Ahmed S. Latif

HIV-1/AIDS and the control of other infectious diseases in Africa.

The effect of HIV-1 on other infectious diseases in Africa is an increasing public health concern. In this review, we describe the role that three major infectious diseases--malaria, sexually transmitted diseases (STDs), and tuberculosis--have had in the HIV-1 epidemic. The high prevalence of untreated STD infections has been a major factor facilitating the spread of HIV-1 in Africa; with the synergistic interaction between HIV-1 transmission and genital herpes being of special concern for control of both diseases. Increased susceptibility to tuberculosis after infection with HIV-1 has led to a rising incidence and threat of increased transmission of tuberculosis. Clinical malaria occurs with an increased frequency and severity in HIV-1-infected individuals, especially during pregnancy. As with tuberculosis, STDs, and other communicable HIV-1-associated diseases, the net effect of HIV-1 might include increased rates of malaria transmission across communities. In addition to enhancing access to HIV-1 prevention and care, public health surveillance and control programmes should be greatly intensified to cope with the new realities of infectious disease control in Africa.

Genital ulcers and transmission of HIV among couples in Zimbabwe.

Seventy-five married men found to be positive for HIV-1 in Harare, Zimbabwe, were interviewed in order to define behaviours associated with acquisition of infection and to determine factors associated with transmission of infection to their wives. The majority of infected men reported sexual intercourse with multiple heterosexual partners and female prostitutes, and gave a history of sexually transmitted diseases (STDs). All subjects denied homosexual activity and parenteral drug abuse. Serological testing of the wives of seropositive men showed that 45 (60%) were HIV-antibody-positive. Wives of men with AIDS and AIDS-related complex (ARC) and wives of men who gave a history of genital ulcer disease were more likely to be seropositive. The study demonstrates that HIV-1 infection in Zimbabwe occurs through heterosexual intercourse and is associated with other STDs. In addition, the study shows that male to female transmission of HIV-1 is facilitated by the presence of genital ulcers in infected men.

Prevalence and Incidence of Herpes Simplex Virus Type 2 Infection among Male Zimbabwean Factory Workers

Stored sera from a cohort of 2397 male factory workers in Harare, Zimbabwe, were screened for herpes simplex virus type 2 (HSV-2)-specific antibodies, to estimate the prevalence and incidence of genital herpes infection and to assess the relation between HSV-2 and human immunodeficiency virus (HIV) acquisition. The prevalence of HSV-2 at enrollment was 39.8%. Correlates of HSV-2 seropositivity were HIV seropositivity, marital status, history of sexually transmitted disease (STD), older age, and higher income. The incidence of HSV-2 seroconversion during follow-up was 6.2/100 person-years. Correlates of HSV-2 seroconversion were enrollment while HIV-positive or seroconversion during follow-up, reported genital ulcer, history of STD, and number of sex partners. No evidence was found that HSV-2 infection was more likely to precede HIV or vice versa. HSV-2 and HIV seropositivity are strong markers for high-risk sexual behavior. Improved interventions targeted to populations in which the incidence of either viral infection is high are needed.

HIV seroincidence and correlates of seroconversion in a cohort of male factory workers in Harare, Zimbabwe.

OBJECTIVES Given that health promotion messages on transmission of HIV and other sexually transmitted diseases (STD) have been widely publicized in Zimbabwe and elsewhere in the late 1980s, it is vital to analyse which risk events still expose individuals to infection. A cohort was established with the objectives of estimating HIV seroincidence, behavioural and biological determinants of infection, and ultimately, evaluating the impact of AIDS prevention interventions in the workplace. METHODS HIV seroincidence was estimated in a prospectively followed cohort of male factory workers recruited in Harare, Zimbabwe during the period prior to a workplace AIDS prevention intervention. Correlates of HIV seroconversion were identified using Cox regression analysis. RESULTS There were 51 seroconversions among 1607 HIV-negative participants following 1738 person-years (PY) of observation [seroincidence, 2.93 per 100 PY; 95% confidence interval (CI), 2.18-3.86]. The prevalence of HIV in the cohort was 19.1%. HIV seroincidence was significantly increased among men who were younger [hazard ratio (HR) per year, 0.96; 95% CI, 0.93-0.99], were single (HR, 3.29; 95% CI, 1.56-6.96), were married but resided separately from their wives (HR, 2.18; 95% CI, 0.99-4.80), reported having any STD (HR, 3.00; 95% CI, 1.53-5.86), reported having a genital ulcer (HR, 4.87; 95% CI, 2.18-10.91), and reported paying for sex (HR, 2.01; 95% CI, 1.06-3.77). Seroincidence also increased with the number of sex partners reported in the year preceding enrolment (HR per partner, 1.10; 95% CI, 1.01-1.21). In multiple Cox regression analysis, three independent associations with HIV seroconversion were reporting a genital ulcer (adjusted HR, 3.55; 95% CI, 1.52-8.29), number of sex partners (adjusted HR, 1.10; 95% CI, 1.01-1.21), and being married but residing separately from ones wife (adjusted HR, 2.21; 95% CI, 1.00-4.89). CONCLUSIONS Innovative and sustained workplace-based interventions are needed to address the high risk of HIV infection in this economically productive population. The predictors of HIV seroconversion described in this study underscore the need for public health efforts to simultaneously address the biological, socioeconomic and behavioural factors that continue to place individuals at risk of HIV in general populations of Africa.

Guillain‐Barré syndrome associated with human immunodeficiency virus infection in Zimbabwe

We studied the clinical features and human immunodeficiency virus (HIV) serology of 32 consecutive adults with inflammatory demyelinating polyneuropathy (IDP) admitted to the teaching hospitals in Harare, Zimbabwe. Twenty-nine of the IDP patients had Guillain-Barré syndrome (GBS), and the other three had chronic IDP. Sixteen of 29 (55%) GBS patients were HIV-seropositive, a higher frequency of HIV infection than in blood donors drawn from the population served by these hospitals. All three chronic IDP patients were HIV-seronegative. In all HIV-seropositive patients, GBS was the initial illness that brought the patient to medical attention and led to the diagnosis of HIV infection. Compared with seronegative patients, the HIV-seropositive GBS patients were more likely to have generalized lymphadenopathy, CSF pleocytosis, coexistent CNS disturbance, and prior sexually transmitted disease. GBS in this region of Africa is frequently associated with HIV infection.

Association of genital shedding of herpes simplex virus type 2 and HIV-1 among sex workers in rural Zimbabwe.

Introduction:Herpes simplex virus type 2 (HSV-2) facilitates sexual acquisition of HIV-1 but data on transmission are less clear. In this study the interaction between genital shedding of HIV-1 and HSV-2 was explored among Zimbabwean sex workers. Methods:Women (n = 214) were interviewed about genital symptoms. Blood samples were analysed for HIV-1 and HSV-2 antibodies, HIV-1 plasma viral load (PVL) and CD4 lymphocyte count and genital swabs for detection of HIV-1 and HSV-2 genital shedding, Chlamydia trachomatis, Neisseria gonorroheae and Trichomonas vaginalis, and a cervico-vaginal lavage (CVL) for quantitative measurement of HIV-1 shedding. Shedding analyses were undertaken on women co-infected with HSV-2 and HIV-1. Results:A total of 124 women were co-infected with HIV-1 and HSV-2; 58 were infected with HSV-2 alone. Most HIV-1-infected women were co-infected with HSV-2 (95.4%). Genital HIV-1 shedding was detected in 84.3% of co-infected women and was associated with low CD4 cell count and high PVL but not with reported symptoms of genital herpes or genital shedding of HSV-2. There was no difference in HIV-1 shedding among women shedding HSV-2 (79.3%) and women not shedding HSV-2 (83.2%) (P = 0.64). The adjusted odds ratio for HIV-1 shedding between HSV-2 shedders and non-shedders was 0.8 [95% confidence interval (CI), 0.2–3.3]. HIV-1 PVL(log10) and CVL viral load(log10) were correlated (r = 0.38; 95%CI, 0.2–0.5). After adjusting for PVL, genital symptoms and age, HSV-2 shedding had no effect on CVL viral load (P = 0.13). Conclusion:Rate and quantity of HIV-1 genital shedding do not appear to be altered by presence of HSV-2 genital shedding.

The appropriateness of core group interventions using presumptive periodic treatment among rural Zimbabwean women who exchange sex for gifts or money.

Summary:To map the characteristics of rural based sex workers in Zimbabwe with regard to demographics, mobility, behavior, HIV and sexually transmitted infection (STI) prevalence, to explore the appropriateness and feasibility of presumptive periodic treatment (PPT) for bacterial STIs as an HIV prevention intervention among these women, and to compare tolerability of 2 PPT regimens (1 g of azithromycin and 2 g of metronidazole ± 500 mg of ciprofloxacin). Five commercial farms and 2 mines in Mashonaland West, Zimbabwe. Three hundred sixty-three sex workers were recruited and completed a structured interviewer-administered questionnaire. Each participant had blood tested for antibody to HIV, herpes simplex virus 2 (HSV-2), and syphilis; urine tested for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG); and a vaginal swab tested for Trichomonas vaginalis (TV). Women were randomly assigned to receive a single dose of 1 of 2 PPT regimens and then followed to assess rates of side effects and reinfection. The overall prevalence of antibody to HIV was 55.7% (95% confidence interval [CI]: 50.6-60.9) and that of HSV-2 was 80.8% (95% CI: 76.7-84.9). The prevalence of CT and NG was low (CT = 1.7%, 95% CI: 0.3-3.0); (NG = 1.9%, 95% CI: 0.5-3.4), with a much higher prevalence of TV (TV = 19.3%, 95% CI: 15.2-23.4). Prevalence of CT, NG, and TV was appreciably reduced 1 month after PPT but rose to pretreatment levels at the 2- and 3-month visits. The rate of moderate or severe side effects after PPT was low, but it was higher in the women who received ciprofloxacin in addition to azithromycin and metronidazole (P = 0.007). It was feasible to access women who reported exchanging money or gifts for sex in rural communities, although many of these women engaged in sex work only infrequently. The prevalence of bacterial STIs was low, suggesting that PPT may not be an appropriate intervention in this setting. Rapid reinfection after PPT suggests that this needs to be given at monthly intervals to reduce prevalence of STIs.

Primary subtype C HIV-1 infection in Harare, Zimbabwe

Heterosexual transmission of HIV-1 is widespread in Southern Africa. Heteroduplex mobility assays (HMA) and phylogenetic analyses of V3-V5 envelope (env) gene sequences demonstrate that subtype C predominates in Zimbabwe. To elucidate factors contributing to the epidemic in Zimbabwe, clinical and virologic characteristics of recently acquired subtype C HIV-1 infection among 21 men and 1 woman were determined. In 12 of 19 men providing clinical histories, a sexually transmitted infection preceded serologic evidence of HIV-1, and 14 of 19 men complained of rash or fever before seroconversion. Quantitative p24 antigen levels, reverse transcriptase activity, and HIV RNA levels of 22 viral isolates correlated with in vitro infectivity in peripheral blood mononuclear cells (p < .05). Biologic phenotype assessed in MT-2 cells demonstrated that 3 of 22 isolates (14%) were syncytia inducing (SI) and the remaining 19 nonsyncytium inducing (NSI). Early growth of virus in culture was associated with increased plasma HIV RNA levels, decreased CD4 cell levels, and SI virus. Recent subtype C HIV-1 infection through heterosexual transmission in Zimbabwe demonstrated clinical and virologic features consistent with reports of seroconversion to subtype B viruses.

The association of tuberculosis and HIV infection in Harare, Zimbabwe.

SETTING The tuberculosis (TB) service responsible for all TB treatment in Harare, Zimbabwe. OBJECTIVES (1) To determine HIV seroprevalence among TB patients and controls. (2) To compare clinical and demographic characteristics of HIV-infected and uninfected TB patients. DESIGN Cohort study. Entry criterion: TB diagnosed during the 18 month study period. Assessment included HIV serology. Matched community controls were HIV serotested. RESULTS In 1434 TB patients tested, HIV seroprevalence was 48% in men and 44% in women, peaked in the 25-34 year age group and was higher than in controls (relative risk [RR] = 3.1, 95% confidence interval [CI] = 2.6-3.7). In adults, seroprevalence was 34%, 49% and 58% in successive 6 month periods. A history of entry of prior TB treatment was less common in the HIV-seropositive (RR = 0.57, CI = 0.37-0.88). In adults, tuberculin negativity, TB at 2 sites, lymph node, pericardial and miliary TB, hilar adenopathy and pleural effusion were significantly more common in HIV-seropositive patients; cavitation and upper lobe involvement were significantly less frequent. Pulmonary TB and sputum smear positivity had similar frequencies in the 2 groups. CONCLUSION HIV was strongly and increasingly associated with TB in Harare and altered the clinical and radiologic features of TB. Failed standard TB treatment in HIV-infected individuals contributed minimally to new cases of TB.

HIV and other sexually transmitted diseases at a rural hospital in Zimbabwe.

OBJECTIVE--To define the epidemiological characteristics of STD patients attending an outpatient clinic in rural Zimbabwe, to examine the aetiologic agents causing infection and to determine their relationship with HIV infection. SUBJECTS--319 men and 146 women, making a sample of about 7% all patients attending an STD clinic during the 3 month study period. Microbiological data were collected from 104 men and 72 women selected randomly from these. Pregnant women were excluded and patients who had received antibiotics within the previous 14 days were excluded from the microbiology sub-sample. SETTING--An outpatient STD clinic at a District Hospital on a major truck route about 300 km north of the capital, Harare. METHODS--All new patients attending the clinic during a 3 month period were enrolled for clinical and epidemiological investigations using a standard procedure. Specimens for microbiological investigation were taken from every second patient seen on the first three days of each week. RESULTS--The typical patient was male (m:f ratio 2.2) aged 20-29 years (68% patients), not married (56% men) and in paid employment (66% men vs. 27% for the district). In men the most common presenting feature was genital ulceration, while in women, discharges were more common. Genital warts were noted frequently in both sexes. In the sub-sample examined microbiologically, H ducreyi was isolated from 46% ulcers clinically diagnosed as chancroid, and motile spirochaetes were detected in 25% painless ulcers. Neither of these were detected in ulcers in women, but HSV antigen was found as frequently in ulcers from men (19%) as from women (17%). In patients with genital discharges, gonococcal infection occurred in 64% men and 17% women, while T vaginalis was isolated from 39% women and only 8% men. Over 60% gonococcal isolates were PPNG, and 18% showed in vitro resistance to tetracycline. Yeasts, mainly C albicans were isolated from 42% women with a discharge and 25% women with ulcers. In men the presence of yeasts was associated with superficial ulceration and itchiness of the glans. Positive HIV-1 serology was found in 64% patients. There was no statistical association with current genital ulcers, though there was an association with previous STD episodes and particularly with serological evidence of syphilis. Apart from yeasts, there was no association between positive HIV-1 serology and the presence of pathogens in the genital tract. CONCLUSIONS--The high prevalence of HIV-1 antibodies in STD patients in Karoi suggests integration of STD and AIDS control programmes to be a necessity. Since paid employment was a common feature of both STD clinic attendance and HIV-1 seropositivity, these programmes may be effectively directed through the work place.