters. No tourist worker tested positive for HIV-1 or HIV-2 infection. 0.3% had active syphilis. 27.6% of the tourist workers tested positive for HBV. 1.6% (5.9% of HBV-positive workers) were positive for hepatitis B surface antigen, indicating an asymptomatic HBV infection. 14.3% of all tourist workers tested positive for HCV. 6.9% tested positive for both HBV and HCV. Rural residence was a significant risk factor for HBV infection (odds ratio [OR] = 1.6; p = 0.02). Significant risk factors for HCV infection included residence in a region highly endemic for schistosomiasis (i.e., Nile delta and valley areas) (OR = 3.2; p 0.01), rural residence (OR = 2.3; p = 0.01), and more than 10 lifetime injections (OR = 2.6; p = 0.02).

Epidemic dengue 2 in the city of Djibouti 1991-1992.

From October 1991 to February 1992, an outbreak of acute fever (in which thick blood films were negative for malaria) spread rapidly in the city of Djibouti, Djibouti Republic, affecting all age groups and both nationals and foreigners. The estimated number of cases was 12,000. The clinical features were consistent with a non-haemorrhagic dengue-like illness. Serum samples from 91 patients were analysed serologically for flavivirus infection (dengue 1-4, West Nile, yellow fever, Zika, Banzi, and Uganda-S), and virus isolation was attempted. Twelve strains of dengue 2 virus were isolated. Dengue infection was confirmed by a 4-fold or greater rise in immunoglobulin (Ig) G antibody in paired serum specimens, the presence of IgM antibody, or isolation of the virus. Overall, 46 of the suspected cases (51%) were confirmed virologically or had serological evidence of a recent flavivirus infection. Statistical analysis showed that the presence of a rash was the best predictor of flavivirus seropositivity. In November 1992, Aedes aegypti was widespread and abundant in several districts of Djibouti city. A serological study of serum samples collected from Djiboutian military personnel 5 months before the epidemic showed that only 15/177 (8.5%) had flavivirus antibodies. These findings, together with a negative serosurvey for dengue serotypes 1-4 and yellow fever virus performed in 1987, support the conclusion that dengue 2 virus has only recently been introduced to Djibouti.

Evaluation of the response of human humoral antibodies to Salmonella typhi lipopolysaccharide in an area of endemic typhoid fever.

Because of the limited value of Widal's test in the diagnosis of typhoid fever in areas of endemicity, individual serum levels of IgM, IgA, IgG, and IgG subclass antibodies to Salmonella typhi lipopolysaccharide were evaluated in samples collected in Egypt. The study involved 106 febrile patients, including 40 patients for whom cultures were positive for S. typhi and 66 patients for whom diseases other than typhoid were diagnosed. Multivariate regression modeling revealed that detection of the combination of IgA, IgG, and IgG2 correlated best, although not perfectly (adjusted r(2) = 68), with a positive culture; the sensitivity and specificity of testing for IgA, IgG, and IgG2 (i.e., all three tests positive vs. all three tests negative) were 91.7% and 98.1%, respectively. These results suggested that testing for IgA, IgG, and IgG2 in combination is of diagnostic value for S. typhi infection.

Serologic evidence of respiratory and rickettsial infections among Somali refugees.

Somali refugees living in a camp located in Djibouti were studied in October 1991 and May 1992. The refugees had been living at the camp for about two years. The median age of volunteers was 25 years, of whom 69% were female. Paired sera obtained seven months apart were evaluated by complement fixation, microimmunofluorescence, indirect fluorescent antibody, streptococcal antibody, and enzyme-linked immunosorbent assay techniques for evidence of pathogen infection. Fifty-two percent, 31.3%, 8.0%, 5.9%, and 25.4% of the volunteers had serologic evidence for pre-enrollment infection with Chlamydia pneumoniae, Mycoplasma pneumoniae, Rickettsia typhi, R. conorii, and Coxiella burnetti, respectively. Similarly, 43.5%, 5.2%, 6.1%, 10.7%, 15.8%, and 11.9% of the volunteers studied had serologic evidence for new infection with Streptococcus pyogenes, C. pneumoniae, M. pneumoniae, R. typhi, R. conorii, and Cox. burnetii, respectively. These data suggest that the studied pathogens may be endemic in displaced populations living in the Horn of Africa.

Recurrence and emergence of infectious diseases in Djibouti city.

Public health authorities are now increasingly concerned by changes in the epidemiology of infectious diseases which may have an adverse impact on their budget plans and control strategies. Rapid increases in population and urban migration, various ecological changes, increasing poverty, and a rise in international travel have contributed to the worldwide vulnerability of human populations to the emergence, recurrence or spread of infectious diseases. In the rapidly growing city of Djibouti in East Africa, public health priorities have been altered during the last 10 years by diseases which were unknown or under control until the early 1980s. These diseases, including malaria, AIDS, tuberculosis, dengue fever and cholera, are consuming considerable resources. This article on Djibouti illustrates the epidemiological changes in the region. Besides the specific ecological and behavioural changes, which accompany rapid population growth, poverty seems to be a major cause for the emergence and recurrence of infectious diseases.

PIP: The growing prevalence of diseases which were unknown or under control until the early 1980s, such as malaria, AIDS, tuberculosis, dengue fever, and cholera, consume considerable resources and have changed public health priorities in Djibouti over the last 10 years. Poverty seems to be a major cause for the emergence and recurrence of these infectious diseases. Epidemiological changes in the region are discussed. Public health authorities are increasingly concerned by those changes which may have an adverse impact upon budget plans and control strategies. Rapid increases in population and urban migration, ecological changes, increasing poverty, and a rise in international travel have contributed to the worldwide vulnerability of human populations to the emergence, recurrence, or spread of infectious diseases.

Clinical features associated with HIV-1 infection in adult patients diagnosed with tuberculosis in Djibouti, Horn of Africa.

PIP: The US Naval Medical Research Unit headed up a retrospective study of all adult patients diagnosed in 1991 with tuberculosis (TB) at the Paul Faure Hospital Center in Djibouti city. 92% (1844) of the medical records had complete information on demographics, clinical, and radiological characteristics associated with TB and HIV serological status. 106 (5.7%) patients had HIV-1 infection. Two patients had both HIV-1 and HIV-2 infection. Clinical predictors for HIV seropositivity included peritonitis (odds ratio [OR] = 5.08; p = 0.0164) and pleural effusion (OR = 2.15; p = 0.0037). Ethiopian nationality also predicted HIV infection among TB patients (OR = 2.13; p = 0.0002). The high percentage of glandular TB in this area of Africa, even before the HIV epidemic, may account for the lack of statistical association between HIV positivity and peripheral lymphadenopathy. These findings indicate that newly diagnosed TB adult patients with peritonitis or pleural effusion are rather likely to also have HIV infection. Physicians should suspect HIV infection in such patients, since they may be at high risk of exposure to body fluids during surgery for peritonitis and drainage of pleural effusion. The high variance makes peritonitis and pleural effusion relatively poor predictors of HIV infection, however.^ieng

HIV infection among secondary school students in Djibouti, horn of Africa: knowledge, exposure and prevalence.

A study of HIV infection among secondary school students was conducted in Djibouti in February 1990 during a national hepatitis survey. Serology was negative for HIV and syphilis among 294 students (ages 14 to 20 years) in spite of a dramatic increase of HIV seropositivity (as high as 41%), and a high level of syphilis positive serology (up to 46%) among adult high-risk groups such as street prostitutes. Results of a face-to-face interview of these pupils indicated that 64% had a basic knowledge of AIDS. As expected, a much better knowledge of AIDS was found among those who recently received AIDS education. However, 80% of secondary school teenagers did not consider themselves at risk for acquiring HIV. Transmission of HIV among school-children would be possible through sexual activity (22% stated to be sexually active) or parenteral therapy (75% had received at least one intramuscular injection), and not likely through blood transfusion or intravenous drug abuse. Results, close to those of a similar study in Zimbabwe, suggest that AIDS education programme should be given to all secondary school pupils and include public health lectures on syphilis, tuberculosis, and HIV infection.

PIP: In February 1990 in Djibouti, a study of 147 male and 147 female students (data obtained from a national hepatitis survey) aimed to determine knowledge about AIDS, sexually transmitted diseases, and sexual experience; exposure to HIV infection; the potential weight of sexual and parenteral routes of HIV infection; and the significance of their exposure to HIV infection. Students represented all the secondary schools in the capital city. None of the students tested seropositive for HIV or syphilis, even though as many as 41% and 46% of high risk adults (e.g., prostitutes) tested positive for HIV and syphilis, respectively. 21.2%, 5.6%, 2.7% and 0.68%, and 0.5% tested positive for anti-hepatitis B (HB) s antibody, HBs antigen, anti-HBe antibody, HBe antigen, and delta hepatitis respectively. Anti-HBs seropositivity rose linearly with age (p .01). About 64% had basic knowledge about AIDS. Almost 100% had at least heard of it. Special lectures on AIDS during a recent national campaign likely contributed to the higher knowledge level among the 18-year-old students. 88.1% of all students wanted more information about AIDS. Boys were more likely to want to learn more about AIDS than girls (91.8% vs. 84.3%; p = .047). About 40% of the students knew about tuberculosis (TB). 78.6% wanted more information about TB. Boys were more likely to be sexually active than were girls (40.8% vs. 2.7%; p .01). Sexual activity increased with age among boys (p .01). 51.6% of sexually active students never used condoms. Just 24.2% always used them. 80% of students did not consider themselves to be at risk for HIV infection. Almost all students had previously been exposed to the risk of parenteral infection, especially vaccines (99%) and intramuscular injections (75.2%). No one had used intravenous drugs. These findings suggested the need for AIDS education for secondary school students which covers HIV prevalence in Djibouti, TB, syphilis, and HIV transmission via sexual and parenteral routes.

Trends of human immunodeficiency virus type-1 infection in female prostitutes and males diagnosed with a sexually transmitted disease in Djibouti, east Africa.

A cross-sectional serosurvey for human immunodeficiency virus type 1 (HIV-1) was conducted during the first quarter of 1991 among high risk groups in Djibouti, East Africa, and compared with previous surveys in 1987, 1988, and 1990. The survey demonstrated evidence of HIV-1 infection in 36.0% (n = 292) of street prostitutes, 15.3% (n = 360) of prostitutes working as bar hostesses, and 10.4% (n = 193) of males diagnosed with a sexually transmitted disease. By multivariate modeling, HIV-1 seropositivity in prostitutes was associated with Ethiopian nationality, working as a street prostitute, and residing in Djibouti for two years or less. We suggest that prostitution, particularly street prostitution, is a major route of HIV-1 transmission in Djibouti.

PIP: Findings from a cross-sectional serosurvey for HIV-1 conducted in 1991 are compared with data from previous surveys conducted in 1987, 1988, and 1990. This most recent study was conducted in the 1st quarter of 1991 among a total 845 individuals belonging to high-risk groups in Djibouti, East Africa. The 1987, 1988, and 1990 surveys respectively sampled 539, 582, and 402 subjects. Individuals were sampled consecutively as they visited the public sexually transmitted diseases (STD) clinic. HIV infection was found in 36.0% of 292 street prostitutes, 15.3% of 360 prostitutes working as bar hostesses, and 10.4% of 193 males diagnosed with a STD. The estimated 1500 women engaged in prostitution in the country with no legal occupation are considered to be street prostitutes. Multivariate modeling found HIV infection in prostitutes to be associated with Ethiopian nationality, working as a street prostitute, and residing in Djibouti for 2 years or less. The prevalence of HIV-1 among street prostitutes was markedly greater than the 4.6% in 1987, yet down from 41.7% in 1990. The authors note that street prostitution is a major route of HIV transmission in Djibouti.

[Viral markers of acute hepatitis: A, B, C, D, and E in Dakar. October 92 - October 93]. / Marqueurs viraux des hépatites aiguës: A, B, C, D et E à Dakar. Octobre 92-Octobre 93.

Inside of 95 patients presented in Hospital with presumed hepatitis: 77 were recruted with liver cytolysis (Amino-Transferases AT > 80 UI/ml) and included in this study. Study of serologic viral markers (A, B, C, D and E type) permited to prove viral acute hepatitis infection and 49 patients were recruted inside the 77 cytolytic cases. Inside these 49 cases: 44% presented enteritic contamination with HAV/HEV markers, 36% with HBV markers: HBs/HBc, 6% with HBs/HBe markers, 10% with HDV marker, 4% with HCV marker. 28 patients presented any viral acute hepatitis marker and in this case can be evocated other hepatitis origin: viral hepatitis type (EBV), CMV, chronic hepatitis evolution, malaria hepatitis or toxic hepatitis.