HIV infection in children is a family disease, with social, economic and medical aspects that make it one of the most challenging diseases of our time. Knowledge about the factors involved in mother-to-child transmission and the natural history of the disease is gradually increasing although there is still much to understand. As the majority of children become infected through mother-to-child transmission, perinatally acquired infection will parallel increases in heterosexual transmission and the numbers of infected women of childbearing age. Current estimates of the rate of vertical transmission range from 14% to 39% in different studies. The relative proportion of transmission occurring in utero, peripartum or postpartum may vary in different localities and remains unclear. A study recently carried out in the USA showed that zidovudine given late in pregnancy, peripartum and in the neonatal period decreases HIV transmission from 25% to 8%. The clinical presentation of HIV infection in children depends in part on exposure to different infections. In developing countries the children usually present with nonspecific signs and symptoms, such as failure to thrive, chronic diarrhoea, cough and recurrent bacterial infections. Other common presentations include generalized lymphadenopathy, oropharyngeal candidiasis, dermatitis, enlargement of parotid glands and neurological problems, including delayed development.
Anti-HIV Agents - therapeutic use ; Child, ; Disease Transmission, Infectious - statistics & ; numerical data ; HIV Infections - drug therapy ; HIV Infections / transmission

Betacoronavirus ; Coronavirus Infections ; epidemiology ; transmission ; Disease Transmission, Infectious ; statistics & numerical data ; Global Health ; Humans ; Incidence ; Pandemics ; Pneumonia, Viral ; epidemiology ; transmission ; Prognosis

OBJECTIVETo develop a new transmission tracking analysis technique during incubation period of respiratory infectious diseases, and to discuss its practical value in the field survey of infectious diseases.

METHODSThe classical epidemiological theory was integrated with geographic information system. The transmission tracking analysis technique was established based on the modeling platform ArcGIS Engine Developer Kit 9.3, using the techniques of address matching, shortest path analysis and buffer analysis, and programming by Visual C++. Eight serious sever acute respiratory syndrome (SARS) cases in Shanghai in year 2003 were then chose as prototype to set up the test cases A-H. The electronic map and population density data were separately collected from Institute of Surveying and Mapping in Shanghai and Shanghai statistical yearbook 2003, to calculate and explore the parameters as length of transmission path, area of buffer zone and key departments by single and multi case analysis module.

RESULTSThe single case transmission tracking analysis showed that the length of transmission track of case A was 129.89 km during April 25th to 29th in 2003, including 12 tracing point and 108 intimate contacts, and the total area of buffer zone was 7.11 km(2) including 81 important institutes, naming 72 schools, 6 kindergartens and 3 gerocomiums. The multi-case transmission tracking analysis showed that the 8 cases shared 5 tracks without any temporal communication. However, there was a spatial communication whose length was 1.42 km and area was 0.60 km(2). There were no important institutes found in this communication area.

CONCLUSIONTransmission tracking technique is practicable and efficient to trace the source of infection, analyze the transmission tracks, establish the isolation buffer area and explore the important geographic positions in epidemiological investigation.

Contact Tracing ; methods ; Disease Transmission, Infectious ; statistics & numerical data ; Epidemiological Monitoring ; Geographic Information Systems ; Humans ; Infectious Disease Incubation Period ; Respiratory Tract Infections ; transmission ; Severe Acute Respiratory Syndrome ; transmission ; Software

OBJECTIVETo explore the change trend of mother-to-child-transmission (MTCT) of HIV-1 in some areas in China.

METHODSThe investigation was conducted in 15 counties or districts of 4 provinces in China with relatively high HIV prevalence from January 2005 to June 2009. The data on the death and HIV-status of the babies born to HIV-positive mothers from January 2005-December 2007 in research sites were collected through 18-month following up after they were born.

RESULTSDuring the time that the research was conducted, there were 644 babies born to HIV-positive mothers who were followed up for 18 months. At the end of 18 months, full data were collected from 550 babies, 44 babies were lost to follow-up and 50 babies died. Among 550 babies who were followed up for 18 months, 53 babies were confirmed as HIV positive. The rate of MTCT of HIV-1 was 13.19% (24/182), 8.90% (17/191) and 6.78% (12/177) in 2005, 2006, 2007 respectively, which showed a descending trend yearly (chi(2) = 4.23, P < 0.05). Adjusted by the death data of the HIV-exposed children, it was found that during 2005-2007 the rate of MTCT of HIV-1 was 16.74%, 12.98%, 9.52% respectively, which was also descending year by year (chi(2) = 4.69, P < 0.05).

CONCLUSIONLong-term, effective prevention of mother-to-child-transmission of HIV (PMTCT) could reduce the level of MTCT of HIV-1 year-by-year. In addition, using death data of HIV-exposed children to adjust the level of MTCT of HIV-1 is valuable to grade the effect of PMTCT.

Acquired Immunodeficiency Syndrome ; mortality ; transmission ; China ; epidemiology ; Female ; HIV-1 ; Humans ; Infant ; Infant Mortality ; trends ; Infant, Newborn ; Infectious Disease Transmission, Vertical ; statistics & numerical data ; Mothers ; Pregnancy

China ; HIV Infections ; prevention & control ; transmission ; Health Knowledge, Attitudes, Practice ; Health Personnel ; statistics & numerical data ; Humans ; Infectious Disease Transmission, Patient-to-Professional ; prevention & control ; Occupational Exposure ; prevention & control

OBJECTIVETo evaluate the costs of preventing AIDS transmission from mothers to children in a high-incidence area and to investigate relations between costs and effects, as well as to study the economical effects of this approach.

METHODSAccording to the number of patients and each strategy on prevention of AIDS transmission, following aspects were calculated as: the cost of preventing each patient with HIV infection, to avoid the cost of one disability adjusted life year (DALY), to evaluate the cost of each patient with either HIV infection or HIV-infected thereafter,and to calculate the HIV-positive rates in mothers at the same levels between costs and effects.

RESULTSThe costs-effects for stopping pregnancy:it was 2264 Yuan for preventing one DALY, the costs of avoiding one case with HIV infection was 46 963 Yuan, but it was 211,000 Yuan from each patient after HIV infection, the ratio between effects and costs was 4.5:1. The costs-effects for comprehensive strategies showed that the cost was 60 853 Yuan for avoiding one case with HIV infection. It was 211,000 Yuan for each patient after HIV infection and the ratio between effects and costs was 3.5:1.

CONCLUSIONThe cost-effect of preventing HIV transmission from mothers to children was significant on the basis of economical level. It was more effective to evaluate the relation between costs and effects according to economical level in screening and preventing transmission from mothers to children under the situation that the HIV-positive rate in pregnant mothers was more than 0.03%.

Acquired Immunodeficiency Syndrome ; economics ; prevention & control ; transmission ; Child ; China ; Cost-Benefit Analysis ; Disabled Persons ; Female ; Health Care Costs ; statistics & numerical data ; Humans ; Infant, Newborn ; Infectious Disease Transmission, Vertical ; economics ; prevention & control ; Pregnancy ; Pregnancy Complications, Infectious ; economics ; prevention & control

OBJECTIVETo explore dynamic characteristics of the HIV mother to child transmission (MTCT) epidemic in China.

METHODSA deterministic dynamic transmission model was used to determine the effect of key parameters on the likely long-term trends of the HIV MTCT epidemic in China. Matlab 7.0 was used to develop the model.

RESULTSThe number of the susceptibles (S), the transmission rate (β), and the screening proportion (α) of HIV positive pregnant women have the greatest impact on the HIV MTCT epidemic in China. The growth of the MTCT epidemic in China could not be controlled only by decreasing the MTCT transmission rate. The prevalence of HIV positive women should be reduced and more pregnant women should be tested for HIV.

CONCLUSIONPrevention of MTCT (PMTCT) should focus not only on the reduction of HIV transmission rates and incidences of HIV among women but also on the increase of HIV testing for pregnant women. The most cost-effective PMTCT means for China should be investigated in future studies.

Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Female ; HIV Infections ; mortality ; transmission ; Humans ; Infant ; Infant, Newborn ; Infectious Disease Transmission, Vertical ; statistics & numerical data ; Models, Statistical ; Pregnancy ; Pregnancy Complications, Infectious ; epidemiology ; virology ; Prevalence

OBJECTIVETo understand the risk factors on severe acute respiratory syndrome (SARS) among their contacts and to develop effective strategy for its control.

METHODSAvailable epidemiological data of SARS cases and close contacts were reviewed and analyzed by SPSS.

RESULTSOut of the 2195 close contacts, 138 (6.3%) were diagnosed as SARS. Among colleagues and classmates of SARS patients, the infection rate was 0.36% versus 31.71% in contacts among families and hospitals, 0.77% in schools. No one was infected among 459 close contacts to SARS in the working unit.

CONCLUSIONSAmong close contacts, factors that facilitating transmission would include: time, extent, frequency and place of contact to the patients, as well as factors related to close contacts as way, time of isolation and age. One of the epidemiological characteristics was that SARS were as clustered in the family among those close contacts. It is important to control the spread of SARS through supervision on the close contacts to patients.

Adult ; Aged ; China ; epidemiology ; Contact Tracing ; Cross Infection ; transmission ; Family Health ; Female ; Humans ; Infectious Disease Transmission, Patient-to-Professional ; Male ; Middle Aged ; Patient Isolation ; Quarantine ; statistics & numerical data ; Retrospective Studies ; Risk Factors ; Severe Acute Respiratory Syndrome ; epidemiology ; prevention & control ; transmission

BACKGROUNDIllegal plasma collecting activities in mid 1990s caused a large number of human immunodeficiency virus (HIV) infections in rural areas of central-eastern China. Although most of these activities have been stopped, there were few reports on secondary transmission from infected former plasma donors to their spouses and from infected mothers to their children. This study was to determine the extent of HIV infections among young children in a rural community with a large proportion of plasma donors.

METHODSA survey was conducted among children aged under 7 years in a former plasma donating community in September 2000: finger blood was collected for HIV antibody testing. Another survey was repeated among children aged under 8 years and their families in the same community in April 2001: urine samples were collected for HIV testing. HIV positive children and samples of HIV negative children, whose mothers were positive based on 2001 survey, were followed up until September 2002 to investigate HIV seroconversion, disease progression and HIV strain analysis. Questionnaires were administered to collect information on children's delivery, breast feeding, medical history and their parents' commercial blood donation history and HIV status.

RESULTSAmong 169 children surveyed in 2000, 10 (5.9%) were HIV positive. Of 224 children, 11 were positive in 2001. The overall prevalence rate in the two surveys was 5.0% (17/337) when counting 56 repeated children only once. Of children born to HIV positive mothers, 28.9% were infected. A seroconversion rate of 2.5 per 100 child-years was observed by following up 28 HIV negative children. No statistically significant associations were found between children's HIV infection and their histories of blood transfusion, surgery, immunization injection or medical injections. All infections were HIV-1 subtype B' strain, the average dispersion rate is 7.4%. DNA sequence analysis showed a close relationship between the seroconverted children and their infected mothers.

CONCLUSIONSHIV vertical transmissions in the rural former plasma donating community was significant. Intervention measures should be taken to prevent further transmission. It was estimated that the HIV spread in this community occurred in 1994 or even earlier. Many infected people are developing AIDS now: treatment and care are urgently needed for these sick people.

Blood Donors ; Child ; Child, Preschool ; China ; epidemiology ; Disease Progression ; Female ; HIV Infections ; epidemiology ; transmission ; HIV Seropositivity ; epidemiology ; Humans ; Infant ; Infant, Newborn ; Infectious Disease Transmission, Vertical ; statistics & numerical data ; Pregnancy ; Prevalence ; Risk Factors

Severe acute respiratory syndrome (SARS) was imported into Singapore in late February 2003 by a local resident who returned from a holiday in Hong Kong and started an outbreak in the hospital where she was admitted on 1 March 2003. The disease subsequently spread to 4 other healthcare institutions and a vegetable wholesale centre. During the period between March and May 2003, 238 probable SARS cases, including 8 imported cases and 33 deaths, were reported. Transmission within the healthcare and household settings accounted for more than 90% of the cases. Factors contributing to the spread of infection included the failure to recognise the high infectivity of this novel infection, resulting in a delay in isolating initial cases and contacts and the implementation of personal protective measures in healthcare institutions; and the super-spreading events by 5 index cases, including 3 with co-morbid conditions presenting with atypical clinical manifestations of SARS. Key public health measures were directed at prevention and control within the community and hospitals, and the prevention of imported and exported cases. An isolated laboratory-acquired case of SARS was reported on 8 September 2003. Based on the lessons learnt, Singapore has further strengthened its operational readiness and laboratory safety to respond to SARS, avian flu and other emerging diseases.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Disease Outbreaks ; prevention & control ; statistics & numerical data ; Disease Transmission, Infectious ; prevention & control ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Middle Aged ; Retrospective Studies ; Severe Acute Respiratory Syndrome ; epidemiology ; transmission ; Singapore ; epidemiology